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Commit b93463aa authored by Avi Kivity's avatar Avi Kivity
Browse files

KVM: Accelerated apic support 



This adds a mechanism for exposing the virtual apic tpr to the guest, and a
protocol for letting the guest update the tpr without causing a vmexit if
conditions allow (e.g. there is no interrupt pending with a higher priority
than the new tpr).

Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent b209749f

arch/x86/kvm/lapic.c

+50 −1
Original line number Original line Diff line number Diff line
@@ -815,7 +815,8 @@ void kvm_lapic_set_tpr(struct kvm_vcpu *vcpu, unsigned long cr8) 




	if (!apic)

	if (!apic)

		return;

		return;

	apic_set_tpr(apic, ((cr8 & 0x0f) << 4));

	apic_set_tpr(apic, ((cr8 & 0x0f) << 4)

		     | (apic_get_reg(apic, APIC_TASKPRI) & 4));

}

}





u64 kvm_lapic_get_cr8(struct kvm_vcpu *vcpu)

u64 kvm_lapic_get_cr8(struct kvm_vcpu *vcpu)
@@ -1104,3 +1105,51 @@ void kvm_migrate_apic_timer(struct kvm_vcpu *vcpu) 
		hrtimer_start(timer, timer->expires, HRTIMER_MODE_ABS);

		hrtimer_start(timer, timer->expires, HRTIMER_MODE_ABS);

}

}

EXPORT_SYMBOL_GPL(kvm_migrate_apic_timer);

EXPORT_SYMBOL_GPL(kvm_migrate_apic_timer);



void kvm_lapic_sync_from_vapic(struct kvm_vcpu *vcpu)

{

	u32 data;

	void *vapic;



	if (!irqchip_in_kernel(vcpu->kvm) || !vcpu->arch.apic->vapic_addr)

		return;



	vapic = kmap_atomic(vcpu->arch.apic->vapic_page, KM_USER0);

	data = *(u32 *)(vapic + offset_in_page(vcpu->arch.apic->vapic_addr));

	kunmap_atomic(vapic, KM_USER0);



	apic_set_tpr(vcpu->arch.apic, data & 0xff);

}



void kvm_lapic_sync_to_vapic(struct kvm_vcpu *vcpu)

{

	u32 data, tpr;

	int max_irr, max_isr;

	struct kvm_lapic *apic;

	void *vapic;



	if (!irqchip_in_kernel(vcpu->kvm) || !vcpu->arch.apic->vapic_addr)

		return;



	apic = vcpu->arch.apic;

	tpr = apic_get_reg(apic, APIC_TASKPRI) & 0xff;

	max_irr = apic_find_highest_irr(apic);

	if (max_irr < 0)

		max_irr = 0;

	max_isr = apic_find_highest_isr(apic);

	if (max_isr < 0)

		max_isr = 0;

	data = (tpr & 0xff) | ((max_isr & 0xf0) << 8) | (max_irr << 24);



	vapic = kmap_atomic(vcpu->arch.apic->vapic_page, KM_USER0);

	*(u32 *)(vapic + offset_in_page(vcpu->arch.apic->vapic_addr)) = data;

	kunmap_atomic(vapic, KM_USER0);

}



void kvm_lapic_set_vapic_addr(struct kvm_vcpu *vcpu, gpa_t vapic_addr)

{

	if (!irqchip_in_kernel(vcpu->kvm))

		return;



	vcpu->arch.apic->vapic_addr = vapic_addr;

}

arch/x86/kvm/lapic.h

+6 −0
Original line number Original line Diff line number Diff line
@@ -18,6 +18,8 @@ struct kvm_lapic { 
	struct kvm_vcpu *vcpu;

	struct kvm_vcpu *vcpu;

	struct page *regs_page;

	struct page *regs_page;

	void *regs;

	void *regs;

	gpa_t vapic_addr;

	struct page *vapic_page;

};

};

int kvm_create_lapic(struct kvm_vcpu *vcpu);

int kvm_create_lapic(struct kvm_vcpu *vcpu);

void kvm_free_lapic(struct kvm_vcpu *vcpu);

void kvm_free_lapic(struct kvm_vcpu *vcpu);
@@ -41,4 +43,8 @@ int kvm_lapic_enabled(struct kvm_vcpu *vcpu); 
int kvm_lapic_find_highest_irr(struct kvm_vcpu *vcpu);

int kvm_lapic_find_highest_irr(struct kvm_vcpu *vcpu);

void kvm_apic_timer_intr_post(struct kvm_vcpu *vcpu, int vec);

void kvm_apic_timer_intr_post(struct kvm_vcpu *vcpu, int vec);





void kvm_lapic_set_vapic_addr(struct kvm_vcpu *vcpu, gpa_t vapic_addr);

void kvm_lapic_sync_from_vapic(struct kvm_vcpu *vcpu);

void kvm_lapic_sync_to_vapic(struct kvm_vcpu *vcpu);



#endif
 
#endif

arch/x86/kvm/x86.c

+55 −0
Original line number Original line Diff line number Diff line
@@ -1173,6 +1173,19 @@ long kvm_arch_vcpu_ioctl(struct file *filp, 
		r = 0;

		r = 0;

		break;

		break;

	};

	};

	case KVM_SET_VAPIC_ADDR: {

		struct kvm_vapic_addr va;



		r = -EINVAL;

		if (!irqchip_in_kernel(vcpu->kvm))

			goto out;

		r = -EFAULT;

		if (copy_from_user(&va, argp, sizeof va))

			goto out;

		r = 0;

		kvm_lapic_set_vapic_addr(vcpu, va.vapic_addr);

		break;

	}

	default:

	default:

		r = -EINVAL;

		r = -EINVAL;

