Re: [Xen-devel] [PATCH 2/3] x86/boot: Cache cpu_has_hypervisor very early on boot

2019-11-05 Thread Sergey Dyasli
On 01/11/2019 20:25, Andrew Cooper wrote: > We cache Long Mode and No Execute early on boot, so take the opportunity to > cache HYPERVISOR early as well. Either: 1. the description needs clarifying that the whole 1c featureset is being stored, or 2. a mask should be applied to store only the hy

Re: [Xen-devel] [PATCH 2/3] x86/boot: Cache cpu_has_hypervisor very early on boot

2019-11-04 Thread Jan Beulich
On 04.11.2019 16:31, Andrew Cooper wrote: > On 04/11/2019 13:32, Jan Beulich wrote: >> On 01.11.2019 21:25, Andrew Cooper wrote: >>> --- a/xen/arch/x86/boot/head.S >>> +++ b/xen/arch/x86/boot/head.S >>> @@ -630,6 +630,10 @@ trampoline_setup: >>> >>> 1: >>> /* Interrogate CPU extended fe

Re: [Xen-devel] [PATCH 2/3] x86/boot: Cache cpu_has_hypervisor very early on boot

2019-11-04 Thread Andrew Cooper
On 04/11/2019 13:32, Jan Beulich wrote: > On 01.11.2019 21:25, Andrew Cooper wrote: >> --- a/xen/arch/x86/boot/head.S >> +++ b/xen/arch/x86/boot/head.S >> @@ -630,6 +630,10 @@ trampoline_setup: >> >> 1: >> /* Interrogate CPU extended features via CPUID. */ >> +mov $1, %eax >

Re: [Xen-devel] [PATCH 2/3] x86/boot: Cache cpu_has_hypervisor very early on boot

2019-11-04 Thread Jan Beulich
On 01.11.2019 21:25, Andrew Cooper wrote: > --- a/xen/arch/x86/boot/head.S > +++ b/xen/arch/x86/boot/head.S > @@ -630,6 +630,10 @@ trampoline_setup: > > 1: > /* Interrogate CPU extended features via CPUID. */ > +mov $1, %eax > +cpuid > +mov %ecx, sym_fs(b

[Xen-devel] [PATCH 2/3] x86/boot: Cache cpu_has_hypervisor very early on boot

2019-11-01 Thread Andrew Cooper
We cache Long Mode and No Execute early on boot, so take the opportunity to cache HYPERVISOR early as well. Replace opencoded early access to the feature bit. Signed-off-by: Andrew Cooper --- CC: Jan Beulich CC: Wei Liu CC: Roger Pau Monné CC: Sergey Dyasli CC: Juergen Gross --- xen/arch/x