diff mbox

[v2,1/1] vhost-user interrupt management fixes

Message ID 1455629067-25370-2-git-send-email-victork@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Victor Kaplansky Feb. 16, 2016, 1:28 p.m. UTC 
From: Didier Pallard <didier.pallard@6wind.com>

Since guest_mask_notifier can not be used in vhost-user mode due
to buffering implied by unix control socket, force
use_mask_notifier on virtio devices of vhost-user interfaces, and
send correct callfd to the guest at vhost start.

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 boolean flag 'use_mask_notifier' to disable the use
of guest_notifier_mask in virtio pci.

Signed-off-by: Victor Kaplansky <victork@redhat.com>
---
 include/hw/virtio/virtio.h |  1 +
 hw/net/vhost_net.c         | 24 ++++++++++++++++++++++--
 hw/virtio/vhost.c          | 13 +++++++++++++
 hw/virtio/virtio-pci.c     | 15 +++++++++------
 hw/virtio/virtio.c         |  1 +
 5 files changed, 46 insertions(+), 8 deletions(-)

Comments

Michael S. Tsirkin Feb. 16, 2016, 1:58 p.m. UTC | #1 
On Tue, Feb 16, 2016 at 03:28:06PM +0200, Victor Kaplansky wrote:
> From: Didier Pallard <didier.pallard@6wind.com>
> 
> Since guest_mask_notifier can not be used in vhost-user mode due
> to buffering implied by unix control socket, force
> use_mask_notifier on virtio devices of vhost-user interfaces, and
> send correct callfd to the guest at vhost start.
> 
> 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 boolean flag 'use_mask_notifier' to disable the use
> of guest_notifier_mask in virtio pci.
> 
> Signed-off-by: Victor Kaplansky <victork@redhat.com>
> ---
>  include/hw/virtio/virtio.h |  1 +
>  hw/net/vhost_net.c         | 24 ++++++++++++++++++++++--
>  hw/virtio/vhost.c          | 13 +++++++++++++
>  hw/virtio/virtio-pci.c     | 15 +++++++++------
>  hw/virtio/virtio.c         |  1 +
>  5 files changed, 46 insertions(+), 8 deletions(-)
> 
> diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
> index 108cdb0f..3acbf999 100644
> --- a/include/hw/virtio/virtio.h
> +++ b/include/hw/virtio/virtio.h
> @@ -90,6 +90,7 @@ struct VirtIODevice
>      VMChangeStateEntry *vmstate;
>      char *bus_name;
>      uint8_t device_endian;
> +    bool use_mask_notifier;
>      QLIST_HEAD(, VirtQueue) *vector_queues;
>  };
>  
> diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
> index 3940a04b..22ba5571 100644
> --- a/hw/net/vhost_net.c
> +++ b/hw/net/vhost_net.c
> @@ -17,6 +17,7 @@
>  #include "net/net.h"
>  #include "net/tap.h"
>  #include "net/vhost-user.h"
> +#include "hw/virtio/virtio-pci.h"
>  
>  #include "hw/virtio/virtio-net.h"
>  #include "net/vhost_net.h"

We definitely don't want a dependency on virtio-pci.


> @@ -306,13 +307,32 @@ int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
>      }
>  
>      for (j = 0; j < total_queues; j++) {
> +        struct vhost_net *net;
> +
>          r = vhost_net_set_vnet_endian(dev, ncs[j].peer, true);
>          if (r < 0) {
>              goto err_endian;
>          }
> -        vhost_net_set_vq_index(get_vhost_net(ncs[j].peer), j * 2);
> -    }
>  
> +        net = get_vhost_net(ncs[j].peer);
> +        vhost_net_set_vq_index(net, j * 2);
> +
> +        /* Force use_mask_notifier reset in vhost user case
> +         * Must be done before set_guest_notifier call
> +         */
> +        if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER) {

Please don't do this. Add some query from vhost and do the
right thing per backend.


> +            BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
> +            DeviceState *d = DEVICE(qbus->parent);
> +            if (!strcmp(object_get_typename(OBJECT(d)), TYPE_VIRTIO_NET_PCI)) {

Again, PCI dependency.


> +                VirtIOPCIProxy *proxy = VIRTIO_PCI(d);

And again here.

