From: Nuno Das Neves <[email protected]> Sent: Wednesday, February 26, 2025 3:08 PM > > From: Stanislav Kinsburskii <[email protected]> > > Extend the "ms_hyperv_info" structure to include a new field, > "ext_features", for capturing extended Hyper-V features. > Update the "ms_hyperv_init_platform" function to retrieve these features > using the cpuid instruction and include them in the informational output. > > Signed-off-by: Stanislav Kinsburskii <[email protected]> > Signed-off-by: Nuno Das Neves <[email protected]> > --- > arch/x86/kernel/cpu/mshyperv.c | 6 ++++-- > include/asm-generic/mshyperv.h | 1 + > 2 files changed, 5 insertions(+), 2 deletions(-) > > diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c > index 4f01f424ea5b..2c29dfd6de19 100644 > --- a/arch/x86/kernel/cpu/mshyperv.c > +++ b/arch/x86/kernel/cpu/mshyperv.c > @@ -434,13 +434,15 @@ static void __init ms_hyperv_init_platform(void) > */ > ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES); > ms_hyperv.priv_high = cpuid_ebx(HYPERV_CPUID_FEATURES); > + ms_hyperv.ext_features = cpuid_ecx(HYPERV_CPUID_FEATURES); > ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES); > ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO); > > hv_max_functions_eax = cpuid_eax(HYPERV_CPUID_VENDOR_AND_MAX_FUNCTIONS); > > - pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, hints 0x%x, misc > 0x%x\n", > - ms_hyperv.features, ms_hyperv.priv_high, ms_hyperv.hints, > + pr_info("Hyper-V: privilege flags low 0x%x, high 0x%x, ext 0x%x, hints > 0x%x, misc 0x%x\n", > + ms_hyperv.features, ms_hyperv.priv_high, > + ms_hyperv.ext_features, ms_hyperv.hints, > ms_hyperv.misc_features); > > ms_hyperv.max_vp_index = cpuid_eax(HYPERV_CPUID_IMPLEMENT_LIMITS); > diff --git a/include/asm-generic/mshyperv.h b/include/asm-generic/mshyperv.h > index dc4729dba9ef..c020d5d0ec2a 100644 > --- a/include/asm-generic/mshyperv.h > +++ b/include/asm-generic/mshyperv.h > @@ -36,6 +36,7 @@ enum hv_partition_type { > struct ms_hyperv_info { > u32 features; > u32 priv_high; > + u32 ext_features; > u32 misc_features; > u32 hints; > u32 nested_features; > -- > 2.34.1
Are any of the extended features available on arm64? This code is obviously x86 specific, so ms_hyperv.ext_features will be zero on arm64. From what I can see, ext_features is referenced only in Patch 10 of this series, and in code that is under #ifdef CONFIG_X86_64, so that should be OK. The pr_info() line will now be slightly different on x86 and arm64 since arm64 won't have the "ext" field, but I think that's OK too. Reviewed-by: Michael Kelley <[email protected]>
