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Commit ff9d07a0 authored by Zhang, Yanmin's avatar Zhang, Yanmin Committed by Avi Kivity
Browse files

KVM: Implement perf callbacks for guest sampling 



Below patch implements the perf_guest_info_callbacks on kvm.

Signed-off-by: default avatarZhang Yanmin <yanmin_zhang@linux.intel.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent 39447b38

arch/x86/kvm/vmx.c

+4 −1
Original line number Diff line number Diff line
@@ -3654,8 +3654,11 @@ static void vmx_complete_interrupts(struct vcpu_vmx *vmx) 


	/* We need to handle NMIs before interrupts are enabled */

	if ((exit_intr_info & INTR_INFO_INTR_TYPE_MASK) == INTR_TYPE_NMI_INTR &&

	    (exit_intr_info & INTR_INFO_VALID_MASK))

	    (exit_intr_info & INTR_INFO_VALID_MASK)) {

		kvm_before_handle_nmi(&vmx->vcpu);

		asm("int $2");

		kvm_after_handle_nmi(&vmx->vcpu);

	}



	idtv_info_valid = idt_vectoring_info & VECTORING_INFO_VALID_MASK;

arch/x86/kvm/x86.c

+46 −0
Original line number Diff line number Diff line
@@ -40,6 +40,7 @@ 
#include <linux/user-return-notifier.h>

#include <linux/srcu.h>

#include <linux/slab.h>

#include <linux/perf_event.h>

#include <trace/events/kvm.h>

#undef TRACE_INCLUDE_FILE

#define CREATE_TRACE_POINTS
@@ -3765,6 +3766,47 @@ static void kvm_timer_init(void) 
	}

}



static DEFINE_PER_CPU(struct kvm_vcpu *, current_vcpu);



static int kvm_is_in_guest(void)

{

	return percpu_read(current_vcpu) != NULL;

}



static int kvm_is_user_mode(void)

{

	int user_mode = 3;

	if (percpu_read(current_vcpu))

		user_mode = kvm_x86_ops->get_cpl(percpu_read(current_vcpu));

	return user_mode != 0;

}



static unsigned long kvm_get_guest_ip(void)

{

	unsigned long ip = 0;

	if (percpu_read(current_vcpu))

		ip = kvm_rip_read(percpu_read(current_vcpu));

	return ip;

}



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,

};



void kvm_before_handle_nmi(struct kvm_vcpu *vcpu)

{

	percpu_write(current_vcpu, vcpu);

}

EXPORT_SYMBOL_GPL(kvm_before_handle_nmi);



void kvm_after_handle_nmi(struct kvm_vcpu *vcpu)

{

	percpu_write(current_vcpu, NULL);

}

EXPORT_SYMBOL_GPL(kvm_after_handle_nmi);



int kvm_arch_init(void *opaque)

{

	int r;
@@ -3801,6 +3843,8 @@ int kvm_arch_init(void *opaque) 


	kvm_timer_init();



	perf_register_guest_info_callbacks(&kvm_guest_cbs);



	return 0;



out:
@@ -3809,6 +3853,8 @@ int kvm_arch_init(void *opaque) 


void kvm_arch_exit(void)

{

	perf_unregister_guest_info_callbacks(&kvm_guest_cbs);



	if (!boot_cpu_has(X86_FEATURE_CONSTANT_TSC))

		cpufreq_unregister_notifier(&kvmclock_cpufreq_notifier_block,

					    CPUFREQ_TRANSITION_NOTIFIER);

arch/x86/kvm/x86.h

+3 −0
Original line number Diff line number Diff line
@@ -65,4 +65,7 @@ static inline int is_paging(struct kvm_vcpu *vcpu) 
	return kvm_read_cr0_bits(vcpu, X86_CR0_PG);

}



void kvm_before_handle_nmi(struct kvm_vcpu *vcpu);

void kvm_after_handle_nmi(struct kvm_vcpu *vcpu);



#endif