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Groups > linux.kernel > #1483945
| From | David Vrabel <david.vrabel@citrix.com> |
|---|---|
| Newsgroups | linux.kernel |
| Subject | Re: [PATCH v2 2/3] x86 Test and expose CPUID faulting capabilities in /proc/cpuinfo |
| Date | 2016-09-15 12:10 +0200 |
| Message-ID | <shBMe-5DZ-21@gated-at.bofh.it> (permalink) |
| References | <shpBn-665-13@gated-at.bofh.it> <shpBn-665-11@gated-at.bofh.it> <shq4p-6gS-7@gated-at.bofh.it> |
| Organization | linux.* mail to news gateway |
On 14/09/16 22:35, Dave Hansen wrote: > On 09/14/2016 02:01 PM, Kyle Huey wrote: >> Xen advertises the underlying support for CPUID faulting but not does pass >> through writes to the relevant MSR, nor does it virtualize it, so it does >> not actually work. For now mask off the relevant bit on MSR_PLATFORM_INFO. > > That needs to make it into a comment, please. > > That *is* a Xen bug, right? This is probably fixed in the latest version of Xen. Andrew Cooper would know for sure. >> --- a/arch/x86/xen/enlighten.c >> +++ b/arch/x86/xen/enlighten.c >> @@ -1050,6 +1050,9 @@ static u64 xen_read_msr_safe(unsigned int msr, int *err) >> #endif >> val &= ~X2APIC_ENABLE; >> break; >> + case MSR_PLATFORM_INFO: >> + val &= ~CPUID_FAULTING_SUPPORT; >> + break; >> } >> return val; >> } > > Does this mean that Xen guests effectively can't take advantage of this > feature? PV guests only. David
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[PATCH v2 2/3] x86 Test and expose CPUID faulting capabilities in /proc/cpuinfo Kyle Huey <me@kylehuey.com> - 2016-09-14 23:10 +0200
Re: [PATCH v2 2/3] x86 Test and expose CPUID faulting capabilities in /proc/cpuinfo Dave Hansen <dave.hansen@linux.intel.com> - 2016-09-14 23:40 +0200
Re: [PATCH v2 2/3] x86 Test and expose CPUID faulting capabilities in /proc/cpuinfo Kyle Huey <me@kylehuey.com> - 2016-09-15 00:10 +0200
Re: [PATCH v2 2/3] x86 Test and expose CPUID faulting capabilities in /proc/cpuinfo Andy Lutomirski <luto@amacapital.net> - 2016-09-15 03:20 +0200
Re: [PATCH v2 2/3] x86 Test and expose CPUID faulting capabilities in /proc/cpuinfo Kyle Huey <me@kylehuey.com> - 2016-09-15 04:30 +0200
Re: [PATCH v2 2/3] x86 Test and expose CPUID faulting capabilities in /proc/cpuinfo "H. Peter Anvin" <hpa@zytor.com> - 2016-09-15 22:50 +0200
Re: [PATCH v2 2/3] x86 Test and expose CPUID faulting capabilities in /proc/cpuinfo Andy Lutomirski <luto@amacapital.net> - 2016-09-16 01:20 +0200
Re: [PATCH v2 2/3] x86 Test and expose CPUID faulting capabilities in /proc/cpuinfo David Vrabel <david.vrabel@citrix.com> - 2016-09-15 12:10 +0200
Re: [Xen-devel] [PATCH v2 2/3] x86 Test and expose CPUID faulting capabilities in /proc/cpuinfo David Vrabel <david.vrabel@citrix.com> - 2016-09-15 12:10 +0200
Re: [Xen-devel] [PATCH v2 2/3] x86 Test and expose CPUID faulting capabilities in /proc/cpuinfo "Jan Beulich" <JBeulich@suse.com> - 2016-09-15 12:30 +0200
Re: [Xen-devel] [PATCH v2 2/3] x86 Test and expose CPUID faulting capabilities in /proc/cpuinfo Kyle Huey <me@kylehuey.com> - 2016-09-15 21:20 +0200
Re: [Xen-devel] [PATCH v2 2/3] x86 Test and expose CPUID faulting capabilities in /proc/cpuinfo Andy Lutomirski <luto@amacapital.net> - 2016-09-15 21:40 +0200
Re: [Xen-devel] [PATCH v2 2/3] x86 Test and expose CPUID faulting capabilities in /proc/cpuinfo Kyle Huey <me@kylehuey.com> - 2016-09-16 01:40 +0200
Re: [Xen-devel] [PATCH v2 2/3] x86 Test and expose CPUID faulting capabilities in /proc/cpuinfo Boris Ostrovsky <boris.ostrovsky@oracle.com> - 2016-09-15 21:50 +0200
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