diff mbox

[RFC,2/9] virtio-pci: support host notifiers in TCG mode

Message ID 1343169246-17636-3-git-send-email-nab@linux-iscsi.org (mailing list archive)
State New, archived
Headers show

Commit Message

Nicholas A. Bellinger July 24, 2012, 10:33 p.m. UTC
From: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>

Normally host notifiers are only used together with vhost-net in KVM
mode.  It is occassionally useful to use vhost with TCG mode, mainly for
testing and development.  This isn't hard to achieve, simply fall back
to notifying the host notifier manually from qemu if KVM mode is
disabled.

Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
---
 hw/virtio-pci.c |   23 ++++++++++++++++++++---
 hw/virtio.c     |    7 +++++++
 2 files changed, 27 insertions(+), 3 deletions(-)

Comments

Paolo Bonzini July 25, 2012, 6:50 a.m. UTC | #1
Il 25/07/2012 00:33, Nicholas A. Bellinger ha scritto:
> From: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
> 
> Normally host notifiers are only used together with vhost-net in KVM
> mode.  It is occassionally useful to use vhost with TCG mode, mainly for
> testing and development.  This isn't hard to achieve, simply fall back
> to notifying the host notifier manually from qemu if KVM mode is
> disabled.
> 
> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
> Cc: Anthony Liguori <aliguori@us.ibm.com>
> Cc: Paolo Bonzini <pbonzini@redhat.com>
> Signed-off-by: Nicholas Bellinger <nab@linux-iscsi.org>
> ---
>  hw/virtio-pci.c |   23 ++++++++++++++++++++---
>  hw/virtio.c     |    7 +++++++
>  2 files changed, 27 insertions(+), 3 deletions(-)
> 
> diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
> index 4e03f0b..538eef4 100644
> --- a/hw/virtio-pci.c
> +++ b/hw/virtio-pci.c
> @@ -249,6 +249,25 @@ void virtio_pci_reset(DeviceState *d)
>      proxy->flags &= ~VIRTIO_PCI_FLAG_BUS_MASTER_BUG;
>  }
>  
> +static void virtio_pci_queue_notify(VirtIOPCIProxy *proxy, uint32_t n)
> +{
> +    VirtQueue *vq;
> +    EventNotifier *notifier;
> +
> +    if (n >= VIRTIO_PCI_QUEUE_MAX) {
> +        return;
> +    }
> +
> +    vq = virtio_get_queue(proxy->vdev, n);
> +    notifier = virtio_queue_get_host_notifier(vq);
> +    if (event_notifier_valid(notifier)) {
> +        printf("notifying vq %u host notifier from userspace\n", n);

Debug printf.

> +        event_notifier_notify(notifier);
> +    } else {
> +        virtio_queue_notify_vq(vq);
> +    }

This can be done directly in virtio_queue_notify, there is nothing
specific to virtio-pci.

> +}
> +
>  static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val)
>  {
>      VirtIOPCIProxy *proxy = opaque;
> @@ -278,9 +297,7 @@ static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val)
>              vdev->queue_sel = val;
>          break;
>      case VIRTIO_PCI_QUEUE_NOTIFY:
> -        if (val < VIRTIO_PCI_QUEUE_MAX) {
> -            virtio_queue_notify(vdev, val);
> -        }
> +        virtio_pci_queue_notify(proxy, val);
>          break;
>      case VIRTIO_PCI_STATUS:
>          if (!(val & VIRTIO_CONFIG_S_DRIVER_OK)) {
> diff --git a/hw/virtio.c b/hw/virtio.c
> index d146f86..36a18b5 100644
> --- a/hw/virtio.c
> +++ b/hw/virtio.c
> @@ -536,6 +536,11 @@ void virtio_reset(void *opaque)
>          vdev->vq[i].signalled_used = 0;
>          vdev->vq[i].signalled_used_valid = false;
>          vdev->vq[i].notification = true;
> +
> +        assert(!event_notifier_valid(&vdev->vq[i].guest_notifier));
> +        assert(!event_notifier_valid(&vdev->vq[i].host_notifier));
> +        vdev->vq[i].guest_notifier = EVENT_NOTIFIER_INITIALIZER;
> +        vdev->vq[i].host_notifier = EVENT_NOTIFIER_INITIALIZER;

Given the assertions, the assignments should be no-ops.

