The long term plan has been to replace Xen PV guests by PVH. The first victim of that plan are now 32-bit PV guests, as those are used only rather seldom these days. Xen on x86 requires 64-bit support and with Grub2 now supporting PVH officially since version 2.04 there is no need to keep 32-bit PV guest support alive in the Linux kernel. Additionally Meltdown mitigation is not available in the kernel running as 32-bit PV guest, so dropping this mode makes sense from security point of view, too. Changes in V2: - rebase to 5.8 kernel - addressed comments to V1 - new patches 3 and 4 Juergen Gross (4): x86/xen: remove 32-bit Xen PV guest support x86/paravirt: remove 32-bit support from PARAVIRT_XXL x86/paravirt: cleanup paravirt macros x86/paravirt: use CONFIG_PARAVIRT_XXL instead of CONFIG_PARAVIRT arch/x86/entry/entry_32.S | 109 +------ arch/x86/entry/entry_64.S | 4 +- arch/x86/entry/vdso/vdso32/vclock_gettime.c | 1 + arch/x86/include/asm/fixmap.h | 2 +- arch/x86/include/asm/paravirt.h | 107 +----- arch/x86/include/asm/paravirt_types.h | 21 -- arch/x86/include/asm/pgtable-3level_types.h | 5 - arch/x86/include/asm/proto.h | 2 +- arch/x86/include/asm/required-features.h | 2 +- arch/x86/include/asm/segment.h | 6 +- arch/x86/kernel/cpu/common.c | 8 - arch/x86/kernel/head_32.S | 31 -- arch/x86/kernel/kprobes/core.c | 1 - arch/x86/kernel/kprobes/opt.c | 1 - arch/x86/kernel/paravirt.c | 18 -- arch/x86/kernel/paravirt_patch.c | 17 - arch/x86/xen/Kconfig | 3 +- arch/x86/xen/Makefile | 3 +- arch/x86/xen/apic.c | 17 - arch/x86/xen/enlighten_pv.c | 52 +-- arch/x86/xen/mmu_pv.c | 340 +++----------------- arch/x86/xen/p2m.c | 6 +- arch/x86/xen/setup.c | 35 +- arch/x86/xen/smp_pv.c | 18 -- arch/x86/xen/xen-asm.S | 182 ++++++++++- arch/x86/xen/xen-asm_32.S | 185 ----------- arch/x86/xen/xen-asm_64.S | 181 ----------- arch/x86/xen/xen-head.S | 6 - drivers/xen/Kconfig | 4 +- 29 files changed, 232 insertions(+), 1135 deletions(-) delete mode 100644 arch/x86/xen/xen-asm_32.S delete mode 100644 arch/x86/xen/xen-asm_64.S -- 2.26.2
Juergen Gross
2020-Jul-01 11:06 UTC
[PATCH v2 2/4] x86/paravirt: remove 32-bit support from PARAVIRT_XXL
The last 32-bit user of stuff under CONFIG_PARAVIRT_XXL is gone.
Remove 32-bit specific parts.
Signed-off-by: Juergen Gross <jgross at suse.com>
---
arch/x86/entry/vdso/vdso32/vclock_gettime.c | 1 +
arch/x86/include/asm/paravirt.h | 92 +++------------------
arch/x86/include/asm/paravirt_types.h | 21 -----
arch/x86/include/asm/pgtable-3level_types.h | 5 --
arch/x86/include/asm/segment.h | 4 -
arch/x86/kernel/cpu/common.c | 8 --
arch/x86/kernel/kprobes/core.c | 1 -
arch/x86/kernel/kprobes/opt.c | 1 -
arch/x86/kernel/paravirt.c | 18 ----
arch/x86/kernel/paravirt_patch.c | 17 ----
arch/x86/xen/enlighten_pv.c | 6 --
11 files changed, 13 insertions(+), 161 deletions(-)
diff --git a/arch/x86/entry/vdso/vdso32/vclock_gettime.c
