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From 5ce249cdb588645adffe5253f1d96bdadd2f4611 Mon Sep 17 00:00:00 2001
From: Jan Kiszka <jan.kiszka@siemens.com>
Date: Wed, 24 Feb 2010 10:41:58 +0100
Subject: [PATCH] KVM: x86: Kick VCPU outside PIC lock again
commit 8452259b8aefef73981b2ffbc23d5245d19bd140 in tip.
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: Jan Kiszka <jan.kiszka@siemens.com>
Cc: Avi Kivity <avi@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
LKML-Reference: <4B84F466.2080009@siemens.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: Paul Gortmaker <paul.gortmaker@windriver.com>
---
arch/x86/kvm/i8259.c | 53 +++++++++++++++++++++++++++++++++++--------------
arch/x86/kvm/irq.h | 1 +
2 files changed, 39 insertions(+), 15 deletions(-)
diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index a790fa1..93825ff 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -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;
}
}
diff --git a/arch/x86/kvm/irq.h b/arch/x86/kvm/irq.h
index 34b1591..cd1f362 100644
--- a/arch/x86/kvm/irq.h
+++ b/arch/x86/kvm/irq.h
@@ -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 */
--
1.7.0.4
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