Re: [Xen-devel] [PATCH v3 2/2] x86/Intel: virtualize support for cpuid faulting

On 10/24/2016 03:22 PM, Kyle Huey wrote: > On Mon, Oct 24, 2016 at 8:05 AM, Boris Ostrovsky > wrote: >> On 10/24/2016 12:18 AM, Kyle Huey wrote: >>> The anomalies we see appear to be related to, or at least triggerable >>> by, the performance monitoring interrupt. The

Re: [Xen-devel] [PATCH v3 2/2] x86/Intel: virtualize support for cpuid faulting

On Mon, Oct 24, 2016 at 8:05 AM, Boris Ostrovsky wrote: > On 10/24/2016 12:18 AM, Kyle Huey wrote: >> >> The anomalies we see appear to be related to, or at least triggerable >> by, the performance monitoring interrupt. The following program runs >> a loop of roughly

Re: [Xen-devel] [PATCH v3 2/2] x86/Intel: virtualize support for cpuid faulting

On 10/24/2016 12:18 AM, Kyle Huey wrote: > > The anomalies we see appear to be related to, or at least triggerable > by, the performance monitoring interrupt. The following program runs > a loop of roughly 2^25 conditional branches. It takes one argument, > the number of conditional branches to

Re: [Xen-devel] [PATCH v3 2/2] x86/Intel: virtualize support for cpuid faulting

On Fri, Oct 21, 2016 at 8:52 AM, Kyle Huey wrote: > On Thu, Oct 20, 2016 at 7:40 AM, Boris Ostrovsky > wrote: >> On 10/20/2016 10:11 AM, Andrew Cooper wrote: >>> On 20/10/16 14:55, Kyle Huey wrote: >> That said, rr currently does not work in Xen

Re: [Xen-devel] [PATCH v3 2/2] x86/Intel: virtualize support for cpuid faulting

On Thu, Oct 20, 2016 at 7:40 AM, Boris Ostrovsky wrote: > On 10/20/2016 10:11 AM, Andrew Cooper wrote: >> On 20/10/16 14:55, Kyle Huey wrote: > That said, rr currently does not work in Xen guests due to some PMU > issues that we haven't tracked down yet.

Re: [Xen-devel] [PATCH v3 2/2] x86/Intel: virtualize support for cpuid faulting

On 10/20/2016 10:11 AM, Andrew Cooper wrote: > On 20/10/16 14:55, Kyle Huey wrote: That said, rr currently does not work in Xen guests due to some PMU issues that we haven't tracked down yet. >>> Is this RR trying to use vPMU and it not functioning, or not >>> specifically trying to use

Re: [Xen-devel] [PATCH v3 2/2] x86/Intel: virtualize support for cpuid faulting

On 20/10/16 14:55, Kyle Huey wrote: > >>> That said, rr currently does not work in Xen guests due to some PMU >>> issues that we haven't tracked down yet. >> Is this RR trying to use vPMU and it not functioning, or not >> specifically trying to use PMU facilities and getting stuck anyway? > The

Re: [Xen-devel] [PATCH v3 2/2] x86/Intel: virtualize support for cpuid faulting

On Thu, Oct 20, 2016 at 12:56 AM, Andrew Cooper wrote: > On 20/10/2016 06:10, Kyle Huey wrote: >> On Mon, Oct 17, 2016 at 5:32 AM, Wei Liu wrote: >>> On Fri, Oct 14, 2016 at 12:47:36PM -0700, Kyle Huey wrote: On HVM guests, the cpuid triggers

Re: [Xen-devel] [PATCH v3 2/2] x86/Intel: virtualize support for cpuid faulting

On 20/10/2016 06:10, Kyle Huey wrote: > On Mon, Oct 17, 2016 at 5:32 AM, Wei Liu wrote: >> On Fri, Oct 14, 2016 at 12:47:36PM -0700, Kyle Huey wrote: >>> On HVM guests, the cpuid triggers a vm exit, so we can check the emulated >>> faulting state in vmx_do_cpuid and inject a

Re: [Xen-devel] [PATCH v3 2/2] x86/Intel: virtualize support for cpuid faulting

On Mon, Oct 17, 2016 at 5:32 AM, Wei Liu wrote: > On Fri, Oct 14, 2016 at 12:47:36PM -0700, Kyle Huey wrote: >> On HVM guests, the cpuid triggers a vm exit, so we can check the emulated >> faulting state in vmx_do_cpuid and inject a GP(0) if CPL > 0. Notably no >> hardware

Re: [Xen-devel] [PATCH v3 2/2] x86/Intel: virtualize support for cpuid faulting

On 14/10/16 20:47, Kyle Huey wrote: > On HVM guests, the cpuid triggers a vm exit, so we can check the emulated > faulting state in vmx_do_cpuid and inject a GP(0) if CPL > 0. Notably no > hardware support for faulting on cpuid is necessary to emulate support with an > HVM guest. > > On PV guests,

Re: [Xen-devel] [PATCH v3 2/2] x86/Intel: virtualize support for cpuid faulting

On Fri, Oct 14, 2016 at 12:47:36PM -0700, Kyle Huey wrote: > On HVM guests, the cpuid triggers a vm exit, so we can check the emulated > faulting state in vmx_do_cpuid and inject a GP(0) if CPL > 0. Notably no > hardware support for faulting on cpuid is necessary to emulate support with an > HVM

[Xen-devel] [PATCH v3 2/2] x86/Intel: virtualize support for cpuid faulting

On HVM guests, the cpuid triggers a vm exit, so we can check the emulated faulting state in vmx_do_cpuid and inject a GP(0) if CPL > 0. Notably no hardware support for faulting on cpuid is necessary to emulate support with an HVM guest. On PV guests, hardware support is required so that userspace