Retry #PF for softmmu only when the current vcpu has the same cr3 as the time when #PF occurs
Changelog: Just compare cr3 value since It's harmless to instantiate an spte for an unused translation from Marcelo's comment Signed-off-by: Xiao Guangrong <[email protected]> --- arch/x86/include/asm/kvm_host.h | 1 + arch/x86/kvm/mmu.c | 2 ++ arch/x86/kvm/paging_tmpl.h | 34 +++++++++++++++++++++++----------- arch/x86/kvm/x86.c | 6 +++++- 4 files changed, 31 insertions(+), 12 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index a0c066e..1e876e5 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -602,6 +602,7 @@ struct kvm_x86_ops { struct kvm_arch_async_pf { u32 token; gfn_t gfn; + unsigned long cr3; bool direct_map; }; diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index c6bb449..3f0d9a0 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -2607,9 +2607,11 @@ static int nonpaging_page_fault(struct kvm_vcpu *vcpu, gva_t gva, static int kvm_arch_setup_async_pf(struct kvm_vcpu *vcpu, gva_t gva, gfn_t gfn) { struct kvm_arch_async_pf arch; + arch.token = (vcpu->arch.apf.id++ << 12) | vcpu->vcpu_id; arch.gfn = gfn; arch.direct_map = vcpu->arch.mmu.direct_map; + arch.cr3 = vcpu->arch.mmu.get_cr3(vcpu); return kvm_setup_async_pf(vcpu, gva, gfn, &arch); } diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index 23275d0..437e11a 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -116,7 +116,7 @@ static unsigned FNAME(gpte_access)(struct kvm_vcpu *vcpu, pt_element_t gpte) */ static int FNAME(walk_addr_generic)(struct guest_walker *walker, struct kvm_vcpu *vcpu, struct kvm_mmu *mmu, - gva_t addr, u32 access) + gva_t addr, u32 access, bool prefault) { pt_element_t pte; gfn_t table_gfn; @@ -194,6 +194,13 @@ walk: #endif if (!eperm && !rsvd_fault && !(pte & PT_ACCESSED_MASK)) { + /* + * Don't set gpte accessed bit if it's on + * speculative path. + */ + if (prefault) + goto error; + trace_kvm_mmu_set_accessed_bit(table_gfn, index, sizeof(pte)); if (FNAME(cmpxchg_gpte)(vcpu->kvm, table_gfn, @@ -287,10 +294,11 @@ error: } static int FNAME(walk_addr)(struct guest_walker *walker, - struct kvm_vcpu *vcpu, gva_t addr, u32 access) + struct kvm_vcpu *vcpu, gva_t addr, + u32 access, bool prefault) { return FNAME(walk_addr_generic)(walker, vcpu, &vcpu->arch.mmu, addr, - access); + access, prefault); } static int FNAME(walk_addr_nested)(struct guest_walker *walker, @@ -298,7 +306,7 @@ static int FNAME(walk_addr_nested)(struct guest_walker *walker, u32 access) { return FNAME(walk_addr_generic)(walker, vcpu, &vcpu->arch.nested_mmu, - addr, access); + addr, access, false); } static bool FNAME(prefetch_invalid_gpte)(struct kvm_vcpu *vcpu, @@ -438,7 +446,8 @@ static void FNAME(pte_prefetch)(struct kvm_vcpu *vcpu, struct guest_walker *gw, static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, struct guest_walker *gw, int user_fault, int write_fault, int hlevel, - int *ptwrite, pfn_t pfn, bool map_writable) + int *ptwrite, pfn_t pfn, bool map_writable, + bool prefault) { unsigned access = gw->pt_access; struct kvm_mmu_page *sp = NULL; @@ -512,7 +521,7 @@ static u64 *FNAME(fetch)(struct kvm_vcpu *vcpu, gva_t addr, mmu_set_spte(vcpu, it.sptep, access, gw->pte_access & access, user_fault, write_fault, dirty, ptwrite, it.level, - gw->gfn, pfn, false, map_writable); + gw->gfn, pfn, prefault, map_writable); FNAME(pte_prefetch)(vcpu, gw, it.sptep); return it.sptep; @@ -561,15 +570,18 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code, /* * Look up the guest pte for the faulting address. */ - r = FNAME(walk_addr)(&walker, vcpu, addr, error_code); + r = FNAME(walk_addr)(&walker, vcpu, addr, error_code, prefault); /* * The page is not mapped by the guest. Let the guest handle it. */ if (!r) { pgprintk("%s: guest page fault\n", __func__); - inject_page_fault(vcpu); - vcpu->arch.last_pt_write_count = 0; /* reset fork detector */ + if (!prefault) { + inject_page_fault(vcpu); + /* reset fork detector */ + vcpu->arch.last_pt_write_count = 0; + } return 0; } @@ -599,7 +611,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code, trace_kvm_mmu_audit(vcpu, AUDIT_PRE_PAGE_FAULT); kvm_mmu_free_some_pages(vcpu); sptep = FNAME(fetch)(vcpu, addr, &walker, user_fault, write_fault, - level, &write_pt, pfn, map_writable); + level, &write_pt, pfn, map_writable, prefault); (void)sptep; pgprintk("%s: shadow pte %p %llx ptwrite %d\n", __func__, sptep, *sptep, write_pt); @@ -685,7 +697,7 @@ static gpa_t FNAME(gva_to_gpa)(struct kvm_vcpu *vcpu, gva_t vaddr, u32 access, gpa_t gpa = UNMAPPED_GVA; int r; - r = FNAME(walk_addr)(&walker, vcpu, vaddr, access); + r = FNAME(walk_addr)(&walker, vcpu, vaddr, access, false); if (r) { gpa = gfn_to_gpa(walker.gfn); diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index bfd2878..de5e57b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6183,7 +6183,7 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) { int r; - if (!vcpu->arch.mmu.direct_map || !work->arch.direct_map || + if ((vcpu->arch.mmu.direct_map != work->arch.direct_map) || is_error_page(work->page)) return; @@ -6191,6 +6191,10 @@ void kvm_arch_async_page_ready(struct kvm_vcpu *vcpu, struct kvm_async_pf *work) if (unlikely(r)) return; + if (!vcpu->arch.mmu.direct_map && + work->arch.cr3 != vcpu->arch.mmu.get_cr3(vcpu)) + return; + vcpu->arch.mmu.page_fault(vcpu, work->gva, 0, true); } -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
