similar to: [RFC, PATCH 10/24] i386 Vmi descriptor changes

Fairly straightforward code motion in system.h into the sub-arch layer. Affected functionality include control register accessors, which are virtualizable but with great overhead due to the #GP cost; wbinvd, and most importantly, halt and interrupt control, which is non-virtualizable. Since read_cr4_safe can never fault on a VMI kernel (P5+ processor is required for VMI), we can omit the fault

Fairly straightforward code motion in system.h into the sub-arch layer. Affected functionality include control register accessors, which are virtualizable but with great overhead due to the #GP cost; wbinvd, and most importantly, halt and interrupt control, which is non-virtualizable. Since read_cr4_safe can never fault on a VMI kernel (P5+ processor is required for VMI), we can omit the fault

Again, more simple code movement. Move page invalidations and local and global flushes to the sub-arch layer. Note global here does not mean SMP, but the global bit of the page table entry. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.16-rc5/include/asm-i386/tlbflush.h =================================================================== ---

Again, more simple code movement. Move page invalidations and local and global flushes to the sub-arch layer. Note global here does not mean SMP, but the global bit of the page table entry. Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.16-rc5/include/asm-i386/tlbflush.h =================================================================== ---

Move I/O instruction building to the sub-arch layer. Some very crafty but esoteric macros are used here to get optimized native instructions for port I/O in Linux be writing raw instruction strings. Adding a wrapper layer here is fairly easy, and makes the full range of I/O instructions available to the VMI interface. Also, slowing down I/O is not a useful operation in a VM, so there is a VMI

Move I/O instruction building to the sub-arch layer. Some very crafty but esoteric macros are used here to get optimized native instructions for port I/O in Linux be writing raw instruction strings. Adding a wrapper layer here is fairly easy, and makes the full range of I/O instructions available to the VMI interface. Also, slowing down I/O is not a useful operation in a VM, so there is a VMI

Move APIC read / write accessors to sub-arch layer. Note that we don't bother to implement apic_write_atomic any different, as it is only present to work around old processor erratums (Pentium Processor Spec update 11AP), and VMI kernels do not offer support for this class of processor. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Daniel Arai <arai@vmware.com>

Move APIC read / write accessors to sub-arch layer. Note that we don't bother to implement apic_write_atomic any different, as it is only present to work around old processor erratums (Pentium Processor Spec update 11AP), and VMI kernels do not offer support for this class of processor. Signed-off-by: Zachary Amsden <zach@vmware.com> Signed-off-by: Daniel Arai <arai@vmware.com>

Fairly straight code motion. Split non-virtualizable pieces of processor.h into default and VMI subarches. CPUID is non-virtualizable, since it doesn't trap, and very often the hypervisor will want to hide specific feature bits from the kernel. To provide a replacement for call sites that use CPUID as a serializing instruction, the sync_core() macro is still available. Signed-off-by:

Fairly straight code motion. Split non-virtualizable pieces of processor.h into default and VMI subarches. CPUID is non-virtualizable, since it doesn't trap, and very often the hypervisor will want to hide specific feature bits from the kernel. To provide a replacement for call sites that use CPUID as a serializing instruction, the sync_core() macro is still available. Signed-off-by:

Fairly straightforward code motion of MSR / TSC / PMC accessors to the sub-arch level. Note that rdmsr/wrmsr_safe functions are not moved; Linux relies on the fault behavior here in the event that certain MSRs are not supported on hardware, and combining this with a VMI wrapper is overly complicated. The instructions are virtualizable with trap and emulate, not on critical code paths, and only

Fairly straightforward code motion of MSR / TSC / PMC accessors to the sub-arch level. Note that rdmsr/wrmsr_safe functions are not moved; Linux relies on the fault behavior here in the event that certain MSRs are not supported on hardware, and combining this with a VMI wrapper is overly complicated. The instructions are virtualizable with trap and emulate, not on critical code paths, and only

In a virtualized environment, virtual machines will time share the system with each other and with other processes running on the host system. Therefore, a VM's virtual CPUs (VCPUs) will be executing on the host's physical CPUs (pcpus) for only some portion of time. The VMI exposes a paravirtual view of time to the guest operating systems so that they may operate more effectively in a

In a virtualized environment, virtual machines will time share the system with each other and with other processes running on the host system. Therefore, a VM's virtual CPUs (VCPUs) will be executing on the host's physical CPUs (pcpus) for only some portion of time. The VMI exposes a paravirtual view of time to the guest operating systems so that they may operate more effectively in a

i386 Transparent paravirtualization subarch patch #5 This change encapsulates descriptor and task register management. Diffs against: 2.6.13-rc4-mm1 Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.13/include/asm-i386/desc.h =================================================================== --- linux-2.6.13.orig/include/asm-i386/desc.h 2005-08-08 17:31:59.000000000 -0700

i386 Transparent paravirtualization subarch patch #5 This change encapsulates descriptor and task register management. Diffs against: 2.6.13-rc4-mm1 Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.13/include/asm-i386/desc.h =================================================================== --- linux-2.6.13.orig/include/asm-i386/desc.h 2005-08-08 17:31:59.000000000 -0700

Xen requires error returns from the hypercall to update LDT entries, and this generates completely equivalent code on native. Patch-base: 2.6.13-rc5-mm1 Patch-keys: i386 desc ldt paravirt xen Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.13/include/asm-i386/mach-default/mach_desc.h =================================================================== ---

Xen requires error returns from the hypercall to update LDT entries, and this generates completely equivalent code on native. Patch-base: 2.6.13-rc5-mm1 Patch-keys: i386 desc ldt paravirt xen Signed-off-by: Zachary Amsden <zach@vmware.com> Index: linux-2.6.13/include/asm-i386/mach-default/mach_desc.h =================================================================== ---

* zach@vmware.com (zach@vmware.com) wrote: > Make the LDT a desc_struct pointer, since this is what it actually is. I like that plan. > There is code which relies on the fact that LDTs are allocated in page > chunks, and it is both cleaner and more convenient to keep the rather > poorly named "size" variable from the LDT in terms of LDT pages. I noticed it's replaced

* zach@vmware.com (zach@vmware.com) wrote: > Make the LDT a desc_struct pointer, since this is what it actually is. I like that plan. > There is code which relies on the fact that LDTs are allocated in page > chunks, and it is both cleaner and more convenient to keep the rather > poorly named "size" variable from the LDT in terms of LDT pages. I noticed it's replaced