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[PULL,v2,08/34] virtio: improve virtio devices initialization time

Message ID 1516121887-32738-9-git-send-email-mst@redhat.com
State New
Headers show
Series [PULL,v2,01/34] MAINTAINERS: Add myself as maintainer to X86 machines | expand

Commit Message

Michael S. Tsirkin Jan. 16, 2018, 5:49 p.m. UTC 
From: Gal Hammer <ghammer@redhat.com>

The loading time of a VM is quite significant when its virtio
devices use a large amount of virt-queues (e.g. a virtio-serial
device with max_ports=511). Most of the time is spend in the
creation of all the required event notifiers (ioeventfd and memory
regions).

This patch pack all the changes to the memory regions in a
single memory transaction.

Reported-by: Sitong Liu <siliu@redhat.com>
Reported-by: Xiaoling Gao <xiagao@redhat.com>
Signed-off-by: Gal Hammer <ghammer@redhat.com>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 hw/virtio/virtio.c | 5 +++++
 1 file changed, 5 insertions(+)
diff mbox series

Patch

diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index d6002ee..3ac3491 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -2574,6 +2574,7 @@  static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev)
     VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev)));
     int n, r, err;
 
+    memory_region_transaction_begin();
     for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
         VirtQueue *vq = &vdev->vq[n];
         if (!virtio_queue_get_num(vdev, n)) {
@@ -2596,6 +2597,7 @@  static int virtio_device_start_ioeventfd_impl(VirtIODevice *vdev)
         }
         event_notifier_set(&vq->host_notifier);
     }
+    memory_region_transaction_commit();
     return 0;
 
 assign_error:
@@ -2609,6 +2611,7 @@  assign_error:
         r = virtio_bus_set_host_notifier(qbus, n, false);
         assert(r >= 0);
     }
+    memory_region_transaction_commit();
     return err;
 }
 
@@ -2625,6 +2628,7 @@  static void virtio_device_stop_ioeventfd_impl(VirtIODevice *vdev)
     VirtioBusState *qbus = VIRTIO_BUS(qdev_get_parent_bus(DEVICE(vdev)));
     int n, r;
 
+    memory_region_transaction_begin();
     for (n = 0; n < VIRTIO_QUEUE_MAX; n++) {
         VirtQueue *vq = &vdev->vq[n];
 
@@ -2635,6 +2639,7 @@  static void virtio_device_stop_ioeventfd_impl(VirtIODevice *vdev)
         r = virtio_bus_set_host_notifier(qbus, n, false);
         assert(r >= 0);
     }
+    memory_region_transaction_commit();
 }
 
 void virtio_device_stop_ioeventfd(VirtIODevice *vdev)