aboutsummaryrefslogtreecommitdiffstats
diff options
context:
space:
mode:
authorMarcelo Tosatti <mtosatti@redhat.com>2009-12-05 12:34:11 -0200
committerMarcelo Tosatti <mtosatti@redhat.com>2009-12-27 13:36:30 -0200
commitfb341f572d26e0786167cd96b90cc4febed830cf (patch)
tree2bf327861e4da2745b66c2dda03c5c5b0afcf7b6
parent6b7b284958d47b77d06745b36bc7f36dab769d9b (diff)
downloadmrst-s0i3-test-fb341f572d26e0786167cd96b90cc4febed830cf.tar.gz
mrst-s0i3-test-fb341f572d26e0786167cd96b90cc4febed830cf.tar.xz
mrst-s0i3-test-fb341f572d26e0786167cd96b90cc4febed830cf.zip
KVM: MMU: remove prefault from invlpg handler
The invlpg prefault optimization breaks Windows 2008 R2 occasionally. The visible effect is that the invlpg handler instantiates a pte which is, microseconds later, written with a different gfn by another vcpu. The OS could have other mechanisms to prevent a present translation from being used, which the hypervisor is unaware of. While the documentation states that the cpu is at liberty to prefetch tlb entries, it looks like this is not heeded, so remove tlb prefetch from invlpg. Cc: stable@kernel.org Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Avi Kivity <avi@redhat.com>
-rw-r--r--arch/x86/kvm/paging_tmpl.h18
1 files changed, 0 insertions, 18 deletions
diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h
index a6017132fba..58a0f1e8859 100644
--- a/arch/x86/kvm/paging_tmpl.h
+++ b/arch/x86/kvm/paging_tmpl.h
@@ -455,8 +455,6 @@ out_unlock:
static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
{
struct kvm_shadow_walk_iterator iterator;
- pt_element_t gpte;
- gpa_t pte_gpa = -1;
int level;
u64 *sptep;
int need_flush = 0;
@@ -470,10 +468,6 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
if (level == PT_PAGE_TABLE_LEVEL ||
((level == PT_DIRECTORY_LEVEL && is_large_pte(*sptep))) ||
((level == PT_PDPE_LEVEL && is_large_pte(*sptep)))) {
- struct kvm_mmu_page *sp = page_header(__pa(sptep));
-
- pte_gpa = (sp->gfn << PAGE_SHIFT);
- pte_gpa += (sptep - sp->spt) * sizeof(pt_element_t);
if (is_shadow_present_pte(*sptep)) {
rmap_remove(vcpu->kvm, sptep);
@@ -492,18 +486,6 @@ static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva)
if (need_flush)
kvm_flush_remote_tlbs(vcpu->kvm);
spin_unlock(&vcpu->kvm->mmu_lock);
-
- if (pte_gpa == -1)
- return;
- if (kvm_read_guest_atomic(vcpu->kvm, pte_gpa, &gpte,
- sizeof(pt_element_t)))
- return;
- if (is_present_gpte(gpte) && (gpte & PT_ACCESSED_MASK)) {
- if (mmu_topup_memory_caches(vcpu))
- return;
- kvm_mmu_pte_write(vcpu, pte_gpa, (const u8 *)&gpte,
- sizeof(pt_element_t), 0);
- }
}
static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr)