Using guest_notifier_mask function in vhost-user case may
break interrupt mask paradigm, because mask/unmask is not
really done when returning from guest_notifier_mask call, instead
message is posted in a unix socket, and processed later.
Add an option bit to disable the use of guest_notifier_mask
in virtio pci.
Signed-off-by: Didier Pallard <didier.pall...@6wind.com>
Reviewed-by: Thibaut Collet <thibaut.col...@6wind.com>
---
hw/virtio/virtio-pci.c | 29 +++++++++++++++++++++++------
hw/virtio/virtio-pci.h | 6 ++++++
2 files changed, 29 insertions(+), 6 deletions(-)
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index dd48562..26bb617 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -806,7 +806,8 @@ static int kvm_virtio_pci_vector_use(VirtIOPCIProxy *proxy,
int nvqs)
/* If guest supports masking, set up irqfd now.
* Otherwise, delay until unmasked in the frontend.
*/
- if (k->guest_notifier_mask) {
+ if ((proxy->flags & VIRTIO_PCI_FLAG_USE_NOTIFIERMASK) &&
+ k->guest_notifier_mask) {
ret = kvm_virtio_pci_irqfd_use(proxy, queue_no, vector);
if (ret < 0) {
kvm_virtio_pci_vq_vector_release(proxy, vector);
@@ -822,7 +823,8 @@ undo:
if (vector >= msix_nr_vectors_allocated(dev)) {
continue;
}
- if (k->guest_notifier_mask) {
+ if ((proxy->flags & VIRTIO_PCI_FLAG_USE_NOTIFIERMASK) &&
+ k->guest_notifier_mask) {
kvm_virtio_pci_irqfd_release(proxy, queue_no, vector);
}
kvm_virtio_pci_vq_vector_release(proxy, vector);
@@ -849,7 +851,8 @@ static void kvm_virtio_pci_vector_release(VirtIOPCIProxy
*proxy, int nvqs)
/* If guest supports masking, clean up irqfd now.
* Otherwise, it was cleaned when masked in the frontend.
*/
- if (k->guest_notifier_mask) {
+ if ((proxy->flags & VIRTIO_PCI_FLAG_USE_NOTIFIERMASK) &&
+ k->guest_notifier_mask) {
kvm_virtio_pci_irqfd_release(proxy, queue_no, vector);
}
kvm_virtio_pci_vq_vector_release(proxy, vector);
@@ -882,7 +885,8 @@ static int virtio_pci_vq_vector_unmask(VirtIOPCIProxy
*proxy,
/* If guest supports masking, irqfd is already setup, unmask it.
* Otherwise, set it up now.
*/
- if (k->guest_notifier_mask) {
+ if ((proxy->flags & VIRTIO_PCI_FLAG_USE_NOTIFIERMASK) &&
+ k->guest_notifier_mask) {
k->guest_notifier_mask(vdev, queue_no, false);
/* Test after unmasking to avoid losing events. */
if (k->guest_notifier_pending &&
@@ -905,7 +909,8 @@ static void virtio_pci_vq_vector_mask(VirtIOPCIProxy *proxy,
/* If guest supports masking, keep irqfd but mask it.
* Otherwise, clean it up now.
