Re: [PATCH 9/9] KVM: VMX: pass correct DR6 for GD userspace exit

From: Peter Xu
Date: Wed May 06 2020 - 13:50:26 EST


On Wed, May 06, 2020 at 07:10:34AM -0400, Paolo Bonzini wrote:
> When KVM_EXIT_DEBUG is raised for the disabled-breakpoints case (DR7.GD),
> DR6 was incorrectly copied from the value in the VM. Instead,
> DR6.BD should be set in order to catch this case.
>
> On AMD this does not need any special code because the processor triggers
> a #DB exception that is intercepted. However, the testcase would fail
> without the previous patch because both DR6.BS and DR6.BD would be set.
>
> Signed-off-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>

Reviewed-by: Peter Xu <peterx@xxxxxxxxxx>

--
Peter Xu