From: Sean Christopherson Date: Wed, 24 Feb 2021 00:56:26 +0000 (-0800) Subject: KVM: SVM: Fix nested VM-Exit on #GP interception handling X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=2df8d3807ce7f75bb975f1aeae8fc6757527c62d;p=linux.git KVM: SVM: Fix nested VM-Exit on #GP interception handling Fix the interpreation of nested_svm_vmexit()'s return value when synthesizing a nested VM-Exit after intercepting an SVM instruction while L2 was running. The helper returns '0' on success, whereas a return value of '0' in the exit handler path means "exit to userspace". The incorrect return value causes KVM to exit to userspace without filling the run state, e.g. QEMU logs "KVM: unknown exit, hardware reason 0". Fixes: 14c2bf81fcd2 ("KVM: SVM: Fix #GP handling for doubly-nested virtualization") Signed-off-by: Sean Christopherson Message-Id: <20210224005627.657028-1-seanjc@google.com> Signed-off-by: Paolo Bonzini --- diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c index e4cc081ad7c1b..c636021b066b0 100644 --- a/arch/x86/kvm/svm/svm.c +++ b/arch/x86/kvm/svm/svm.c @@ -2211,15 +2211,20 @@ static int emulate_svm_instr(struct kvm_vcpu *vcpu, int opcode) [SVM_INSTR_VMSAVE] = vmsave_interception, }; struct vcpu_svm *svm = to_svm(vcpu); + int ret; if (is_guest_mode(vcpu)) { svm->vmcb->control.exit_code = guest_mode_exit_codes[opcode]; svm->vmcb->control.exit_info_1 = 0; svm->vmcb->control.exit_info_2 = 0; - return nested_svm_vmexit(svm); - } else - return svm_instr_handlers[opcode](svm); + /* Returns '1' or -errno on failure, '0' on success. */ + ret = nested_svm_vmexit(svm); + if (ret) + return ret; + return 1; + } + return svm_instr_handlers[opcode](svm); } /*