ioeventfd: error handling cleanup

- Don't return status from start/stop functions where it's ignored
- report errors to make debugging easier
- assert on unexpected failures
- don't disable notifiers on error so that we'll
  retry when guest driver restarts

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
This commit is contained in:
Michael S. Tsirkin 2011-01-11 14:10:15 +02:00
parent 65d6dcbde8
commit b36e391441

View File

@ -195,12 +195,16 @@ static int virtio_pci_set_host_notifier_internal(VirtIOPCIProxy *proxy,
if (assign) {
r = event_notifier_init(notifier, 1);
if (r < 0) {
error_report("%s: unable to init event notifier: %d",
__func__, r);
return r;
}
r = kvm_set_ioeventfd_pio_word(event_notifier_get_fd(notifier),
proxy->addr + VIRTIO_PCI_QUEUE_NOTIFY,
n, assign);
if (r < 0) {
error_report("%s: unable to map ioeventfd: %d",
__func__, r);
event_notifier_cleanup(notifier);
}
} else {
@ -208,6 +212,8 @@ static int virtio_pci_set_host_notifier_internal(VirtIOPCIProxy *proxy,
proxy->addr + VIRTIO_PCI_QUEUE_NOTIFY,
n, assign);
if (r < 0) {
error_report("%s: unable to unmap ioeventfd: %d",
__func__, r);
return r;
}
@ -246,14 +252,14 @@ static void virtio_pci_set_host_notifier_fd_handler(VirtIOPCIProxy *proxy,
}
}
static int virtio_pci_start_ioeventfd(VirtIOPCIProxy *proxy)
static void virtio_pci_start_ioeventfd(VirtIOPCIProxy *proxy)
{
int n, r;
if (!(proxy->flags & VIRTIO_PCI_FLAG_USE_IOEVENTFD) ||
proxy->ioeventfd_disabled ||
proxy->ioeventfd_started) {
return 0;
return;
}
for (n = 0; n < VIRTIO_PCI_QUEUE_MAX; n++) {
@ -269,7 +275,7 @@ static int virtio_pci_start_ioeventfd(VirtIOPCIProxy *proxy)
virtio_pci_set_host_notifier_fd_handler(proxy, n, true);
}
proxy->ioeventfd_started = true;
return 0;
return;
assign_error:
while (--n >= 0) {
@ -278,19 +284,20 @@ assign_error:
}
virtio_pci_set_host_notifier_fd_handler(proxy, n, false);
virtio_pci_set_host_notifier_internal(proxy, n, false);
r = virtio_pci_set_host_notifier_internal(proxy, n, false);
assert(r >= 0);
}
proxy->ioeventfd_started = false;
proxy->ioeventfd_disabled = true;
return r;
error_report("%s: failed. Fallback to a userspace (slower).", __func__);
}
static int virtio_pci_stop_ioeventfd(VirtIOPCIProxy *proxy)
static void virtio_pci_stop_ioeventfd(VirtIOPCIProxy *proxy)
{
int r;
int n;
if (!proxy->ioeventfd_started) {
return 0;
return;
}
for (n = 0; n < VIRTIO_PCI_QUEUE_MAX; n++) {
@ -299,10 +306,10 @@ static int virtio_pci_stop_ioeventfd(VirtIOPCIProxy *proxy)
}
virtio_pci_set_host_notifier_fd_handler(proxy, n, false);
virtio_pci_set_host_notifier_internal(proxy, n, false);
r = virtio_pci_set_host_notifier_internal(proxy, n, false);
assert(r >= 0);
}
proxy->ioeventfd_started = false;
return 0;
}
static void virtio_pci_reset(DeviceState *d)
@ -706,7 +713,6 @@ static void virtio_init_pci(VirtIOPCIProxy *proxy, VirtIODevice *vdev,
proxy->host_features |= 0x1 << VIRTIO_F_NOTIFY_ON_EMPTY;
proxy->host_features |= 0x1 << VIRTIO_F_BAD_FEATURE;
proxy->host_features = vdev->get_features(vdev, proxy->host_features);
}
static int virtio_blk_init_pci(PCIDevice *pci_dev)