Some guests mask a vector then unmask without changing it.
Store vectors to avoid kvm system calls in this case.
Signed-off-by: Michael S. Tsirkin <m...@redhat.com>
---
hw/virtio-pci.c | 119 ++++++++++++++++++++++++++++++++++++++++++++++----------
hw/virtio-pci.h | 1 +
2 files changed, 100 insertions(+), 20 deletions(-)
diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
index 3c258a4..1d77146 100644
--- a/hw/virtio-pci.c
+++ b/hw/virtio-pci.c
@@ -487,8 +487,6 @@ static int kvm_virtio_pci_vq_vector_use(VirtIOPCIProxy
*proxy,
unsigned int vector,
MSIMessage msg)
{
- VirtQueue *vq = virtio_get_queue(proxy->vdev, queue_no);
- EventNotifier *n = virtio_queue_get_guest_notifier(vq);
VirtIOIRQFD *irqfd = &proxy->vector_irqfd[vector];
int ret;
@@ -500,18 +498,94 @@ static int kvm_virtio_pci_vq_vector_use(VirtIOPCIProxy
*proxy,
irqfd->virq = ret;
}
irqfd->users++;
+ return 0;
+}
- ret = kvm_irqchip_add_irqfd_notifier(kvm_state, n, irqfd->virq);
- if (ret < 0) {
- if (--irqfd->users == 0) {
- kvm_irqchip_release_virq(kvm_state, irqfd->virq);
+static void kvm_virtio_pci_vq_vector_release(VirtIOPCIProxy *proxy,
+ unsigned int vector)
+{
+ VirtIOIRQFD *irqfd = &proxy->vector_irqfd[vector];
+ if (--irqfd->users == 0) {
+ kvm_irqchip_release_virq(kvm_state, irqfd->virq);
+ }
+}
+
+static int kvm_virtio_pci_vector_use(VirtIOPCIProxy *proxy, int nvqs)
+{
+ PCIDevice *dev = &proxy->pci_dev;
+ VirtIODevice *vdev = proxy->vdev;
+ unsigned int vector;
+ int ret, queue_no;
+ MSIMessage msg;
+
+ for (queue_no = 0; queue_no < nvqs; queue_no++) {
+ if (!virtio_queue_get_num(vdev, queue_no)) {
+ break;
+ }
+ vector = virtio_queue_vector(vdev, queue_no);
+ if (vector >= msix_nr_vectors_allocated(dev)) {
+ continue;
+ }
+ msg = msix_get_message(dev, vector);
+ ret = kvm_virtio_pci_vq_vector_use(proxy, queue_no, vector, msg);
+ if (ret < 0) {
+ goto undo;
}
- return ret;
}
return 0;
+
+undo:
+ while (--queue_no >= 0) {
+ vector = virtio_queue_vector(vdev, queue_no);
+ if (vector >= msix_nr_vectors_allocated(dev)) {
+ continue;
+ }
+ kvm_virtio_pci_vq_vector_release(proxy, vector);
+ }
+ return ret;
}
-static void kvm_virtio_pci_vq_vector_release(VirtIOPCIProxy *proxy,
+static void kvm_virtio_pci_vector_release(VirtIOPCIProxy *proxy, int nvqs)
+{
+ PCIDevice *dev = &proxy->pci_dev;
+ VirtIODevice *vdev = proxy->vdev;
+ unsigned int vector;
+ int queue_no;
+
+ for (queue_no = 0; queue_no < nvqs; queue_no++) {
+ if (!virtio_queue_get_num(vdev, queue_no)) {
+ break;
+ }
+ vector = virtio_queue_vector(vdev, queue_no);
+ if (vector >= msix_nr_vectors_allocated(dev)) {
+ continue;
+ }
+ kvm_virtio_pci_vq_vector_release(proxy, vector);
+ }
+}
+
+static int kvm_virtio_pci_vq_vector_unmask(VirtIOPCIProxy *proxy,
+ unsigned int queue_no,
+ unsigned int vector,
+ MSIMessage msg)
+{
+ VirtQueue *vq = virtio_get_queue(proxy->vdev, queue_no);
+ EventNotifier *n = virtio_queue_get_guest_notifier(vq);
+ VirtIOIRQFD *irqfd = &proxy->vector_irqfd[vector];
+ int ret;
+
+ if (irqfd->msg.data != msg.data || irqfd->msg.address != msg.address) {
+ ret = kvm_irqchip_update_msi_route(kvm_state, irqfd->virq, msg);
+ if (ret < 0) {
+ return ret;
+ }
+ }
+
