From mboxrd@z Thu Jan 1 00:00:00 1970 From: Cornelia Huck Subject: Re: [PATCH] x86/kvm/nVMX: don't skip emulated instruction twice when vmptr address is not backed Date: Wed, 9 Jan 2019 18:51:47 +0100 Message-ID: <20190109185147.3d9ecec4.cohuck@redhat.com> References: <20190109172256.16711-1-vkuznets@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, Paolo Bonzini , Radim =?UTF-8?B?S3LEjW3DocWZ?= , linux-kernel@vger.kernel.org, Andrew Jones , Jim Mattson , Sean Christopherson To: Vitaly Kuznetsov Return-path: In-Reply-To: <20190109172256.16711-1-vkuznets@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On Wed, 9 Jan 2019 18:22:56 +0100 Vitaly Kuznetsov wrote: > Since commit 09abb5e3e5e50 ("KVM: nVMX: call kvm_skip_emulated_instruction > in nested_vmx_{fail,succeed}") nested_vmx_failValid() results in > kvm_skip_emulated_instruction() so doing it again in handle_vmptrld() when > vmptr address is not backed is wrong, we end up advancing RIP twice. > > Fixes: fca91f6d60b6e ("kvm: nVMX: Set VM instruction error for VMPTRLD of unbacked page") > Reported-by: Cornelia Huck > Signed-off-by: Vitaly Kuznetsov > --- > arch/x86/kvm/vmx/nested.c | 3 +-- > 1 file changed, 1 insertion(+), 2 deletions(-) > > diff --git a/arch/x86/kvm/vmx/nested.c b/arch/x86/kvm/vmx/nested.c > index 3170e291215d..2616bd2c7f2c 100644 > --- a/arch/x86/kvm/vmx/nested.c > +++ b/arch/x86/kvm/vmx/nested.c > @@ -4540,9 +4540,8 @@ static int handle_vmptrld(struct kvm_vcpu *vcpu) > * given physical address won't match the required > * VMCS12_REVISION identifier. > */ > - nested_vmx_failValid(vcpu, > + return nested_vmx_failValid(vcpu, > VMXERR_VMPTRLD_INCORRECT_VMCS_REVISION_ID); > - return kvm_skip_emulated_instruction(vcpu); > } > new_vmcs12 = kmap(page); > if (new_vmcs12->hdr.revision_id != VMCS12_REVISION || Not that I would be a nested vmx expert, but this looks correct. Reviewed-by: Cornelia Huck