linux-kernel - Re: [PATCH v2 1/5] x86: KVM: svm: don't pretend to advance RIP in case wrmsr

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Message-ID: <20190806152943.GC27766@linux.intel.com>
Date:   Tue, 6 Aug 2019 08:29:43 -0700
From:   Sean Christopherson <sean.j.christopherson@...el.com>
To:     Vitaly Kuznetsov <vkuznets@...hat.com>
Cc:     kvm@...r.kernel.org, linux-kernel@...r.kernel.org,
        Paolo Bonzini <pbonzini@...hat.com>,
        Radim Krčmář <rkrcmar@...hat.com>,
        Joerg Roedel <joro@...tes.org>,
        Jim Mattson <jmattson@...gle.com>
Subject: Re: [PATCH v2 1/5] x86: KVM: svm: don't pretend to advance RIP in
 case wrmsr_interception() results in #GP

On Tue, Aug 06, 2019 at 08:01:46AM +0200, Vitaly Kuznetsov wrote:
> 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@...hat.com>

Reviewed-by: Sean Christopherson <sean.j.christopherson@...el.com>