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authorSean Christopherson <seanjc@google.com>2021-02-22 11:45:21 +0900
committerPaolo Bonzini <pbonzini@redhat.com>2021-02-22 13:13:30 -0500
commit5f8a7cf25a7da5c2bbde25b3f0aca31459d20741 (patch)
tree9fecd14d3a0057cbc81d5b04b9738e9bb95a519f
parent356c7558d453338c9184809c0926071dfbfb9c80 (diff)
KVM: x86/mmu: Skip mmu_notifier check when handling MMIO page fault
Don't retry a page fault due to an mmu_notifier invalidation when handling a page fault for a GPA that did not resolve to a memslot, i.e. an MMIO page fault. Invalidations from the mmu_notifier signal a change in a host virtual address (HVA) mapping; without a memslot, there is no HVA and thus no possibility that the invalidation is relevant to the page fault being handled. Note, the MMIO vs. memslot generation checks handle the case where a pending memslot will create a memslot overlapping the faulting GPA. The mmu_notifier checks are orthogonal to memslot updates. Signed-off-by: Sean Christopherson <seanjc@google.com> Message-Id: <20210222024522.1751719-2-stevensd@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
-rw-r--r--arch/x86/kvm/mmu/mmu.c2
-rw-r--r--arch/x86/kvm/mmu/paging_tmpl.h2
2 files changed, 2 insertions, 2 deletions
diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c
index 6e78d8e51aa2..752b4b7ab01b 100644
--- a/arch/x86/kvm/mmu/mmu.c
+++ b/arch/x86/kvm/mmu/mmu.c
@@ -3712,7 +3712,7 @@ static int direct_page_fault(struct kvm_vcpu *vcpu, gpa_t gpa, u32 error_code,
else
write_lock(&vcpu->kvm->mmu_lock);
- if (mmu_notifier_retry(vcpu->kvm, mmu_seq))
+ if (!is_noslot_pfn(pfn) && mmu_notifier_retry(vcpu->kvm, mmu_seq))
goto out_unlock;
r = make_mmu_pages_available(vcpu);
if (r)
diff --git a/arch/x86/kvm/mmu/paging_tmpl.h b/arch/x86/kvm/mmu/paging_tmpl.h
index d9f66cc459e8..5844d3979bb8 100644
--- a/arch/x86/kvm/mmu/paging_tmpl.h
+++ b/arch/x86/kvm/mmu/paging_tmpl.h
@@ -869,7 +869,7 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gpa_t addr, u32 error_code,
r = RET_PF_RETRY;
write_lock(&vcpu->kvm->mmu_lock);
- if (mmu_notifier_retry(vcpu->kvm, mmu_seq))
+ if (!is_noslot_pfn(pfn) && mmu_notifier_retry(vcpu->kvm, mmu_seq))
goto out_unlock;
kvm_mmu_audit(vcpu, AUDIT_PRE_PAGE_FAULT);