Re: [PATCH 6/7] xen/evtch: use smp barriers for user event ring

Jan Beulich
2021-02-08T10:04:11Z

On 08.02.2021 10:44, Andrew Cooper wrote:
> On 06/02/2021 10:49, Juergen Gross wrote:
>> The ring buffer for user events is used in the local system only, so
>> smp barriers are fine for ensuring consistency.
>>
>> Reported-by: Andrew Cooper <andrew.cooper3@citrix.com>
>> Signed-off-by: Juergen Gross <jgross@suse.com>
>
> These need to be virt_* to not break in UP builds (on non-x86).

Initially I though so, too, but isn't the sole vCPU of such a
VM getting re-scheduled to a different pCPU in the hypervisor
an implied barrier anyway?

Jan