Introduce new function kvm_notifier_set_irq() that should be used
to change irq line level from irq notifiers. When irq notifier
change irq line level it calls into irq chip code recursively. The
function avoids taking a lock recursively.
Signed-off-by: Gleb Natapov <gleb@xxxxxxxxxx>
---
arch/ia64/kvm/kvm-ia64.c | 27 ++++++++++++++-----
arch/x86/include/asm/kvm_host.h | 2 +-
arch/x86/kvm/i8259.c | 8 +++--
arch/x86/kvm/lapic.c | 5 +---
arch/x86/kvm/x86.c | 30 ++++++++++++++-------
include/linux/kvm_host.h | 3 +-
virt/kvm/ioapic.c | 53 ++++++++++++++++++++++++--------------
virt/kvm/ioapic.h | 4 ++-
virt/kvm/irq_comm.c | 25 ++++++++++++++----
virt/kvm/kvm_main.c | 2 +-
10 files changed, 105 insertions(+), 54 deletions(-)
diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index 0ad09f0..dd7ef2d 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -850,9 +850,16 @@ static int kvm_vm_ioctl_get_irqchip(struct kvm *kvm,
r = 0;
switch (chip->chip_id) {
- case KVM_IRQCHIP_IOAPIC:
- memcpy(&chip->chip.ioapic, ioapic_irqchip(kvm),
- sizeof(struct kvm_ioapic_state));
+ case KVM_IRQCHIP_IOAPIC: {
+ struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
+ if (ioapic) {
+ spin_lock(&ioapic->lock);
+ memcpy(&chip->chip.ioapic, ioapic,
+ sizeof(struct kvm_ioapic_state));
+ spin_unlock(&ioapic->lock);
+ } else
+ r = -EINVAL;
+ }
break;
default:
r = -EINVAL;
@@ -867,10 +874,16 @@ static int kvm_vm_ioctl_set_irqchip(struct kvm *kvm, struct kvm_irqchip *chip)
r = 0;
switch (chip->chip_id) {
- case KVM_IRQCHIP_IOAPIC:
- memcpy(ioapic_irqchip(kvm),
- &chip->chip.ioapic,
- sizeof(struct kvm_ioapic_state));
+ case KVM_IRQCHIP_IOAPIC: {
+ struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
+ if (ioapic) {
+ spin_lock(&ioapic->lock);
+ memcpy(ioapic, &chip->chip.ioapic,
+ sizeof(struct kvm_ioapic_state));
+ spin_unlock(&ioapic->lock);
+ } else
+ r = -EINVAL;
+ }
break;
default:
r = -EINVAL;
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 7dfde38..09b2ef9 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -623,7 +623,7 @@ void kvm_queue_exception_e(struct kvm_vcpu *vcpu, unsigned nr, u32 error_code);
void kvm_inject_page_fault(struct kvm_vcpu *vcpu, unsigned long cr2,
u32 error_code);
-int kvm_pic_set_irq(void *opaque, int irq, int level);
+int kvm_pic_set_irq(void *opaque, int irq, int level, bool notifier);
void kvm_inject_nmi(struct kvm_vcpu *vcpu);
diff --git a/arch/x86/kvm/i8259.c b/arch/x86/kvm/i8259.c
index 01f1516..d579ff1 100644
--- a/arch/x86/kvm/i8259.c
+++ b/arch/x86/kvm/i8259.c
@@ -153,19 +153,21 @@ void kvm_pic_update_irq(struct kvm_pic *s)
spin_unlock(&s->lock);
}
-int kvm_pic_set_irq(void *opaque, int irq, int level)
+int kvm_pic_set_irq(void *opaque, int irq, int level, bool notifier)
{
struct kvm_pic *s = opaque;
int ret = -1;
- spin_lock(&s->lock);
+ if (!notifier)
+ spin_lock(&s->lock);
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);
}
- spin_unlock(&s->lock);
+ if (!notifier)
+ spin_unlock(&s->lock);
return ret;
}
diff --git a/arch/x86/kvm/lapic.c b/arch/x86/kvm/lapic.c
index ce195f8..f24d4d0 100644
--- a/arch/x86/kvm/lapic.c
+++ b/arch/x86/kvm/lapic.c
@@ -471,11 +471,8 @@ static void apic_set_eoi(struct kvm_lapic *apic)
trigger_mode = IOAPIC_LEVEL_TRIG;
else
trigger_mode = IOAPIC_EDGE_TRIG;
- if (!(apic_get_reg(apic, APIC_SPIV) & APIC_SPIV_DIRECTED_EOI)) {
- mutex_lock(&apic->vcpu->kvm->irq_lock);
+ if (!(apic_get_reg(apic, APIC_SPIV) & APIC_SPIV_DIRECTED_EOI))
kvm_ioapic_update_eoi(apic->vcpu->kvm, vector, trigger_mode);
- mutex_unlock(&apic->vcpu->kvm->irq_lock);
- }
}
static void apic_send_ipi(struct kvm_lapic *apic)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 5a69ad1..1ac1695 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -2022,10 +2022,16 @@ static int kvm_vm_ioctl_get_irqchip(struct kvm *kvm, struct kvm_irqchip *chip)
&pic_irqchip(kvm)->pics[1],
sizeof(struct kvm_pic_state));
break;
- case KVM_IRQCHIP_IOAPIC:
- memcpy(&chip->chip.ioapic,
- ioapic_irqchip(kvm),
- sizeof(struct kvm_ioapic_state));
+ case KVM_IRQCHIP_IOAPIC: {
+ struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
+ if (ioapic) {
+ spin_lock(&ioapic->lock);
+ memcpy(&chip->chip.ioapic, ioapic,
+ sizeof(struct kvm_ioapic_state));
+ spin_unlock(&ioapic->lock);
+ } else
+ r = -EINVAL;
+ }
break;
default:
r = -EINVAL;
@@ -2054,12 +2060,16 @@ static int kvm_vm_ioctl_set_irqchip(struct kvm *kvm, struct kvm_irqchip *chip)
sizeof(struct kvm_pic_state));
spin_unlock(&pic_irqchip(kvm)->lock);
break;
- case KVM_IRQCHIP_IOAPIC:
- mutex_lock(&kvm->irq_lock);
- memcpy(ioapic_irqchip(kvm),
- &chip->chip.ioapic,
- sizeof(struct kvm_ioapic_state));
- mutex_unlock(&kvm->irq_lock);
+ case KVM_IRQCHIP_IOAPIC: {
+ struct kvm_ioapic *ioapic = ioapic_irqchip(kvm);
+ if (ioapic) {
+ spin_lock(&ioapic->lock);
+ memcpy(ioapic, &chip->chip.ioapic,
+ sizeof(struct kvm_ioapic_state));
+ spin_unlock(&ioapic->lock);
+ } else
+ r = -EINVAL;
+ }
break;
default:
r = -EINVAL;
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 8791ce8..3610661 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -121,7 +121,7 @@ struct kvm_kernel_irq_routing_entry {
u32 gsi;
u32 type;
int (*set)(struct kvm_kernel_irq_routing_entry *e,
- struct kvm *kvm, int level);
+ struct kvm *kvm, int level, bool notifier);
union {
struct {
unsigned irqchip;
@@ -407,6 +407,7 @@ void kvm_get_intr_delivery_bitmask(struct kvm_ioapic *ioapic,
unsigned long *deliver_bitmask);
#endif
int kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level);
+int kvm_notifier_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level);
void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin);
void kvm_register_irq_ack_notifier(struct kvm *kvm,
struct kvm_irq_ack_notifier *kian);
diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
index fa05f67..5a74649 100644
--- a/virt/kvm/ioapic.c
+++ b/virt/kvm/ioapic.c
@@ -175,13 +175,17 @@ static int ioapic_deliver(struct kvm_ioapic *ioapic, int irq)
return kvm_irq_delivery_to_apic(ioapic->kvm, NULL, &irqe);
}
-int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level)
+int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level,
+ bool notifier)
{
u32 old_irr = ioapic->irr;
u32 mask = 1 << irq;
union kvm_ioapic_redirect_entry entry;
int ret = 1;
+ /* notifier may call ioapic recursively */
+ if (!notifier)
+ spin_lock(&ioapic->lock);
if (irq >= 0 && irq < IOAPIC_NUM_PINS) {
entry = ioapic->redirtbl[irq];
level ^= entry.fields.polarity;
@@ -196,34 +200,42 @@ int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level)
}
trace_kvm_ioapic_set_irq(entry.bits, irq, ret == 0);
}
+ if (!notifier)
+ spin_unlock(&ioapic->lock);
+
return ret;
}
-static void __kvm_ioapic_update_eoi(struct kvm_ioapic *ioapic, int pin,
- int trigger_mode)
+static void __kvm_ioapic_update_eoi(struct kvm_ioapic *ioapic, int vector,
+ int trigger_mode)
{
- union kvm_ioapic_redirect_entry *ent;
+ int i;
+
+ for (i = 0; i < IOAPIC_NUM_PINS; i++) {
+ union kvm_ioapic_redirect_entry *ent = &ioapic->redirtbl[i];
+
+ if (ent->fields.vector != vector)
+ continue;
- ent = &ioapic->redirtbl[pin];
+ kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, i);
- kvm_notify_acked_irq(ioapic->kvm, KVM_IRQCHIP_IOAPIC, pin);
+ if (trigger_mode != IOAPIC_LEVEL_TRIG)
+ continue;
- if (trigger_mode == IOAPIC_LEVEL_TRIG) {
ASSERT(ent->fields.trig_mode == IOAPIC_LEVEL_TRIG);
ent->fields.remote_irr = 0;
- if (!ent->fields.mask && (ioapic->irr & (1 << pin)))
- ioapic_service(ioapic, pin);
+ if (!ent->fields.mask && (ioapic->irr & (1 << i)))
+ ioapic_service(ioapic, i);
}
}
void kvm_ioapic_update_eoi(struct kvm *kvm, int vector, int trigger_mode)
{
struct kvm_ioapic *ioapic = kvm->arch.vioapic;
- int i;
- for (i = 0; i < IOAPIC_NUM_PINS; i++)
- if (ioapic->redirtbl[i].fields.vector == vector)
- __kvm_ioapic_update_eoi(ioapic, i, trigger_mode);
+ spin_lock(&ioapic->lock);
+ __kvm_ioapic_update_eoi(ioapic, vector, trigger_mode);
+ spin_unlock(&ioapic->lock);
}
static inline struct kvm_ioapic *to_ioapic(struct kvm_io_device *dev)
@@ -248,8 +260,8 @@ static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
ioapic_debug("addr %lx\n", (unsigned long)addr);
ASSERT(!(addr & 0xf)); /* check alignment */
- mutex_lock(&ioapic->kvm->irq_lock);
addr &= 0xff;
+ spin_lock(&ioapic->lock);
switch (addr) {
case IOAPIC_REG_SELECT:
result = ioapic->ioregsel;
@@ -263,6 +275,8 @@ static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
result = 0;
break;
}
+ spin_unlock(&ioapic->lock);
+
switch (len) {
case 8:
*(u64 *) val = result;
@@ -275,7 +289,6 @@ static int ioapic_mmio_read(struct kvm_io_device *this, gpa_t addr, int len,
default:
printk(KERN_WARNING "ioapic: wrong length %d\n", len);
}
- mutex_unlock(&ioapic->kvm->irq_lock);
return 0;
}
@@ -291,15 +304,15 @@ static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
(void*)addr, len, val);
ASSERT(!(addr & 0xf)); /* check alignment */
- mutex_lock(&ioapic->kvm->irq_lock);
if (len == 4 || len == 8)
data = *(u32 *) val;
else {
printk(KERN_WARNING "ioapic: Unsupported size %d\n", len);
- goto unlock;
+ return 0;
}
addr &= 0xff;
+ spin_lock(&ioapic->lock);
switch (addr) {
case IOAPIC_REG_SELECT:
ioapic->ioregsel = data;
@@ -310,15 +323,14 @@ static int ioapic_mmio_write(struct kvm_io_device *this, gpa_t addr, int len,
break;
#ifdef CONFIG_IA64
case IOAPIC_REG_EOI:
- kvm_ioapic_update_eoi(ioapic->kvm, data, IOAPIC_LEVEL_TRIG);
+ __kvm_ioapic_update_eoi(ioapic, data, IOAPIC_LEVEL_TRIG);
break;
#endif
default:
break;
}
-unlock:
- mutex_unlock(&ioapic->kvm->irq_lock);
+ spin_unlock(&ioapic->lock);
return 0;
}
@@ -347,6 +359,7 @@ int kvm_ioapic_init(struct kvm *kvm)
ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL);
if (!ioapic)
return -ENOMEM;
+ spin_lock_init(&ioapic->lock);
kvm->arch.vioapic = ioapic;
kvm_ioapic_reset(ioapic);
kvm_iodevice_init(&ioapic->dev, &ioapic_mmio_ops);
diff --git a/virt/kvm/ioapic.h b/virt/kvm/ioapic.h
index 7080b71..2cfa662 100644
--- a/virt/kvm/ioapic.h
+++ b/virt/kvm/ioapic.h
@@ -44,6 +44,7 @@ struct kvm_ioapic {
struct kvm_io_device dev;
struct kvm *kvm;
