From mboxrd@z Thu Jan 1 00:00:00 1970 From: Paolo Bonzini Subject: Re: [PATCH] kvm:x86:Fix incorrect error paths in the function process_smi Date: Fri, 18 Sep 2015 16:52:01 +0200 Message-ID: <55FC2511.6080406@redhat.com> References: <1442587584-8164-1-git-send-email-xerofoify@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org, x86@kernel.org, linux-kernel@vger.kernel.org To: Nicholas Krause , gleb@kernel.org Return-path: In-Reply-To: <1442587584-8164-1-git-send-email-xerofoify@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: kvm.vger.kernel.org On 18/09/2015 16:46, Nicholas Krause wrote: > This fixes the incorrect assumation that the function > kvm_vcpu_write_guest always runs successfully and > therefore checks if it fails by returning a error code > and if so return immediately to the caller of the function > process_smi as we cannot this work's intended work after > this failed call to kvm_vcpu_write_guest. > > Signed-off-by: Nicholas Krause > --- > arch/x86/kvm/x86.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c > index a60bdbc..4743a4b 100644 > --- a/arch/x86/kvm/x86.c > +++ b/arch/x86/kvm/x86.c > @@ -6088,7 +6088,8 @@ static void process_smi(struct kvm_vcpu *vcpu) > else > process_smi_save_state_32(vcpu, buf); > > - kvm_vcpu_write_guest(vcpu, vcpu->arch.smbase + 0xfe00, buf, sizeof(buf)); > + if (kvm_vcpu_write_guest(vcpu, vcpu->arch.smbase + 0xfe00, buf, sizeof(buf))) > + return; > > if (kvm_x86_ops->get_nmi_mask(vcpu)) > vcpu->arch.hflags |= HF_SMM_INSIDE_NMI_MASK; > The SMI was requested by the guest. If the guest failed to set up SMM correctly, it's the guest's problem. Aborting the SMI does not match what a real processor does. Thanks, Paolo