Re: [Xen-devel] [PATCH 2/3] x86emul: check host features alongside guest ones where needed
On 14/03/2016 08:29, Jan Beulich wrote: On 11.03.16 at 18:41, wrote: >> On 11/03/16 17:34, Jan Beulich wrote: >>> Signed-off-by: Jan Beulich >>> >>> --- a/xen/arch/x86/x86_emulate/x86_emulate.c >>> +++ b/xen/arch/x86/x86_emulate/x86_emulate.c >>> @@ -1093,6 +1093,22 @@ static bool_t vcpu_has( >>> #define vcpu_must_have_cx16() vcpu_must_have(0x0001, ECX, 13) >>> #define vcpu_must_have_avx() vcpu_must_have(0x0001, ECX, 28) >>> >>> +#ifdef __XEN__ >>> +/* >>> + * Note the (subtle?) difference between vcpu_must_have_() and >>> + * vcpu_must_have(): The former only checks guest feature flags, >>> + * while the latter also checks host ones, i.e. is required to be used when >>> + * emulation code is using the same instruction class for carrying out the >>> + * actual operation). >>> + */ >> This comment is now stale. >> >> With this dropped, Reviewed-by: Andrew Cooper > I suppose you're okay with it being adjusted instead of fully dropped: > > /* > * Note the difference between vcpu_must_have_() and > * host_and_vcpu_must_have(): The latter needs to be used when > * emulation code is using the same instruction class for carrying out > * the actual operation. > */ Yes - that's great. ~Andrew ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
Re: [Xen-devel] [PATCH 2/3] x86emul: check host features alongside guest ones where needed
>>> On 11.03.16 at 18:41, wrote: > On 11/03/16 17:34, Jan Beulich wrote: >> Signed-off-by: Jan Beulich >> >> --- a/xen/arch/x86/x86_emulate/x86_emulate.c >> +++ b/xen/arch/x86/x86_emulate/x86_emulate.c >> @@ -1093,6 +1093,22 @@ static bool_t vcpu_has( >> #define vcpu_must_have_cx16() vcpu_must_have(0x0001, ECX, 13) >> #define vcpu_must_have_avx() vcpu_must_have(0x0001, ECX, 28) >> >> +#ifdef __XEN__ >> +/* >> + * Note the (subtle?) difference between vcpu_must_have_() and >> + * vcpu_must_have(): The former only checks guest feature flags, >> + * while the latter also checks host ones, i.e. is required to be used when >> + * emulation code is using the same instruction class for carrying out the >> + * actual operation). >> + */ > > This comment is now stale. > > With this dropped, Reviewed-by: Andrew Cooper I suppose you're okay with it being adjusted instead of fully dropped: /* * Note the difference between vcpu_must_have_() and * host_and_vcpu_must_have(): The latter needs to be used when * emulation code is using the same instruction class for carrying out * the actual operation. */ Jan ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel
Re: [Xen-devel] [PATCH 2/3] x86emul: check host features alongside guest ones where needed
On 11/03/16 17:34, Jan Beulich wrote: > Signed-off-by: Jan Beulich > > --- a/xen/arch/x86/x86_emulate/x86_emulate.c > +++ b/xen/arch/x86/x86_emulate/x86_emulate.c > @@ -1093,6 +1093,22 @@ static bool_t vcpu_has( > #define vcpu_must_have_cx16() vcpu_must_have(0x0001, ECX, 13) > #define vcpu_must_have_avx() vcpu_must_have(0x0001, ECX, 28) > > +#ifdef __XEN__ > +/* > + * Note the (subtle?) difference between vcpu_must_have_() and > + * vcpu_must_have(): The former only checks guest feature flags, > + * while the latter also checks host ones, i.e. is required to be used when > + * emulation code is using the same instruction class for carrying out the > + * actual operation). > + */ This comment is now stale. With this dropped, Reviewed-by: Andrew Cooper ___ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel