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authorJason Wang <jasowang@redhat.com>2021-10-19 15:01:46 +0800
committerMichael S. Tsirkin <mst@redhat.com>2021-11-01 05:26:48 -0400
commit9e35276a5344f74d4a3600fc4100b3dd251d5c56 (patch)
treefef437132497b7a4dcf7ff1e8e4ebbbb0da23f43
parentd50497eb4e554e1f0351e1836ee7241c059592e6 (diff)
virtio_pci: harden MSI-X interrupts
We used to synchronize pending MSI-X irq handlers via synchronize_irq(), this may not work for the untrusted device which may keep sending interrupts after reset which may lead unexpected results. Similarly, we should not enable MSI-X interrupt until the device is ready. So this patch fixes those two issues by: 1) switching to use disable_irq() to prevent the virtio interrupt handlers to be called after the device is reset. 2) using IRQF_NO_AUTOEN and enable the MSI-X irq during .ready() This can make sure the virtio interrupt handler won't be called before virtio_device_ready() and after reset. Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Paul E. McKenney <paulmck@kernel.org> Signed-off-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20211019070152.8236-5-jasowang@redhat.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
-rw-r--r--drivers/virtio/virtio_pci_common.c27
-rw-r--r--drivers/virtio/virtio_pci_common.h6
-rw-r--r--drivers/virtio/virtio_pci_legacy.c5
-rw-r--r--drivers/virtio/virtio_pci_modern.c6
4 files changed, 32 insertions, 12 deletions
diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index d724f676608b..3f51fdb7be45 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -24,8 +24,8 @@ MODULE_PARM_DESC(force_legacy,
"Force legacy mode for transitional virtio 1 devices");
#endif
-/* wait for pending irq handlers */
-void vp_synchronize_vectors(struct virtio_device *vdev)
+/* disable irq handlers */
+void vp_disable_cbs(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
int i;
@@ -34,7 +34,20 @@ void vp_synchronize_vectors(struct virtio_device *vdev)
synchronize_irq(vp_dev->pci_dev->irq);
for (i = 0; i < vp_dev->msix_vectors; ++i)
- synchronize_irq(pci_irq_vector(vp_dev->pci_dev, i));
+ disable_irq(pci_irq_vector(vp_dev->pci_dev, i));
+}
+
+/* enable irq handlers */
+void vp_enable_cbs(struct virtio_device *vdev)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ int i;
+
+ if (vp_dev->intx_enabled)
+ return;
+
+ for (i = 0; i < vp_dev->msix_vectors; ++i)
+ enable_irq(pci_irq_vector(vp_dev->pci_dev, i));
}
/* the notify function used when creating a virt queue */
@@ -141,7 +154,8 @@ static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
"%s-config", name);
err = request_irq(pci_irq_vector(vp_dev->pci_dev, v),
- vp_config_changed, 0, vp_dev->msix_names[v],
+ vp_config_changed, IRQF_NO_AUTOEN,
+ vp_dev->msix_names[v],
vp_dev);
if (err)
goto error;
@@ -160,7 +174,8 @@ static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
"%s-virtqueues", name);
err = request_irq(pci_irq_vector(vp_dev->pci_dev, v),
- vp_vring_interrupt, 0, vp_dev->msix_names[v],
+ vp_vring_interrupt, IRQF_NO_AUTOEN,
+ vp_dev->msix_names[v],
vp_dev);
if (err)
goto error;
@@ -337,7 +352,7 @@ static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs,
"%s-%s",
dev_name(&vp_dev->vdev.dev), names[i]);
err = request_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec),
- vring_interrupt, 0,
+ vring_interrupt, IRQF_NO_AUTOEN,
vp_dev->msix_names[msix_vec],
vqs[i]);
if (err)
diff --git a/drivers/virtio/virtio_pci_common.h b/drivers/virtio/virtio_pci_common.h
index eb17a29fc7ef..d3c6f72c7390 100644
--- a/drivers/virtio/virtio_pci_common.h
+++ b/drivers/virtio/virtio_pci_common.h
@@ -101,8 +101,10 @@ static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
return container_of(vdev, struct virtio_pci_device, vdev);
}
-/* wait for pending irq handlers */
-void vp_synchronize_vectors(struct virtio_device *vdev);
+/* disable irq handlers */
+void vp_disable_cbs(struct virtio_device *vdev);
+/* enable irq handlers */
+void vp_enable_cbs(struct virtio_device *vdev);
/* the notify function used when creating a virt queue */
bool vp_notify(struct virtqueue *vq);
/* the config->del_vqs() implementation */
diff --git a/drivers/virtio/virtio_pci_legacy.c b/drivers/virtio/virtio_pci_legacy.c
index 82eb437ad920..b3f8128b7983 100644
--- a/drivers/virtio/virtio_pci_legacy.c
+++ b/drivers/virtio/virtio_pci_legacy.c
@@ -98,8 +98,8 @@ static void vp_reset(struct virtio_device *vdev)
/* Flush out the status write, and flush in device writes,
* including MSi-X interrupts, if any. */
vp_legacy_get_status(&vp_dev->ldev);
- /* Flush pending VQ/configuration callbacks. */
- vp_synchronize_vectors(vdev);
+ /* Disable VQ/configuration callbacks. */
+ vp_disable_cbs(vdev);
}
static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
@@ -185,6 +185,7 @@ static void del_vq(struct virtio_pci_vq_info *info)
}
static const struct virtio_config_ops virtio_pci_config_ops = {
+ .enable_cbs = vp_enable_cbs,
.get = vp_get,
.set = vp_set,
.get_status = vp_get_status,
diff --git a/drivers/virtio/virtio_pci_modern.c b/drivers/virtio/virtio_pci_modern.c
index 30654d3a0b41..5455bc041fb6 100644
--- a/drivers/virtio/virtio_pci_modern.c
+++ b/drivers/virtio/virtio_pci_modern.c
@@ -172,8 +172,8 @@ static void vp_reset(struct virtio_device *vdev)
*/
while (vp_modern_get_status(mdev))
msleep(1);
- /* Flush pending VQ/configuration callbacks. */
- vp_synchronize_vectors(vdev);
+ /* Disable VQ/configuration callbacks. */
+ vp_disable_cbs(vdev);
}
static u16 vp_config_vector(struct virtio_pci_device *vp_dev, u16 vector)
@@ -380,6 +380,7 @@ static bool vp_get_shm_region(struct virtio_device *vdev,
}
static const struct virtio_config_ops virtio_pci_config_nodev_ops = {
+ .enable_cbs = vp_enable_cbs,
.get = NULL,
.set = NULL,
.generation = vp_generation,
@@ -397,6 +398,7 @@ static const struct virtio_config_ops virtio_pci_config_nodev_ops = {
};
static const struct virtio_config_ops virtio_pci_config_ops = {
+ .enable_cbs = vp_enable_cbs,
.get = vp_get,
.set = vp_set,
.generation = vp_generation,