linux-kernel - Re: [PATCH v2 7/9] KVM: SVM: keep DR6 synchronized with vcpu->arch.dr6

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Message-ID: <d6e61be1-f1e0-59a5-f5a0-538c739d0805@redhat.com>
Date:   Fri, 8 May 2020 00:21:02 +0200
From:   Paolo Bonzini <pbonzini@...hat.com>
To:     Peter Xu <peterx@...hat.com>
Cc:     linux-kernel@...r.kernel.org, kvm@...r.kernel.org
Subject: Re: [PATCH v2 7/9] KVM: SVM: keep DR6 synchronized with
 vcpu->arch.dr6

On 07/05/20 20:22, Peter Xu wrote:
>> -	svm->vmcb->save.dr6 = nested_vmcb->save.dr6;
>> +	svm->vcpu.arch.dr6  = nested_vmcb->save.dr6;
> The rest looks very sane to me, but here I failed to figure out how arch.dr6
> finally applied to save.dr6.  I saw it is applied in svm_vcpu_run() in the next
> patch, but if that's the case then iiuc this commit may break bisection. Thanks,

You're right, this needs a call to kvm_update_dr6 (which would go away
on the next patch).

Paolo