+ ret = kvm_irqchip_add_irqfd_notifier(kvm_state, n, irqfd->virq);
+ return ret;
+}
+
+static void kvm_virtio_pci_vq_vector_mask(VirtIOPCIProxy *proxy,
unsigned int queue_no,
unsigned int vector)
{
@@ -522,13 +596,9 @@ static void
kvm_virtio_pci_vq_vector_release(VirtIOPCIProxy *proxy,
ret = kvm_irqchip_remove_irqfd_notifier(kvm_state, n, irqfd->virq);
assert(ret == 0);
-
- if (--irqfd->users == 0) {
- kvm_irqchip_release_virq(kvm_state, irqfd->virq);
- }
}
-static int kvm_virtio_pci_vector_use(PCIDevice *dev, unsigned vector,
+static int kvm_virtio_pci_vector_unmask(PCIDevice *dev, unsigned vector,
MSIMessage msg)
{
VirtIOPCIProxy *proxy = container_of(dev, VirtIOPCIProxy, pci_dev);
@@ -542,7 +612,7 @@ static int kvm_virtio_pci_vector_use(PCIDevice *dev,
unsigned vector,
if (virtio_queue_vector(vdev, queue_no) != vector) {
continue;
}
- ret = kvm_virtio_pci_vq_vector_use(proxy, queue_no, vector, msg);
+ ret = kvm_virtio_pci_vq_vector_unmask(proxy, queue_no, vector, msg);
if (ret < 0) {
goto undo;
}
@@ -554,12 +624,12 @@ undo:
if (virtio_queue_vector(vdev, queue_no) != vector) {
continue;
}
- kvm_virtio_pci_vq_vector_release(proxy, queue_no, vector);
+ kvm_virtio_pci_vq_vector_mask(proxy, queue_no, vector);
}
return ret;
}
-static void kvm_virtio_pci_vector_release(PCIDevice *dev, unsigned vector)
+static void kvm_virtio_pci_vector_mask(PCIDevice *dev, unsigned vector)
{
VirtIOPCIProxy *proxy = container_of(dev, VirtIOPCIProxy, pci_dev);
VirtIODevice *vdev = proxy->vdev;
@@ -572,7 +642,7 @@ static void kvm_virtio_pci_vector_release(PCIDevice *dev,
unsigned vector)
if (virtio_queue_vector(vdev, queue_no) != vector) {
continue;
}
- kvm_virtio_pci_vq_vector_release(proxy, queue_no, vector);
+ kvm_virtio_pci_vq_vector_mask(proxy, queue_no, vector);
}
}
@@ -651,6 +721,7 @@ static int virtio_pci_set_guest_notifiers(DeviceState *d,
int nvqs, bool assign)
/* Must unset vector notifier while guest notifier is still assigned */
if (proxy->vector_irqfd && !assign) {
msix_unset_vector_notifiers(&proxy->pci_dev);
+ kvm_virtio_pci_vector_release(proxy, nvqs);
g_free(proxy->vector_irqfd);
proxy->vector_irqfd = NULL;
}
@@ -672,17 +743,25 @@ static int virtio_pci_set_guest_notifiers(DeviceState *d,
int nvqs, bool assign)
proxy->vector_irqfd =
g_malloc0(sizeof(*proxy->vector_irqfd) *
msix_nr_vectors_allocated(&proxy->pci_dev));
+ r = kvm_virtio_pci_vector_use(proxy, nvqs);
+ if (r < 0) {
+ goto assign_error;
+ }
r = msix_set_vector_notifiers(&proxy->pci_dev,
- kvm_virtio_pci_vector_use,
- kvm_virtio_pci_vector_release,
+ kvm_virtio_pci_vector_unmask,
+ kvm_virtio_pci_vector_mask,
kvm_virtio_pci_vector_poll);
if (r < 0) {
- goto assign_error;
+ goto notifiers_error;
}
}
return 0;
+notifiers_error:
+ assert(assign);
+ kvm_virtio_pci_vector_release(proxy, nvqs);
+
assign_error:
/* We get here on assignment failure. Recover by undoing for VQs 0 .. n. */
assert(assign);
diff --git a/hw/virtio-pci.h b/hw/virtio-pci.h
index b0f17e2..9ff3139 100644
--- a/hw/virtio-pci.h
+++ b/hw/virtio-pci.h
@@ -27,6 +27,7 @@
#define VIRTIO_PCI_FLAG_USE_IOEVENTFD (1 <<
VIRTIO_PCI_FLAG_USE_IOEVENTFD_BIT)
typedef struct {
+ MSIMessage msg;
int virq;
unsigned int users;
} VirtIOIRQFD;
--
MST
