From: Andrew Cooper <andrew.cooper3@citrix.com> To: Jan Beulich <JBeulich@suse.com> Cc: xen-devel <xen-devel@lists.xenproject.org>, Wei Liu <wei.liu2@citrix.com>, Roger Pau Monne <roger.pau@citrix.com> Subject: Re: [PATCH] libx86: Introduce wrappers for extracting XCR0/XSS from a cpuid policy Date: Thu, 23 May 2019 12:59:25 +0100 [thread overview] Message-ID: <2c57c495-3149-f883-ac6c-3db50334d21b@citrix.com> (raw) In-Reply-To: <5CE689970200007800231AD9@prv1-mh.provo.novell.com> On 23/05/2019 12:52, Jan Beulich wrote: >>>> On 23.05.19 at 12:27, <andrew.cooper3@citrix.com> wrote: >> --- a/xen/arch/x86/xstate.c >> +++ b/xen/arch/x86/xstate.c >> @@ -660,9 +660,7 @@ static bool valid_xcr0(u64 xcr0) >> int validate_xstate(const struct domain *d, uint64_t xcr0, uint64_t xcr0_accum, >> const struct xsave_hdr *hdr) >> { >> - const struct cpuid_policy *cp = d->arch.cpuid; >> - uint64_t xcr0_max = >> - ((uint64_t)cp->xstate.xcr0_high << 32) | cp->xstate.xcr0_low; >> + uint64_t xcr0_max = cpuid_policy_xcr0(d->arch.cpuid); >> unsigned int i; >> >> if ( (hdr->xstate_bv & ~xcr0_accum) || >> @@ -686,9 +684,7 @@ int validate_xstate(const struct domain *d, uint64_t xcr0, uint64_t xcr0_accum, >> int handle_xsetbv(u32 index, u64 new_bv) >> { >> struct vcpu *curr = current; >> - const struct cpuid_policy *cp = curr->domain->arch.cpuid; >> - uint64_t xcr0_max = >> - ((uint64_t)cp->xstate.xcr0_high << 32) | cp->xstate.xcr0_low; >> + uint64_t xcr0_max = cpuid_policy_xcr0(curr->domain->arch.cpuid); > In both cases the variables are more appropriately named than > the new helper. While I agree it's slightly more typing, did you > consider calling it cpuid_policy_xcr0_max()? Fine. > >> --- a/xen/include/xen/lib/x86/cpuid.h >> +++ b/xen/include/xen/lib/x86/cpuid.h >> @@ -308,6 +308,18 @@ static inline void cpuid_featureset_to_policy( >> p->feat._7a1 = fs[FEATURESET_7a1]; >> } >> >> +static inline uint64_t cpuid_policy_xcr0(const struct cpuid_policy *p) >> +{ >> + return ((uint64_t)p->xstate.xcr0_high << 32) | p->xstate.xcr0_low; >> +} >> + >> +static inline uint64_t cpuid_policy_xstates(const struct cpuid_policy *p) >> +{ >> + uint64_t val = p->xstate.xcr0_high | p->xstate.xss_high; >> + >> + return (val << 32) | p->xstate.xcr0_low | p->xstate.xss_low; >> +} > How about also having cpuid_policy_xss() (or cpuid_policy_xss_max()) > and then simply making cpuid_policy_xstates() combine the two > results? I started with that, but the resulting code was a little awkward to read, and the asm generation was a little worse due to promoting everything first. I don't think we need cpuid_policy_xss{,_max}() until we actually implement something for guests (most likely CET at this rate). > > Anyway, as I can also live with things as they are, with or without > either of the suggested changes > Reviewed-by: Jan Beulich <jbeulich@suse.com> Thanks (although I'm still happy to play around with naming). ~Andrew _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
WARNING: multiple messages have this Message-ID (diff)