> +                VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
> +
> +                /* Force virtual device not use mask notifier */
> +                vdev->use_mask_notifier = false;
> +            }
> +        }
> +     }
> + 
>      r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
>      if (r < 0) {
>          error_report("Error binding guest notifier: %d", -r);
> diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
> index 7dff7554..80744386 100644
> --- a/hw/virtio/vhost.c
> +++ b/hw/virtio/vhost.c
> @@ -855,8 +855,21 @@ static int vhost_virtqueue_start(struct vhost_dev *dev,
>      /* Clear and discard previous events if any. */
>      event_notifier_test_and_clear(&vq->masked_notifier);
>  
> +    /* If vhost user, register now the call eventfd, guest_notifier_mask
> +     * function is not used anymore
> +     */

Can't this look at use_mask_notifier then?

> +    if (dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER) {
> +        file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq));
> +        r = dev->vhost_ops->vhost_set_vring_call(dev, &file);
> +        if (r) {
> +            r = -errno;
> +            goto fail_call;
> +        }
> +    }
> +
>      return 0;
>  
> +fail_call:
>  fail_kick:
>  fail_alloc:
>      cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx),
> diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> index 5494ff4a..70f64cf7 100644
> --- a/hw/virtio/virtio-pci.c
> +++ b/hw/virtio/virtio-pci.c
> @@ -806,7 +806,7 @@ 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 (vdev->use_mask_notifier && 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);

Would be cleaner to move guest_notifier_mask out from class
so we don't have to check two things.
But not a must.

> @@ -822,7 +822,7 @@ undo:
>          if (vector >= msix_nr_vectors_allocated(dev)) {
>              continue;
>          }
> -        if (k->guest_notifier_mask) {
> +        if (vdev->use_mask_notifier && k->guest_notifier_mask) {
>              kvm_virtio_pci_irqfd_release(proxy, queue_no, vector);
>          }
>          kvm_virtio_pci_vq_vector_release(proxy, vector);
> @@ -849,7 +849,7 @@ 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 (vdev->use_mask_notifier && k->guest_notifier_mask) {
>              kvm_virtio_pci_irqfd_release(proxy, queue_no, vector);
>          }
>          kvm_virtio_pci_vq_vector_release(proxy, vector);
> @@ -882,7 +882,7 @@ 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 (vdev->use_mask_notifier && 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 +905,7 @@ 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 (vdev->use_mask_notifier && k->guest_notifier_mask) {
>          k->guest_notifier_mask(vdev, queue_no, true);
>      } else {
>          kvm_virtio_pci_irqfd_release(proxy, queue_no, vector);
> @@ -1022,7 +1022,9 @@ 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) &&
> +        vdev->use_mask_notifier &&
> +        vdc->guest_notifier_mask) {
>          vdc->guest_notifier_mask(vdev, n, !assign);
>      }
>  
> @@ -1879,6 +1881,7 @@ static Property virtio_pci_properties[] = {
>                      VIRTIO_PCI_FLAG_MODERN_PIO_NOTIFY_BIT, false),
>      DEFINE_PROP_BIT("x-disable-pcie", VirtIOPCIProxy, flags,
>                      VIRTIO_PCI_FLAG_DISABLE_PCIE_BIT, false),
> +
>      DEFINE_PROP_END_OF_LIST(),
>  };
>  

drop this one pls.

> diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
> index 90f25451..c0238b39 100644
> --- a/hw/virtio/virtio.c
> +++ b/hw/virtio/virtio.c
> @@ -792,6 +792,7 @@ void virtio_reset(void *opaque)
>      vdev->queue_sel = 0;
>      vdev->status = 0;
>      vdev->isr = 0;
> +    vdev->use_mask_notifier = true;
>      vdev->config_vector = VIRTIO_NO_VECTOR;
>      virtio_notify_vector(vdev, vdev->config_vector);
>  
> -- 
> Victor
diff mbox

Patch

diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h
index 108cdb0f..3acbf999 100644
--- a/include/hw/virtio/virtio.h
+++ b/include/hw/virtio/virtio.h
@@ -90,6 +90,7 @@  struct VirtIODevice
     VMChangeStateEntry *vmstate;
     char *bus_name;
     uint8_t device_endian;
+    bool use_mask_notifier;
     QLIST_HEAD(, VirtQueue) *vector_queues;
 };
 
diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c
index 3940a04b..22ba5571 100644
--- a/hw/net/vhost_net.c
+++ b/hw/net/vhost_net.c
@@ -17,6 +17,7 @@ 
 #include "net/net.h"
 #include "net/tap.h"
 #include "net/vhost-user.h"
+#include "hw/virtio/virtio-pci.h"
 
 #include "hw/virtio/virtio-net.h"
 #include "net/vhost_net.h"
@@ -306,13 +307,32 @@  int vhost_net_start(VirtIODevice *dev, NetClientState *ncs,
     }
 
     for (j = 0; j < total_queues; j++) {
+        struct vhost_net *net;
+
         r = vhost_net_set_vnet_endian(dev, ncs[j].peer, true);
         if (r < 0) {
             goto err_endian;
         }
-        vhost_net_set_vq_index(get_vhost_net(ncs[j].peer), j * 2);
-    }
 
+        net = get_vhost_net(ncs[j].peer);
+        vhost_net_set_vq_index(net, j * 2);
+
+        /* Force use_mask_notifier reset in vhost user case
+         * Must be done before set_guest_notifier call
+         */
+        if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER) {
+            BusState *qbus = BUS(qdev_get_parent_bus(DEVICE(dev)));
+            DeviceState *d = DEVICE(qbus->parent);
+            if (!strcmp(object_get_typename(OBJECT(d)), TYPE_VIRTIO_NET_PCI)) {
+                VirtIOPCIProxy *proxy = VIRTIO_PCI(d);
+                VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
+
+                /* Force virtual device not use mask notifier */
+                vdev->use_mask_notifier = false;
+            }
+        }
+     }
+ 
     r = k->set_guest_notifiers(qbus->parent, total_queues * 2, true);
     if (r < 0) {
         error_report("Error binding guest notifier: %d", -r);
diff --git a/hw/virtio/vhost.c b/hw/virtio/vhost.c
index 7dff7554..80744386 100644
--- a/hw/virtio/vhost.c
+++ b/hw/virtio/vhost.c
@@ -855,8 +855,21 @@  static int vhost_virtqueue_start(struct vhost_dev *dev,
     /* Clear and discard previous events if any. */
     event_notifier_test_and_clear(&vq->masked_notifier);
 
+    /* If vhost user, register now the call eventfd, guest_notifier_mask
+     * function is not used anymore
+     */
+    if (dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_USER) {
+        file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq));
+        r = dev->vhost_ops->vhost_set_vring_call(dev, &file);
+        if (r) {
+            r = -errno;
+            goto fail_call;
+        }
+    }
+
     return 0;
 
+fail_call:
 fail_kick:
 fail_alloc:
     cpu_physical_memory_unmap(vq->ring, virtio_queue_get_ring_size(vdev, idx),
diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
index 5494ff4a..70f64cf7 100644
--- a/hw/virtio/virtio-pci.c
+++ b/hw/virtio/virtio-pci.c
@@ -806,7 +806,7 @@  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 (vdev->use_mask_notifier && 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 +822,7 @@  undo:
         if (vector >= msix_nr_vectors_allocated(dev)) {
             continue;
         }
-        if (k->guest_notifier_mask) {
+        if (vdev->use_mask_notifier && k->guest_notifier_mask) {
             kvm_virtio_pci_irqfd_release(proxy, queue_no, vector);
         }
         kvm_virtio_pci_vq_vector_release(proxy, vector);
@@ -849,7 +849,7 @@  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 (vdev->use_mask_notifier && k->guest_notifier_mask) {
             kvm_virtio_pci_irqfd_release(proxy, queue_no, vector);
         }
         kvm_virtio_pci_vq_vector_release(proxy, vector);
@@ -882,7 +882,7 @@  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 (vdev->use_mask_notifier && 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 +905,7 @@  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 (vdev->use_mask_notifier && k->guest_notifier_mask) {
         k->guest_notifier_mask(vdev, queue_no, true);
     } else {
         kvm_virtio_pci_irqfd_release(proxy, queue_no, vector);
@@ -1022,7 +1022,9 @@  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) &&
+        vdev->use_mask_notifier &&
+        vdc->guest_notifier_mask) {
         vdc->guest_notifier_mask(vdev, n, !assign);
     }
 
@@ -1879,6 +1881,7 @@  static Property virtio_pci_properties[] = {
                     VIRTIO_PCI_FLAG_MODERN_PIO_NOTIFY_BIT, false),
     DEFINE_PROP_BIT("x-disable-pcie", VirtIOPCIProxy, flags,
                     VIRTIO_PCI_FLAG_DISABLE_PCIE_BIT, false),
+
     DEFINE_PROP_END_OF_LIST(),
 };
 
diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c
index 90f25451..c0238b39 100644
--- a/hw/virtio/virtio.c
+++ b/hw/virtio/virtio.c
@@ -792,6 +792,7 @@  void virtio_reset(void *opaque)
     vdev->queue_sel = 0;
     vdev->status = 0;
     vdev->isr = 0;
+    vdev->use_mask_notifier = true;
     vdev->config_vector = VIRTIO_NO_VECTOR;
     virtio_notify_vector(vdev, vdev->config_vector);