b/arch/x86/entry/vdso/vdso32/vclock_gettime.c
index 84a4a73f77f7..283ed9d00426 100644
--- a/arch/x86/entry/vdso/vdso32/vclock_gettime.c
+++ b/arch/x86/entry/vdso/vdso32/vclock_gettime.c
@@ -14,6 +14,7 @@
#undef CONFIG_ILLEGAL_POINTER_VALUE
#undef CONFIG_SPARSEMEM_VMEMMAP
#undef CONFIG_NR_CPUS
+#undef CONFIG_PARAVIRT_XXL
#define CONFIG_X86_32 1
#define CONFIG_PGTABLE_LEVELS 2
diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h
index 5ca5d297df75..cfe9f6e472b5 100644
--- a/arch/x86/include/asm/paravirt.h
+++ b/arch/x86/include/asm/paravirt.h
@@ -160,8 +160,6 @@ static inline void wbinvd(void)
PVOP_VCALL0(cpu.wbinvd);
}
-#define get_kernel_rpl() (pv_info.kernel_rpl)
-
static inline u64 paravirt_read_msr(unsigned msr)
{
return PVOP_CALL1(u64, cpu.read_msr, msr);
@@ -277,12 +275,10 @@ static inline void load_TLS(struct thread_struct *t,
unsigned cpu)
PVOP_VCALL2(cpu.load_tls, t, cpu);
}
-#ifdef CONFIG_X86_64
static inline void load_gs_index(unsigned int gs)
{
PVOP_VCALL1(cpu.load_gs_index, gs);
}
-#endif
static inline void write_ldt_entry(struct desc_struct *dt, int entry,
const void *desc)
@@ -372,10 +368,7 @@ static inline pte_t __pte(pteval_t val)
{
pteval_t ret;
- if (sizeof(pteval_t) > sizeof(long))
- ret = PVOP_CALLEE2(pteval_t, mmu.make_pte, val, (u64)val >> 32);
- else
- ret = PVOP_CALLEE1(pteval_t, mmu.make_pte, val);
+ ret = PVOP_CALLEE1(pteval_t, mmu.make_pte, val);
return (pte_t) { .pte = ret };
}
@@ -384,11 +377,7 @@ static inline pteval_t pte_val(pte_t pte)
{
pteval_t ret;
- if (sizeof(pteval_t) > sizeof(long))
- ret = PVOP_CALLEE2(pteval_t, mmu.pte_val,
- pte.pte, (u64)pte.pte >> 32);
- else
- ret = PVOP_CALLEE1(pteval_t, mmu.pte_val, pte.pte);
+ ret = PVOP_CALLEE1(pteval_t, mmu.pte_val, pte.pte);
return ret;
}
@@ -397,10 +386,7 @@ static inline pgd_t __pgd(pgdval_t val)
{
pgdval_t ret;
- if (sizeof(pgdval_t) > sizeof(long))
- ret = PVOP_CALLEE2(pgdval_t, mmu.make_pgd, val, (u64)val >> 32);
- else
- ret = PVOP_CALLEE1(pgdval_t, mmu.make_pgd, val);
+ ret = PVOP_CALLEE1(pgdval_t, mmu.make_pgd, val);
return (pgd_t) { ret };
}
@@ -409,11 +395,7 @@ static inline pgdval_t pgd_val(pgd_t pgd)
{
pgdval_t ret;
- if (sizeof(pgdval_t) > sizeof(long))
- ret = PVOP_CALLEE2(pgdval_t, mmu.pgd_val,
- pgd.pgd, (u64)pgd.pgd >> 32);
- else
- ret = PVOP_CALLEE1(pgdval_t, mmu.pgd_val, pgd.pgd);
+ ret = PVOP_CALLEE1(pgdval_t, mmu.pgd_val, pgd.pgd);
return ret;
}
@@ -433,51 +415,32 @@ static inline void ptep_modify_prot_commit(struct
vm_area_struct *vma, unsigned
pte_t *ptep, pte_t old_pte, pte_t pte)
{
- if (sizeof(pteval_t) > sizeof(long))
- /* 5 arg words */
- pv_ops.mmu.ptep_modify_prot_commit(vma, addr, ptep, pte);
- else
- PVOP_VCALL4(mmu.ptep_modify_prot_commit,
- vma, addr, ptep, pte.pte);
+ PVOP_VCALL4(mmu.ptep_modify_prot_commit, vma, addr, ptep, pte.pte);
}
static inline void set_pte(pte_t *ptep, pte_t pte)
{