From: Andrew Cooper <andrew.cooper3@citrix.com> To: Jan Beulich <JBeulich@suse.com> Cc: xen-devel <xen-devel@lists.xenproject.org>, Wei Liu <wei.liu2@citrix.com>, Roger Pau Monne <roger.pau@citrix.com> Subject: Re: [Xen-devel] [PATCH] libx86: Introduce wrappers for extracting XCR0/XSS from a cpuid policy Date: Thu, 23 May 2019 12:59:25 +0100 [thread overview] Message-ID: <2c57c495-3149-f883-ac6c-3db50334d21b@citrix.com> (raw) Message-ID: <20190523115925.PQ0NI0j7IqJ4GQ67shgdKmcenSD3KAuWcee2irktarE@z> (raw) In-Reply-To: <5CE689970200007800231AD9@prv1-mh.provo.novell.com> On 23/05/2019 12:52, Jan Beulich wrote: >>>> On 23.05.19 at 12:27, <andrew.cooper3@citrix.com> wrote: >> --- a/xen/arch/x86/xstate.c >> +++ b/xen/arch/x86/xstate.c >> @@ -660,9 +660,7 @@ static bool valid_xcr0(u64 xcr0) >> int validate_xstate(const struct domain *d, uint64_t xcr0, uint64_t xcr0_accum, >> const struct xsave_hdr *hdr) >> { >> - const struct cpuid_policy *cp = d->arch.cpuid; >> - uint64_t xcr0_max = >> - ((uint64_t)cp->xstate.xcr0_high << 32) | cp->xstate.xcr0_low; >> + uint64_t xcr0_max = cpuid_policy_xcr0(d->arch.cpuid); >> unsigned int i; >> >> if ( (hdr->xstate_bv & ~xcr0_accum) || >> @@ -686,9 +684,7 @@ int validate_xstate(const struct domain *d, uint64_t xcr0, uint64_t xcr0_accum, >> int handle_xsetbv(u32 index, u64 new_bv) >> { >> struct vcpu *curr = current; >> - const struct cpuid_policy *cp = curr->domain->arch.cpuid; >> - uint64_t xcr0_max = >> - ((uint64_t)cp->xstate.xcr0_high << 32) | cp->xstate.xcr0_low; >> + uint64_t xcr0_max = cpuid_policy_xcr0(curr->domain->arch.cpuid); > In both cases the variables are more appropriately named than > the new helper. While I agree it's slightly more typing, did you > consider calling it cpuid_policy_xcr0_max()? Fine. > >> --- a/xen/include/xen/lib/x86/cpuid.h >> +++ b/xen/include/xen/lib/x86/cpuid.h >> @@ -308,6 +308,18 @@ static inline void cpuid_featureset_to_policy( >> p->feat._7a1 = fs[FEATURESET_7a1]; >> } >> >> +static inline uint64_t cpuid_policy_xcr0(const struct cpuid_policy *p) >> +{ >> + return ((uint64_t)p->xstate.xcr0_high << 32) | p->xstate.xcr0_low; >> +} >> + >> +static inline uint64_t cpuid_policy_xstates(const struct cpuid_policy *p) >> +{ >> + uint64_t val = p->xstate.xcr0_high | p->xstate.xss_high; >> + >> + return (val << 32) | p->xstate.xcr0_low | p->xstate.xss_low; >> +} > How about also having cpuid_policy_xss() (or cpuid_policy_xss_max()) > and then simply making cpuid_policy_xstates() combine the two > results? I started with that, but the resulting code was a little awkward to read, and the asm generation was a little worse due to promoting everything first. I don't think we need cpuid_policy_xss{,_max}() until we actually implement something for guests (most likely CET at this rate). > > Anyway, as I can also live with things as they are, with or without > either of the suggested changes > Reviewed-by: Jan Beulich <jbeulich@suse.com> Thanks (although I'm still happy to play around with naming). ~Andrew _______________________________________________ Xen-devel mailing list Xen-devel@lists.xenproject.org https://lists.xenproject.org/mailman/listinfo/xen-devel
next prev parent reply other threads:[~2019-05-23 11:59 UTC|newest] Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top 2019-05-22 15:50 [PATCH] libx86: Elide more empty CPUID leaves when serialising a policy Andrew Cooper 2019-05-22 15:50 ` [Xen-devel] " Andrew Cooper 2019-05-23 8:33 ` Jan Beulich 2019-05-23 8:33 ` [Xen-devel] " Jan Beulich 2019-05-23 10:38 ` Andrew Cooper 2019-05-23 10:38 ` [Xen-devel] " Andrew Cooper 2019-05-23 10:27 ` [PATCH] libx86: Introduce wrappers for extracting XCR0/XSS from a cpuid policy Andrew Cooper 2019-05-23 10:27 ` [Xen-devel] " Andrew Cooper 2019-05-23 11:52 ` Jan Beulich 2019-05-23 11:52 ` [Xen-devel] " Jan Beulich 2019-05-23 11:59 ` Andrew Cooper [this message] 2019-05-23 11:59 ` Andrew Cooper 2019-05-23 12:08 ` Jan Beulich 2019-05-23 12:08 ` [Xen-devel] " Jan Beulich
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