Chris Wright
2007-Apr-18 13:02 UTC
[PATCH 4/7] Allow selected bug checks to be skipped by paravirt kernels
Allow selected bug checks to be skipped by paravirt kernels. The two most important are the F00F workaround (which is either done by the hypervisor, or not required), and the 'hlt' instruction check, which can break under some hypervisors. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jeremy Fitzhardinge <jeremy@goop.org> --- arch/i386/kernel/cpu/intel.c | 2 +- include/asm-i386/bugs.h | 4 ++++ 2 files changed, 5 insertions(+), 1 deletion(-) --- linux-2.6-pv.orig/arch/i386/kernel/cpu/intel.c +++ linux-2.6-pv/arch/i386/kernel/cpu/intel.c @@ -107,7 +107,7 @@ static void __cpuinit init_intel(struct * Note that the workaround only should be initialized once... */ c->f00f_bug = 0; - if ( c->x86 == 5 ) { + if (!paravirt_enabled() && c->x86 == 5) { static int f00f_workaround_enabled = 0; c->f00f_bug = 1; --- linux-2.6-pv.orig/include/asm-i386/bugs.h +++ linux-2.6-pv/include/asm-i386/bugs.h @@ -21,6 +21,7 @@ #include <asm/processor.h> #include <asm/i387.h> #include <asm/msr.h> +#include <asm/paravirt.h> static int __init no_halt(char *s) { @@ -91,6 +92,9 @@ static void __init check_fpu(void) static void __init check_hlt(void) { + if (paravirt_enabled()) + return; + printk(KERN_INFO "Checking 'hlt' instruction... "); if (!boot_cpu_data.hlt_works_ok) { printk("disabled\n"); --
Chris Wright
2007-Apr-18 13:02 UTC
[PATCH 5/7] Allow disabling legacy power management modes with paravirt kernels
Two legacy power management modes are much easier to just explicitly disable when running in paravirtualized mode - neither APM nor PnP is still relevant. The status of ACPI is still debatable, and noacpi is still a common enough boot parameter that it is not necessary to explicitly disable ACPI. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jeremy Fitzhardinge <jeremy@goop.org> --- arch/i386/kernel/apm.c | 3 ++- drivers/pnp/pnpbios/core.c | 3 ++- 2 files changed, 4 insertions(+), 2 deletions(-) --- linux-2.6-pv.orig/arch/i386/kernel/apm.c +++ linux-2.6-pv/arch/i386/kernel/apm.c @@ -231,6 +231,7 @@ #include <asm/uaccess.h> #include <asm/desc.h> #include <asm/i8253.h> +#include <asm/paravirt.h> #include "io_ports.h" @@ -2191,7 +2192,7 @@ static int __init apm_init(void) dmi_check_system(apm_dmi_table); - if (apm_info.bios.version == 0) { + if (apm_info.bios.version == 0 || paravirt_enabled()) { printk(KERN_INFO "apm: BIOS not found.\n"); return -ENODEV; } --- linux-2.6-pv.orig/drivers/pnp/pnpbios/core.c +++ linux-2.6-pv/drivers/pnp/pnpbios/core.c @@ -530,7 +530,8 @@ static int __init pnpbios_init(void) if (check_legacy_ioport(PNPBIOS_BASE)) return -ENODEV; #endif - if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table)) { + if (pnpbios_disabled || dmi_check_system(pnpbios_dmi_table) || + paravirt_enabled()) { printk(KERN_INFO "PnPBIOS: Disabled\n"); return -ENODEV; } --
Chris Wright
2007-Apr-18 13:02 UTC
[PATCH 3/7] More generic paravirtualization entry point.
1) Each hypervisor writes a probe function to detect whether we are running under that hypervisor. paravirt_probe() registers this function. 2) If vmlinux is booted with ring != 0, we call all the probe functions (with registers except %esp intact) in link order: the winner will not return. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Zachary Amsden <zach@vmware.com> --- arch/i386/kernel/Makefile | 2 ++ arch/i386/kernel/head.S | 33 +++++++++++++++++++++++++++++++++ arch/i386/kernel/paravirt.c | 6 +++++- arch/i386/kernel/vmlinux.lds.S | 6 ++++++ include/asm-i386/paravirt.h | 5 +++++ 5 files changed, 51 insertions(+), 1 deletion(-) --- linux-2.6-pv.orig/arch/i386/kernel/Makefile +++ linux-2.6-pv/arch/i386/kernel/Makefile @@ -39,6 +39,8 @@ obj-$(CONFIG_VM86) += vm86.o obj-$(CONFIG_EARLY_PRINTK) += early_printk.o obj-$(CONFIG_HPET_TIMER) += hpet.o obj-$(CONFIG_K8_NB) += k8.o + +# Make sure this is linked after any other paravirt_ops structs: see head.S obj-$(CONFIG_PARAVIRT) += paravirt.o EXTRA_AFLAGS := -traditional --- linux-2.6-pv.orig/arch/i386/kernel/head.S +++ linux-2.6-pv/arch/i386/kernel/head.S @@ -55,6 +55,12 @@ */ ENTRY(startup_32) +#ifdef CONFIG_PARAVIRT + movl %cs, %eax + testl $0x3, %eax + jnz startup_paravirt +#endif + /* * Set segments to known values. */ @@ -486,6 +492,33 @@ ignore_int: #endif iret +#ifdef CONFIG_PARAVIRT +startup_paravirt: + cld + movl $(init_thread_union+THREAD_SIZE),%esp + + /* We take pains to preserve all the regs. */ + pushl %edx + pushl %ecx + pushl %eax + + /* paravirt.o is last in link, and that probe fn never returns */ + pushl $__start_paravirtprobe +1: + movl 0(%esp), %eax + pushl (%eax) + movl 8(%esp), %eax + call *(%esp) + popl %eax + + movl 4(%esp), %eax + movl 8(%esp), %ecx + movl 12(%esp), %edx + + addl $4, (%esp) + jmp 1b +#endif + /* * Real beginning of normal "text" segment */ --- linux-2.6-pv.orig/arch/i386/kernel/paravirt.c +++ linux-2.6-pv/arch/i386/kernel/paravirt.c @@ -392,7 +392,11 @@ static int __init print_banner(void) return 0; } core_initcall(print_banner); - + +/* We simply declare start_kernel to be the paravirt probe of last resort. */ +asmlinkage void __init start_kernel(void); +paravirt_probe(start_kernel); + struct paravirt_ops paravirt_ops = { .name = "bare hardware", .paravirt_enabled = 0, --- linux-2.6-pv.orig/arch/i386/kernel/vmlinux.lds.S +++ linux-2.6-pv/arch/i386/kernel/vmlinux.lds.S @@ -60,6 +60,12 @@ SECTIONS CONSTRUCTORS } :data + __start_paravirtprobe = .; + .paravirtprobe : AT(ADDR(.paravirtprobe) - LOAD_OFFSET) { + *(.paravirtprobe) + } + __stop_paravirtprobe = .; + . = ALIGN(4096); __nosave_begin = .; .data_nosave : AT(ADDR(.data_nosave) - LOAD_OFFSET) { *(.data.nosave) } --- linux-2.6-pv.orig/include/asm-i386/paravirt.h +++ linux-2.6-pv/include/asm-i386/paravirt.h @@ -120,6 +120,11 @@ struct paravirt_ops void (fastcall *iret)(void); }; +/* Mark a paravirt probe function. */ +#define paravirt_probe(fn) \ + static void (*__paravirtprobe_##fn)(void) __attribute_used__ \ + __attribute__((__section__(".paravirtprobe"))) = fn + extern struct paravirt_ops paravirt_ops; #define paravirt_enabled() (paravirt_ops.paravirt_enabled) --
Chris Wright
2007-Apr-18 13:02 UTC
[PATCH 1/7] header and stubs for paravirtualizing critical operations
Create a paravirt.h header for all the critical operations which need to be replaced with hypervisor calls, and include that instead of defining native operations, when CONFIG_PARAVIRT. This patch does the dumbest possible replacement of paravirtualized instructions: calls through a "paravirt_ops" structure. Currently these are function implementations of native hardware: hypervisors will override the ops structure with their own variants. All the pv-ops functions are declared "fastcall" so that a specific register-based ABI is used, to make inlining assember easier. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Cc: Jeremy Fitzhardinge <jeremy@goop.org> Cc: Zachary Amsden <zach@vmware.com> --- arch/i386/Kconfig | 11 arch/i386/boot/compressed/misc.c | 1 arch/i386/kernel/Makefile | 1 arch/i386/kernel/asm-offsets.c | 10 arch/i386/kernel/entry.S | 34 +- arch/i386/kernel/i8259.c | 2 arch/i386/kernel/paravirt.c | 410 +++++++++++++++++++++++++++++ arch/i386/kernel/setup.c | 2 arch/i386/kernel/smpboot.c | 5 arch/i386/kernel/time.c | 15 - drivers/net/de600.c | 1 include/asm-i386/delay.h | 8 include/asm-i386/desc.h | 4 include/asm-i386/io.h | 10 include/asm-i386/irq.h | 10 include/asm-i386/irqflags.h | 42 +- include/asm-i386/mach-default/setup_arch.h | 2 include/asm-i386/msr.h | 5 include/asm-i386/paravirt.h | 291 ++++++++++++++++++++ include/asm-i386/processor.h | 15 - include/asm-i386/segment.h | 2 include/asm-i386/setup.h | 8 include/asm-i386/spinlock.h | 4 include/asm-i386/system.h | 16 - include/asm-i386/time.h | 41 ++ 25 files changed, 902 insertions(+), 48 deletions(-) --- linux-2.6-pv.orig/arch/i386/Kconfig +++ linux-2.6-pv/arch/i386/Kconfig @@ -197,6 +197,17 @@ config X86_ES7000 endchoice +config PARAVIRT + bool "Paravirtualization support (EXPERIMENTAL)" + depends on EXPERIMENTAL + help + Paravirtualization is a way of running multiple instances of + Linux on the same machine, under a hypervisor. This option + changes the kernel so it can modify itself when it is run + under a hypervisor, improving performance significantly. + However, when run without a hypervisor the kernel is + theoretically slower. If in doubt, say N. + config ACPI_SRAT bool default y --- linux-2.6-pv.orig/arch/i386/boot/compressed/misc.c +++ linux-2.6-pv/arch/i386/boot/compressed/misc.c @@ -9,6 +9,7 @@ * High loaded stuff by Hans Lermen & Werner Almesberger, Feb. 1996 */ +#undef CONFIG_PARAVIRT #include <linux/linkage.h> #include <linux/vmalloc.h> #include <linux/screen_info.h> --- linux-2.6-pv.orig/arch/i386/kernel/Makefile +++ linux-2.6-pv/arch/i386/kernel/Makefile @@ -39,6 +39,7 @@ obj-$(CONFIG_VM86) += vm86.o obj-$(CONFIG_EARLY_PRINTK) += early_printk.o obj-$(CONFIG_HPET_TIMER) += hpet.o obj-$(CONFIG_K8_NB) += k8.o +obj-$(CONFIG_PARAVIRT) += paravirt.o EXTRA_AFLAGS := -traditional --- linux-2.6-pv.orig/arch/i386/kernel/asm-offsets.c +++ linux-2.6-pv/arch/i386/kernel/asm-offsets.c @@ -101,4 +101,14 @@ void foo(void) BLANK(); OFFSET(PDA_cpu, i386_pda, cpu_number); OFFSET(PDA_pcurrent, i386_pda, pcurrent); + +#ifdef CONFIG_PARAVIRT + BLANK(); + OFFSET(PARAVIRT_enabled, paravirt_ops, paravirt_enabled); + OFFSET(PARAVIRT_irq_disable, paravirt_ops, irq_disable); + OFFSET(PARAVIRT_irq_enable, paravirt_ops, irq_enable); + OFFSET(PARAVIRT_irq_enable_sysexit, paravirt_ops, irq_enable_sysexit); + OFFSET(PARAVIRT_iret, paravirt_ops, iret); + OFFSET(PARAVIRT_read_cr0, paravirt_ops, read_cr0); +#endif } --- linux-2.6-pv.orig/arch/i386/kernel/entry.S +++ linux-2.6-pv/arch/i386/kernel/entry.S @@ -62,13 +62,6 @@ DF_MASK = 0x00000400 NT_MASK = 0x00004000 VM_MASK = 0x00020000 -/* These are replaces for paravirtualization */ -#define DISABLE_INTERRUPTS cli -#define ENABLE_INTERRUPTS sti -#define ENABLE_INTERRUPTS_SYSEXIT sti; sysexit -#define INTERRUPT_RETURN iret -#define GET_CR0_INTO_EAX movl %cr0, %eax - #ifdef CONFIG_PREEMPT #define preempt_stop DISABLE_INTERRUPTS; TRACE_IRQS_OFF #else @@ -416,6 +409,20 @@ ldt_ss: jnz restore_nocheck testl $0x00400000, %eax # returning to 32bit stack? jnz restore_nocheck # allright, normal return + +#ifdef CONFIG_PARAVIRT + /* + * The kernel can't run on a non-flat stack if paravirt mode + * is active. Rather than try to fixup the high bits of + * ESP, bypass this code entirely. This may break DOSemu + * and/or Wine support in a paravirt VM, although the option + * is still available to implement the setting of the high + * 16-bits in the INTERRUPT_RETURN paravirt-op. + */ + cmpl $0, paravirt_ops+PARAVIRT_enabled + jne restore_nocheck +#endif + /* If returning to userspace with 16bit stack, * try to fix the higher word of ESP, as the CPU * won't restore it. @@ -831,6 +838,19 @@ nmi_espfix_stack: .previous KPROBE_END(nmi) +#ifdef CONFIG_PARAVIRT +ENTRY(native_iret) +1: iret +.section __ex_table,"a" + .align 4 + .long 1b,iret_exc +.previous + +ENTRY(native_irq_enable_sysexit) + sti + sysexit +#endif + KPROBE_ENTRY(int3) RING0_INT_FRAME pushl $-1 # mark this as an int --- linux-2.6-pv.orig/arch/i386/kernel/i8259.c +++ linux-2.6-pv/arch/i386/kernel/i8259.c @@ -392,7 +392,7 @@ void __init init_ISA_irqs (void) } } -void __init init_IRQ(void) +void __init native_init_IRQ(void) { int i; --- linux-2.6-pv.orig/arch/i386/kernel/setup.c +++ linux-2.6-pv/arch/i386/kernel/setup.c @@ -1404,7 +1404,7 @@ void __init setup_arch(char **cmdline_p) efi_init(); else { printk(KERN_INFO "BIOS-provided physical RAM map:\n"); - print_memory_map(machine_specific_memory_setup()); + print_memory_map(memory_setup()); } copy_edd(); --- linux-2.6-pv.orig/arch/i386/kernel/smpboot.c +++ linux-2.6-pv/arch/i386/kernel/smpboot.c @@ -33,6 +33,11 @@ * Dave Jones : Report invalid combinations of Athlon CPUs. * Rusty Russell : Hacked into shape for new "hotplug" boot process. */ + +/* SMP boot always wants to use real time delay to allow sufficient time for + * the APs to come online */ +#define USE_REAL_TIME_DELAY + #include <linux/module.h> #include <linux/init.h> #include <linux/kernel.h> --- linux-2.6-pv.orig/arch/i386/kernel/time.c +++ linux-2.6-pv/arch/i386/kernel/time.c @@ -56,6 +56,7 @@ #include <asm/uaccess.h> #include <asm/processor.h> #include <asm/timer.h> +#include <asm/time.h> #include "mach_time.h" @@ -116,10 +117,7 @@ static int set_rtc_mmss(unsigned long no /* gets recalled with irq locally disabled */ /* XXX - does irqsave resolve this? -johnstul */ spin_lock_irqsave(&rtc_lock, flags); - if (efi_enabled) - retval = efi_set_rtc_mmss(nowtime); - else - retval = mach_set_rtc_mmss(nowtime); + retval = set_wallclock(nowtime); spin_unlock_irqrestore(&rtc_lock, flags); return retval; @@ -211,10 +209,7 @@ unsigned long read_persistent_clock(void spin_lock_irqsave(&rtc_lock, flags); - if (efi_enabled) - retval = efi_get_time(); - else - retval = mach_get_cmos_time(); + retval = get_wallclock(); spin_unlock_irqrestore(&rtc_lock, flags); @@ -280,7 +275,7 @@ static void __init hpet_time_init(void) printk("Using HPET for base-timer\n"); } - time_init_hook(); + do_time_init(); } #endif @@ -296,5 +291,5 @@ void __init time_init(void) return; } #endif - time_init_hook(); + do_time_init(); } --- linux-2.6-pv.orig/drivers/net/de600.c +++ linux-2.6-pv/drivers/net/de600.c @@ -43,7 +43,6 @@ static const char version[] = "de600.c: * modify the following "#define": (see <asm/io.h> for more info) #define REALLY_SLOW_IO */ -#define SLOW_IO_BY_JUMPING /* Looks "better" than dummy write to port 0x80 :-) */ /* use 0 for production, 1 for verification, >2 for debug */ #ifdef DE600_DEBUG --- linux-2.6-pv.orig/include/asm-i386/delay.h +++ linux-2.6-pv/include/asm-i386/delay.h @@ -15,6 +15,13 @@ extern void __ndelay(unsigned long nsecs extern void __const_udelay(unsigned long usecs); extern void __delay(unsigned long loops); +#if defined(CONFIG_PARAVIRT) && !defined(USE_REAL_TIME_DELAY) +#define udelay(n) paravirt_ops.const_udelay((n) * 0x10c7ul) + +#define ndelay(n) paravirt_ops.const_udelay((n) * 5ul) + +#else /* !PARAVIRT || USE_REAL_TIME_DELAY */ + #define udelay(n) (__builtin_constant_p(n) ? \ ((n) > 20000 ? __bad_udelay() : __const_udelay((n) * 0x10c7ul)) : \ __udelay(n)) @@ -22,6 +29,7 @@ extern void __delay(unsigned long loops) #define ndelay(n) (__builtin_constant_p(n) ? \ ((n) > 20000 ? __bad_ndelay() : __const_udelay((n) * 5ul)) : \ __ndelay(n)) +#endif void use_tsc_delay(void); --- linux-2.6-pv.orig/include/asm-i386/desc.h +++ linux-2.6-pv/include/asm-i386/desc.h @@ -55,6 +55,9 @@ static inline void pack_gate(u32 *low, u #define DESCTYPE_DPL3 0x60 /* DPL-3 */ #define DESCTYPE_S 0x10 /* !system */ +#ifdef CONFIG_PARAVIRT +#include <asm/paravirt.h> +#else #define load_TR_desc() __asm__ __volatile__("ltr %w0"::"q" (GDT_ENTRY_TSS*8)) #define load_gdt(dtr) __asm__ __volatile("lgdt %0"::"m" (*dtr)) @@ -104,6 +107,7 @@ static inline void set_ldt(void *addr, u __asm__ __volatile__("lldt %w0"::"q" (GDT_ENTRY_LDT*8)); } } +#endif /* CONFIG_PARAVIRT */ static inline void _set_gate(int gate, unsigned int type, void *addr, unsigned short seg) { --- linux-2.6-pv.orig/include/asm-i386/io.h +++ linux-2.6-pv/include/asm-i386/io.h @@ -256,11 +256,11 @@ static inline void flush_write_buffers(v #endif /* __KERNEL__ */ -#ifdef SLOW_IO_BY_JUMPING -#define __SLOW_DOWN_IO "jmp 1f; 1: jmp 1f; 1:" -#else +#if defined(CONFIG_PARAVIRT) +#include <asm/paravirt.h> +#else + #define __SLOW_DOWN_IO "outb %%al,$0x80;" -#endif static inline void slow_down_io(void) { __asm__ __volatile__( @@ -271,6 +271,8 @@ static inline void slow_down_io(void) { : : ); } +#endif + #ifdef CONFIG_X86_NUMAQ extern void *xquad_portio; /* Where the IO area was mapped */ #define XQUAD_PORT_ADDR(port, quad) (xquad_portio + (XQUAD_PORTIO_QUAD*quad) + port) --- linux-2.6-pv.orig/include/asm-i386/irq.h +++ linux-2.6-pv/include/asm-i386/irq.h @@ -41,4 +41,14 @@ extern int irqbalance_disable(char *str) extern void fixup_irqs(cpumask_t map); #endif +void __init native_init_IRQ(void); +#ifdef CONFIG_PARAVIRT +#include <asm/paravirt.h> +#else +static inline void init_IRQ(void) +{ + native_init_IRQ(); +} +#endif /* CONFIG_PARAVIRT */ + #endif /* _ASM_IRQ_H */ --- linux-2.6-pv.orig/include/asm-i386/irqflags.h +++ linux-2.6-pv/include/asm-i386/irqflags.h @@ -10,6 +10,9 @@ #ifndef _ASM_IRQFLAGS_H #define _ASM_IRQFLAGS_H +#ifdef CONFIG_PARAVIRT +#include <asm/paravirt.h> +#else #ifndef __ASSEMBLY__ static inline unsigned long __raw_local_save_flags(void) @@ -25,9 +28,6 @@ static inline unsigned long __raw_local_ return flags; } -#define raw_local_save_flags(flags) \ - do { (flags) = __raw_local_save_flags(); } while (0) - static inline void raw_local_irq_restore(unsigned long flags) { __asm__ __volatile__( @@ -66,18 +66,6 @@ static inline void halt(void) __asm__ __volatile__("hlt": : :"memory"); } -static inline int raw_irqs_disabled_flags(unsigned long flags) -{ - return !(flags & (1 << 9)); -} - -static inline int raw_irqs_disabled(void) -{ - unsigned long flags = __raw_local_save_flags(); - - return raw_irqs_disabled_flags(flags); -} - /* * For spinlocks, etc: */ @@ -90,9 +78,33 @@ static inline unsigned long __raw_local_ return flags; } +#else +#define DISABLE_INTERRUPTS cli +#define ENABLE_INTERRUPTS sti +#define ENABLE_INTERRUPTS_SYSEXIT sti; sysexit +#define INTERRUPT_RETURN iret +#define GET_CR0_INTO_EAX movl %cr0, %eax +#endif /* __ASSEMBLY__ */ +#endif /* CONFIG_PARAVIRT */ + +#ifndef __ASSEMBLY__ +#define raw_local_save_flags(flags) \ + do { (flags) = __raw_local_save_flags(); } while (0) + #define raw_local_irq_save(flags) \ do { (flags) = __raw_local_irq_save(); } while (0) +static inline int raw_irqs_disabled_flags(unsigned long flags) +{ + return !