Re: [Xen-devel] [PATCH v2 3/9] x86/mm: honor opt_pcid also for 32-bit PV domains

2019-09-18 Thread Jan Beulich
On 18.09.2019 13:55, Andrew Cooper wrote: > On 18/09/2019 10:22, Jan Beulich wrote: >> On 17.09.2019 21:00, Andrew Cooper wrote: >>> On 17/09/2019 07:14, Jan Beulich wrote: I can't see any technical or performance reason why we should treat 32-bit PV different from 64-bit PV in this

Re: [Xen-devel] [PATCH v2 3/9] x86/mm: honor opt_pcid also for 32-bit PV domains

2019-09-18 Thread Andrew Cooper
On 18/09/2019 10:22, Jan Beulich wrote: > On 17.09.2019 21:00, Andrew Cooper wrote: >> On 17/09/2019 07:14, Jan Beulich wrote: >>> I can't see any technical or performance reason why we should treat >>> 32-bit PV different from 64-bit PV in this regard. >> Well, other than the fact this setting is

Re: [Xen-devel] [PATCH v2 3/9] x86/mm: honor opt_pcid also for 32-bit PV domains

2019-09-18 Thread Jan Beulich
On 17.09.2019 21:00, Andrew Cooper wrote: > On 17/09/2019 07:14, Jan Beulich wrote: >> I can't see any technical or performance reason why we should treat >> 32-bit PV different from 64-bit PV in this regard. > > Well, other than the fact this setting is only read for a 64bit guest... How come?

Re: [Xen-devel] [PATCH v2 3/9] x86/mm: honor opt_pcid also for 32-bit PV domains

2019-09-17 Thread Andrew Cooper
On 17/09/2019 07:14, Jan Beulich wrote: > I can't see any technical or performance reason why we should treat > 32-bit PV different from 64-bit PV in this regard. Well, other than the fact this setting is only read for a 64bit guest... The reason it isn't set for 32bit guests is that there is no

[Xen-devel] [PATCH v2 3/9] x86/mm: honor opt_pcid also for 32-bit PV domains

2019-09-17 Thread Jan Beulich
I can't see any technical or performance reason why we should treat 32-bit PV different from 64-bit PV in this regard. Signed-off-by: Jan Beulich Reviewed-by: Roger Pau Monné --- a/xen/arch/x86/pv/domain.c +++ b/xen/arch/x86/pv/domain.c @@ -180,7 +180,24 @@ int switch_compat(struct domain *d)