Messages in this thread Patch in this message | | | From | Wanpeng Li <> | Subject | [PATCH v2] KVM: MMU: Fix guest stuck during boot due to read/write emulation against GVA | Date | Thu, 10 Aug 2017 23:37:23 -0700 |
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From: Wanpeng Li <wanpeng.li@hotmail.com>
Commit c016004494b0 (KVM: x86: Avoid guest page table walk when gpa_available is set) avoids the page table walk when cr2 has already contained a valid GPA. However, that is not the truth if ept == 0 and shadow page table is used. In this scenario cr2 can just contains a valid GVA. The commit results in guest stuck during boot due to read/write emulation against GVA instead of GPA of the guest.
This patch fixes it by setting the gpa_available flag under direct mode.
Cc: Paolo Bonzini <pbonzini@redhat.com> Cc: Radim Krčmář <rkrcmar@redhat.com> Cc: Brijesh Singh <brijesh.singh@amd.com> Signed-off-by: Wanpeng Li <wanpeng.li@hotmail.com> --- arch/x86/kvm/mmu.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-)
diff --git a/arch/x86/kvm/mmu.c b/arch/x86/kvm/mmu.c index 849312d..a038879 100644 --- a/arch/x86/kvm/mmu.c +++ b/arch/x86/kvm/mmu.c @@ -3791,8 +3791,10 @@ int kvm_handle_page_fault(struct kvm_vcpu *vcpu, u64 error_code, if (need_unprotect && kvm_event_needs_reinjection(vcpu)) kvm_mmu_unprotect_page_virt(vcpu, fault_address); - vcpu->arch.gpa_available = true; - vcpu->arch.gpa_val = fault_address; + if (vcpu->arch.mmu.direct_map) { + vcpu->arch.gpa_available = true; + vcpu->arch.gpa_val = fault_address; + } r = kvm_mmu_page_fault(vcpu, fault_address, error_code, insn, insn_len); break; -- 2.7.4
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