projects / thirdparty / kernel / stable-queue.git / blame
| Commit | Line | Data |
|---|---|---|
| 80e6ae8f GKH |
1 | From fb341f572d26e0786167cd96b90cc4febed830cf Mon Sep 17 00:00:00 2001 |
| 2 | From: Marcelo Tosatti <mtosatti@redhat.com> | |
| 3 | Date: Sat, 5 Dec 2009 12:34:11 -0200 | |
| 4 | Subject: KVM: MMU: remove prefault from invlpg handler | |
| 5 | ||
| 6 | From: Marcelo Tosatti <mtosatti@redhat.com> | |
| 7 | ||
| 8 | commit fb341f572d26e0786167cd96b90cc4febed830cf upstream. | |
| 9 | ||
| 10 | The invlpg prefault optimization breaks Windows 2008 R2 occasionally. | |
| 11 | ||
| 12 | The visible effect is that the invlpg handler instantiates a pte which | |
| 13 | is, microseconds later, written with a different gfn by another vcpu. | |
| 14 | ||
| 15 | The OS could have other mechanisms to prevent a present translation from | |
| 16 | being used, which the hypervisor is unaware of. | |
| 17 | ||
| 18 | While the documentation states that the cpu is at liberty to prefetch tlb | |
| 19 | entries, it looks like this is not heeded, so remove tlb prefetch from | |
| 20 | invlpg. | |
| 21 | ||
| 22 | Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com> | |
| 23 | Signed-off-by: Avi Kivity <avi@redhat.com> | |
| 24 | Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de> | |
| 25 | ||
| 26 | --- | |
| 27 | arch/x86/kvm/paging_tmpl.h | 18 ------------------ | |
| 28 | 1 file changed, 18 deletions(-) | |
| 29 | ||
| 30 | --- a/arch/x86/kvm/paging_tmpl.h | |
| 31 | +++ b/arch/x86/kvm/paging_tmpl.h | |
| 32 | @@ -455,8 +455,6 @@ out_unlock: | |
| 33 | static void FNAME(invlpg)(struct kvm_vcpu *vcpu, gva_t gva) | |
| 34 | { | |
| 35 | struct kvm_shadow_walk_iterator iterator; | |
| 36 | - pt_element_t gpte; | |
| 37 | - gpa_t pte_gpa = -1; | |
| 38 | int level; | |
| 39 | u64 *sptep; | |
| 40 | int need_flush = 0; | |
| 41 | @@ -471,10 +469,6 @@ static void FNAME(invlpg)(struct kvm_vcp | |
| 42 | if (level == PT_PAGE_TABLE_LEVEL || | |
| 43 | ((level == PT_DIRECTORY_LEVEL && is_large_pte(*sptep))) || | |
| 44 | ((level == PT_PDPE_LEVEL && is_large_pte(*sptep)))) { | |
| 45 | - struct kvm_mmu_page *sp = page_header(__pa(sptep)); | |
| 46 | - | |
| 47 | - pte_gpa = (sp->gfn << PAGE_SHIFT); | |
| 48 | - pte_gpa += (sptep - sp->spt) * sizeof(pt_element_t); | |
| 49 | ||
| 50 | if (is_shadow_present_pte(*sptep)) { | |
| 51 | rmap_remove(vcpu->kvm, sptep); | |
| 52 | @@ -493,18 +487,6 @@ static void FNAME(invlpg)(struct kvm_vcp | |
| 53 | if (need_flush) | |
| 54 | kvm_flush_remote_tlbs(vcpu->kvm); | |
| 55 | spin_unlock(&vcpu->kvm->mmu_lock); | |
| 56 | - | |
| 57 | - if (pte_gpa == -1) | |
| 58 | - return; | |
| 59 | - if (kvm_read_guest_atomic(vcpu->kvm, pte_gpa, &gpte, | |
| 60 | - sizeof(pt_element_t))) | |
| 61 | - return; | |
| 62 | - if (is_present_gpte(gpte) && (gpte & PT_ACCESSED_MASK)) { | |
| 63 | - if (mmu_topup_memory_caches(vcpu)) | |
| 64 | - return; | |
| 65 | - kvm_mmu_pte_write(vcpu, pte_gpa, (const u8 *)&gpte, | |
| 66 | - sizeof(pt_element_t), 0); | |
| 67 | - } | |
| 68 | } | |
| 69 | ||
| 70 | static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr) |