- if (sizeof(pteval_t) > sizeof(long))
- PVOP_VCALL3(mmu.set_pte, ptep, pte.pte, (u64)pte.pte >> 32);
- else
- PVOP_VCALL2(mmu.set_pte, ptep, pte.pte);
+ PVOP_VCALL2(mmu.set_pte, ptep, pte.pte);
}
static inline void set_pte_at(struct mm_struct *mm, unsigned long addr,
pte_t *ptep, pte_t pte)
{
- if (sizeof(pteval_t) > sizeof(long))
- /* 5 arg words */
- pv_ops.mmu.set_pte_at(mm, addr, ptep, pte);
- else
- PVOP_VCALL4(mmu.set_pte_at, mm, addr, ptep, pte.pte);
+ PVOP_VCALL4(mmu.set_pte_at, mm, addr, ptep, pte.pte);
}
static inline void set_pmd(pmd_t *pmdp, pmd_t pmd)
{
pmdval_t val = native_pmd_val(pmd);
- if (sizeof(pmdval_t) > sizeof(long))
- PVOP_VCALL3(mmu.set_pmd, pmdp, val, (u64)val >> 32);
- else
- PVOP_VCALL2(mmu.set_pmd, pmdp, val);
+ PVOP_VCALL2(mmu.set_pmd, pmdp, val);
}
-#if CONFIG_PGTABLE_LEVELS >= 3
static inline pmd_t __pmd(pmdval_t val)
{
pmdval_t ret;
- if (sizeof(pmdval_t) > sizeof(long))
- ret = PVOP_CALLEE2(pmdval_t, mmu.make_pmd, val, (u64)val >> 32);
- else
- ret = PVOP_CALLEE1(pmdval_t, mmu.make_pmd, val);
+ ret = PVOP_CALLEE1(pmdval_t, mmu.make_pmd, val);
return (pmd_t) { ret };
}
@@ -486,11 +449,7 @@ static inline pmdval_t pmd_val(pmd_t pmd)
{
pmdval_t ret;
- if (sizeof(pmdval_t) > sizeof(long))
- ret = PVOP_CALLEE2(pmdval_t, mmu.pmd_val,
- pmd.pmd, (u64)pmd.pmd >> 32);
- else
- ret = PVOP_CALLEE1(pmdval_t, mmu.pmd_val, pmd.pmd);
+ ret = PVOP_CALLEE1(pmdval_t, mmu.pmd_val, pmd.pmd);
return ret;
}
@@ -499,12 +458,9 @@ static inline void set_pud(pud_t *pudp, pud_t pud)
{
pudval_t val = native_pud_val(pud);
- if (sizeof(pudval_t) > sizeof(long))
- PVOP_VCALL3(mmu.set_pud, pudp, val, (u64)val >> 32);
- else
- PVOP_VCALL2(mmu.set_pud, pudp, val);
+ PVOP_VCALL2(mmu.set_pud, pudp, val);
}
-#if CONFIG_PGTABLE_LEVELS >= 4
+
static inline pud_t __pud(pudval_t val)
{
pudval_t ret;
@@ -569,29 +525,6 @@ static inline void p4d_clear(p4d_t *p4dp)
set_p4d(p4dp, __p4d(0));
}
-#endif /* CONFIG_PGTABLE_LEVELS == 4 */
-
-#endif /* CONFIG_PGTABLE_LEVELS >= 3 */
-
-#ifdef CONFIG_X86_PAE
-/* Special-case pte-setting operations for PAE, which can't update a
- 64-bit pte atomically */
-static inline void set_pte_atomic(pte_t *ptep, pte_t pte)
-{
- PVOP_VCALL3(mmu.set_pte_atomic, ptep, pte.pte, pte.pte >> 32);
-}
-
-static inline void pte_clear(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep)
-{
- PVOP_VCALL3(mmu.pte_clear, mm, addr, ptep);
-}
-
-static inline void pmd_clear(pmd_t *pmdp)
-{
- PVOP_VCALL1(mmu.pmd_clear, pmdp);
-}
-#else /* !CONFIG_X86_PAE */
static inline void set_pte_atomic(pte_t *ptep, pte_t pte)
{
set_pte(ptep, pte);
@@ -607,7 +540,6 @@ static inline void pmd_clear(pmd_t *pmdp)
{
set_pmd(pmdp, __pmd(0));
}
-#endif /* CONFIG_X86_PAE */
#define __HAVE_ARCH_START_CONTEXT_SWITCH
static inline void arch_start_context_switch(struct task_struct *prev)
diff --git a/arch/x86/include/asm/paravirt_types.h
b/arch/x86/include/asm/paravirt_types.h
