Commit cc2dd402 authored by Denis V. Lunev's avatar Denis V. Lunev Committed by Greg Kroah-Hartman
Browse files

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: default avatarAndrey Smetanin <asmetanin@virtuozzo.com>
Signed-off-by: default avatarDenis V. Lunev <den@openvz.org>
Signed-off-by: default avatarK. Y. Srinivasan <kys@microsoft.com>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 4a54243f

arch/x86/include/asm/mshyperv.h

+1 −0
Original line number Diff line number Diff line
@@ -7,6 +7,7 @@ 


struct ms_hyperv_info {

	u32 features;

	u32 misc_features;

	u32 hints;

};

arch/x86/kernel/cpu/mshyperv.c

+1 −0
Original line number Diff line number Diff line
@@ -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",

drivers/hv/vmbus_drv.c

+2 −2
Original line number Diff line number Diff line
@@ -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);

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