	}

	}
@@ -2214,6 +2227,9 @@ int kvm_emulate_hypercall(struct kvm_vcpu *vcpu) 
	}

	}





	switch (nr) {

	switch (nr) {

	case KVM_HC_VAPIC_POLL_IRQ:

		ret = 0;

		break;

	default:

	default:

		ret = -KVM_ENOSYS;

		ret = -KVM_ENOSYS;

		break;

		break;
@@ -2421,6 +2437,29 @@ static void post_kvm_run_save(struct kvm_vcpu *vcpu, 
					 vcpu->arch.irq_summary == 0);

					 vcpu->arch.irq_summary == 0);

}

}





static void vapic_enter(struct kvm_vcpu *vcpu)

{

	struct kvm_lapic *apic = vcpu->arch.apic;

	struct page *page;



	if (!apic || !apic->vapic_addr)

		return;



	page = gfn_to_page(vcpu->kvm, apic->vapic_addr >> PAGE_SHIFT);

	vcpu->arch.apic->vapic_page = page;

}



static void vapic_exit(struct kvm_vcpu *vcpu)

{

	struct kvm_lapic *apic = vcpu->arch.apic;



	if (!apic || !apic->vapic_addr)

		return;



	kvm_release_page_dirty(apic->vapic_page);

	mark_page_dirty(vcpu->kvm, apic->vapic_addr >> PAGE_SHIFT);

}



static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)

static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)

{

{

	int r;

	int r;
@@ -2435,6 +2474,8 @@ static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
		vcpu->arch.mp_state = VCPU_MP_STATE_RUNNABLE;

		vcpu->arch.mp_state = VCPU_MP_STATE_RUNNABLE;

	}

	}





	vapic_enter(vcpu);



preempted:

preempted:

	if (vcpu->guest_debug.enabled)

	if (vcpu->guest_debug.enabled)

		kvm_x86_ops->guest_debug_pre(vcpu);

		kvm_x86_ops->guest_debug_pre(vcpu);
@@ -2444,6 +2485,14 @@ static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	if (unlikely(r))

	if (unlikely(r))

		goto out;

		goto out;





	if (vcpu->requests)

		if (test_and_clear_bit(KVM_REQ_REPORT_TPR_ACCESS,

				       &vcpu->requests)) {

			kvm_run->exit_reason = KVM_EXIT_TPR_ACCESS;

			r = 0;

			goto out;

		}



	kvm_inject_pending_timer_irqs(vcpu);

	kvm_inject_pending_timer_irqs(vcpu);





	preempt_disable();

	preempt_disable();
@@ -2469,6 +2518,8 @@ static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	else

	else

		kvm_x86_ops->inject_pending_vectors(vcpu, kvm_run);

		kvm_x86_ops->inject_pending_vectors(vcpu, kvm_run);





	kvm_lapic_sync_to_vapic(vcpu);



	vcpu->guest_mode = 1;

	vcpu->guest_mode = 1;

	kvm_guest_enter();

	kvm_guest_enter();
@@ -2506,6 +2557,8 @@ static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 
	if (vcpu->arch.exception.pending && kvm_x86_ops->exception_injected(vcpu))

	if (vcpu->arch.exception.pending && kvm_x86_ops->exception_injected(vcpu))

		vcpu->arch.exception.pending = false;

		vcpu->arch.exception.pending = false;





	kvm_lapic_sync_from_vapic(vcpu);



	r = kvm_x86_ops->handle_exit(kvm_run, vcpu);

	r = kvm_x86_ops->handle_exit(kvm_run, vcpu);





	if (r > 0) {

	if (r > 0) {
@@ -2527,6 +2580,8 @@ static int __vcpu_run(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run) 




	post_kvm_run_save(vcpu, kvm_run);

	post_kvm_run_save(vcpu, kvm_run);





	vapic_exit(vcpu);



	return r;

	return r;

}

}

include/linux/kvm.h

+7 −0
Original line number Original line Diff line number Diff line
@@ -216,6 +216,11 @@ struct kvm_tpr_access_ctl { 
	__u32 reserved[8];

	__u32 reserved[8];

};

};





/* for KVM_SET_VAPIC_ADDR */

struct kvm_vapic_addr {

	__u64 vapic_addr;

};



#define KVMIO 0xAE

#define KVMIO 0xAE





/*

/*
@@ -291,5 +296,7 @@ struct kvm_tpr_access_ctl { 
#define KVM_GET_CPUID2            _IOWR(KVMIO, 0x91, struct kvm_cpuid2)

#define KVM_GET_CPUID2            _IOWR(KVMIO, 0x91, struct kvm_cpuid2)

/* Available with KVM_CAP_VAPIC */

/* Available with KVM_CAP_VAPIC */

#define KVM_TPR_ACCESS_REPORTING  _IOWR(KVMIO,  0x92, struct kvm_tpr_access_ctl)

#define KVM_TPR_ACCESS_REPORTING  _IOWR(KVMIO,  0x92, struct kvm_tpr_access_ctl)

/* Available with KVM_CAP_VAPIC */

#define KVM_SET_VAPIC_ADDR        _IOW(KVMIO,  0x93, struct kvm_vapic_addr)





#endif
 
#endif

include/linux/kvm_para.h

+2 −0
Original line number Original line Diff line number Diff line
@@ -12,6 +12,8 @@ 
/* Return values for hypercalls */

/* Return values for hypercalls */

#define KVM_ENOSYS		1000

#define KVM_ENOSYS		1000





#define KVM_HC_VAPIC_POLL_IRQ            1



#ifdef __KERNEL__

#ifdef __KERNEL__

/*

/*

 * hypercalls use architecture specific

 * hypercalls use architecture specific