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: Jan Kiszka <jan.kiszka@siemens.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index a790fa1..93825ff 100644 (file)
--- 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 (file)
--- 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 */