(flags & (1 << 9)); +} + +static inline int raw_irqs_disabled(void) +{ + unsigned long flags = __raw_local_save_flags(); + + return raw_irqs_disabled_flags(flags); +} #endif /* __ASSEMBLY__ */ /* --- linux-2.6-pv.orig/include/asm-i386/mach-default/setup_arch.h +++ linux-2.6-pv/include/asm-i386/mach-default/setup_arch.h @@ -2,4 +2,6 @@ /* no action for generic */ +#ifndef ARCH_SETUP #define ARCH_SETUP +#endif --- linux-2.6-pv.orig/include/asm-i386/msr.h +++ linux-2.6-pv/include/asm-i386/msr.h @@ -1,6 +1,10 @@ #ifndef __ASM_MSR_H #define __ASM_MSR_H +#ifdef CONFIG_PARAVIRT +#include <asm/paravirt.h> +#else + /* * Access to machine-specific registers (available on 586 and better only) * Note: the rd* operations modify the parameters directly (without using @@ -77,6 +81,7 @@ static inline void wrmsrl (unsigned long __asm__ __volatile__("rdpmc" \ : "=a" (low), "=d" (high) \ : "c" (counter)) +#endif /* !CONFIG_PARAVIRT */ /* symbolic names for some interesting MSRs */ /* Intel defined MSRs. */ --- linux-2.6-pv.orig/include/asm-i386/processor.h +++ linux-2.6-pv/include/asm-i386/processor.h @@ -146,8 +146,8 @@ static inline void detect_ht(struct cpui #define X86_EFLAGS_VIP 0x00100000 /* Virtual Interrupt Pending */ #define X86_EFLAGS_ID 0x00200000 /* CPUID detection flag */ -static inline void __cpuid(unsigned int *eax, unsigned int *ebx, - unsigned int *ecx, unsigned int *edx) +static inline fastcall void native_cpuid(unsigned int *eax, unsigned int *ebx, + unsigned int *ecx, unsigned int *edx) { /* ecx is often an input as well as an output. */ __asm__("cpuid" @@ -548,6 +548,12 @@ static inline void rep_nop(void) #define cpu_relax() rep_nop() +#ifdef CONFIG_PARAVIRT +#include <asm/paravirt.h> +#else +#define paravirt_enabled() 0 +#define __cpuid native_cpuid + static inline void load_esp0(struct tss_struct *tss, struct thread_struct *thread) { tss->esp0 = thread->esp0; @@ -570,10 +576,13 @@ static inline void load_esp0(struct tss_ : /* no output */ \ :"r" (value)) +#define set_iopl_mask native_set_iopl_mask +#endif /* CONFIG_PARAVIRT */ + /* * Set IOPL bits in EFLAGS from given mask */ -static inline void set_iopl_mask(unsigned mask) +static fastcall inline void native_set_iopl_mask(unsigned mask) { unsigned int reg; __asm__ __volatile__ ("pushfl;" --- linux-2.6-pv.orig/include/asm-i386/segment.h +++ linux-2.6-pv/include/asm-i386/segment.h @@ -131,5 +131,7 @@ #define SEGMENT_LDT 0x4 #define SEGMENT_GDT 0x0 +#ifndef CONFIG_PARAVIRT #define get_kernel_rpl() 0 #endif +#endif --- linux-2.6-pv.orig/include/asm-i386/setup.h +++ linux-2.6-pv/include/asm-i386/setup.h @@ -70,6 +70,14 @@ extern unsigned char boot_params[PARAM_S struct e820entry; char * __init machine_specific_memory_setup(void); +#ifndef CONFIG_PARAVIRT +static inline char *memory_setup(void) +{ + return machine_specific_memory_setup(); +} +#else +#include <asm/paravirt.h> +#endif int __init copy_e820_map(struct e820entry * biosmap, int nr_map); int __init sanitize_e820_map(struct e820entry * biosmap, char * pnr_map); --- linux-2.6-pv.orig/include/asm-i386/spinlock.h +++ linux-2.6-pv/include/asm-i386/spinlock.h @@ -7,8 +7,12 @@ #include <asm/processor.h> #include <linux/compiler.h> +#ifdef CONFIG_PARAVIRT +#include <asm/paravirt.h> +#else #define CLI_STRING "cli" #define STI_STRING "sti" +#endif /* CONFIG_PARAVIRT */ /* * Your basic SMP spinlocks, allowing only a single CPU anywhere --- linux-2.6-pv.orig/include/asm-i386/system.h +++ linux-2.6-pv/include/asm-i386/system.h @@ -88,6 +88,9 @@ __asm__ __volatile__ ("movw %%dx,%1\n\t" #define savesegment(seg, value) \ asm volatile("mov %%" #seg ",%0":"=rm" (value)) +#ifdef CONFIG_PARAVIRT +#include <asm/paravirt.h> +#else #define read_cr0() ({ \ unsigned int __dummy; \ __asm__ __volatile__( \ @@ -139,17 +142,18 @@ __asm__ __volatile__ ("movw %%dx,%1\n\t" #define write_cr4(x) \ __asm__ __volatile__("movl %0,%%cr4": :"r" (x)) -/* - * Clear and set 'TS' bit respectively - */ +#define wbinvd() \ + __asm__ __volatile__ ("wbinvd": : :"memory") + +/* Clear the 'TS' bit */ #define clts() __asm__ __volatile__ ("clts") +#endif/* CONFIG_PARAVIRT */ + +/* Set the 'TS' bit */ #define stts() write_cr0(8 | read_cr0()) #endif /* __KERNEL__ */ -#define wbinvd() \ - __asm__ __volatile__ ("wbinvd": : :"memory") - static inline unsigned long get_limit(unsigned long segment) { unsigned long __limit; --- /dev/null +++ linux-2.6-pv/arch/i386/kernel/paravirt.c @@ -0,0 +1,410 @@ +/* Paravirtualization interfaces + Copyright (C) 2006 Rusty Russell IBM Corporation + + This program is free software; you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation; either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program; if not, write to the Free Software + Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA +*/ +#include <linux/errno.h> +#include <linux/module.h> +#include <linux/efi.h> +#include <linux/bcd.h> + +#include <asm/bug.h> +#include <asm/paravirt.h> +#include <asm/desc.h> +#include <asm/setup.h> +#include <asm/arch_hooks.h> +#include <asm/time.h> +#include <asm/irq.h> +#include <asm/delay.h> + +/* nop stub */ +static void native_nop(void) +{ +} + +static void __init default_banner(void) +{ + printk(KERN_INFO "Booting paravirtualized kernel on %s\n", + paravirt_ops.name); +} + +static fastcall unsigned long native_get_debugreg(int regno) +{ + unsigned long val = 0; /* Damn you, gcc! */ + + switch (regno) { + case 0: + asm("movl %%db0, %0" :"=r" (val)); break; + case 1: + asm("movl %%db1, %0" :"=r" (val)); break; + case 2: + asm("movl %%db2, %0" :"=r" (val)); break; + case 3: + asm("movl %%db3, %0" :"=r" (val)); break; + case 6: + asm("movl %%db6, %0" :"=r" (val)); break; + case 7: + asm("movl %%db7, %0" :"=r" (val)); break; + default: + BUG(); + } + return val; +} + +static fastcall void native_set_debugreg(int regno, unsigned long value) +{ + switch (regno) { + case 0: + asm("movl %0,%%db0" : /* no output */ :"r" (value)); + break; + case 1: + asm("movl %0,%%db1" : /* no output */ :"r" (value)); + break; + case 2: + asm("movl %0,%%db2" : /* no output */ :"r" (value)); + break; + case 3: + asm("movl %0,%%db3" : /* no output */ :"r" (value)); + break; + case 6: + asm("movl %0,%%db6" : /* no output */ :"r" (value)); + break; + case 7: + asm("movl %0,%%db7" : /* no output */ :"r" (value)); + break; + default: + BUG(); + } +} + +static fastcall void native_clts(void) +{ + asm volatile ("clts"); +} + +static fastcall unsigned long native_read_cr0(void) +{ + unsigned long val; + asm volatile("movl %%cr0,%0\n\t" :"=r" (val)); + return val; +} + +static fastcall void native_write_cr0(unsigned long val) +{ + asm volatile("movl %0,%%cr0": :"r" (val)); +} + +static fastcall unsigned long native_read_cr2(void) +{ + unsigned long val; + asm volatile("movl %%cr2,%0\n\t" :"=r" (val)); + return val; +} + +static fastcall void native_write_cr2(unsigned long val) +{ + asm volatile("movl %0,%%cr2": :"r" (val)); +} + +static fastcall unsigned long native_read_cr3(void) +{ + unsigned long val; + asm volatile("movl %%cr3,%0\n\t" :"=r" (val)); + return val; +} + +static fastcall void native_write_cr3(unsigned long val) +{ + asm volatile("movl %0,%%cr3": :"r" (val)); +} + +static fastcall unsigned long native_read_cr4(void) +{ + unsigned long val; + asm volatile("movl %%cr4,%0\n\t" :"=r" (val)); + return val; +} + +static fastcall unsigned long native_read_cr4_safe(void) +{ + unsigned long val; + /* This could fault if %cr4 does not exist */ + asm("1: movl %%cr4, %0 \n" + "2: \n" + ".section __ex_table,\"a\" \n" + ".long 1b,2b \n" + ".previous \n" + : "=r" (val): "0" (0)); + return val; +} + +static fastcall void native_write_cr4(unsigned long val) +{ + asm volatile("movl %0,%%cr4": :"r" (val)); +} + +static fastcall unsigned long native_save_fl(void) +{ + unsigned long f; + asm volatile("pushfl ; popl %0":"=g" (f): /* no input */); + return f; +} + +static fastcall void native_restore_fl(unsigned long f) +{ + asm volatile("pushl %0 ; popfl": /* no output */ + :"g" (f) + :"memory", "cc"); +} + +static fastcall void native_irq_disable(void) +{ + asm volatile("cli": : :"memory"); +} + +static fastcall void native_irq_enable(void) +{ + asm volatile("sti": : :"memory"); +} + +static fastcall void native_safe_halt(void) +{ + asm volatile("sti; hlt": : :"memory"); +} + +static fastcall void native_halt(void) +{ + asm volatile("hlt": : :"memory"); +} + +static fastcall void native_wbinvd(void) +{ + asm volatile("wbinvd": : :"memory"); +} + +static fastcall unsigned long long native_read_msr(unsigned int msr, int *err) +{ + unsigned long long val; + + asm volatile("2: rdmsr ; xorl %0,%0\n" + "1:\n\t" + ".section .fixup,\"ax\"\n\t" + "3: movl %3,%0 ; jmp 1b\n\t" + ".previous\n\t" + ".section __ex_table,\"a\"\n" + " .align 4\n\t" + " .long 2b,3b\n\t" + ".previous" + : "=r" (*err), "=A" (val) + : "c" (msr), "i" (-EFAULT)); + + return val; +} + +static fastcall int native_write_msr(unsigned int msr, unsigned long long val) +{ + int err; + asm volatile("2: wrmsr ; xorl %0,%0\n" + "1:\n\t" + ".section .fixup,\"ax\"\n\t" + "3: movl %4,%0 ; jmp 1b\n\t" + ".previous\n\t" + ".section __ex_table,\"a\"\n" + " .align 4\n\t" + " .long 2b,3b\n\t" + ".previous" + : "=a" (err) + : "c" (msr), "0" ((u32)val), "d" ((u32)(val>>32)), + "i" (-EFAULT)); + return err; +} + +static fastcall unsigned long long native_read_tsc(void) +{ + unsigned long long val; + asm volatile("rdtsc" : "=A" (val)); + return val; +} + +static fastcall unsigned long long native_read_pmc(void) +{ + unsigned long long val; + asm volatile("rdpmc" : "=A" (val)); + return val; +} + +static fastcall void native_load_tr_desc(void) +{ + asm volatile("ltr %w0"::"q" (GDT_ENTRY_TSS*8)); +} + +static fastcall void native_set_ldt(const void *addr, unsigned int entries) +{ + if (likely(entries == 0)) + __asm__ __volatile__("lldt %w0"::"q" (0)); + else { + unsigned cpu = smp_processor_id(); + __u32 a, b; + + pack_descriptor(&a, &b, (unsigned long)addr, + entries * sizeof(struct desc_struct) - 1, + DESCTYPE_LDT, 0); + write_gdt_entry(get_cpu_gdt_table(cpu), GDT_ENTRY_LDT, a, b); + __asm__ __volatile__("lldt %w0"::"q" (GDT_ENTRY_LDT*8)); + } +} + +static fastcall void native_load_gdt(const struct Xgt_desc_struct *dtr) +{ + asm volatile("lgdt %0"::"m" (*dtr)); +} + +static fastcall void native_load_idt(const struct Xgt_desc_struct *dtr) +{ + asm volatile("lidt %0"::"m" (*dtr)); +} + +static fastcall void native_store_gdt(struct Xgt_desc_struct *dtr) +{ + asm ("sgdt %0":"=m" (*dtr)); +} + +static fastcall void native_store_idt(struct Xgt_desc_struct *dtr) +{ + asm ("sidt %0":"=m" (*dtr)); +} + +static fastcall unsigned long native_store_tr(void) +{ + unsigned long tr; + asm ("str %0":"=r" (tr)); + return tr; +} + +static fastcall void native_load_tls(struct thread_struct *t, unsigned int cpu) +{ +#define