This patch tries to make sure the virtio interrupt handler for INTX
won't be called after a reset and before virtio_device_ready(). We
can't use IRQF_NO_AUTOEN since we're using shared interrupt
(IRQF_SHARED). So this patch tracks the INTX enabling status in a new
intx_soft_enabled variable and toggle it during in
vp_disable/enable_vectors(). The INTX interrupt handler will check
intx_soft_enabled before processing the actual interrupt.
Signed-off-by: Jason Wang <jasowang@xxxxxxxxxx>
---
drivers/virtio/virtio_pci_common.c | 18 ++++++++++++++++--
drivers/virtio/virtio_pci_common.h | 1 +
2 files changed, 17 insertions(+), 2 deletions(-)
diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index 0b9523e6dd39..835197151dc1 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -30,8 +30,12 @@ void vp_disable_vectors(struct virtio_device *vdev)
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
int i;
- if (vp_dev->intx_enabled)
+ if (vp_dev->intx_enabled) {
+ vp_dev->intx_soft_enabled = false;
+ /* ensure the vp_interrupt see this intx_soft_enabled value */
+ smp_wmb();
synchronize_irq(vp_dev->pci_dev->irq);
+ }
for (i = 0; i < vp_dev->msix_vectors; ++i)
disable_irq(pci_irq_vector(vp_dev->pci_dev, i));
@@ -43,8 +47,12 @@ void vp_enable_vectors(struct virtio_device *vdev)
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
int i;
- if (vp_dev->intx_enabled)
+ if (vp_dev->intx_enabled) {
+ vp_dev->intx_soft_enabled = true;
+ /* ensure the vp_interrupt see this intx_soft_enabled value */
+ smp_wmb();
return;
+ }
for (i = 0; i < vp_dev->msix_vectors; ++i)
enable_irq(pci_irq_vector(vp_dev->pci_dev, i));
@@ -97,6 +105,12 @@ static irqreturn_t vp_interrupt(int irq, void *opaque)
struct virtio_pci_device *vp_dev = opaque;
u8 isr;
+ if (!vp_dev->intx_soft_enabled)
+ return IRQ_NONE;
+
+ /* read intx_soft_enabled before read others */
+ smp_rmb();
+
/* reading the ISR has the effect of also clearing it so it's very
* important to save off the value. */
isr = ioread8(vp_dev->isr);
diff --git a/drivers/virtio/virtio_pci_common.h b/drivers/virtio/virtio_pci_common.h
index a235ce9ff6a5..3c06e0f92ee4 100644
--- a/drivers/virtio/virtio_pci_common.h
+++ b/drivers/virtio/virtio_pci_common.h
@@ -64,6 +64,7 @@ struct virtio_pci_device {
/* MSI-X support */
int msix_enabled;
int intx_enabled;
+ bool intx_soft_enabled;
cpumask_var_t *msix_affinity_masks;
/* Name strings for interrupts. This size should be enough,
* and I'm too lazy to allocate each name separately. */
--
2.25.1
_______________________________________________
Virtualization mailing list
Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx
https://lists.linuxfoundation.org/mailman/listinfo/virtualization
