Re: [Xen-devel] [PATCH] x86/hvm: Don't let hvm_set_efer() raise #GP behind the emulators back

[Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>]

On 02/24/2017 05:59 AM, Andrew Cooper wrote:
> c/s 49de10f3c "x86/hvm: Don't raise #GP behind the emulators back for MSR
> accesses" missed an edge case.
>
> hvm_set_efer() raises #GP itself, so deliberately avoided the goto gp_fault
> path in hvm_msr_write_intercept().
>
> With the above change, guest updates to MSR_EFER which end up faulting raises
> hvm_msr_write_intercept() returning X86EMUL_EXCEPTION.  The second #GP gets
> combined to #DF and handed back to the guest.
>
> Update hvm_set_efer() to avoid raising #GP, requiring its callers to do so.
>
> Signed-off-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
> CC: Jan Beulich <JBeulich@xxxxxxxx>

Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>



_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel