Re: [Qemu-devel] [PATCH RFC v2 4/4] xen/MSI: re-expose masking capability

[Jan Beulich]

>>> On 07.12.15 at 13:45, <address@hidden> wrote:
> On Tue, 24 Nov 2015, Jan Beulich wrote:
>> Now that the hypervisor intercepts all config space writes and monitors
>> changes to the masking flags, this undoes the main effect of the
>> XSA-129 fix, exposing the masking capability again to guests.
>> 
>> Signed-off-by: Jan Beulich <address@hidden>
>> ---
>> TBD: We probably need to deal with running on an older hypervisor. I
>>      can't, however, immediately see a way for qemu to find out.
> 
> Actually QEMU has already an infrastructure to detect the hypervisor
> version at compile time, see include/hw/xen/xen_common.h. You could
> #define the right emu_mask depending on the hypervisor.

We don't want compile time detection here, but runtime one.

Jan