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Re: [Xen-devel] [PATCH 1/4] x86/vmx: Don't leak host syscall MSR state into HVM guests



> From: Andrew Cooper [mailto:andrew.cooper3@xxxxxxxxxx]
> Sent: Monday, February 13, 2017 10:32 PM
> 
> hvm_hw_cpu->msr_flags is in fact the VMX dirty bitmap of MSRs needing to be
> restored when switching into guest context.  It should never have been part of
> the migration state to start with, and Xen must not make any decisions based
> on the value seen during restore.
> 
> Identify it as obsolete in the header files, consistently save it as zero and
> ignore it on restore.
> 
> The MSRs must be considered dirty during VMCS creation to cause the proper
> defaults of 0 to be visible to the guest.
> 
> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>

Reviewed-by: Kevin Tian <kevin.tian@xxxxxxxxx>, with one small comment.

the effect of this patch should be more than not leaking syscall MSR.
what about making the subject clearer when check-in?

Thanks
Kevin

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