Re: [Xen-devel] MSR_SPEC_CTRL intercept

2018-05-25 Thread Jan Beulich
>>> On 25.05.18 at 17:25, wrote: > On 24/05/18 11:23, Jan Beulich wrote: > On 24.05.18 at 12:13, wrote: >>> On 24/05/18 09:13, Jan Beulich wrote: >>> On 24.05.18 at 00:09, wrote: > It is, as documented,

Re: [Xen-devel] MSR_SPEC_CTRL intercept

2018-05-25 Thread Andrew Cooper
On 24/05/18 11:23, Jan Beulich wrote: On 24.05.18 at 12:13, wrote: >> On 24/05/18 09:13, Jan Beulich wrote: >> On 24.05.18 at 00:09, wrote: It is, as documented, not completely strictly true (according to the latest

Re: [Xen-devel] MSR_SPEC_CTRL intercept

2018-05-24 Thread Jan Beulich
>>> On 24.05.18 at 12:13, wrote: > On 24/05/18 09:13, Jan Beulich wrote: > On 24.05.18 at 00:09, wrote: >>> It is, as documented, not completely strictly true (according to the >>> latest revision of the spec), but is there deliberately

Re: [Xen-devel] MSR_SPEC_CTRL intercept

2018-05-24 Thread Andrew Cooper
On 24/05/18 09:13, Jan Beulich wrote: On 24.05.18 at 00:09, wrote: >> It is, as documented, not completely strictly true (according to the >> latest revision of the spec), but is there deliberately to simply so we >> don't give the guest implausible configurations.

Re: [Xen-devel] MSR_SPEC_CTRL intercept

2018-05-24 Thread Jan Beulich
>>> On 24.05.18 at 00:09, wrote: > It is, as documented, not completely strictly true (according to the > latest revision of the spec), but is there deliberately to simply so we > don't give the guest implausible configurations. There is not a > processor with STIBP

Re: [Xen-devel] MSR_SPEC_CTRL intercept

2018-05-23 Thread Andrew Cooper
On 23/05/2018 23:53, Boris Ostrovsky wrote: > On 05/23/2018 06:34 PM, Andrew Cooper wrote: >> On 23/05/2018 23:27, Boris Ostrovsky wrote: >>> On 05/23/2018 06:09 PM, Andrew Cooper wrote: On 23/05/2018 22:59, Boris Ostrovsky wrote: > On 05/23/2018 05:49 PM, Andrew Cooper wrote: >> On

Re: [Xen-devel] MSR_SPEC_CTRL intercept

2018-05-23 Thread Boris Ostrovsky
On 05/23/2018 06:34 PM, Andrew Cooper wrote: > On 23/05/2018 23:27, Boris Ostrovsky wrote: >> On 05/23/2018 06:09 PM, Andrew Cooper wrote: >>> On 23/05/2018 22:59, Boris Ostrovsky wrote: On 05/23/2018 05:49 PM, Andrew Cooper wrote: > On 23/05/2018 22:40, Boris Ostrovsky wrote: >>

Re: [Xen-devel] MSR_SPEC_CTRL intercept

2018-05-23 Thread Andrew Cooper
On 23/05/2018 23:27, Boris Ostrovsky wrote: > On 05/23/2018 06:09 PM, Andrew Cooper wrote: >> On 23/05/2018 22:59, Boris Ostrovsky wrote: >>> On 05/23/2018 05:49 PM, Andrew Cooper wrote: On 23/05/2018 22:40, Boris Ostrovsky wrote: > Looking at vmx_cpuid_policy_changed(): > > >

Re: [Xen-devel] MSR_SPEC_CTRL intercept

2018-05-23 Thread Boris Ostrovsky
On 05/23/2018 06:09 PM, Andrew Cooper wrote: > On 23/05/2018 22:59, Boris Ostrovsky wrote: >> On 05/23/2018 05:49 PM, Andrew Cooper wrote: >>> On 23/05/2018 22:40, Boris Ostrovsky wrote: Looking at vmx_cpuid_policy_changed():    if ( cp->feat.ibrsb )    

Re: [Xen-devel] MSR_SPEC_CTRL intercept

2018-05-23 Thread Andrew Cooper
On 23/05/2018 22:59, Boris Ostrovsky wrote: > On 05/23/2018 05:49 PM, Andrew Cooper wrote: >> On 23/05/2018 22:40, Boris Ostrovsky wrote: >>> Looking at vmx_cpuid_policy_changed(): >>> >>> >>>    if ( cp->feat.ibrsb ) >>>     vmx_clear_msr_intercept(v, MSR_SPEC_CTRL, VMX_MSR_RW); >>>     else

Re: [Xen-devel] MSR_SPEC_CTRL intercept

2018-05-23 Thread Boris Ostrovsky
On 05/23/2018 05:49 PM, Andrew Cooper wrote: > On 23/05/2018 22:40, Boris Ostrovsky wrote: >> Looking at vmx_cpuid_policy_changed(): >> >> >>    if ( cp->feat.ibrsb ) >>     vmx_clear_msr_intercept(v, MSR_SPEC_CTRL, VMX_MSR_RW); >>     else >>     vmx_set_msr_intercept(v, MSR_SPEC_CTRL,

Re: [Xen-devel] MSR_SPEC_CTRL intercept

2018-05-23 Thread Andrew Cooper
On 23/05/2018 22:40, Boris Ostrovsky wrote: > Looking at vmx_cpuid_policy_changed(): > > >    if ( cp->feat.ibrsb ) >     vmx_clear_msr_intercept(v, MSR_SPEC_CTRL, VMX_MSR_RW); >     else >     vmx_set_msr_intercept(v, MSR_SPEC_CTRL, VMX_MSR_RW); > > > Is there a reason why we are not

[Xen-devel] MSR_SPEC_CTRL intercept

2018-05-23 Thread Boris Ostrovsky
Looking at vmx_cpuid_policy_changed():    if ( cp->feat.ibrsb )     vmx_clear_msr_intercept(v, MSR_SPEC_CTRL, VMX_MSR_RW);     else     vmx_set_msr_intercept(v, MSR_SPEC_CTRL, VMX_MSR_RW); Is there a reason why we are not checking cp->feat.ssbd as well? -boris