| Message ID | 1455791490-4316-1-git-send-email-victork@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Feb 18, 2016 at 12:40:36PM +0200, Victor Kaplansky wrote: > 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: Didier Pallard <didier.pallard@6wind.com> > Signed-off-by: Victor Kaplansky <victork@redhat.com> I still dislike two things here, but I'll apply the bugfix for now - pls clean it up later. > --- > > v4 changes: > In respond to Michael S. Tsirkin comments: > - changed the name of new field to use_guest_notifier_mask > - clarified comments > - vhost_virtqueue_mask() called for unmask > - cosmetic changes > - moved the initialization of the new field from virtio_reset > to virtio_init. > > v3 changes: > In respond to Michael S. Tsirkin comments: > - vhost_net.c: removed dependency on virtio-pci.h > - vhost.c: simplified the check for vhost-user backend, > replaced by checking use_mask_notifier; added comment > explaining why vring for vhost-user initialized in > unmasked state; > - cosmetic fixes. > > v2 changes: > - a new boolean field is added to all virtio devices instead > of defining a property in some virtio-pci devices. > > include/hw/virtio/virtio.h | 1 + > hw/net/vhost_net.c | 16 ++++++++++++++-- > hw/virtio/vhost.c | 9 +++++++++ > hw/virtio/virtio-pci.c | 14 ++++++++------ > hw/virtio/virtio.c | 1 + > 5 files changed, 33 insertions(+), 8 deletions(-) > > diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h > index 108cdb0f..c38a2fef 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_guest_notifier_mask; > QLIST_HEAD(, VirtQueue) *vector_queues; > }; > > diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c > index 3940a04b..0ca16388 100644 > --- a/hw/net/vhost_net.c > +++ b/hw/net/vhost_net.c > @@ -306,13 +306,25 @@ 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); > + > + /* Suppress the masking guest notifiers on vhost user > + * because vhost user doesn't interrupt masking/unmasking > + * properly. > + */ > + if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER) { > + dev->use_guest_notifier_mask = false; > + } We should move this code and comment to vhost-user where it belongs. > + } > + > 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..30467b38 100644 > --- a/hw/virtio/vhost.c > +++ b/hw/virtio/vhost.c > @@ -855,6 +855,14 @@ static int vhost_virtqueue_start(struct vhost_dev *dev, > /* Clear and discard previous events if any. */ > event_notifier_test_and_clear(&vq->masked_notifier); > > + /* Init vring in unmasked state, unless guest_notifier_mask > + * will do it later. > + */ > + if (!vdev->use_guest_notifier_mask) { > + /* TODO: check and handle errors. */ > + vhost_virtqueue_mask(dev, vdev, idx, false); > + } > + > return 0; > > fail_kick: > @@ -1148,6 +1156,7 @@ void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, > struct vhost_vring_file file; > > if (mask) { > + assert(vdev->use_guest_notifier_mask); > file.fd = event_notifier_get_fd(&hdev->vqs[index].masked_notifier); > } else { > file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq)); > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > index 5494ff4a..440776c0 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_guest_notifier_mask && k->guest_notifier_mask) { It's nasty that we have to check two things. We should move guest_notifier_mask out from class it seems, then we can go back to only checking it. > 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_guest_notifier_mask && 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_guest_notifier_mask && 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_guest_notifier_mask && 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_guest_notifier_mask && 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_guest_notifier_mask && > + vdc->guest_notifier_mask) { > vdc->guest_notifier_mask(vdev, n, !assign); > } > > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c > index 90f25451..e365960b 100644 > --- a/hw/virtio/virtio.c > +++ b/hw/virtio/virtio.c > @@ -1677,6 +1677,7 @@ void virtio_init(VirtIODevice *vdev, const char *name, > vdev->vmstate = qemu_add_vm_change_state_handler(virtio_vmstate_change, > vdev); > vdev->device_endian = virtio_default_endian(); > + vdev->use_guest_notifier_mask = true; > } > > hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n) > -- > Victor
On Thu, Feb 18, 2016 at 12:40:36PM +0200, Victor Kaplansky wrote: > 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: Didier Pallard <didier.pallard@6wind.com> > Signed-off-by: Victor Kaplansky <victork@redhat.com> Conflicts with endian cleanup in my tree - can you rebase pls? There's also a trailing whitespace somewhere. > --- > > v4 changes: > In respond to Michael S. Tsirkin comments: > - changed the name of new field to use_guest_notifier_mask > - clarified comments > - vhost_virtqueue_mask() called for unmask > - cosmetic changes > - moved the initialization of the new field from virtio_reset > to virtio_init. > > v3 changes: > In respond to Michael S. Tsirkin comments: > - vhost_net.c: removed dependency on virtio-pci.h > - vhost.c: simplified the check for vhost-user backend, > replaced by checking use_mask_notifier; added comment > explaining why vring for vhost-user initialized in > unmasked state; > - cosmetic fixes. > > v2 changes: > - a new boolean field is added to all virtio devices instead > of defining a property in some virtio-pci devices. > > include/hw/virtio/virtio.h | 1 + > hw/net/vhost_net.c | 16 ++++++++++++++-- > hw/virtio/vhost.c | 9 +++++++++ > hw/virtio/virtio-pci.c | 14 ++++++++------ > hw/virtio/virtio.c | 1 + > 5 files changed, 33 insertions(+), 8 deletions(-) > > diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h > index 108cdb0f..c38a2fef 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_guest_notifier_mask; > QLIST_HEAD(, VirtQueue) *vector_queues; > }; > > diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c > index 3940a04b..0ca16388 100644 > --- a/hw/net/vhost_net.c > +++ b/hw/net/vhost_net.c > @@ -306,13 +306,25 @@ 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); > + > + /* Suppress the masking guest notifiers on vhost user > + * because vhost user doesn't interrupt masking/unmasking > + * properly. > + */ > + if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER) { > + dev->use_guest_notifier_mask = 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..30467b38 100644 > --- a/hw/virtio/vhost.c > +++ b/hw/virtio/vhost.c > @@ -855,6 +855,14 @@ static int vhost_virtqueue_start(struct vhost_dev *dev, > /* Clear and discard previous events if any. */ > event_notifier_test_and_clear(&vq->masked_notifier); > > + /* Init vring in unmasked state, unless guest_notifier_mask > + * will do it later. > + */ > + if (!vdev->use_guest_notifier_mask) { > + /* TODO: check and handle errors. */ > + vhost_virtqueue_mask(dev, vdev, idx, false); > + } > + > return 0; > > fail_kick: > @@ -1148,6 +1156,7 @@ void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, > struct vhost_vring_file file; > > if (mask) { > + assert(vdev->use_guest_notifier_mask); > file.fd = event_notifier_get_fd(&hdev->vqs[index].masked_notifier); > } else { > file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq)); > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c > index 5494ff4a..440776c0 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_guest_notifier_mask && 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_guest_notifier_mask && 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_guest_notifier_mask && 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_guest_notifier_mask && 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_guest_notifier_mask && 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_guest_notifier_mask && > + vdc->guest_notifier_mask) { > vdc->guest_notifier_mask(vdev, n, !assign); > } > > diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c > index 90f25451..e365960b 100644 > --- a/hw/virtio/virtio.c > +++ b/hw/virtio/virtio.c > @@ -1677,6 +1677,7 @@ void virtio_init(VirtIODevice *vdev, const char *name, > vdev->vmstate = qemu_add_vm_change_state_handler(virtio_vmstate_change, > vdev); > vdev->device_endian = virtio_default_endian(); > + vdev->use_guest_notifier_mask = true; > } > > hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n) > -- > Victor
diff --git a/include/hw/virtio/virtio.h b/include/hw/virtio/virtio.h index 108cdb0f..c38a2fef 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_guest_notifier_mask; QLIST_HEAD(, VirtQueue) *vector_queues; }; diff --git a/hw/net/vhost_net.c b/hw/net/vhost_net.c index 3940a04b..0ca16388 100644 --- a/hw/net/vhost_net.c +++ b/hw/net/vhost_net.c @@ -306,13 +306,25 @@ 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); + + /* Suppress the masking guest notifiers on vhost user + * because vhost user doesn't interrupt masking/unmasking + * properly. + */ + if (net->nc->info->type == NET_CLIENT_OPTIONS_KIND_VHOST_USER) { + dev->use_guest_notifier_mask = 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..30467b38 100644 --- a/hw/virtio/vhost.c +++ b/hw/virtio/vhost.c @@ -855,6 +855,14 @@ static int vhost_virtqueue_start(struct vhost_dev *dev, /* Clear and discard previous events if any. */ event_notifier_test_and_clear(&vq->masked_notifier); + /* Init vring in unmasked state, unless guest_notifier_mask + * will do it later. + */ + if (!vdev->use_guest_notifier_mask) { + /* TODO: check and handle errors. */ + vhost_virtqueue_mask(dev, vdev, idx, false); + } + return 0; fail_kick: @@ -1148,6 +1156,7 @@ void vhost_virtqueue_mask(struct vhost_dev *hdev, VirtIODevice *vdev, int n, struct vhost_vring_file file; if (mask) { + assert(vdev->use_guest_notifier_mask); file.fd = event_notifier_get_fd(&hdev->vqs[index].masked_notifier); } else { file.fd = event_notifier_get_fd(virtio_queue_get_guest_notifier(vvq)); diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c index 5494ff4a..440776c0 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_guest_notifier_mask && 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_guest_notifier_mask && 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_guest_notifier_mask && 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_guest_notifier_mask && 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_guest_notifier_mask && 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_guest_notifier_mask && + vdc->guest_notifier_mask) { vdc->guest_notifier_mask(vdev, n, !assign); } diff --git a/hw/virtio/virtio.c b/hw/virtio/virtio.c index 90f25451..e365960b 100644 --- a/hw/virtio/virtio.c +++ b/hw/virtio/virtio.c @@ -1677,6 +1677,7 @@ void virtio_init(VirtIODevice *vdev, const char *name, vdev->vmstate = qemu_add_vm_change_state_handler(virtio_vmstate_change, vdev); vdev->device_endian = virtio_default_endian(); + vdev->use_guest_notifier_mask = true; } hwaddr virtio_queue_get_desc_addr(VirtIODevice *vdev, int n)