*/
- if (k->guest_notifier_mask) {
+ if ((proxy->flags & VIRTIO_PCI_FLAG_USE_NOTIFIERMASK) &&
+ k->guest_notifier_mask) {
k->guest_notifier_mask(vdev, queue_no, true);
} else {
kvm_virtio_pci_irqfd_release(proxy, queue_no, vector);
@@ -1022,7 +1027,9 @@ static int virtio_pci_set_guest_notifier(DeviceState *d,
int n, bool assign,
event_notifier_cleanup(notifier);
}
- if (!msix_enabled(&proxy->pci_dev) && vdc->guest_notifier_mask) {
+ if (!msix_enabled(&proxy->pci_dev) &&
+ (proxy->flags & VIRTIO_PCI_FLAG_USE_NOTIFIERMASK) &&
+ vdc->guest_notifier_mask) {
vdc->guest_notifier_mask(vdev, n, !assign);
}
@@ -1164,6 +1171,8 @@ static void virtio_9p_pci_realize(VirtIOPCIProxy
*vpci_dev, Error **errp)
static Property virtio_9p_pci_properties[] = {
DEFINE_PROP_BIT("ioeventfd", VirtIOPCIProxy, flags,
VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, true),
+ DEFINE_PROP_BIT("usenotifiermask", VirtIOPCIProxy, flags,
+ VIRTIO_PCI_FLAG_USE_NOTIFIERMASK_BIT, true),
DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, 2),
DEFINE_PROP_END_OF_LIST(),
};
@@ -1908,6 +1917,8 @@ static Property virtio_blk_pci_properties[] = {
DEFINE_PROP_UINT32("class", VirtIOPCIProxy, class_code, 0),
DEFINE_PROP_BIT("ioeventfd", VirtIOPCIProxy, flags,
VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, true),
+ DEFINE_PROP_BIT("usenotifiermask", VirtIOPCIProxy, flags,
+ VIRTIO_PCI_FLAG_USE_NOTIFIERMASK_BIT, true),
DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, 2),
DEFINE_PROP_END_OF_LIST(),
};
@@ -1961,6 +1972,8 @@ static const TypeInfo virtio_blk_pci_info = {
static Property virtio_scsi_pci_properties[] = {
DEFINE_PROP_BIT("ioeventfd", VirtIOPCIProxy, flags,
VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, true),
+ DEFINE_PROP_BIT("usenotifiermask", VirtIOPCIProxy, flags,
+ VIRTIO_PCI_FLAG_USE_NOTIFIERMASK_BIT, true),
DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors,
DEV_NVECTORS_UNSPECIFIED),
DEFINE_PROP_END_OF_LIST(),
@@ -2175,6 +2188,8 @@ static void virtio_serial_pci_realize(VirtIOPCIProxy
*vpci_dev, Error **errp)
static Property virtio_serial_pci_properties[] = {
DEFINE_PROP_BIT("ioeventfd", VirtIOPCIProxy, flags,
VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, true),
+ DEFINE_PROP_BIT("usenotifiermask", VirtIOPCIProxy, flags,
+ VIRTIO_PCI_FLAG_USE_NOTIFIERMASK_BIT, true),
DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, 2),
DEFINE_PROP_UINT32("class", VirtIOPCIProxy, class_code, 0),
DEFINE_PROP_END_OF_LIST(),
@@ -2215,6 +2230,8 @@ static const TypeInfo virtio_serial_pci_info = {
static Property virtio_net_properties[] = {
DEFINE_PROP_BIT("ioeventfd", VirtIOPCIProxy, flags,
VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT, false),
+ DEFINE_PROP_BIT("usenotifiermask", VirtIOPCIProxy, flags,
+ VIRTIO_PCI_FLAG_USE_NOTIFIERMASK_BIT, true),
DEFINE_PROP_UINT32("vectors", VirtIOPCIProxy, nvectors, 3),
DEFINE_PROP_END_OF_LIST(),
};
diff --git a/hw/virtio/virtio-pci.h b/hw/virtio/virtio-pci.h
index ffb74bb..aecd4eb 100644
--- a/hw/virtio/virtio-pci.h
+++ b/hw/virtio/virtio-pci.h
@@ -86,6 +86,12 @@ typedef struct VirtioBusClass VirtioPCIBusClass;
#define VIRTIO_PCI_FLAG_MODERN_PIO_NOTIFY \
(1 << VIRTIO_PCI_FLAG_MODERN_PIO_NOTIFY_BIT)
+/* Where vhost-user implementation exists, using the guest notifier mask
+ * feature can lead to improper interrupt management. Add a flag to
+ * allow to disable this guest notifier mask if desired */
+#define VIRTIO_PCI_FLAG_USE_NOTIFIERMASK_BIT 6
+#define VIRTIO_PCI_FLAG_USE_NOTIFIERMASK (1 <<
VIRTIO_PCI_FLAG_USE_NOTIFIERMASK_BIT)
+
typedef struct {
MSIMessage msg;
int virq;
--
2.1.4
