From cc2dd4027a43bb36c846f195a764edabc0828602 Mon Sep 17 00:00:00 2001 From: "Denis V. Lunev" Date: Sat, 1 Aug 2015 16:08:20 -0700 Subject: [PATCH] mshyperv: fix recognition of Hyper-V guest crash MSR's Hypervisor Top Level Functional Specification v3.1/4.0 notes that cpuid (0x40000003) EDX's 10th bit should be used to check that Hyper-V guest crash MSR's functionality available. This patch should fix this recognition. Currently the code checks EAX register instead of EDX. Signed-off-by: Andrey Smetanin Signed-off-by: Denis V. Lunev Signed-off-by: K. Y. Srinivasan Signed-off-by: Greg Kroah-Hartman --- arch/x86/include/asm/mshyperv.h | 1 + arch/x86/kernel/cpu/mshyperv.c | 1 + drivers/hv/vmbus_drv.c | 4 ++-- 3 files changed, 4 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/mshyperv.h b/arch/x86/include/asm/mshyperv.h index d02f9c9a6592..aaf59b7da98a 100644 --- a/arch/x86/include/asm/mshyperv.h +++ b/arch/x86/include/asm/mshyperv.h @@ -7,6 +7,7 @@ struct ms_hyperv_info { u32 features; + u32 misc_features; u32 hints; }; diff --git a/arch/x86/kernel/cpu/mshyperv.c b/arch/x86/kernel/cpu/mshyperv.c index 5ea5bbcc85b3..f794bfa3c138 100644 --- a/arch/x86/kernel/cpu/mshyperv.c +++ b/arch/x86/kernel/cpu/mshyperv.c @@ -158,6 +158,7 @@ static void __init ms_hyperv_init_platform(void) * Extract the features and hints */ ms_hyperv.features = cpuid_eax(HYPERV_CPUID_FEATURES); + ms_hyperv.misc_features = cpuid_edx(HYPERV_CPUID_FEATURES); ms_hyperv.hints = cpuid_eax(HYPERV_CPUID_ENLIGHTMENT_INFO); printk(KERN_INFO "HyperV: features 0x%x, hints 0x%x\n", diff --git a/drivers/hv/vmbus_drv.c b/drivers/hv/vmbus_drv.c index b6114cc89aeb..e7b0bcd453e7 100644 --- a/drivers/hv/vmbus_drv.c +++ b/drivers/hv/vmbus_drv.c @@ -871,7 +871,7 @@ static int vmbus_bus_init(int irq) /* * Only register if the crash MSRs are available */ - if (ms_hyperv.features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) { + if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) { register_die_notifier(&hyperv_die_block); atomic_notifier_chain_register(&panic_notifier_list, &hyperv_panic_block); @@ -1169,7 +1169,7 @@ static void __exit vmbus_exit(void) hv_remove_vmbus_irq(); tasklet_kill(&msg_dpc); vmbus_free_channels(); - if (ms_hyperv.features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) { + if (ms_hyperv.misc_features & HV_FEATURE_GUEST_CRASH_MSR_AVAILABLE) { unregister_die_notifier(&hyperv_die_block); atomic_notifier_chain_unregister(&panic_notifier_list, &hyperv_panic_block); -- 2.39.5