From 17bb6d40880d4178f5f8a75900ed8c9ff47d3fb2 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Tue, 28 Aug 2012 13:54:13 +0200 Subject: virtio-ring: move queue_index to vring_virtqueue Instead of storing the queue index in transport-specific virtio structs, this patch moves them to vring_virtqueue and introduces an helper to get the value. This lets drivers simplify their management and tracing of virtqueues. Signed-off-by: Jason Wang Signed-off-by: Paolo Bonzini Signed-off-by: Rusty Russell --- include/linux/virtio.h | 2 ++ include/linux/virtio_ring.h | 3 ++- 2 files changed, 4 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/include/linux/virtio.h b/include/linux/virtio.h index a1ba8bbd9fbe..533b1157f22e 100644 --- a/include/linux/virtio.h +++ b/include/linux/virtio.h @@ -50,6 +50,8 @@ void *virtqueue_detach_unused_buf(struct virtqueue *vq); unsigned int virtqueue_get_vring_size(struct virtqueue *vq); +int virtqueue_get_queue_index(struct virtqueue *vq); + /** * virtio_device - representation of a device using virtio * @index: unique position on the virtio bus diff --git a/include/linux/virtio_ring.h b/include/linux/virtio_ring.h index e338730c2660..c2d793a06ad7 100644 --- a/include/linux/virtio_ring.h +++ b/include/linux/virtio_ring.h @@ -165,7 +165,8 @@ static inline int vring_need_event(__u16 event_idx, __u16 new_idx, __u16 old) struct virtio_device; struct virtqueue; -struct virtqueue *vring_new_virtqueue(unsigned int num, +struct virtqueue *vring_new_virtqueue(unsigned int index, + unsigned int num, unsigned int vring_align, struct virtio_device *vdev, bool weak_barriers, -- cgit v1.2.3 From 75a0a52be3c27b58654fbed2c8f2ff401482b9a4 Mon Sep 17 00:00:00 2001 From: Jason Wang Date: Tue, 28 Aug 2012 13:54:14 +0200 Subject: virtio: introduce an API to set affinity for a virtqueue Sometimes, virtio device need to configure irq affinity hint to maximize the performance. Instead of just exposing the irq of a virtqueue, this patch introduce an API to set the affinity for a virtqueue. The api is best-effort, the affinity hint may not be set as expected due to platform support, irq sharing or irq type. Currently, only pci method were implemented and we set the affinity according to: - if device uses INTX, we just ignore the request - if device has per vq vector, we force the affinity hint - if the virtqueues share MSI, make the affinity OR over all affinities requested Signed-off-by: Jason Wang Signed-off-by: Paolo Bonzini Signed-off-by: Rusty Russell --- drivers/virtio/virtio_pci.c | 46 +++++++++++++++++++++++++++++++++++++++++++ include/linux/virtio_config.h | 21 ++++++++++++++++++++ 2 files changed, 67 insertions(+) (limited to 'include/linux') diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index d902464b89ce..f5dfe6bdb959 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -48,6 +48,7 @@ struct virtio_pci_device int msix_enabled; int intx_enabled; struct msix_entry *msix_entries; + cpumask_var_t *msix_affinity_masks; /* Name strings for interrupts. This size should be enough, * and I'm too lazy to allocate each name separately. */ char (*msix_names)[256]; @@ -276,6 +277,10 @@ static void vp_free_vectors(struct virtio_device *vdev) for (i = 0; i < vp_dev->msix_used_vectors; ++i) free_irq(vp_dev->msix_entries[i].vector, vp_dev); + for (i = 0; i < vp_dev->msix_vectors; i++) + if (vp_dev->msix_affinity_masks[i]) + free_cpumask_var(vp_dev->msix_affinity_masks[i]); + if (vp_dev->msix_enabled) { /* Disable the vector used for configuration */ iowrite16(VIRTIO_MSI_NO_VECTOR, @@ -293,6 +298,8 @@ static void vp_free_vectors(struct virtio_device *vdev) vp_dev->msix_names = NULL; kfree(vp_dev->msix_entries); vp_dev->msix_entries = NULL; + kfree(vp_dev->msix_affinity_masks); + vp_dev->msix_affinity_masks = NULL; } static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors, @@ -311,6 +318,15 @@ static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors, GFP_KERNEL); if (!vp_dev->msix_names) goto error; + vp_dev->msix_affinity_masks + = kzalloc(nvectors * sizeof *vp_dev->msix_affinity_masks, + GFP_KERNEL); + if (!vp_dev->msix_affinity_masks) + goto error; + for (i = 0; i < nvectors; ++i) + if (!alloc_cpumask_var(&vp_dev->msix_affinity_masks[i], + GFP_KERNEL)) + goto error; for (i = 0; i < nvectors; ++i) vp_dev->msix_entries[i].entry = i; @@ -606,6 +622,35 @@ static const char *vp_bus_name(struct virtio_device *vdev) return pci_name(vp_dev->pci_dev); } +/* Setup the affinity for a virtqueue: + * - force the affinity for per vq vector + * - OR over all affinities for shared MSI + * - ignore the affinity request if we're using INTX + */ +static int vp_set_vq_affinity(struct