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Commit 50a085bd authored by Jan Kiszka's avatar Jan Kiszka Committed by Avi Kivity
Browse files

KVM: x86: Kick VCPU outside PIC lock again 



This restores the deferred VCPU kicking before 956f97cf. We need this
over -rt as wake_up* requires non-atomic context in this configuration.

Signed-off-by: default avatarJan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: default avatarAvi Kivity <avi@redhat.com>
parent a595405d

arch/x86/kvm/i8259.c

+38 −15
Original line number Diff line number Diff line
@@ -33,6 +33,29 @@ 
#include <linux/kvm_host.h>

#include "trace.h"



static void pic_lock(struct kvm_pic *s)

	__acquires(&s->lock)

{

	raw_spin_lock(&s->lock);

}



static void pic_unlock(struct kvm_pic *s)

	__releases(&s->lock)

{

	bool wakeup = s->wakeup_needed;

	struct kvm_vcpu *vcpu;



	s->wakeup_needed = false;



	raw_spin_unlock(&s->lock);



	if (wakeup) {

		vcpu = s->kvm->bsp_vcpu;

		if (vcpu)

			kvm_vcpu_kick(vcpu);

	}

}



static void pic_clear_isr(struct kvm_kpic_state *s, int irq)

{

	s->isr &= ~(1 << irq);
@@ -45,19 +68,19 @@ static void pic_clear_isr(struct kvm_kpic_state *s, int irq) 
	 * Other interrupt may be delivered to PIC while lock is dropped but

	 * it should be safe since PIC state is already updated at this stage.

	 */

	raw_spin_unlock(&s->pics_state->lock);

	pic_unlock(s->pics_state);

	kvm_notify_acked_irq(s->pics_state->kvm, SELECT_PIC(irq), irq);

	raw_spin_lock(&s->pics_state->lock);

	pic_lock(s->pics_state);

}



void kvm_pic_clear_isr_ack(struct kvm *kvm)

{

	struct kvm_pic *s = pic_irqchip(kvm);



	raw_spin_lock(&s->lock);

	pic_lock(s);

	s->pics[0].isr_ack = 0xff;

	s->pics[1].isr_ack = 0xff;

	raw_spin_unlock(&s->lock);

	pic_unlock(s);

}



/*
@@ -158,9 +181,9 @@ static void pic_update_irq(struct kvm_pic *s) 


void kvm_pic_update_irq(struct kvm_pic *s)

{

	raw_spin_lock(&s->lock);

	pic_lock(s);

	pic_update_irq(s);

	raw_spin_unlock(&s->lock);

	pic_unlock(s);

}



int kvm_pic_set_irq(void *opaque, int irq, int level)
@@ -168,14 +191,14 @@ int kvm_pic_set_irq(void *opaque, int irq, int level) 
	struct kvm_pic *s = opaque;

	int ret = -1;



	raw_spin_lock(&s->lock);

	pic_lock(s);

	if (irq >= 0 && irq < PIC_NUM_PINS) {

		ret = pic_set_irq1(&s->pics[irq >> 3], irq & 7, level);

		pic_update_irq(s);

		trace_kvm_pic_set_irq(irq >> 3, irq & 7, s->pics[irq >> 3].elcr,

				      s->pics[irq >> 3].imr, ret == 0);

	}

	raw_spin_unlock(&s->lock);

	pic_unlock(s);



	return ret;

}
@@ -205,7 +228,7 @@ int kvm_pic_read_irq(struct kvm *kvm) 
	int irq, irq2, intno;

	struct kvm_pic *s = pic_irqchip(kvm);



	raw_spin_lock(&s->lock);

	pic_lock(s);

	irq = pic_get_irq(&s->pics[0]);

	if (irq >= 0) {

		pic_intack(&s->pics[0], irq);
@@ -230,7 +253,7 @@ int kvm_pic_read_irq(struct kvm *kvm) 
		intno = s->pics[0].irq_base + irq;

	}

	pic_update_irq(s);

	raw_spin_unlock(&s->lock);

	pic_unlock(s);



	return intno;

}
@@ -444,7 +467,7 @@ static int picdev_write(struct kvm_io_device *this, 
			printk(KERN_ERR "PIC: non byte write\n");

		return 0;

	}

	raw_spin_lock(&s->lock);

	pic_lock(s);

	switch (addr) {

	case 0x20:

	case 0x21:
@@ -457,7 +480,7 @@ static int picdev_write(struct kvm_io_device *this, 
		elcr_ioport_write(&s->pics[addr & 1], addr, data);

		break;

	}

	raw_spin_unlock(&s->lock);

	pic_unlock(s);

	return 0;

}
@@ -474,7 +497,7 @@ static int picdev_read(struct kvm_io_device *this, 
			printk(KERN_ERR "PIC: non byte read\n");

		return 0;

	}

	raw_spin_lock(&s->lock);

	pic_lock(s);

	switch (addr) {

	case 0x20:

	case 0x21:
@@ -488,7 +511,7 @@ static int picdev_read(struct kvm_io_device *this, 
		break;

	}

	*(unsigned char *)val = data;

	raw_spin_unlock(&s->lock);

	pic_unlock(s);

	return 0;

}
@@ -505,7 +528,7 @@ static void pic_irq_request(void *opaque, int level) 
	s->output = level;

	if (vcpu && level && (s->pics[0].isr_ack & (1 << irq))) {

		s->pics[0].isr_ack &= ~(1 << irq);

		kvm_vcpu_kick(vcpu);

		s->wakeup_needed = true;

	}

}

arch/x86/kvm/irq.h

+1 −0
Original line number Diff line number Diff line
@@ -63,6 +63,7 @@ struct kvm_kpic_state { 


struct kvm_pic {

	raw_spinlock_t lock;

	bool wakeup_needed;

	unsigned pending_acks;

	struct kvm *kvm;

	struct kvm_kpic_state pics[2]; /* 0 is master pic, 1 is slave pic */