Commit f4b027c5 authored by Sean Christopherson's avatar Sean Christopherson Committed by Peter Zijlstra
Browse files

KVM: x86: Register Processor Trace interrupt hook iff PT enabled in guest 



Override the Processor Trace (PT) interrupt handler for guest mode if and
only if PT is configured for host+guest mode, i.e. is being used
independently by both host and guest.  If PT is configured for system
mode, the host fully controls PT and must handle all events.

Fixes: 8479e04e ("KVM: x86: Inject PMI for KVM guest")
Reported-by: default avatarAlexander Shishkin <alexander.shishkin@linux.intel.com>
Reported-by: default avatarArtem Kashkanov <artem.kashkanov@intel.com>
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
Signed-off-by: default avatarPeter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: default avatarPaolo Bonzini <pbonzini@redhat.com>
Cc: stable@vger.kernel.org
Link: https://lore.kernel.org/r/20211111020738.2512932-4-seanjc@google.com
parent 5c7df80e

arch/x86/include/asm/kvm_host.h

+1 −0
Original line number Diff line number Diff line
@@ -1516,6 +1516,7 @@ struct kvm_x86_init_ops { 
	int (*disabled_by_bios)(void);

	int (*check_processor_compatibility)(void);

	int (*hardware_setup)(void);

	bool (*intel_pt_intr_in_guest)(void);



	struct kvm_x86_ops *runtime_ops;

};

arch/x86/kvm/vmx/vmx.c

+1 −0
Original line number Diff line number Diff line
@@ -7865,6 +7865,7 @@ static struct kvm_x86_init_ops vmx_init_ops __initdata = { 
	.disabled_by_bios = vmx_disabled_by_bios,

	.check_processor_compatibility = vmx_check_processor_compat,

	.hardware_setup = hardware_setup,

	.intel_pt_intr_in_guest = vmx_pt_mode_is_host_guest,



	.runtime_ops = &vmx_x86_ops,

};

arch/x86/kvm/x86.c

+4 −1
Original line number Diff line number Diff line
@@ -8510,7 +8510,7 @@ static struct perf_guest_info_callbacks kvm_guest_cbs = { 
	.is_in_guest		= kvm_is_in_guest,

	.is_user_mode		= kvm_is_user_mode,

	.get_guest_ip		= kvm_get_guest_ip,

	.handle_intel_pt_intr	= kvm_handle_intel_pt_intr,

	.handle_intel_pt_intr	= NULL,

};



#ifdef CONFIG_X86_64
@@ -11222,6 +11222,8 @@ int kvm_arch_hardware_setup(void *opaque) 
	memcpy(&kvm_x86_ops, ops->runtime_ops, sizeof(kvm_x86_ops));

	kvm_ops_static_call_update();



	if (ops->intel_pt_intr_in_guest && ops->intel_pt_intr_in_guest())

		kvm_guest_cbs.handle_intel_pt_intr = kvm_handle_intel_pt_intr;

	perf_register_guest_info_callbacks(&kvm_guest_cbs);



	if (!kvm_cpu_cap_has(X86_FEATURE_XSAVES))
@@ -11252,6 +11254,7 @@ int kvm_arch_hardware_setup(void *opaque) 
void kvm_arch_hardware_unsetup(void)

{

	perf_unregister_guest_info_callbacks(&kvm_guest_cbs);

	kvm_guest_cbs.handle_intel_pt_intr = NULL;



	static_call(kvm_x86_hardware_unsetup)();

}