index 732f62e04ddb..9d0c16315869 100644
--- a/arch/x86/include/asm/paravirt_types.h
+++ b/arch/x86/include/asm/paravirt_types.h
@@ -68,12 +68,7 @@ struct paravirt_callee_save {
/* general info */
struct pv_info {
#ifdef CONFIG_PARAVIRT_XXL
- unsigned int kernel_rpl;
- int shared_kernel_pmd;
-
-#ifdef CONFIG_X86_64
u16 extra_user_64bit_cs; /* __USER_CS if none */
-#endif
#endif
const char *name;
@@ -126,9 +121,7 @@ struct pv_cpu_ops {
void (*set_ldt)(const void *desc, unsigned entries);
unsigned long (*store_tr)(void);
void (*load_tls)(struct thread_struct *t, unsigned int cpu);
-#ifdef CONFIG_X86_64
void (*load_gs_index)(unsigned int idx);
-#endif
void (*write_ldt_entry)(struct desc_struct *ldt, int entrynum,
const void *desc);
void (*write_gdt_entry)(struct desc_struct *,
@@ -263,21 +256,11 @@ struct pv_mmu_ops {
struct paravirt_callee_save pgd_val;
struct paravirt_callee_save make_pgd;
-#if CONFIG_PGTABLE_LEVELS >= 3
-#ifdef CONFIG_X86_PAE
- void (*set_pte_atomic)(pte_t *ptep, pte_t pteval);
- void (*pte_clear)(struct mm_struct *mm, unsigned long addr,
- pte_t *ptep);
- void (*pmd_clear)(pmd_t *pmdp);
-
-#endif /* CONFIG_X86_PAE */
-
void (*set_pud)(pud_t *pudp, pud_t pudval);
struct paravirt_callee_save pmd_val;
struct paravirt_callee_save make_pmd;
-#if CONFIG_PGTABLE_LEVELS >= 4
struct paravirt_callee_save pud_val;
struct paravirt_callee_save make_pud;
@@ -290,10 +273,6 @@ struct pv_mmu_ops {
void (*set_pgd)(pgd_t *pgdp, pgd_t pgdval);
#endif /* CONFIG_PGTABLE_LEVELS >= 5 */
-#endif /* CONFIG_PGTABLE_LEVELS >= 4 */
-
-#endif /* CONFIG_PGTABLE_LEVELS >= 3 */
-
struct pv_lazy_ops lazy_mode;
/* dom0 ops */
diff --git a/arch/x86/include/asm/pgtable-3level_types.h
b/arch/x86/include/asm/pgtable-3level_types.h
index 80fbb4a9ed87..56baf43befb4 100644
--- a/arch/x86/include/asm/pgtable-3level_types.h
+++ b/arch/x86/include/asm/pgtable-3level_types.h
@@ -20,12 +20,7 @@ typedef union {
} pte_t;
#endif /* !__ASSEMBLY__ */
-#ifdef CONFIG_PARAVIRT_XXL
-#define SHARED_KERNEL_PMD ((!static_cpu_has(X86_FEATURE_PTI) && \
- (pv_info.shared_kernel_pmd)))
-#else
#define SHARED_KERNEL_PMD (!static_cpu_has(X86_FEATURE_PTI))
-#endif
#define ARCH_PAGE_TABLE_SYNC_MASK (SHARED_KERNEL_PMD ? 0 : PGTBL_PMD_MODIFIED)
diff --git a/arch/x86/include/asm/segment.h b/arch/x86/include/asm/segment.h
index 9646c300f128..517920928989 100644
--- a/arch/x86/include/asm/segment.h
+++ b/arch/x86/include/asm/segment.h
@@ -222,10 +222,6 @@
#endif
-#ifndef CONFIG_PARAVIRT_XXL
-# define get_kernel_rpl() 0
-#endif
-
#define IDT_ENTRIES 256
#define NUM_EXCEPTION_VECTORS 32
diff --git a/arch/x86/kernel/cpu/common.c b/arch/x86/kernel/cpu/common.c
index 043d93cdcaad..65cdfa433370 100644
--- a/arch/x86/kernel/cpu/common.c
+++ b/arch/x86/kernel/cpu/common.c
@@ -1396,15 +1396,7 @@ static void generic_identify(struct cpuinfo_x86 *c)
* ESPFIX issue, we can change this.
