virtio/pci: Use the correct eventfd for vhost notification
Legacy virtio drivers write to the I/O port BAR, and the modern virtio
device uses the MMIO BAR. Since vhost can only listen on one ioeventfd,
select the one that the guest will use.
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Link: https://lore.kernel.org/r/20220701142434.75170-5-jean-philippe.brucker@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
diff --git a/virtio/pci.c b/virtio/pci.c
index c02534a..320865c 100644
--- a/virtio/pci.c
+++ b/virtio/pci.c
@@ -83,7 +83,7 @@
u16 port_addr = virtio_pci__port_addr(vpci);
off_t offset = vpci->doorbell_offset;
int r, flags = 0;
- int fd;
+ int pio_fd, mmio_fd;
vpci->ioeventfds[vq] = (struct virtio_pci_ioevent_param) {
.vdev = vdev,
@@ -107,7 +107,7 @@
/* ioport */
ioevent.io_addr = port_addr + offset;
ioevent.io_len = sizeof(u16);
- ioevent.fd = fd = eventfd(0, 0);
+ ioevent.fd = pio_fd = eventfd(0, 0);
r = ioeventfd__add_event(&ioevent, flags | IOEVENTFD_FLAG_PIO);
if (r)
return r;
@@ -115,13 +115,14 @@
/* mmio */
ioevent.io_addr = mmio_addr + offset;
ioevent.io_len = sizeof(u16);
- ioevent.fd = eventfd(0, 0);
+ ioevent.fd = mmio_fd = eventfd(0, 0);
r = ioeventfd__add_event(&ioevent, flags);
if (r)
goto free_ioport_evt;
if (vdev->ops->notify_vq_eventfd)
- vdev->ops->notify_vq_eventfd(kvm, vpci->dev, vq, fd);
+ vdev->ops->notify_vq_eventfd(kvm, vpci->dev, vq,
+ vdev->legacy ? pio_fd : mmio_fd);
return 0;
free_ioport_evt:
