Skip to contentSkip to conversation

iosignalfd

PATCH Superseded Gregory Haskins 1 participant 3 messages May 21, 2009

Subsystems (4)
x86 VFS KVM KVM x86

v3 of 10 Superseded Latest is v10 →

lore
Share & tools
lore

Gregory Haskins

author
#0 lore raw

v3 cover iosignalfd

(Applies to kvm.git/master:7391a6d5)

This is v3 of the series. For more details, please see the header to patch 4/4.

This series has been tested against the kvm-eventfd unit test, and appears to be functioning properly. You can download this test here:

ftp://ftp.novell.com/dev/ghaskins/kvm-eventfd.tar.bz2

(Note that the test released with irqfd had a bug in it that prevented iosignalfd from working properly. The tarball has been updated with the fix)

This series is ready to be considered for inclusion, pending any further review comments.

[
Changelog:

v3:
*) fixed patch 2/4 to handle error cases instead of BUG_ON *) implemented same HAVE_EVENTFD protection mechanism as
irqfd to prevent compilation errors on unsupported arches
*) completed testing
*) rebased to kvm.git/master:7391a6d5

v2:
*) added optional data-matching capability (via cookie field) *) changed name from iofd to iosignalfd
*) added io_bus unregister function
*) implemented deassign feature

v1:
*) original release (integrated into irqfd v7 series as "iofd")
]

---

Gregory Haskins (4):
kvm: add iosignalfd support
kvm: add io_bus unregister function
kvm: add return value to kvm_io_bus_register_dev
eventfd: export eventfd interfaces for module use

 arch/x86/kvm/i8254.c      |   27 +++++--
 arch/x86/kvm/i8259.c      |    9 ++
 arch/x86/kvm/x86.c        |    1 
 fs/eventfd.c              |    3 +
 include/linux/kvm.h       |   15 ++++
 include/linux/kvm_host.h  |   18 ++++-
 virt/kvm/coalesced_mmio.c |    8 ++
 virt/kvm/eventfd.c        |  165 +++++++++++++++++++++++++++++++++++++++++++++
 virt/kvm/ioapic.c         |    9 ++
 virt/kvm/kvm_main.c       |   60 ++++++++++++++--
 10 files changed, 286 insertions(+), 29 deletions(-)
Signature · 1 line
Signature
author
#1 lore raw

PATCH v3 1/4 eventfd: export eventfd interfaces for module use

We want to use eventfd from KVM which can be compiled as a module, so export the interfaces.

Signed-off-by Gregory Haskins <[email protected]>

---

 fs/eventfd.c |    3 +++
 1 files changed, 3 insertions(+), 0 deletions(-)
fs/eventfd.c +3 -0
index 2a701d5..3f0e197 100644
@@ -16,6 +16,7 @@
 #include <linux/anon_inodes.h>
 #include <linux/eventfd.h>
 #include <linux/syscalls.h>
+#include <linux/module.h>
 
 struct eventfd_ctx {
 	wait_queue_head_t wqh;

@@ -56,6 +57,7 @@ int eventfd_signal(struct file *file, int n)
 
 	return n;
 }
+EXPORT_SYMBOL_GPL(eventfd_signal);
 
 static int eventfd_release(struct inode *inode, struct file *file)
 {

@@ -197,6 +199,7 @@ struct file *eventfd_fget(int fd)
 
 	return file;
 }
+EXPORT_SYMBOL_GPL(eventfd_fget);
 
 SYSCALL_DEFINE2(eventfd2, unsigned int, count, int, flags)
 {
author
#2 lore raw

PATCH v3 2/4 kvm: add return value to kvm_io_bus_register_dev

In reply to Gregory Haskins

Today this function returns void and will internally BUG_ON if it fails. We want to create dynamic MMIO/PIO entries driven from userspace later in the series, so enhance this API to return an error code on failure.

We also fix up all the callsites to check the return code, handle any failures, and percolate the error up to the caller.

Signed-off-by Gregory Haskins <[email protected]>

---

 arch/x86/kvm/i8254.c      |   27 +++++++++++++++++----------
 arch/x86/kvm/i8259.c      |    9 ++++++++-
 include/linux/kvm_host.h  |    4 ++--
 virt/kvm/coalesced_mmio.c |    8 ++++++--
 virt/kvm/ioapic.c         |    9 +++++++--
 virt/kvm/kvm_main.c       |    7 +++++--
 6 files changed, 45 insertions(+), 19 deletions(-)
arch/x86/kvm/i8254.c +17 -10
index 4d6f0d2..3ef8b1b 100644
@@ -564,33 +564,36 @@ struct kvm_pit *kvm_create_pit(struct kvm *kvm)
 {
 	struct kvm_pit *pit;
 	struct kvm_kpit_state *pit_state;
+	int ret;
 
 	pit = kzalloc(sizeof(struct kvm_pit), GFP_KERNEL);
 	if (!pit)
 		return NULL;
 
 	pit->irq_source_id = kvm_request_irq_source_id(kvm);
-	if (pit->irq_source_id < 0) {
-		kfree(pit);
-		return NULL;
-	}
-
-	mutex_init(&pit->pit_state.lock);
-	mutex_lock(&pit->pit_state.lock);
-	spin_lock_init(&pit->pit_state.inject_lock);
+	if (pit->irq_source_id < 0)
+		goto fail;
 
 	/* Initialize PIO device */
 	pit->dev.read = pit_ioport_read;
 	pit->dev.write = pit_ioport_write;
 	pit->dev.in_range = pit_in_range;
 	pit->dev.private = pit;
-	kvm_io_bus_register_dev(&kvm->pio_bus, &pit->dev);
+	ret = kvm_io_bus_register_dev(&kvm->pio_bus, &pit->dev);
+	if (ret < 0)
+		goto fail;
 
 	pit->speaker_dev.read = speaker_ioport_read;
 	pit->speaker_dev.write = speaker_ioport_write;
 	pit->speaker_dev.in_range = speaker_in_range;
 	pit->speaker_dev.private = pit;
-	kvm_io_bus_register_dev(&kvm->pio_bus, &pit->speaker_dev);
+	ret = kvm_io_bus_register_dev(&kvm->pio_bus, &pit->speaker_dev);
+	if (ret < 0)
+		goto fail;
+
+	mutex_init(&pit->pit_state.lock);
+	mutex_lock(&pit->pit_state.lock);
+	spin_lock_init(&pit->pit_state.inject_lock);
 
 	kvm->arch.vpit = pit;
 	pit->kvm = kvm;

@@ -611,6 +614,10 @@ struct kvm_pit *kvm_create_pit(struct kvm *kvm)
 	kvm_register_irq_mask_notifier(kvm, 0, &pit->mask_notifier);
 
 	return pit;
+
+fail:
+	kfree(pit);
+	return NULL;
 }
 
 void kvm_free_pit(struct kvm *kvm)
arch/x86/kvm/i8259.c +8 -1
index 1ccb50c..0caf7d4 100644
@@ -519,6 +519,8 @@ static void pic_irq_request(void *opaque, int level)
 struct kvm_pic *kvm_create_pic(struct kvm *kvm)
 {
 	struct kvm_pic *s;
+	int ret;
+
 	s = kzalloc(sizeof(struct kvm_pic), GFP_KERNEL);
 	if (!s)
 		return NULL;

@@ -538,6 +540,11 @@ struct kvm_pic *kvm_create_pic(struct kvm *kvm)
 	s->dev.write = picdev_write;
 	s->dev.in_range = picdev_in_range;
 	s->dev.private = s;
-	kvm_io_bus_register_dev(&kvm->pio_bus, &s->dev);
+	ret = kvm_io_bus_register_dev(&kvm->pio_bus, &s->dev);
+	if (ret < 0) {
+		kfree(s);
+		return NULL;
+	}
+
 	return s;
 }
include/linux/kvm_host.h +2 -2
index 28bd112..5289552 100644
@@ -61,8 +61,8 @@ void kvm_io_bus_init(struct kvm_io_bus *bus);
 void kvm_io_bus_destroy(struct kvm_io_bus *bus);
 struct kvm_io_device *kvm_io_bus_find_dev(struct kvm_io_bus *bus,
 					  gpa_t addr, int len, int is_write);
-void kvm_io_bus_register_dev(struct kvm_io_bus *bus,
-			     struct kvm_io_device *dev);
+int kvm_io_bus_register_dev(struct kvm_io_bus *bus,
+			    struct kvm_io_device *dev);
 
 struct kvm_vcpu {
 	struct kvm *kvm;
virt/kvm/coalesced_mmio.c +6 -2
index 5ae620d..ede9087 100644
@@ -86,6 +86,7 @@ static void coalesced_mmio_destructor(struct kvm_io_device *this)
 int kvm_coalesced_mmio_init(struct kvm *kvm)
 {
 	struct kvm_coalesced_mmio_dev *dev;
+	int ret;
 
 	dev = kzalloc(sizeof(struct kvm_coalesced_mmio_dev), GFP_KERNEL);
 	if (!dev)

@@ -96,9 +97,12 @@ int kvm_coalesced_mmio_init(struct kvm *kvm)
 	dev->dev.private  = dev;
 	dev->kvm = kvm;
 	kvm->coalesced_mmio_dev = dev;
-	kvm_io_bus_register_dev(&kvm->mmio_bus, &dev->dev);
 
-	return 0;
+	ret = kvm_io_bus_register_dev(&kvm->mmio_bus, &dev->dev);
+	if (ret < 0)
+		kfree(dev);
+
+	return ret;
 }
 
 int kvm_vm_ioctl_register_coalesced_mmio(struct kvm *kvm,
virt/kvm/ioapic.c +7 -2
index 1eddae9..9be89f5 100644
@@ -317,6 +317,7 @@ void kvm_ioapic_reset(struct kvm_ioapic *ioapic)
 int kvm_ioapic_init(struct kvm *kvm)
 {
 	struct kvm_ioapic *ioapic;
+	int ret;
 
 	ioapic = kzalloc(sizeof(struct kvm_ioapic), GFP_KERNEL);
 	if (!ioapic)

@@ -328,7 +329,11 @@ int kvm_ioapic_init(struct kvm *kvm)
 	ioapic->dev.in_range = ioapic_in_range;
 	ioapic->dev.private = ioapic;
 	ioapic->kvm = kvm;
-	kvm_io_bus_register_dev(&kvm->mmio_bus, &ioapic->dev);
-	return 0;
+
+	ret = kvm_io_bus_register_dev(&kvm->mmio_bus, &ioapic->dev);
+	if (ret < 0)
+		kfree(ioapic);
+
+	return ret;
 }
virt/kvm/kvm_main.c +5 -2
index de042cb..c71f276 100644
@@ -2463,11 +2463,14 @@ struct kvm_io_device *kvm_io_bus_find_dev(struct kvm_io_bus *bus,
 	return NULL;
 }
 
-void kvm_io_bus_register_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev)
+int kvm_io_bus_register_dev(struct kvm_io_bus *bus, struct kvm_io_device *dev)
 {
-	BUG_ON(bus->dev_count > (NR_IOBUS_DEVS-1));
+	if (bus->dev_count > (NR_IOBUS_DEVS-1))
+		return -ENOSPC;
 
 	bus->devs[bus->dev_count++] = dev;
+
+	return 0;
 }
 
 static struct notifier_block kvm_cpu_notifier = {