C(i) get_cpu_gdt_table(cpu)[GDT_ENTRY_TLS_MIN + i] = t->tls_array[i] + C(0); C(1); C(2); +#undef C +} + +static inline void native_write_dt_entry(void *dt, int entry, u32 entry_low, u32 entry_high) +{ + u32 *lp = (u32 *)((char *)dt + entry*8); + lp[0] = entry_low; + lp[1] = entry_high; +} + +static fastcall void native_write_ldt_entry(void *dt, int entrynum, u32 low, u32 high) +{ + native_write_dt_entry(dt, entrynum, low, high); +} + +static fastcall void native_write_gdt_entry(void *dt, int entrynum, u32 low, u32 high) +{ + native_write_dt_entry(dt, entrynum, low, high); +} + +static fastcall void native_write_idt_entry(void *dt, int entrynum, u32 low, u32 high) +{ + native_write_dt_entry(dt, entrynum, low, high); +} + +static fastcall void native_load_esp0(struct tss_struct *tss, + struct thread_struct *thread) +{ + tss->esp0 = thread->esp0; + + /* This can only happen when SEP is enabled, no need to test "SEP"arately */ + if (unlikely(tss->ss1 != thread->sysenter_cs)) { + tss->ss1 = thread->sysenter_cs; + wrmsr(MSR_IA32_SYSENTER_CS, thread->sysenter_cs, 0); + } +} + +static fastcall void native_io_delay(void) +{ + asm volatile("outb %al,$0x80"); +} + +/* These are in entry.S */ +extern fastcall void native_iret(void); +extern fastcall void native_irq_enable_sysexit(void); + +static int __init print_banner(void) +{ + paravirt_ops.banner(); + return 0; +} +core_initcall(print_banner); + +struct paravirt_ops paravirt_ops = { + .name = "bare hardware", + .paravirt_enabled = 0, + .kernel_rpl = 0, + + .banner = default_banner, + .arch_setup = native_nop, + .memory_setup = machine_specific_memory_setup, + .get_wallclock = native_get_wallclock, + .set_wallclock = native_set_wallclock, + .time_init = time_init_hook, + .init_IRQ = native_init_IRQ, + + .cpuid = native_cpuid, + .get_debugreg = native_get_debugreg, + .set_debugreg = native_set_debugreg, + .clts = native_clts, + .read_cr0 = native_read_cr0, + .write_cr0 = native_write_cr0, + .read_cr2 = native_read_cr2, + .write_cr2 = native_write_cr2, + .read_cr3 = native_read_cr3, + .write_cr3 = native_write_cr3, + .read_cr4 = native_read_cr4, + .read_cr4_safe = native_read_cr4_safe, + .write_cr4 = native_write_cr4, + .save_fl = native_save_fl, + .restore_fl = native_restore_fl, + .irq_disable = native_irq_disable, + .irq_enable = native_irq_enable, + .safe_halt = native_safe_halt, + .halt = native_halt, + .wbinvd = native_wbinvd, + .read_msr = native_read_msr, + .write_msr = native_write_msr, + .read_tsc = native_read_tsc, + .read_pmc = native_read_pmc, + .load_tr_desc = native_load_tr_desc, + .set_ldt = native_set_ldt, + .load_gdt = native_load_gdt, + .load_idt = native_load_idt, + .store_gdt = native_store_gdt, + .store_idt = native_store_idt, + .store_tr = native_store_tr, + .load_tls = native_load_tls, + .write_ldt_entry = native_write_ldt_entry, + .write_gdt_entry = native_write_gdt_entry, + .write_idt_entry = native_write_idt_entry, + .load_esp0 = native_load_esp0, + + .set_iopl_mask = native_set_iopl_mask, + .io_delay = native_io_delay, + .const_udelay = __const_udelay, + + .irq_enable_sysexit = native_irq_enable_sysexit, + .iret = native_iret, +}; +EXPORT_SYMBOL(paravirt_ops); --- /dev/null +++ linux-2.6-pv/include/asm-i386/paravirt.h @@ -0,0 +1,291 @@ +#ifndef __ASM_PARAVIRT_H +#define __ASM_PARAVIRT_H +/* Various instructions on x86 need to be replaced for + * para-virtualization: those hooks are defined here. */ +#include <linux/linkage.h> + +#ifdef CONFIG_PARAVIRT +#ifndef __ASSEMBLY__ +struct thread_struct; +struct Xgt_desc_struct; +struct tss_struct; +struct paravirt_ops +{ + unsigned int kernel_rpl; + int paravirt_enabled; + const char *name; + + void (*arch_setup)(void); + char *(*memory_setup)(void); + void (*init_IRQ)(void); + + void (*banner)(void); + + unsigned long (*get_wallclock)(void); + int (*set_wallclock)(unsigned long); + void (*time_init)(void); + + /* All the function pointers here are declared as "fastcall" + so that we get a specific register-based calling + convention. This makes it easier to implement inline + assembler replacements. */ + + void (fastcall *cpuid)(unsigned int *eax, unsigned int *ebx, + unsigned int *ecx, unsigned int *edx); + + unsigned long (fastcall *get_debugreg)(int regno); + void (fastcall *set_debugreg)(int regno, unsigned long value); + + void (fastcall *clts)(void); + + unsigned long (fastcall *read_cr0)(void); + void (fastcall *write_cr0)(unsigned long); + + unsigned long (fastcall *read_cr2)(void); + void (fastcall *write_cr2)(unsigned long); + + unsigned long (fastcall *read_cr3)(void); + void (fastcall *write_cr3)(unsigned long); + + unsigned long (fastcall *read_cr4_safe)(void); + unsigned long (fastcall *read_cr4)(void); + void (fastcall *write_cr4)(unsigned long); + + unsigned long (fastcall *save_fl)(void); + void (fastcall *restore_fl)(unsigned long); + void (fastcall *irq_disable)(void); + void (fastcall *irq_enable)(void); + void (fastcall *safe_halt)(void); + void (fastcall *halt)(void); + void (fastcall *wbinvd)(void); + + /* err = 0/-EFAULT. wrmsr returns 0/-EFAULT. */ + u64 (fastcall *read_msr)(unsigned int msr, int *err); + int (fastcall *write_msr)(unsigned int msr, u64 val); + + u64 (fastcall *read_tsc)(void); + u64 (fastcall *read_pmc)(void); + + void (fastcall *load_tr_desc)(void); + void (fastcall *load_gdt)(const struct Xgt_desc_struct *); + void (fastcall *load_idt)(const struct Xgt_desc_struct *); + void (fastcall *store_gdt)(struct Xgt_desc_struct *); + void (fastcall *store_idt)(struct Xgt_desc_struct *); + void (fastcall *set_ldt)(const void *desc, unsigned entries); + unsigned long (fastcall *store_tr)(void); + void (fastcall *load_tls)(struct thread_struct *t, unsigned int cpu); + void (fastcall *write_ldt_entry)(void *dt, int entrynum, + u32 low, u32 high); + void (fastcall *write_gdt_entry)(void *dt, int entrynum, + u32 low, u32 high); + void (fastcall *write_idt_entry)(void *dt, int entrynum, + u32 low, u32 high); + void (fastcall *load_esp0)(struct tss_struct *tss, + struct thread_struct *thread); + + void (fastcall *set_iopl_mask)(unsigned mask); + + void (fastcall *io_delay)(void); + void (*const_udelay)(unsigned long loops); + + /* These two are jmp to, not actually called. */ + void (fastcall *irq_enable_sysexit)(void); + void (fastcall *iret)(void); +}; + +extern struct paravirt_ops paravirt_ops; + +#define paravirt_enabled() (paravirt_ops.paravirt_enabled) + +static inline void init_IRQ(void) +{ + paravirt_ops.init_IRQ(); +} + +static inline void load_esp0(struct tss_struct *tss, + struct thread_struct *thread) +{ + paravirt_ops.load_esp0(tss, thread); +} + +#define ARCH_SETUP paravirt_ops.arch_setup(); +static inline char *memory_setup(void) +{ + return paravirt_ops.memory_setup(); +} + +static inline unsigned long get_wallclock(void) +{ + return paravirt_ops.get_wallclock(); +} + +static inline int set_wallclock(unsigned long nowtime) +{ + return paravirt_ops.set_wallclock(nowtime); +} + +static inline void do_time_init(void) +{ + return paravirt_ops.time_init(); +} + +/* The paravirtualized CPUID instruction. */ +static inline void __cpuid(unsigned int *eax, unsigned int *ebx, + unsigned int *ecx, unsigned int *edx) +{ + paravirt_ops.cpuid(eax, ebx, ecx, edx); +} + +/* + * These special macros can be used to get or set a debugging register + */ +#define get_debugreg(var, reg) var = paravirt_ops.get_debugreg(reg) +#define set_debugreg(val, reg) paravirt_ops.set_debugreg(reg, val) + +#define clts() paravirt_ops.clts() + +#define read_cr0() paravirt_ops.read_cr0() +#define write_cr0(x) paravirt_ops.write_cr0(x) + +#define read_cr2() paravirt_ops.read_cr2() +#define write_cr2(x) paravirt_ops.write_cr2(x) + +#define read_cr3() paravirt_ops.read_cr3() +#define write_cr3(x) paravirt_ops.write_cr3(x) + +#define read_cr4() paravirt_ops.read_cr4() +#define read_cr4_safe(x) paravirt_ops.read_cr4_safe() +#define write_cr4(x) paravirt_ops.write_cr4(x) + +static inline unsigned long __raw_local_save_flags(void) +{ + return paravirt_ops.save_fl(); +} + +static inline void raw_local_irq_restore(unsigned long flags) +{ + return paravirt_ops.restore_fl(flags); +} + +static inline void raw_local_irq_disable(void) +{ + paravirt_ops.irq_disable(); +} + +static inline void raw_local_irq_enable(void) +{ + paravirt_ops.irq_enable(); +} + +static inline unsigned long __raw_local_irq_save(void) +{ + unsigned long flags = paravirt_ops.save_fl(); + + paravirt_ops.irq_disable(); + + return flags; +} + +static inline void raw_safe_halt(void) +{ + paravirt_ops.safe_halt(); +} + +static inline void halt(void) +{ + paravirt_ops.safe_halt(); +} +#define wbinvd() paravirt_ops.wbinvd() + +#define get_kernel_rpl() (paravirt_ops.kernel_rpl) + +#define rdmsr(msr,val1,val2) do { \ + int _err; \ + u64 _l = paravirt_ops.read_msr(msr,&_err); \ + val1 = (u32)_l; \ + val2 = _l >> 32; \ +} while(0) + +#define wrmsr(msr,val1,val2) do { \ + u64 _l = ((u64)(val2) << 32) | (val1); \ + paravirt_ops.write_msr((msr), _l); \ +} while(0) + +#define rdmsrl(msr,val) do { \ + int _err; \ + val = paravirt_ops.read_msr((msr),&_err); \ +} while(0) + +#define wrmsrl(msr,val) (paravirt_ops.write_msr((msr),(val))) +#define wrmsr_safe(msr,a,b) ({ \ + u64 _l = ((u64)(b) << 32) | (a); \ + paravirt_ops.write_msr((msr),_l); \ +}) + +/* rdmsr with exception handling */ +#define rdmsr_safe(msr,a,b) ({ \ + int _err; \ + u64 _l = paravirt_ops.read_msr(msr,&_err); \ + (*a) = (u32)_l; \ + (*b) = _l >> 32; \ + _err; }) + +#define rdtsc(low,high) do { \ + u64 _l = paravirt_ops.read_tsc(); \ + low = (u32)_l; \ + high = _l >> 32; \ +} while(0) + +#define rdtscl(low) do { \ + u64 _l = paravirt_ops.read_tsc(); \ + low = (int)_l; \ +} while(0) + +#define rdtscll(val) (val = paravirt_ops.read_tsc()) + +#define write_tsc(val1,val2) wrmsr(0x10, val1, val2) + +#define rdpmc(counter,low,high) do { \ + u64 _l = paravirt_ops.read_pmc(); \ + low = (u32)_l; \ + high = _l >> 32; \ +} while(0) + +#define load_TR_desc() (paravirt_ops.load_tr_desc()) +#define load_gdt(dtr) (paravirt_ops.load_gdt(dtr)) +#define load_idt(dtr) (paravirt_ops.load_idt(dtr)) +#define set_ldt(addr, entries) (paravirt_ops.set_ldt((addr), (entries))) +#define store_gdt(dtr) (paravirt_ops.store_gdt(dtr)) +#define store_idt(dtr) (paravirt_ops.store_idt(dtr)) +#define store_tr(tr) ((tr) = paravirt_ops.store_tr()) +#define load_TLS(t,cpu) (paravirt_ops.load_tls((t),(cpu))) +#define write_ldt_entry(dt, entry, low, high) \ + (paravirt_ops.write_ldt_entry((dt), (entry), (low), (high))) +#define write_gdt_entry(dt, entry, low, high) \ + (paravirt_ops.write_gdt_entry((dt), (entry), (low), (high))) +#define write_idt_entry(dt, entry, low, high) \ + (paravirt_ops.write_idt_entry((dt), (entry), (low), (high))) +#define set_iopl_mask(mask) (paravirt_ops.set_iopl_mask(mask)) + +/* The paravirtualized I/O functions */ +static inline void slow_down_io(void) { + paravirt_ops.io_delay(); +#ifdef REALLY_SLOW_IO + paravirt_ops.io_delay(); + paravirt_ops.io_delay(); + paravirt_ops.io_delay(); +#endif +} + +#define CLI_STRING "pushl %eax; pushl %ecx; pushl %edx; call *paravirt_ops+PARAVIRT_irq_disable; popl %edx; popl %ecx; popl %eax" +#define STI_STRING "pushl %eax; pushl %ecx; pushl %edx; call *paravirt_ops+PARAVIRT_irq_enable; popl %edx; popl %ecx; popl %eax" +#else /* __ASSEMBLY__ */ + +#define INTERRUPT_RETURN jmp *%cs:paravirt_ops+PARAVIRT_iret +#define DISABLE_INTERRUPTS pushl %eax; pushl %ecx; pushl %edx; call *paravirt_ops+PARAVIRT_irq_disable; popl %edx; popl %ecx; popl %eax +#define ENABLE_INTERRUPTS pushl %eax; pushl %ecx; pushl %edx; call *%cs:paravirt_ops+PARAVIRT_irq_enable; popl %edx; popl %ecx; popl %eax +#define ENABLE_INTERRUPTS_SYSEXIT jmp *%cs:paravirt_ops+PARAVIRT_irq_enable_sysexit +#define GET_CR0_INTO_EAX call *paravirt_ops+PARAVIRT_read_cr0 +#endif /* __ASSEMBLY__ */ +#endif /* CONFIG_PARAVIRT */ +#endif /* __ASM_PARAVIRT_H */ --- /dev/null +++ linux-2.6-pv/include/asm-i386/time.h @@ -0,0 +1,41 @@ +#ifndef _ASMi386_TIME_H +#define _ASMi386_TIME_H + +#include <linux/efi.h> +#include "mach_time.h" + +static inline unsigned long native_get_wallclock(void) +{ + unsigned long retval; + + if (efi_enabled) + retval = efi_get_time(); + else + retval = mach_get_cmos_time(); + + return retval; +} + +static inline int native_set_wallclock(unsigned long nowtime) +{ + int retval; + + if (efi_enabled) + retval = efi_set_rtc_mmss(nowtime); + else + retval = mach_set_rtc_mmss(nowtime); + + return retval; +} + +#ifdef CONFIG_PARAVIRT +#include <asm/paravirt.h> +#else /* !CONFIG_PARAVIRT */ + +#define get_wallclock() native_get_wallclock() +#define set_wallclock(x) native_set_wallclock(x) +#define do_time_init() time_init_hook() + +#endif /* CONFIG_PARAVIRT */ + +#endif --
Add APIC accessors to paravirt-ops. Unfortunately, we need two write functions, as some older broken hardware requires workarounds for Pentium APIC errata - this is the purpose of apic_write_atomic. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jeremy Fitzhardinge <jeremy@goop.org> --- arch/i386/kernel/paravirt.c | 28 ++++++++++++++++++++++++++++ include/asm-i386/apic.h | 5 ++++- include/asm-i386/paravirt.h | 27 +++++++++++++++++++++++++++ 3 files changed, 59 insertions(+), 1 deletion(-) --- linux-2.6-pv.orig/arch/i386/kernel/paravirt.c +++ linux-2.6-pv/arch/i386/kernel/paravirt.c @@ -28,6 +28,8 @@ #include <asm/time.h> #include <asm/irq.h> #include <asm/delay.h> +#include <asm/fixmap.h> +#include <asm/apic.h> /* nop stub */ static void native_nop(void) @@ -382,6 +384,26 @@ static fastcall void native_io_delay(voi asm volatile("outb %al,$0x80"); } +#ifdef CONFIG_X86_LOCAL_APIC +/* + * Basic functions for reading and writing APIC registers + */ +static fastcall void native_apic_write(unsigned long reg, unsigned long v) +{ + *((volatile unsigned long *)(APIC_BASE+reg)) = v; +} + +static fastcall void native_apic_write_atomic(unsigned long reg, unsigned long v) +{ + xchg((volatile unsigned long *)(APIC_BASE+reg), v); +} + +static fastcall unsigned long native_apic_read(unsigned long reg) +{ + return *((volatile unsigned long *)(APIC_BASE+reg)); +} +#endif /* CONFIG_X86_LOCAL_APIC */ + /* These are in entry.S */ extern fastcall void native_iret(void); extern fastcall void native_irq_enable_sysexit(void); @@ -452,6 +474,12 @@ struct paravirt_ops paravirt_ops = { .io_delay = native_io_delay, .const_udelay = __const_udelay, +#ifdef CONFIG_X86_LOCAL_APIC + .apic_write = native_apic_write, + .apic_write_atomic = native_apic_write_atomic, + .apic_read = native_apic_read, +#endif + .irq_enable_sysexit = native_irq_enable_sysexit, .iret = native_iret, }; --- linux-2.6-pv.orig/include/asm-i386/apic.h +++ linux-2.6-pv/include/asm-i386/apic.h @@ -37,7 +37,9 @@ extern void generic_apic_probe(void); /* * Basic functions accessing APICs. */ - +#ifdef CONFIG_PARAVIRT +#include <asm/paravirt.h> +#else static __inline void apic_write(unsigned long reg, unsigned long v) { *((volatile unsigned long *)(APIC_BASE+reg)) = v; @@ -52,6 +54,7 @@ static __inline unsigned long apic_read( { return *((volatile unsigned long *)(APIC_BASE+reg)); } +#endif static __inline__ void apic_wait_icr_idle(void) { --- linux-2.6-pv.orig/include/asm-i386/paravirt.h +++ linux-2.6-pv/include/asm-i386/paravirt.h @@ -115,6 +115,12 @@ struct paravirt_ops void (fastcall *io_delay)(void); void (*const_udelay)(unsigned long loops); +#ifdef CONFIG_X86_LOCAL_APIC + void (fastcall *apic_write)(unsigned long reg, unsigned long v); + void (fastcall *apic_write_atomic)(unsigned long reg, unsigned long v); + unsigned long (fastcall *apic_read)(unsigned long reg); +#endif + /* These two are jmp to, not actually called. */ void (fastcall *irq_enable_sysexit)(void); void (fastcall *iret)(void); @@ -280,6 +286,27 @@ static inline void slow_down_io(void) { #endif } +#ifdef CONFIG_X86_LOCAL_APIC +/* + * Basic functions accessing APICs. + */ +static __inline void apic_write(unsigned long reg, unsigned long v) +{ + paravirt_ops.apic_write(reg,v); +} + +static __inline void apic_write_atomic(unsigned long reg, unsigned long v) +{ + paravirt_ops.apic_write_atomic(reg,v); +} + +static __inline unsigned long apic_read(unsigned long reg) +{ + return paravirt_ops.apic_read(reg); +} +#endif + + /* These all sit in the .parainstructions section to tell us what to patch. */ struct paravirt_patch { u8 *instr; /* original instructions */ --
Add the three bare TLB accessor functions to paravirt-ops. Most amusingly, flush_tlb is redefined on SMP, so I can't call the paravirt op flush_tlb. Instead, I chose to indicate the actual flush type, kernel (global) vs. user (non-global). Global in this sense means using the global bit in the page table entry, which makes TLB entries persistent across CR3 reloads, not global as in the SMP sense of invoking remote shootdowns, so the term is confusingly overloaded. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Cc: Rusty Russell <rusty@rustcorp.com.au> Cc: Jeremy Fitzhardinge <jeremy@goop.org> --- arch/i386/kernel/paravirt.c | 109 ++++++++++++++++++++++++++++++++++++++ arch/i386/mm/boot_ioremap.c | 1 include/asm-i386/paravirt.h | 75 ++++++++++++++++++++++++++ include/asm-i386/pgtable-2level.h | 5 + include/asm-i386/pgtable-3level.h | 42 +++++++------- include/asm-i386/pgtable.h | 4 + include/asm-i386/tlbflush.h | 18 ++++-- 7 files changed, 227 insertions(+), 27 deletions(-) --- linux-2.6-pv.orig/arch/i386/kernel/paravirt.c +++ linux-2.6-pv/arch/i386/kernel/paravirt.c @@ -30,6 +30,7 @@ #include <asm/delay.h> #include <asm/fixmap.h> #include <asm/apic.h> +#include <asm/tlbflush.h> /* nop stub */ static void native_nop(void) @@ -404,6 +405,97 @@ static fastcall unsigned long native_api } #endif /* CONFIG_X86_LOCAL_APIC */ +static fastcall void native_flush_tlb(void) +{ + __native_flush_tlb(); +} + +/* + * Global pages have to be flushed a bit differently. Not a real + * performance problem because this does not happen often. + */ +static fastcall void native_flush_tlb_global(void) +{ + __native_flush_tlb_global(); +} + +static fastcall void native_flush_tlb_single(u32 addr) +{ + __native_flush_tlb_single(addr); +} + +#ifndef CONFIG_X86_PAE +static fastcall void native_set_pte(pte_t *ptep, pte_t pteval) +{ + *ptep = pteval; +} + +static fastcall void native_set_pte_at(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pteval) +{ + *ptep = pteval; +} + +static fastcall void native_set_pmd(pmd_t *pmdp, pmd_t pmdval) +{ + *pmdp = pmdval; +} + +#else /* CONFIG_X86_PAE */ + +static fastcall void native_set_pte(pte_t *ptep, pte_t pte) +{ + ptep->pte_high = pte.pte_high; + smp_wmb(); + ptep->pte_low = pte.pte_low; +} + +static fastcall void native_set_pte_at(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pte) +{ + ptep->pte_high = pte.pte_high; + smp_wmb(); + ptep->pte_low = pte.pte_low; +} + +static fastcall void native_set_pte_present(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte) +{ + ptep->pte_low = 0; + smp_wmb(); + ptep->pte_high = pte.pte_high; + smp_wmb(); + ptep->pte_low = pte.pte_low; +} + +static fastcall void native_set_pte_atomic(pte_t *ptep, pte_t pteval) +{ + set_64bit((unsigned long long *)ptep,pte_val(pteval)); +} + +static fastcall void native_set_pmd(pmd_t *pmdp, pmd_t pmdval) +{ + set_64bit((unsigned long long *)pmdp,pmd_val(pmdval)); +} + +static fastcall void native_set_pud(pud_t *pudp, pud_t pudval) +{ + *pudp = pudval; +} + +static fastcall void native_pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) +{ + ptep->pte_low = 0; + smp_wmb(); + ptep->pte_high = 0; +} + +static fastcall void native_pmd_clear(pmd_t *pmd) +{ + u32 *tmp = (u32 *)pmd; + *tmp = 0; + smp_wmb(); + *(tmp + 1) = 0; +} +#endif /* CONFIG_X86_PAE */ + /* These are in entry.S */ extern fastcall void native_iret(void); extern fastcall void native_irq_enable_sysexit(void); @@ -480,6 +572,23 @@ struct paravirt_ops paravirt_ops = { .apic_read = native_apic_read, #endif + .flush_tlb_user = native_flush_tlb, + .flush_tlb_kernel = native_flush_tlb_global, + .flush_tlb_single = native_flush_tlb_single, + + .set_pte = native_set_pte, + .set_pte_at = native_set_pte_at, + .set_pmd = native_set_pmd, + .pte_update = (void *)native_nop, + .pte_update_defer = (void *)native_nop, +#ifdef CONFIG_X86_PAE + .set_pte_atomic = native_set_pte_atomic, + .set_pte_present = native_set_pte_present, + .set_pud = native_set_pud, + .pte_clear = native_pte_clear, + .pmd_clear = native_pmd_clear, +#endif + .irq_enable_sysexit = native_irq_enable_sysexit, .iret = native_iret, }; --- linux-2.6-pv.orig/arch/i386/mm/boot_ioremap.c +++ linux-2.6-pv/arch/i386/mm/boot_ioremap.c @@ -16,6 +16,7 @@ */ #undef CONFIG_X86_PAE +#undef CONFIG_PARAVIRT #include <asm/page.h> #include <asm/pgtable.h> #include <asm/tlbflush.h> --- linux-2.6-pv.orig/include/asm-i386/paravirt.h +++ linux-2.6-pv/include/asm-i386/paravirt.h @@ -4,6 +4,7 @@ * para-virtualization: those hooks are defined here. */ #include <linux/linkage.h> #include <linux/stringify.h> +#include <asm/page.h> #ifdef CONFIG_PARAVIRT /* These are the most performance critical ops, so we want to be able to patch @@ -27,6 +28,7 @@ struct thread_struct; struct Xgt_desc_struct; struct tss_struct; +struct mm_struct; struct paravirt_ops { unsigned int kernel_rpl; @@ -121,6 +123,23 @@ struct paravirt_ops unsigned long (fastcall *apic_read)(unsigned long reg); #endif + void (fastcall *flush_tlb_user)(void); + void (fastcall *flush_tlb_kernel)(void); + void (fastcall *flush_tlb_single)(u32 addr); + + void (fastcall *set_pte)(pte_t *ptep, pte_t pteval); + void (fastcall *set_pte_at)(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pteval); + void (fastcall *set_pmd)(pmd_t *pmdp, pmd_t pmdval); + void (fastcall *pte_update)(struct mm_struct *mm, u32 addr, pte_t *ptep); + void (fastcall *pte_update_defer)(struct mm_struct *mm, u32 addr, pte_t *ptep); +#ifdef CONFIG_X86_PAE + void (fastcall *set_pte_atomic)(pte_t *ptep, pte_t pteval); + void (fastcall *set_pte_present)(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte); + void (fastcall *set_pud)(pud_t *pudp, pud_t pudval); + void (fastcall *pte_clear)(struct mm_struct *mm, unsigned long addr, pte_t *ptep); + void (fastcall *pmd_clear)(pmd_t *pmdp); +#endif + /* These two are jmp to, not actually called. */ void (fastcall *irq_enable_sysexit)(void); void (fastcall *iret)(void); @@ -307,6 +326,62 @@ static __inline unsigned long apic_read( #endif +#define __flush_tlb() paravirt_ops.flush_tlb_user() +#define __flush_tlb_global() paravirt_ops.flush_tlb_kernel() +#define __flush_tlb_single(addr) paravirt_ops.flush_tlb_single(addr) + +static inline void set_pte(pte_t *ptep, pte_t pteval) +{ + paravirt_ops.set_pte(ptep, pteval); +} + +static inline void set_pte_at(struct mm_struct *mm, u32 addr, pte_t *ptep, pte_t pteval) +{ + paravirt_ops.set_pte_at(mm, addr, ptep, pteval); +} + +static inline void set_pmd(pmd_t *pmdp, pmd_t pmdval) +{ + paravirt_ops.set_pmd(pmdp, pmdval); +} + +static inline void pte_update(struct mm_struct *mm, u32 addr, pte_t *ptep) +{ + paravirt_ops.pte_update(mm, addr, ptep); +} + +static inline void pte_update_defer(struct mm_struct *mm, u32 addr, pte_t *ptep) +{ + paravirt_ops.pte_update_defer(mm, addr, ptep); +} + +#ifdef CONFIG_X86_PAE +static inline void set_pte_atomic(pte_t *ptep, pte_t pteval) +{ + paravirt_ops.set_pte_atomic(ptep, pteval); +} + +static inline void set_pte_present(struct mm_struct *mm, unsigned long addr, pte_t *ptep, pte_t pte) +{ + paravirt_ops.set_pte_present(mm, addr, ptep, pte); +} + +static inline void set_pud(pud_t *pudp, pud_t pudval) +{ + paravirt_ops.set_pud(pudp, pudval); +} + +static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) +{ + paravirt_ops.pte_clear(mm, addr, ptep); +} + +static inline void pmd_clear(pmd_t *pmdp) +{ + paravirt_ops.pmd_clear(pmdp); +} +#endif + /* These all sit in the .parainstructions section to tell us what to patch. */ struct paravirt_patch { u8 *instr; /* original instructions */ --- linux-2.6-pv.orig/include/asm-i386/pgtable-2level.h +++ linux-2.6-pv/include/asm-i386/pgtable-2level.h @@ -11,11 +11,14 @@ * within a page table are directly modified. Thus, the following * hook is made available. */ +#ifndef CONFIG_PARAVIRT #define set_pte(pteptr, pteval) (*(pteptr) = pteval) #define set_pte_at(mm,addr,ptep,pteval) set_pte(ptep,pteval) +#define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval)) +#endif + #define set_pte_atomic(pteptr, pteval) set_pte(pteptr,pteval) #define set_pte_present(mm,addr,ptep,pteval) set_pte_at(mm,addr,ptep,pteval) -#define set_pmd(pmdptr, pmdval) (*(pmdptr) = (pmdval)) #define pte_clear(mm,addr,xp) do { set_pte_at(mm, addr, xp, __pte(0)); } while (0) #define pmd_clear(xp) do { set_pmd(xp, __pmd(0)); } while (0) --- linux-2.6-pv.orig/include/asm-i386/pgtable-3level.h +++ linux-2.6-pv/include/asm-i386/pgtable-3level.h @@ -42,6 +42,7 @@ static inline int pte_exec_kernel(pte_t return pte_x(pte); } +#ifndef CONFIG_PARAVIRT /* Rules for using set_pte: the pte being assigned *must* be * either not present or in a state where the hardware will * not attempt to update the pte. In places where this is @@ -71,12 +72,33 @@ static inline void set_pte_present(struc ptep->pte_low = pte.pte_low; } +/* + * For PTEs and PDEs, we must clear the P-bit first when clearing a page table + * entry, so clear the bottom half first and enforce ordering with a compiler + * barrier. + */ +static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) +{ + ptep->pte_low = 0; + smp_wmb(); + ptep->pte_high = 0; +} + +static inline void pmd_clear(pmd_t *pmd) +{ + u32 *tmp = (u32 *)pmd; + *tmp = 0; + smp_wmb(); + *(tmp + 1) = 0; +} + #define set_pte_atomic(pteptr,pteval) \ set_64bit((unsigned long long *)(pteptr),pte_val(pteval)) #define set_pmd(pmdptr,pmdval) \ set_64bit((unsigned long long *)(pmdptr),pmd_val(pmdval)) #define set_pud(pudptr,pudval) \ (*(pudptr) = (pudval)) +#endif /* * Pentium-II erratum A13: in PAE mode we explicitly have to flush @@ -97,26 +119,6 @@ static inline void pud_clear (pud_t * pu #define pmd_offset(pud, address) ((pmd_t *) pud_page(*(pud)) + \ pmd_index(address)) -/* - * For PTEs and PDEs, we must clear the P-bit first when clearing a page table - * entry, so clear the bottom half first and enforce ordering with a compiler - * barrier. - */ -static inline void pte_clear(struct mm_struct *mm, unsigned long addr, pte_t *ptep) -{ - ptep->pte_low = 0; - smp_wmb(); - ptep->pte_high = 0; -} - -static inline void pmd_clear(pmd_t *pmd) -{ - u32 *tmp = (u32 *)pmd; - *tmp = 0; - smp_wmb(); - *(tmp + 1) = 0; -} - static inline pte_t raw_ptep_get_and_clear(pte_t *ptep) { pte_t res; --- linux-2.6-pv.orig/include/asm-i386/pgtable.h +++ linux-2.6-pv/include/asm-i386/pgtable.h @@ -15,6 +15,7 @@ #include <asm/processor.h> #include <asm/fixmap.h> #include <linux/threads.h> +#include <asm/paravirt.h> #ifndef _I386_BITOPS_H #include <asm/bitops.h> @@ -246,6 +247,7 @@ static inline pte_t pte_mkhuge(pte_t pte # include <asm/pgtable-2level.h> #endif +#ifndef CONFIG_PARAVIRT /* * Rules for using pte_update - it must be called after any PTE update which * has not been done using the set_pte / clear_pte interfaces. It is used by @@ -261,7 +263,7 @@ static inline pte_t pte_mkhuge(pte_t pte */ #define pte_update(mm, addr, ptep) do { } while (0) #define pte_update_defer(mm, addr, ptep) do { } while (0) - +#endif /* * We only update the dirty/accessed state if we set --- linux-2.6-pv.orig/include/asm-i386/tlbflush.h +++ linux-2.6-pv/include/asm-i386/tlbflush.h @@ -4,7 +4,15 @@ #include <linux/mm.h> #include <asm/processor.h> -#define __flush_tlb() \ +#ifdef CONFIG_PARAVIRT +#include <asm/paravirt.h> +#else +#define __flush_tlb() __native_flush_tlb() +#define __flush_tlb_global() __native_flush_tlb_global() +#define __flush_tlb_single(addr) __native_flush_tlb_single(addr) +#endif + +#define __native_flush_tlb() \ do { \ unsigned int tmpreg; \ \ @@ -19,7 +27,7 @@ * Global pages have to be flushed a bit differently. Not a real * performance problem because this does not happen often. */ -#define __flush_tlb_global() \ +#define __native_flush_tlb_global() \ do { \ unsigned int tmpreg, cr4, cr4_orig; \ \ @@ -36,6 +44,9 @@ : "memory"); \ } while (0) +#define __native_flush_tlb_single(addr) \ + __asm__ __volatile__("invlpg (%0)" ::"r" (addr) : "memory") + # define __flush_tlb_all() \ do { \ if (cpu_has_pge) \ @@ -46,9 +57,6 @@ #define cpu_has_invlpg (boot_cpu_data.x86 > 3) -#define __flush_tlb_single(addr) \ - __asm__ __volatile__("invlpg (%0)" ::"r" (addr) : "memory") - #ifdef CONFIG_X86_INVLPG # define __flush_tlb_one(addr) __flush_tlb_single(addr) #else --
Chris Wright
2007-Apr-18 13:02 UTC
[PATCH 2/7] Patch inline replacements for common paravirt operations.
