On 9/1/2022 11:13 PM, Jim Mattson wrote: > On Thu, Sep 1, 2022 at 5:45 AM Shukla, Santosh <santosh.shukla@xxxxxxx> wrote: >> >> Hi Jim, >> >> On 9/1/2022 5:12 AM, Jim Mattson wrote: >>> On Mon, Aug 29, 2022 at 3:09 AM Santosh Shukla <santosh.shukla@xxxxxxx> wrote: >>>> >>>> VNMI feature allows the hypervisor to inject NMI into the guest w/o >>>> using Event injection mechanism, The benefit of using VNMI over the >>>> event Injection that does not require tracking the Guest's NMI state and >>>> intercepting the IRET for the NMI completion. VNMI achieves that by >>>> exposing 3 capability bits in VMCB intr_cntrl which helps with >>>> virtualizing NMI injection and NMI_Masking. >>>> >>>> The presence of this feature is indicated via the CPUID function >>>> 0x8000000A_EDX[25]. >>>> >>>> Reviewed-by: Maxim Levitsky <mlevitsk@xxxxxxxxxx> >>>> Signed-off-by: Santosh Shukla <santosh.shukla@xxxxxxx> >>>> --- >>>> arch/x86/include/asm/cpufeatures.h | 1 + >>>> 1 file changed, 1 insertion(+) >>>> >>>> diff --git a/arch/x86/include/asm/cpufeatures.h b/arch/x86/include/asm/cpufeatures.h >>>> index ef4775c6db01..33e3603be09e 100644 >>>> --- a/arch/x86/include/asm/cpufeatures.h >>>> +++ b/arch/x86/include/asm/cpufeatures.h >>>> @@ -356,6 +356,7 @@ >>>> #define X86_FEATURE_VGIF (15*32+16) /* Virtual GIF */ >>>> #define X86_FEATURE_X2AVIC (15*32+18) /* Virtual x2apic */ >>>> #define X86_FEATURE_V_SPEC_CTRL (15*32+20) /* Virtual SPEC_CTRL */ >>>> +#define X86_FEATURE_V_NMI (15*32+25) /* Virtual NMI */ >>>> #define X86_FEATURE_SVME_ADDR_CHK (15*32+28) /* "" SVME addr check */ >>> >>> Why is it "V_NMI," but "VGIF"? >>> >> I guess you are asking why I chose V_NMI and not VNMI, right? >> if so then there are two reasons for going with V_NMI - IP bits are named in order >> V_NMI, V_NMI_MASK, and V_NMI_ENABLE style and also Intel already using VNMI (X86_FEATURE_VNMI) > > I would argue that inconsistency and arbitrary underscores > unnecessarily increase the cognitive load. It is not immediately > obvious to me that an extra underscore implies AMD. What's wrong with > X86_FEATURE_AMD_VNMI? We already have over half a dozen AMD feature AMD prefix (X86_FEATURE_AMD_VNMI) is fine with me. > bits that are distinguished from the Intel version by an AMD prefix. Hi Paolo, Is there any other suggestions/comment on v4? Should I send v5 with Prefix change or you're ok to consider v4 with AMD prefix change? Thanks, Santosh
