From 5431390b3039624a371549926f74a1c470b2ecaa Mon Sep 17 00:00:00 2001 From: Vitaly Kuznetsov Date: Tue, 20 Mar 2018 15:02:10 +0100 Subject: x86/hyper-v: detect nested features MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit TLFS 5.0 says: "Support for an enlightened VMCS interface is reported with CPUID leaf 0x40000004. If an enlightened VMCS interface is supported, additional nested enlightenments may be discovered by reading the CPUID leaf 0x4000000A (see 2.4.11)." Signed-off-by: Vitaly Kuznetsov Reviewed-by: Michael Kelley Reviewed-by: Thomas Gleixner Signed-off-by: Radim Krčmář --- arch/x86/kernel/cpu/mshyperv.c | 5 +++++ 1 file changed, 5 insertions(+) (limited to 'arch/x86/kernel/cpu') diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 0dfc568c110c..1afc0a453bba 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -208,6 +208,11 @@ static void __init ms_hyperv_init_platform(void) x86_platform.calibrate_cpu = hv_get_tsc_khz; } + if (ms_hyperv.hints & HV_X64_ENLIGHTENED_VMCS_RECOMMENDED) { + ms_hyperv.nested_features = + cpuid_eax(HYPERV_CPUID_NESTED_FEATURES); + } + #ifdef CONFIG_X86_LOCAL_APIC if (ms_hyperv.features & HV_X64_ACCESS_FREQUENCY_MSRS && ms_hyperv.misc_features & HV_FEATURE_FREQUENCY_MSRS_AVAILABLE) { -- cgit v1.2.3