*/
#ifdef CONFIG_X86_32
-# ifdef CONFIG_PARAVIRT_XXL
- do {
- extern void native_iret(void);
- if (pv_ops.cpu.iret == native_iret)
- set_cpu_bug(c, X86_BUG_ESPFIX);
- } while (0);
-# else
set_cpu_bug(c, X86_BUG_ESPFIX);
-# endif
#endif
}
diff --git a/arch/x86/kernel/kprobes/core.c b/arch/x86/kernel/kprobes/core.c
index ada39ddbc922..fa1b6f2f5222 100644
--- a/arch/x86/kernel/kprobes/core.c
+++ b/arch/x86/kernel/kprobes/core.c
@@ -780,7 +780,6 @@ __used __visible void *trampoline_handler(struct pt_regs
*regs)
/* fixup registers */
regs->cs = __KERNEL_CS;
#ifdef CONFIG_X86_32
- regs->cs |= get_kernel_rpl();
regs->gs = 0;
#endif
/* We use pt_regs->sp for return address holder. */
diff --git a/arch/x86/kernel/kprobes/opt.c b/arch/x86/kernel/kprobes/opt.c
index 7af4c61dde52..816f00e89d04 100644
--- a/arch/x86/kernel/kprobes/opt.c
+++ b/arch/x86/kernel/kprobes/opt.c
@@ -180,7 +180,6 @@ optimized_callback(struct optimized_kprobe *op, struct
pt_regs *regs)
/* Save skipped registers */
regs->cs = __KERNEL_CS;
#ifdef CONFIG_X86_32
- regs->cs |= get_kernel_rpl();
regs->gs = 0;
#endif
regs->ip = (unsigned long)op->kp.addr + INT3_INSN_SIZE;
diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c
index 674a7d66d960..b318700c5ada 100644
--- a/arch/x86/kernel/paravirt.c
+++ b/arch/x86/kernel/paravirt.c
@@ -263,13 +263,8 @@ enum paravirt_lazy_mode paravirt_get_lazy_mode(void)
struct pv_info pv_info = {
.name = "bare hardware",
#ifdef CONFIG_PARAVIRT_XXL
- .kernel_rpl = 0,
- .shared_kernel_pmd = 1, /* Only used when CONFIG_X86_PAE is set */
-
-#ifdef CONFIG_X86_64
.extra_user_64bit_cs = __USER_CS,
#endif
-#endif
};
/* 64-bit pagetable entries */
@@ -305,9 +300,7 @@ struct paravirt_patch_template pv_ops = {
.cpu.load_idt = native_load_idt,
.cpu.store_tr = native_store_tr,
.cpu.load_tls = native_load_tls,
-#ifdef CONFIG_X86_64
.cpu.load_gs_index = native_load_gs_index,
-#endif
.cpu.write_ldt_entry = native_write_ldt_entry,
.cpu.write_gdt_entry = native_write_gdt_entry,
.cpu.write_idt_entry = native_write_idt_entry,
@@ -317,9 +310,7 @@ struct paravirt_patch_template pv_ops = {
.cpu.load_sp0 = native_load_sp0,
-#ifdef CONFIG_X86_64
.cpu.usergs_sysret64 = native_usergs_sysret64,
-#endif
.cpu.iret = native_iret,
.cpu.swapgs = native_swapgs,
@@ -374,18 +365,11 @@ struct paravirt_patch_template pv_ops = {
.mmu.ptep_modify_prot_start = __ptep_modify_prot_start,
.mmu.ptep_modify_prot_commit = __ptep_modify_prot_commit,
-#if CONFIG_PGTABLE_LEVELS >= 3
-#ifdef CONFIG_X86_PAE
- .mmu.set_pte_atomic = native_set_pte_atomic,
- .mmu.pte_clear = native_pte_clear,
- .mmu.pmd_clear = native_pmd_clear,
-#endif
.mmu.set_pud = native_set_pud,
.mmu.pmd_val = PTE_IDENT,
.mmu.make_pmd = PTE_IDENT,
-#if CONFIG_PGTABLE_LEVELS >= 4
.mmu.pud_val = PTE_IDENT,
.mmu.make_pud = PTE_IDENT,
@@ -397,8 +381,6 @@ struct paravirt_patch_template pv_ops = {
.mmu.set_pgd = native_set_pgd,
#endif /* CONFIG_PGTABLE_LEVELS >= 5 */
-#endif /* CONFIG_PGTABLE_LEVELS >= 4 */
-#endif /* CONFIG_PGTABLE_LEVELS >= 3 */
.mmu.pte_val = PTE_IDENT,
.mmu.pgd_val = PTE_IDENT,
diff --git a/arch/x86/kernel/paravirt_patch.c b/arch/x86/kernel/paravirt_patch.c
index 3eff63c090d2..ace6e334cb39 100644
