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Revert "KVM: SVM: avoid infinite loop on NPF from bad address"
commit31c2558569
upstream. Revert a completely broken check on an "invalid" RIP in SVM's workaround for the DecodeAssists SMAP errata. kvm_vcpu_gfn_to_memslot() obviously expects a gfn, i.e. operates in the guest physical address space, whereas RIP is a virtual (not even linear) address. The "fix" worked for the problematic KVM selftest because the test identity mapped RIP. Fully revert the hack instead of trying to translate RIP to a GPA, as the non-SEV case is now handled earlier, and KVM cannot access guest page tables to translate RIP. This reverts commite72436bc3a
. Fixes:e72436bc3a
("KVM: SVM: avoid infinite loop on NPF from bad address") Reported-by: Liam Merwick <liam.merwick@oracle.com> Cc: stable@vger.kernel.org Signed-off-by: Sean Christopherson <seanjc@google.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Message-Id: <20220120010719.711476-3-seanjc@google.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
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2 changed files with 0 additions and 8 deletions
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@ -4146,13 +4146,6 @@ static bool svm_can_emulate_instruction(struct kvm_vcpu *vcpu, void *insn, int i
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if (likely(!insn || insn_len))
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return true;
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/*
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* If RIP is invalid, go ahead with emulation which will cause an
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* internal error exit.
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*/
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if (!kvm_vcpu_gfn_to_memslot(vcpu, kvm_rip_read(vcpu) >> PAGE_SHIFT))
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return true;
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cr4 = kvm_read_cr4(vcpu);
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smep = cr4 & X86_CR4_SMEP;
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smap = cr4 & X86_CR4_SMAP;
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@ -1691,7 +1691,6 @@ struct kvm_memory_slot *kvm_vcpu_gfn_to_memslot(struct kvm_vcpu *vcpu, gfn_t gfn
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{
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return __gfn_to_memslot(kvm_vcpu_memslots(vcpu), gfn);
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}
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EXPORT_SYMBOL_GPL(kvm_vcpu_gfn_to_memslot);
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bool kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn)
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{
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