>      }
>  }
>  
> @@ -905,6 +910,8 @@ VirtIODevice *virtio_common_init(const char *name, uint16_t device_id,
>      for(i = 0; i < VIRTIO_PCI_QUEUE_MAX; i++) {
>          vdev->vq[i].vector = VIRTIO_NO_VECTOR;
>          vdev->vq[i].vdev = vdev;
> +        vdev->vq[i].guest_notifier = EVENT_NOTIFIER_INITIALIZER;
> +        vdev->vq[i].host_notifier = EVENT_NOTIFIER_INITIALIZER;
>      }
>  
>      vdev->name = name;
> 


--
To unsubscribe from this list: send the line "unsubscribe kvm" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
diff mbox

Patch

diff --git a/hw/virtio-pci.c b/hw/virtio-pci.c
index 4e03f0b..538eef4 100644
--- a/hw/virtio-pci.c
+++ b/hw/virtio-pci.c
@@ -249,6 +249,25 @@  void virtio_pci_reset(DeviceState *d)
     proxy->flags &= ~VIRTIO_PCI_FLAG_BUS_MASTER_BUG;
 }
 
+static void virtio_pci_queue_notify(VirtIOPCIProxy *proxy, uint32_t n)
+{
+    VirtQueue *vq;
+    EventNotifier *notifier;
+
+    if (n >= VIRTIO_PCI_QUEUE_MAX) {
+        return;
+    }
+
+    vq = virtio_get_queue(proxy->vdev, n);
+    notifier = virtio_queue_get_host_notifier(vq);
+    if (event_notifier_valid(notifier)) {
+        printf("notifying vq %u host notifier from userspace\n", n);
+        event_notifier_notify(notifier);
+    } else {
+        virtio_queue_notify_vq(vq);
+    }
+}
+
 static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val)
 {
     VirtIOPCIProxy *proxy = opaque;
@@ -278,9 +297,7 @@  static void virtio_ioport_write(void *opaque, uint32_t addr, uint32_t val)
             vdev->queue_sel = val;
         break;
     case VIRTIO_PCI_QUEUE_NOTIFY:
-        if (val < VIRTIO_PCI_QUEUE_MAX) {
-            virtio_queue_notify(vdev, val);
-        }
+        virtio_pci_queue_notify(proxy, val);
         break;
     case VIRTIO_PCI_STATUS:
         if (!(val & VIRTIO_CONFIG_S_DRIVER_OK)) {
diff --git a/hw/virtio.c b/hw/virtio.c
index d146f86..36a18b5 100644
--- a/hw/virtio.c
+++ b/hw/virtio.c
@@ -536,6 +536,11 @@  void virtio_reset(void *opaque)
         vdev->vq[i].signalled_used = 0;
         vdev->vq[i].signalled_used_valid = false;
         vdev->vq[i].notification = true;
+
+        assert(!event_notifier_valid(&vdev->vq[i].guest_notifier));
+        assert(!event_notifier_valid(&vdev->vq[i].host_notifier));
+        vdev->vq[i].guest_notifier = EVENT_NOTIFIER_INITIALIZER;
+        vdev->vq[i].host_notifier = EVENT_NOTIFIER_INITIALIZER;
     }
 }
 
@@ -905,6 +910,8 @@  VirtIODevice *virtio_common_init(const char *name, uint16_t device_id,
     for(i = 0; i < VIRTIO_PCI_QUEUE_MAX; i++) {
         vdev->vq[i].vector = VIRTIO_NO_VECTOR;
         vdev->vq[i].vdev = vdev;
+        vdev->vq[i].guest_notifier = EVENT_NOTIFIER_INITIALIZER;
+        vdev->vq[i].host_notifier = EVENT_NOTIFIER_INITIALIZER;
     }
 
     vdev->name = name;