From: Vitaly Kuznetsov <vkuznets@redhat.com>
To: kvm@vger.kernel.org
Cc: linux-kernel@vger.kernel.org,
"Paolo Bonzini" <pbonzini@redhat.com>,
"Radim Krčmář" <rkrcmar@redhat.com>,
"Joerg Roedel" <joro@8bytes.org>,
"Jim Mattson" <jmattson@google.com>,
"Sean Christopherson" <sean.j.christopherson@intel.com>
Subject: [PATCH v2 1/5] x86: KVM: svm: don't pretend to advance RIP in case wrmsr_interception() results in #GP
Date: Tue, 6 Aug 2019 08:01:46 +0200 [thread overview]
Message-ID: <20190806060150.32360-2-vkuznets@redhat.com> (raw)
In-Reply-To: <20190806060150.32360-1-vkuznets@redhat.com>
svm->next_rip is only used by skip_emulated_instruction() and in case
kvm_set_msr() fails we rightfully don't do that. Move svm->next_rip
advancement to 'else' branch to avoid creating false impression that
it's always advanced (and make it look like rdmsr_interception()).
This is a preparatory change to removing hardcoded RIP advancement
from instruction intercepts, no functional change.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
---
arch/x86/kvm/svm.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 7eafc6907861..7e843b340490 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -4447,13 +4447,13 @@ static int wrmsr_interception(struct vcpu_svm *svm)
msr.index = ecx;
msr.host_initiated = false;
- svm->next_rip = kvm_rip_read(&svm->vcpu) + 2;
if (kvm_set_msr(&svm->vcpu, &msr)) {
trace_kvm_msr_write_ex(ecx, data);
kvm_inject_gp(&svm->vcpu, 0);
return 1;
} else {
trace_kvm_msr_write(ecx, data);
+ svm->next_rip = kvm_rip_read(&svm->vcpu) + 2;
return kvm_skip_emulated_instruction(&svm->vcpu);
}
}
--
2.20.1
next prev parent reply other threads:[~2019-08-06 6:01 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-08-06 6:01 [PATCH v2 0/5] x86: KVM: svm: get rid of hardcoded instructions lengths Vitaly Kuznetsov
2019-08-06 6:01 ` Vitaly Kuznetsov [this message]
2019-08-06 15:29 ` [PATCH v2 1/5] x86: KVM: svm: don't pretend to advance RIP in case wrmsr_interception() results in #GP Sean Christopherson
2019-08-06 6:01 ` [PATCH v2 2/5] x86: KVM: svm: avoid flooding logs when skip_emulated_instruction() fails Vitaly Kuznetsov
2019-08-06 15:40 ` Sean Christopherson
2019-08-07 11:17 ` Vitaly Kuznetsov
2019-08-06 6:01 ` [PATCH v2 3/5] x86: KVM: clear interrupt shadow on EMULTYPE_SKIP Vitaly Kuznetsov
2019-08-06 15:45 ` Sean Christopherson
2019-08-06 6:01 ` [PATCH v2 4/5] x86: KVM: add xsetbv to the emulator Vitaly Kuznetsov
2019-08-06 6:01 ` [PATCH v2 5/5] x86: KVM: svm: remove hardcoded instruction length from intercepts Vitaly Kuznetsov
2019-08-06 16:11 ` Sean Christopherson
2019-08-07 11:14 ` Vitaly Kuznetsov
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