void (*ack_notifier)(void *opaque, int irq);
+ spinlock_t lock;
};
#ifdef DEBUG
@@ -69,7 +70,8 @@ int kvm_apic_match_dest(struct kvm_vcpu *vcpu, struct kvm_lapic *source,
int kvm_apic_compare_prio(struct kvm_vcpu *vcpu1, struct kvm_vcpu *vcpu2);
void kvm_ioapic_update_eoi(struct kvm *kvm, int vector, int trigger_mode);
int kvm_ioapic_init(struct kvm *kvm);
-int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level);
+int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int level,
+ bool notifier);
void kvm_ioapic_reset(struct kvm_ioapic *ioapic);
int kvm_irq_delivery_to_apic(struct kvm *kvm, struct kvm_lapic *src,
struct kvm_lapic_irq *irq);
diff --git a/virt/kvm/irq_comm.c b/virt/kvm/irq_comm.c
index 65f66f1..43ace95 100644
--- a/virt/kvm/irq_comm.c
+++ b/virt/kvm/irq_comm.c
@@ -32,19 +32,21 @@
#include "ioapic.h"
static int kvm_set_pic_irq(struct kvm_kernel_irq_routing_entry *e,
- struct kvm *kvm, int level)
+ struct kvm *kvm, int level, bool notifier)
{
#ifdef CONFIG_X86
- return kvm_pic_set_irq(pic_irqchip(kvm), e->irqchip.pin, level);
+ return kvm_pic_set_irq(pic_irqchip(kvm), e->irqchip.pin, level,
+ notifier);
#else
return -1;
#endif
}
static int kvm_set_ioapic_irq(struct kvm_kernel_irq_routing_entry *e,
- struct kvm *kvm, int level)
+ struct kvm *kvm, int level, bool notifier)
{
- return kvm_ioapic_set_irq(kvm->arch.vioapic, e->irqchip.pin, level);
+ return kvm_ioapic_set_irq(kvm->arch.vioapic, e->irqchip.pin, level,
+ notifier);
}
inline static bool kvm_is_dm_lowest_prio(struct kvm_lapic_irq *irq)
@@ -122,7 +124,8 @@ static int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
* = 0 Interrupt was coalesced (previous irq is still pending)
* > 0 Number of CPUs interrupt was delivered to
*/
-int kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level)
+static int __kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level,
+ bool notifier)
{
struct kvm_kernel_irq_routing_entry *e;
unsigned long *irq_state, sig_level;
@@ -156,7 +159,7 @@ int kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level)
irq_rt = rcu_dereference(kvm->irq_routing);
if (irq < irq_rt->max_gsi)
hlist_for_each_entry(e, n, &irq_rt->map[irq], link) {
- int r = e->set(e, kvm, sig_level);
+ int r = e->set(e, kvm, sig_level, notifier);
if (r < 0)
continue;
@@ -166,6 +169,16 @@ int kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level)
return ret;
}
+int kvm_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level)
+{
+ return __kvm_set_irq(kvm, irq_source_id, irq, level, 0);
+}
+
+int kvm_notifier_set_irq(struct kvm *kvm, int irq_source_id, int irq, int level)
+{
+ return __kvm_set_irq(kvm, irq_source_id, irq, level, 1);
+}
+
void kvm_notify_acked_irq(struct kvm *kvm, unsigned irqchip, unsigned pin)
{
struct kvm_irq_ack_notifier *kian;
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index c108edc..d8dc75c 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -198,7 +198,7 @@ static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
dev = container_of(kian, struct kvm_assigned_dev_kernel,
ack_notifier);
- kvm_set_irq(dev->kvm, dev->irq_source_id, dev->guest_irq, 0);
+ kvm_notifier_set_irq(dev->kvm, dev->irq_source_id, dev->guest_irq, 0);
/* The guest irq may be shared so this ack may be
* from another device.
--
1.6.3.3
--
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