--- a/arch/x86/kernel/paravirt_patch.c
+++ b/arch/x86/kernel/paravirt_patch.c
@@ -26,14 +26,10 @@ struct patch_xxl {
const unsigned char mmu_read_cr3[3];
const unsigned char mmu_write_cr3[3];
const unsigned char irq_restore_fl[2];
-# ifdef CONFIG_X86_64
const unsigned char cpu_wbinvd[2];
const unsigned char cpu_usergs_sysret64[6];
const unsigned char cpu_swapgs[3];
const unsigned char mov64[3];
-# else
- const unsigned char cpu_iret[1];
-# endif
};
static const struct patch_xxl patch_data_xxl = {
@@ -42,7 +38,6 @@ static const struct patch_xxl patch_data_xxl = {
.irq_save_fl = { 0x9c, 0x58 }, // pushf; pop %[re]ax
.mmu_read_cr2 = { 0x0f, 0x20, 0xd0 }, // mov %cr2, %[re]ax
.mmu_read_cr3 = { 0x0f, 0x20, 0xd8 }, // mov %cr3, %[re]ax
-# ifdef CONFIG_X86_64
.mmu_write_cr3 = { 0x0f, 0x22, 0xdf }, // mov %rdi, %cr3
.irq_restore_fl = { 0x57, 0x9d }, // push %rdi; popfq
.cpu_wbinvd = { 0x0f, 0x09 }, // wbinvd
@@ -50,19 +45,11 @@ static const struct patch_xxl patch_data_xxl = {
0x48, 0x0f, 0x07 }, // swapgs; sysretq
.cpu_swapgs = { 0x0f, 0x01, 0xf8 }, // swapgs
.mov64 = { 0x48, 0x89, 0xf8 }, // mov %rdi, %rax
-# else
- .mmu_write_cr3 = { 0x0f, 0x22, 0xd8 }, // mov %eax, %cr3
- .irq_restore_fl = { 0x50, 0x9d }, // push %eax; popf
- .cpu_iret = { 0xcf }, // iret
-# endif
};
unsigned int paravirt_patch_ident_64(void *insn_buff, unsigned int len)
{
-#ifdef CONFIG_X86_64
return PATCH(xxl, mov64, insn_buff, len);
-#endif
- return 0;
}
# endif /* CONFIG_PARAVIRT_XXL */
@@ -98,13 +85,9 @@ unsigned int native_patch(u8 type, void *insn_buff, unsigned
long addr,
PATCH_CASE(mmu, read_cr3, xxl, insn_buff, len);
PATCH_CASE(mmu, write_cr3, xxl, insn_buff, len);
-# ifdef CONFIG_X86_64
PATCH_CASE(cpu, usergs_sysret64, xxl, insn_buff, len);
PATCH_CASE(cpu, swapgs, xxl, insn_buff, len);
PATCH_CASE(cpu, wbinvd, xxl, insn_buff, len);
-# else
- PATCH_CASE(cpu, iret, xxl, insn_buff, len);
-# endif
#endif
#ifdef CONFIG_PARAVIRT_SPINLOCKS
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index 44562d30878c..659e59140ef1 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -1002,8 +1002,6 @@ void __init xen_setup_vcpu_info_placement(void)
}
static const struct pv_info xen_info __initconst = {
- .shared_kernel_pmd = 0,
-
.extra_user_64bit_cs = FLAT_USER_CS64,
.name = "Xen",
};
@@ -1301,10 +1299,6 @@ asmlinkage __visible void __init xen_start_kernel(void)
xen_start_info->nr_pages);
xen_reserve_special_pages();
- /* keep using Xen gdt for now; no urgent need to change it */
-
- pv_info.kernel_rpl = 0;
-
/* set the limit of our address space */
xen_reserve_top();
--
2.26.2
Some paravirt macros are no longer used, delete them. Signed-off-by: Juergen Gross <jgross at suse.com> --- arch/x86/include/asm/paravirt.h | 15 --------------- 1 file changed, 15 deletions(-) diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index cfe9f6e472b5..cff2fbd1edd5 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -609,16 +609,9 @@ bool __raw_callee_save___native_vcpu_is_preempted(long cpu); #endif /* SMP && PARAVIRT_SPINLOCKS */ #ifdef CONFIG_X86_32 -#define PV_SAVE_REGS "pushl %ecx; pushl %edx;" -#define PV_RESTORE_REGS "popl %edx; popl %ecx;" - /* save and