[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH v2 1/2] x86/hvm: allow guest to use clflushopt and clwb
>>> On 07.01.16 at 15:01, <andrew.cooper3@xxxxxxxxxx> wrote: > On 07/01/16 13:49, Jan Beulich wrote: >>>>> On 30.12.15 at 12:48, <haozhong.zhang@xxxxxxxxx> wrote: >>> --- a/xen/arch/x86/hvm/hvm.c >>> +++ b/xen/arch/x86/hvm/hvm.c >>> @@ -4583,21 +4583,30 @@ void hvm_cpuid(unsigned int input, unsigned int >>> *eax, > unsigned int *ebx, >>> *edx &= ~cpufeat_mask(X86_FEATURE_PSE36); >>> break; >>> case 0x7: >>> - if ( (count == 0) && !cpu_has_smep ) >>> - *ebx &= ~cpufeat_mask(X86_FEATURE_SMEP); >>> + if ( count == 0 ) >>> + { >>> + if ( !cpu_has_smep ) >>> + *ebx &= ~cpufeat_mask(X86_FEATURE_SMEP); >>> + >>> + if ( !cpu_has_smap ) >>> + *ebx &= ~cpufeat_mask(X86_FEATURE_SMAP); >>> + >>> + /* Don't expose MPX to hvm when VMX support is not available */ >>> + if ( !(vmx_vmexit_control & VM_EXIT_CLEAR_BNDCFGS) || >>> + !(vmx_vmentry_control & VM_ENTRY_LOAD_BNDCFGS) ) >>> + *ebx &= ~cpufeat_mask(X86_FEATURE_MPX); >>> >>> - if ( (count == 0) && !cpu_has_smap ) >>> - *ebx &= ~cpufeat_mask(X86_FEATURE_SMAP); >>> + /* Don't expose INVPCID to non-hap hvm. */ >>> + if ( !hap_enabled(d) ) >>> + *ebx &= ~cpufeat_mask(X86_FEATURE_INVPCID); >>> >>> - /* Don't expose MPX to hvm when VMX support is not available */ >>> - if ( (count == 0) && >>> - (!(vmx_vmexit_control & VM_EXIT_CLEAR_BNDCFGS) || >>> - !(vmx_vmentry_control & VM_ENTRY_LOAD_BNDCFGS)) ) >>> - *ebx &= ~cpufeat_mask(X86_FEATURE_MPX); >>> + if ( !cpu_has_clflushopt ) >>> + *ebx &= ~cpufeat_mask(X86_FEATURE_CLFLUSHOPT); >>> + >>> + if ( !cpu_has_clwb ) >>> + *ebx &= ~cpufeat_mask(X86_FEATURE_CLWB); >> I don't think we need this: Other than other things adjusted here, >> there's nothing disabling these two features when found available, >> and there are no extra conditions to consider. Otherwise, if we >> were to follow this route, quite a bit of code would need to be >> added to other case statements in this function. But that's all (I >> think) going to be taken care of by Andrew's CPUID leveling series. > > My series does take care of all of this. > > I would prefer that these two changes get taken as soon as they are > ready, so I can rebase. If we don't need the change quoted above, your rebase will actually be easier to do. Jan _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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