It turns out that the most called ops, by several orders of magnitude, are the interrupt manipulation ops. These are obvious candidates for patching, so mark them up and create infrastructure for it. The method used is that the ops structure has a patch function, which is called for each place which needs to be patched: this returns a number of instructions (the rest are NOP-padded). Usually we can spare a register (%eax) for the binary patched code to use, but in a couple of critical places in entry.S we can't: we make the clobbers explicit at the call site, and manually clobber the allowed registers in debug mode as an extra check. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au> Signed-off-by: Jeremy Fitzhardinge <jeremy@xensource.com> Signed-off-by: Chris Wright <chrisw@sous-sol.org> Signed-off-by: Zachary Amsden <zach@vmware.com> --- arch/i386/kernel/alternative.c | 66 ++++++++++++-- arch/i386/kernel/entry.S | 26 ++--- arch/i386/kernel/module.c | 9 + arch/i386/kernel/paravirt.c | 44 +++++++++ arch/i386/kernel/vmlinux.lds.S | 6 + include/asm-i386/alternative.h | 3 include/asm-i386/irqflags.h | 4 include/asm-i386/paravirt.h | 185 +++++++++++++++++++++++++++++++++-------- include/asm-i386/spinlock.h | 5 - 9 files changed, 284 insertions(+), 64 deletions(-) --- linux-2.6-pv.orig/arch/i386/kernel/alternative.c +++ linux-2.6-pv/arch/i386/kernel/alternative.c @@ -123,6 +123,20 @@ static unsigned char** find_nop_table(vo #endif /* CONFIG_X86_64 */ +static void nop_out(void *insns, unsigned int len) +{ + unsigned char **noptable = find_nop_table(); + + while (len > 0) { + unsigned int noplen = len; + if (noplen > ASM_NOP_MAX) + noplen = ASM_NOP_MAX; + memcpy(insns, noptable[noplen], noplen); + insns += noplen; + len -= noplen; + } +} + extern struct alt_instr __alt_instructions[], __alt_instructions_end[]; extern struct alt_instr __smp_alt_instructions[], __smp_alt_instructions_end[]; extern u8 *__smp_locks[], *__smp_locks_end[]; @@ -137,10 +151,9 @@ extern u8 __smp_alt_begin[], __smp_alt_e void apply_alternatives(struct alt_instr *start, struct alt_instr *end) { - unsigned char **noptable = find_nop_table(); struct alt_instr *a; u8 *instr; - int diff, i, k; + int diff; DPRINTK("%s: alt table %p -> %p\n", __FUNCTION__, start, end); for (a = start; a < end; a++) { @@ -158,13 +171,7 @@ void apply_alternatives(struct alt_instr #endif memcpy(instr, a->replacement, a->replacementlen); diff = a->instrlen - a->replacementlen; - /* Pad the rest with nops */ - for (i = a->replacementlen; diff > 0; diff -= k, i += k) { - k = diff; - if (k > ASM_NOP_MAX) - k = ASM_NOP_MAX; - memcpy(a->instr + i, noptable[k], k); - } + nop_out(instr + a->replacementlen, diff); } } @@ -208,7 +215,6 @@ static void alternatives_smp_lock(u8 **s static void alternatives_smp_unlock(u8 **start, u8 **end, u8 *text, u8 *text_end) { - unsigned char **noptable = find_nop_table(); u8 **ptr; for (ptr = start; ptr < end; ptr++) { @@ -216,7 +222,7 @@ static void alternatives_smp_unlock(u8 * continue; if (*ptr > text_end) continue; - **ptr = noptable[1][0]; + nop_out(*ptr, 1); }; } @@ -342,6 +348,43 @@ void alternatives_smp_switch(int smp) #endif +#ifdef CONFIG_PARAVIRT +void apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end) +{ + struct paravirt_patch *p; + int i; + + for (p = start; p < end; p++) { + unsigned int used; + + used = paravirt_ops.patch(p->instrtype, p->clobbers, p->instr, + p->len); +#ifdef CONFIG_DEBUG_KERNEL + /* Deliberately clobber regs using "not %reg" to find bugs. */ + for (i = 0; i < 3; i++) { + if (p->len - used >= 2 && (p->clobbers & (1 << i))) { + memcpy(p->instr + used, "\xf7\xd0", 2); + p->instr[used+1] |= i; + used += 2; + } + } +#endif + /* Pad the rest with nops */ + nop_out(p->instr + used, p->len - used); + } + + /* Sync to be conservative, in case we patched following instructions */ + sync_core(); +} +extern struct paravirt_patch __start_parainstructions[], + __stop_parainstructions[]; +#else +void apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end) +{ +} +extern struct paravirt_patch *__start_parainstructions, *__stop_parainstructions; +#endif /* CONFIG_PARAVIRT */ + void __init alternative_instructions(void) { unsigned long flags; @@ -389,5 +432,6 @@ void __init alternative_instructions(voi alternatives_smp_switch(0); } #endif + apply_paravirt(__start_parainstructions, __stop_parainstructions); local_irq_restore(flags); } --- linux-2.6-pv.orig/arch/i386/kernel/entry.S +++ linux-2.6-pv/arch/i386/kernel/entry.S @@ -63,9 +63,9 @@ NT_MASK = 0x00004000 VM_MASK = 0x00020000 #ifdef CONFIG_PREEMPT -#define preempt_stop DISABLE_INTERRUPTS; TRACE_IRQS_OFF +#define preempt_stop(clobbers) DISABLE_INTERRUPTS(clobbers); TRACE_IRQS_OFF #else -#define preempt_stop +#define preempt_stop(clobbers) #define resume_kernel restore_nocheck #endif @@ -226,7 +226,7 @@ ENTRY(ret_from_fork) ALIGN RING0_PTREGS_FRAME ret_from_exception: - preempt_stop + preempt_stop(CLBR_ANY) ret_from_intr: GET_THREAD_INFO(%ebp) check_userspace: @@ -237,7 +237,7 @@ check_userspace: jb resume_kernel # not returning to v8086 or userspace ENTRY(resume_userspace) - DISABLE_INTERRUPTS # make sure we don't miss an interrupt + DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt # setting need_resched or sigpending # between sampling and the iret movl TI_flags(%ebp), %ecx @@ -248,7 +248,7 @@ ENTRY(resume_userspace) #ifdef CONFIG_PREEMPT ENTRY(resume_kernel) - DISABLE_INTERRUPTS + DISABLE_INTERRUPTS(CLBR_ANY) cmpl $0,TI_preempt_count(%ebp) # non-zero preempt_count ? jnz restore_nocheck need_resched: @@ -277,7 +277,7 @@ sysenter_past_esp: * No need to follow this irqs on/off section: the syscall * disabled irqs and here we enable it straight after entry: */ - ENABLE_INTERRUPTS + ENABLE_INTERRUPTS(CLBR_NONE) pushl $(__USER_DS) CFI_ADJUST_CFA_OFFSET 4 /*CFI_REL_OFFSET ss, 0*/ @@ -322,7 +322,7 @@ sysenter_past_esp: jae syscall_badsys call *sys_call_table(,%eax,4) movl %eax,PT_EAX(%esp) - DISABLE_INTERRUPTS + DISABLE_INTERRUPTS(CLBR_ECX|CLBR_EDX) TRACE_IRQS_OFF movl TI_flags(%ebp), %ecx testw $_TIF_ALLWORK_MASK, %cx @@ -364,7 +364,7 @@ syscall_call: call *sys_call_table(,%eax,4) movl %eax,PT_EAX(%esp) # store the return value syscall_exit: - DISABLE_INTERRUPTS # make sure we don't miss an interrupt + DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt # setting need_resched or sigpending # between sampling and the iret TRACE_IRQS_OFF @@ -393,7 +393,7 @@ restore_nocheck_notrace: .section .fixup,"ax" iret_exc: TRACE_IRQS_ON - ENABLE_INTERRUPTS + ENABLE_INTERRUPTS(CLBR_NONE) pushl $0 # no error code pushl $do_iret_error jmp error_code @@ -436,7 +436,7 @@ ldt_ss: CFI_ADJUST_CFA_OFFSET 4 pushl %eax CFI_ADJUST_CFA_OFFSET 4 - DISABLE_INTERRUPTS + DISABLE_INTERRUPTS(CLBR_EAX) TRACE_IRQS_OFF lss (%esp), %esp CFI_ADJUST_CFA_OFFSET -8 @@ -451,7 +451,7 @@ work_pending: jz work_notifysig work_resched: call schedule - DISABLE_INTERRUPTS # make sure we don't miss an interrupt + DISABLE_INTERRUPTS(CLBR_ANY) # make sure we don't miss an interrupt # setting need_resched or sigpending # between sampling and the iret TRACE_IRQS_OFF @@ -507,7 +507,7 @@ syscall_exit_work: testb $(_TIF_SYSCALL_TRACE|_TIF_SYSCALL_AUDIT|_TIF_SINGLESTEP), %cl jz work_pending TRACE_IRQS_ON - ENABLE_INTERRUPTS # could let do_syscall_trace() call + ENABLE_INTERRUPTS(CLBR_ANY) # could let do_syscall_trace() call # schedule() instead movl %esp, %eax movl $1, %edx @@ -691,7 +691,7 @@ ENTRY(device_not_available) GET_CR0_INTO_EAX testl $0x4, %eax # EM (math emulation bit) jne device_not_available_emulate - preempt_stop + preempt_stop(CLBR_ANY) call math_state_restore jmp ret_from_exception device_not_available_emulate: --- linux-2.6-pv.orig/arch/i386/kernel/module.c +++ linux-2.6-pv/arch/i386/kernel/module.c @@ -109,7 +109,8 @@ int module_finalize(const Elf_Ehdr *hdr, const Elf_Shdr *sechdrs, struct module *me) { - const Elf_Shdr *s, *text = NULL, *alt = NULL, *locks = NULL; + const Elf_Shdr *s, *text = NULL, *alt = NULL, *locks = NULL, + *para = NULL; char *secstrings = (void *)hdr + sechdrs[hdr->e_shstrndx].sh_offset; for (s = sechdrs; s < sechdrs + hdr->e_shnum; s++) { @@ -119,6 +120,8 @@ int module_finalize(const Elf_Ehdr *hdr, alt = s; if (!strcmp(".smp_locks", secstrings + s->sh_name)) locks= s; + if (!strcmp(".parainstructions", secstrings + s->sh_name)) + para = s; } if (alt) { @@ -133,6 +136,10 @@ int module_finalize(const Elf_Ehdr *hdr, lseg, lseg + locks->sh_size, tseg, tseg + text->sh_size); } + if (para) { + void *pseg = (void *)para->sh_addr; + apply_paravirt(pseg, pseg + para->sh_size); + } return module_bug_finalize(hdr, sechdrs, me); } --- linux-2.6-pv.orig/arch/i386/kernel/paravirt.c +++ linux-2.6-pv/arch/i386/kernel/paravirt.c @@ -40,6 +40,49 @@ static void __init default_banner(void) paravirt_ops.name); } +/* Simple instruction patching code. */ +#define DEF_NATIVE(name, code) \ + extern const char start_##name[], end_##name[]; \ + asm("start_" #name ": " code "; end_" #name ":") +DEF_NATIVE(cli, "cli"); +DEF_NATIVE(sti, "sti"); +DEF_NATIVE(popf, "push %eax; popf"); +DEF_NATIVE(pushf, "pushf; pop %eax"); +DEF_NATIVE(pushf_cli, "pushf; pop %eax; cli"); +DEF_NATIVE(iret, "iret"); +DEF_NATIVE(sti_sysexit, "sti; sysexit"); + +static const struct native_insns +{ + const char *start, *end; +} native_insns[] = { + [PARAVIRT_IRQ_DISABLE] = { start_cli, end_cli }, + [PARAVIRT_IRQ_ENABLE] = { start_sti, end_sti }, + [PARAVIRT_RESTORE_FLAGS] = { start_popf, end_popf }, + [PARAVIRT_SAVE_FLAGS] = { start_pushf, end_pushf }, + [PARAVIRT_SAVE_FLAGS_IRQ_DISABLE] = { start_pushf_cli, end_pushf_cli }, + [PARAVIRT_INTERRUPT_RETURN] = { start_iret, end_iret }, + [PARAVIRT_STI_SYSEXIT] = { start_sti_sysexit, end_sti_sysexit }, +}; + +static unsigned native_patch(u8 type, u16 clobbers, void *insns, unsigned len) +{ + unsigned int insn_len; + + /* Don't touch it if we don't have a replacement */ + if (type >= ARRAY_SIZE(native_insns) || !native_insns[type].start) + return len; + + insn_len = native_insns[type].end - native_insns[type].start; + + /* Similarly if we can't fit replacement. */ + if (len < insn_len) + return len; + + memcpy(insns, native_insns[type].start, insn_len); + return insn_len; +} + static fastcall unsigned long native_get_debugreg(int regno) { unsigned long val = 0; /* Damn you, gcc! */ @@ -355,6 +398,7 @@ struct paravirt_ops paravirt_ops = { .paravirt_enabled = 0, .kernel_rpl = 0, + .patch = native_patch, .banner = default_banner, .arch_setup = native_nop, .memory_setup = machine_specific_memory_setup, --- linux-2.6-pv.orig/arch/i386/kernel/vmlinux.lds.S +++ linux-2.6-pv/arch/i386/kernel/vmlinux.lds.S @@ -154,6 +154,12 @@ SECTIONS .altinstr_replacement : AT(ADDR(.altinstr_replacement) - LOAD_OFFSET) { *(.altinstr_replacement) } + . = ALIGN(4); + __start_parainstructions = .; + .parainstructions : AT(ADDR(.parainstructions) - LOAD_OFFSET) { + *(.parainstructions) + } + __stop_parainstructions = .; /* .exit.text is discard at runtime, not link time, to deal with references from .altinstructions and .eh_frame */ .exit.text : AT(ADDR(.exit.text) - LOAD_OFFSET) { *(.exit.text) } --- linux-2.6-pv.orig/include/asm-i386/alternative.h +++ linux-2.6-pv/include/asm-i386/alternative.h @@ -118,4 +118,7 @@ static inline void alternatives_smp_swit #define LOCK_PREFIX "" #endif +struct paravirt_patch; +void apply_paravirt(struct paravirt_patch *start, struct paravirt_patch *end); + #endif /* _I386_ALTERNATIVE_H */ --- linux-2.6-pv.orig/include/asm-i386/irqflags.h +++ linux-2.6-pv/include/asm-i386/irqflags.h @@ -79,8 +79,8 @@ static inline unsigned long __raw_local_ } #else -#define DISABLE_INTERRUPTS cli -#define ENABLE_INTERRUPTS sti +#define DISABLE_INTERRUPTS(clobbers) cli +#define ENABLE_INTERRUPTS(clobbers) sti #define ENABLE_INTERRUPTS_SYSEXIT sti; sysexit #define INTERRUPT_RETURN iret #define GET_CR0_INTO_EAX movl %cr0, %eax --- linux-2.6-pv.orig/include/asm-i386/paravirt.h +++ linux-2.6-pv/include/asm-i386/paravirt.h @@ -3,8 +3,26 @@ /* Various instructions on x86 need to be replaced for * para-virtualization: those hooks are defined here. */ #include <linux/linkage.h> +#include <linux/stringify.h> #ifdef CONFIG_PARAVIRT +/* These are the most performance critical ops, so we want to be able to patch + * callers */ +#define PARAVIRT_IRQ_DISABLE 0 +#define PARAVIRT_IRQ_ENABLE 1 +#define PARAVIRT_RESTORE_FLAGS 2 +#define PARAVIRT_SAVE_FLAGS 3 +#define PARAVIRT_SAVE_FLAGS_IRQ_DISABLE 4 +#define PARAVIRT_INTERRUPT_RETURN 5 +#define PARAVIRT_STI_SYSEXIT 6 + +/* Bitmask of what can be clobbered: usually at least eax. */ +#define CLBR_NONE 0x0 +#define CLBR_EAX 0x1 +#define CLBR_ECX 0x2 +#define CLBR_EDX 0x4 +#define CLBR_ANY 0x7 + #ifndef __ASSEMBLY__ struct thread_struct; struct Xgt_desc_struct; @@ -15,6 +33,15 @@ struct paravirt_ops int paravirt_enabled; const char *name; + /* + * Patch may replace one of the defined code sequences with arbitrary + * code, subject to the same register constraints. This generally + * means the code is not free to clobber any registers other than EAX. + * The patch function should return the number of bytes of code + * generated, as we nop pad the rest in generic code. + */ + unsigned (*patch)(u8 type, u16 clobber, void *firstinsn, unsigned len); + void (*arch_setup)(void); char *(*memory_setup)(void); void (*init_IRQ)(void); @@ -157,35 +184,6 @@ static inline void __cpuid(unsigned int #define read_cr4_safe(x) paravirt_ops.read_cr4_safe() #define write_cr4(x) paravirt_ops.write_cr4(x) -static inline unsigned long __raw_local_save_flags(void) -{ - return paravirt_ops.save_fl(); -} - -static inline void raw_local_irq_restore(unsigned long flags) -{ - return paravirt_ops.restore_fl(flags); -} - -static inline void raw_local_irq_disable(void) -{ - paravirt_ops.irq_disable(); -} - -static inline void raw_local_irq_enable(void) -{ - paravirt_ops.irq_enable(); -} - -static inline unsigned long __raw_local_irq_save(void) -{ - unsigned long flags = paravirt_ops.save_fl(); - - paravirt_ops.irq_disable(); - - return flags; -} - static inline void raw_safe_halt(void) { paravirt_ops.safe_halt(); @@ -277,15 +275,130 @@ static inline void slow_down_io(void) { #endif } -#define CLI_STRING "pushl %eax; pushl %ecx; pushl %edx; call *paravirt_ops+PARAVIRT_irq_disable; popl %edx; popl %ecx; popl %eax" -#define STI_STRING "pushl %eax; pushl %ecx; pushl %edx; call *paravirt_ops+PARAVIRT_irq_enable; popl %edx; popl %ecx; popl %eax" +/* These all sit in the .parainstructions section to tell us what to patch. */ +struct paravirt_patch { + u8 *instr; /* original instructions */ + u8 instrtype; /* type of this instruction */ + u8 len; /* length of original instruction */ + u16 clobbers; /* what registers you may clobber */ +}; + +#define paravirt_alt(insn_string, typenum, clobber) \ + "771:\n\t" insn_string "\n" "772:\n" \ + ".pushsection .parainstructions,\"a\"\n" \ + " .long 771b\n" \ + " .byte " __stringify(typenum) "\n" \ + " .byte 772b-771b\n" \ + " .short " __stringify(clobber) "\n" \ + ".popsection" + +static inline unsigned long __raw_local_save_flags(void) +{ + unsigned long f; + + __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;" + "call *%1;" + "popl %%edx; popl %%ecx", + PARAVIRT_SAVE_FLAGS, CLBR_NONE) + : "=a"(f): "m"(paravirt_ops.save_fl) + : "memory", "cc"); + return f; +} + +static inline void raw_local_irq_restore(unsigned long f) +{ + __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;" + "call *%1;" + "popl %%edx; popl %%ecx", + PARAVIRT_RESTORE_FLAGS, CLBR_EAX) + : "=a"(f) : "m" (paravirt_ops.restore_fl), "0"(f) + : "memory", "cc"); +} + +static inline void raw_local_irq_disable(void) +{ + __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;" + "call *%0;" + "popl %%edx; popl %%ecx", + PARAVIRT_IRQ_DISABLE, CLBR_EAX) + : : "m" (paravirt_ops.irq_disable) + : "memory", "eax", "cc"); +} + +static inline void raw_local_irq_enable(void) +{ + __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;" + "call *%0;" + "popl %%edx; popl %%ecx", + PARAVIRT_IRQ_ENABLE, CLBR_EAX) + : : "m" (paravirt_ops.irq_enable) + : "memory", "eax", "cc"); +} + +static inline unsigned long __raw_local_irq_save(void) +{ + unsigned long f; + + __asm__ __volatile__(paravirt_alt( "pushl %%ecx; pushl %%edx;" + "call *%1; pushl %%eax;" + "call *%2; popl %%eax;" + "popl %%edx; popl %%ecx", + PARAVIRT_SAVE_FLAGS_IRQ_DISABLE, + CLBR_NONE) + : "=a"(f) + : "m" (paravirt_ops.save_fl), + "m" (paravirt_ops.irq_disable) + : "memory", "cc"); + return f; +} + +#define CLI_STRING paravirt_alt("pushl %ecx; pushl %edx;" \ + "call *paravirt_ops+PARAVIRT_irq_disable;" \ + "popl %edx; popl %ecx", \ + PARAVIRT_IRQ_DISABLE, CLBR_EAX) + +#define STI_STRING paravirt_alt("pushl %ecx; pushl %edx;" \ + "call *paravirt_ops+PARAVIRT_irq_enable;" \ + "popl %edx; popl %ecx", \ + PARAVIRT_IRQ_ENABLE, CLBR_EAX) +#define CLI_STI_CLOBBERS , "%eax" + #else /* __ASSEMBLY__ */ + +#define PARA_PATCH(ptype, clobbers, ops) \ +771:; \ + ops; \ +772:; \ + .pushsection .parainstructions,"a"; \ + .long 771b; \ + .byte ptype; \ + .byte 772b-771b; \ + .short clobbers; \ + .popsection + +#define INTERRUPT_RETURN \ + PARA_PATCH(PARAVIRT_INTERRUPT_RETURN, CLBR_ANY, \ + jmp *%cs:paravirt_ops+PARAVIRT_iret) + +#define DISABLE_INTERRUPTS(clobbers) \ + PARA_PATCH(PARAVIRT_IRQ_DISABLE, clobbers, \ + pushl %ecx; pushl %edx; \ + call *paravirt_ops+PARAVIRT_irq_disable; \ + popl %edx; popl %ecx) \ + +#define ENABLE_INTERRUPTS(clobbers) \ + PARA_PATCH(PARAVIRT_IRQ_ENABLE, clobbers, \ + pushl %ecx; pushl %edx; \ + call *%cs:paravirt_ops+PARAVIRT_irq_enable; \ + popl %edx; popl %ecx) + +#define ENABLE_INTERRUPTS_SYSEXIT \ + PARA_PATCH(PARAVIRT_STI_SYSEXIT, CLBR_ANY, \ + jmp *%cs:paravirt_ops+PARAVIRT_irq_enable_sysexit) + +#define GET_CR0_INTO_EAX \ + call *paravirt_ops+PARAVIRT_read_cr0 -#define INTERRUPT_RETURN jmp *%cs:paravirt_ops+PARAVIRT_iret -#define DISABLE_INTERRUPTS pushl %eax; pushl %ecx; pushl %edx; call *paravirt_ops+PARAVIRT_irq_disable; popl %edx; popl %ecx; popl %eax -#define ENABLE_INTERRUPTS pushl %eax; pushl %ecx; pushl %edx; call *%cs:paravirt_ops+PARAVIRT_irq_enable; popl %edx; popl %ecx; popl %eax -#define ENABLE_INTERRUPTS_SYSEXIT jmp *%cs:paravirt_ops+PARAVIRT_irq_enable_sysexit -#define GET_CR0_INTO_EAX call *paravirt_ops+PARAVIRT_read_cr0 #endif /* __ASSEMBLY__ */ #endif /* CONFIG_PARAVIRT */ #endif /* __ASM_PARAVIRT_H */ --- linux-2.6-pv.orig/include/asm-i386/spinlock.h +++ linux-2.6-pv/include/asm-i386/spinlock.h @@ -12,6 +12,7 @@ #else #define CLI_STRING "cli" #define STI_STRING "sti" +#define CLI_STI_CLOBBERS #endif /* CONFIG_PARAVIRT */ /* @@ -75,7 +76,9 @@ static inline void __raw_spin_lock_flags "jg 1b\n\t" "jmp 4b\n" "5:\n\t" - : "+m" (lock->slock) : "r" (flags) : "memory"); + : "+m" (lock->slock) + : "r" (flags) + : "memory" CLI_STI_CLOBBERS); } #endif --
The following patches introduce the core infrastructure needed to paravirtualize the 32-bit x86 Linux kernel. This is done by moving virtualization sensitive insn's or code paths to a function table, paravirt_ops. This structure can be populated with hypervisor specific calls or native stubs and currently support running on bare metal, VMI, Xen, or Lhype. These patches apply to 2.6.19-rc2-mm2 plus the last set of paravirt prep patches that Rusty sent. thanks, -chris --
Pavel Machek
2007-Apr-18 13:02 UTC
[PATCH 4/7] Allow selected bug checks to be skipped by paravirt kernels
On Sat 2006-10-28 00:00:04, Chris Wright wrote:> Allow selected bug checks to be skipped by paravirt kernels. The two most > important are the F00F workaround (which is either done by the hypervisor, > or not required), and the 'hlt' instruction check, which can break under > some hypervisors.How can hlt check break? It is hlt;hlt;hlt, IIRC, that looks fairly innocent to me.> --- linux-2.6-pv.orig/arch/i386/kernel/cpu/intel.c > +++ linux-2.6-pv/arch/i386/kernel/cpu/intel.c > @@ -107,7 +107,7 @@ static void __cpuinit init_intel(struct > * Note that the workaround only should be initialized once... > */ > c->f00f_bug = 0; > - if ( c->x86 == 5 ) { > + if (!paravirt_enabled() && c->x86 == 5) {I'd do x86==5 check first... pentiums are not common any more. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html