restore all caller-save registers, except return value */ #define PV_SAVE_ALL_CALLER_REGS "pushl %ecx;" #define PV_RESTORE_ALL_CALLER_REGS "popl %ecx;" - -#define PV_FLAGS_ARG "0" -#define PV_EXTRA_CLOBBERS -#define PV_VEXTRA_CLOBBERS #else /* save and restore all caller-save registers, except return value */ #define PV_SAVE_ALL_CALLER_REGS \ @@ -639,14 +632,6 @@ bool __raw_callee_save___native_vcpu_is_preempted(long cpu); "pop %rsi;" \ "pop %rdx;" \ "pop %rcx;" - -/* We save some registers, but all of them, that's too much. We clobber all - * caller saved registers but the argument parameter */ -#define PV_SAVE_REGS "pushq %%rdi;" -#define PV_RESTORE_REGS "popq %%rdi;" -#define PV_EXTRA_CLOBBERS EXTRA_CLOBBERS, "rcx" , "rdx", "rsi" -#define PV_VEXTRA_CLOBBERS EXTRA_CLOBBERS, "rdi", "rcx" , "rdx", "rsi" -#define PV_FLAGS_ARG "D" #endif /* -- 2.26.2
On Wed, Jul 01, 2020 at 01:06:46PM +0200, Juergen Gross wrote:> The long term plan has been to replace Xen PV guests by PVH. The first > victim of that plan are now 32-bit PV guests, as those are used only > rather seldom these days. Xen on x86 requires 64-bit support and with > Grub2 now supporting PVH officially since version 2.04 there is no > need to keep 32-bit PV guest support alive in the Linux kernel. > Additionally Meltdown mitigation is not available in the kernel running > as 32-bit PV guest, so dropping this mode makes sense from security > point of view, too.Hooray!!! Much thanks!
On Wed, Jul 1, 2020 at 7:07 AM Juergen Gross <jgross at suse.com> wrote:> > The long term plan has been to replace Xen PV guests by PVH. The first > victim of that plan are now 32-bit PV guests, as those are used only > rather seldom these days. Xen on x86 requires 64-bit support and with > Grub2 now supporting PVH officially since version 2.04 there is no > need to keep 32-bit PV guest support alive in the Linux kernel. > Additionally Meltdown mitigation is not available in the kernel running > as 32-bit PV guest, so dropping this mode makes sense from security > point of view, too.One thing that you missed is removing VDSO_NOTE_NONEGSEG_BIT from vdso32/note.S. With that removed there is no difference from the 64-bit version. Otherwise this series looks good to me. -- Brian Gerst
On 02.07.20 16:48, Brian Gerst wrote:> On Wed, Jul 1, 2020 at 7:07 AM Juergen Gross <jgross at suse.com> wrote: >> >> The long term plan has been to replace Xen PV guests by PVH. The first >> victim of that plan are now 32-bit PV guests, as those are used only >> rather seldom these days. Xen on x86 requires 64-bit support and with >> Grub2 now supporting PVH officially since version 2.04 there is no >> need to keep 32-bit PV guest support alive in the Linux kernel. >> Additionally Meltdown mitigation is not available in the kernel running >> as 32-bit PV guest, so dropping this mode makes sense from security >> point of view, too. > > One thing that you missed is removing VDSO_NOTE_NONEGSEG_BIT from > vdso32/note.S. With that removed there is no difference from the > 64-bit version.Oh, this means we can probably remove arch/x86/xen/vdso.h completely.> > Otherwise this series looks good to me.Thanks, Juergen