virtqueue *vq, int cpu) +{ + struct virtio_device *vdev = vq->vdev; + struct virtio_pci_device *vp_dev = to_vp_device(vdev); + struct virtio_pci_vq_info *info = vq->priv; + struct cpumask *mask; + unsigned int irq; + + if (!vq->callback) + return -EINVAL; + + if (vp_dev->msix_enabled) { + mask = vp_dev->msix_affinity_masks[info->msix_vector]; + irq = vp_dev->msix_entries[info->msix_vector].vector; + if (cpu == -1) + irq_set_affinity_hint(irq, NULL); + else { + cpumask_set_cpu(cpu, mask); + irq_set_affinity_hint(irq, mask); + } + } + return 0; +} + static struct virtio_config_ops virtio_pci_config_ops = { .get = vp_get, .set = vp_set, @@ -617,6 +662,7 @@ static struct virtio_config_ops virtio_pci_config_ops = { .get_features = vp_get_features, .finalize_features = vp_finalize_features, .bus_name = vp_bus_name, + .set_vq_affinity = vp_set_vq_affinity, }; static void virtio_pci_release_dev(struct device *_d) diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index fc457f452f64..2c4a9895379d 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -98,6 +98,7 @@ * vdev: the virtio_device * This returns a pointer to the bus name a la pci_name from which * the caller can then copy. + * @set_vq_affinity: set the affinity for a virtqueue. */ typedef void vq_callback_t(struct virtqueue *); struct virtio_config_ops { @@ -116,6 +117,7 @@ struct virtio_config_ops { u32 (*get_features)(struct virtio_device *vdev); void (*finalize_features)(struct virtio_device *vdev); const char *(*bus_name)(struct virtio_device *vdev); + int (*set_vq_affinity)(struct virtqueue *vq, int cpu); }; /* If driver didn't advertise the feature, it will never appear. */ @@ -190,5 +192,24 @@ const char *virtio_bus_name(struct virtio_device *vdev) return vdev->config->bus_name(vdev); } +/** + * virtqueue_set_affinity - setting affinity for a virtqueue + * @vq: the virtqueue + * @cpu: the cpu no. + * + * Pay attention the function are best-effort: the affinity hint may not be set + * due to config support, irq type and sharing. + * + */ +static inline +int virtqueue_set_affinity(struct virtqueue *vq, int cpu) +{ + struct virtio_device *vdev = vq->vdev; + if (vdev->config->set_vq_affinity) + return vdev->config->set_vq_affinity(vq, cpu); + return 0; +} + + #endif /* __KERNEL__ */ #endif /* _LINUX_VIRTIO_CONFIG_H */ -- cgit v1.2.3 From 6457f126c888b3481fdae6f702e616cd0c79646e Mon Sep 17 00:00:00 2001 From: Michael S. Tsirkin Date: Wed, 5 Sep 2012 21:47:45 +0300 Subject: virtio: support reserved vqs virtio network device multiqueue support reserves vq 3 for future use (useful both for future extensions and to make it pretty - this way receive vqs have even and transmit - odd numbers). Make it possible to skip initialization for specific vq numbers by specifying NULL for name. Document this usage as well as (existing) NULL callback. Drivers using this not coded up yet, so I simply tested with virtio-pci and verified that this patch does not break existing drivers. Signed-off-by: Michael S. Tsirkin Signed-off-by: Rusty Russell --- drivers/lguest/lguest_device.c | 3 +++ drivers/remoteproc/remoteproc_virtio.c | 3 +++ drivers/s390/kvm/kvm_virtio.c | 3 +++ drivers/virtio/virtio_mmio.c | 3 +++ drivers/virtio/virtio_pci.c | 5 ++++- include/linux/virtio_config.h | 2 ++ 6 files changed, 18 insertions(+), 1 deletion(-) (limited to 'include/linux') diff --git a/drivers/lguest/lguest_device.c b/drivers/lguest/lguest_device.c index ccb7dfb028fa..fc92ccbd71dc 100644 --- a/drivers/lguest/lguest_device.c +++ b/drivers/lguest/lguest_device.c @@ -263,6 +263,9 @@ static struct virtqueue *lg_find_vq(struct virtio_device *vdev, struct virtqueue *vq; int err; + if (!name) + return NULL; + /* We must have this many virtqueues. */ if (index >= ldev->desc->num_vq) return ERR_PTR(-ENOENT); diff --git a/drivers/remoteproc/remoteproc_virtio.c b/drivers/remoteproc/remoteproc_virtio.c index 343c1941c123..e7a4780e93db 100644 --- a/drivers/remoteproc/remoteproc_virtio.c +++ b/drivers/remoteproc/remoteproc_virtio.c @@ -84,6 +84,9 @@ static struct virtqueue *rp_find_vq(struct virtio_device *vdev, if (id >= ARRAY_SIZE(rvdev->vring)) return ERR_PTR(-EINVAL); + if (!name) + return NULL; + ret = rproc_alloc_vring(rvdev, id); if (ret) return ERR_PTR(ret); diff --git a/drivers/s390/kvm/kvm_virtio.c b/drivers/s390/kvm/kvm_virtio.c index 5565af20592f..7dabef624da3 100644 --- a/drivers/s390/kvm/kvm_virtio.c +++ b/drivers/s390/kvm/kvm_virtio.c @@ -190,6 +190,9 @@ static struct virtqueue *kvm_find_vq(struct virtio_device *vdev, if (index >= kdev->desc->num_vq) return ERR_PTR(-ENOENT); + if (!name) + return NULL; + config = kvm_vq_config(kdev->desc)+index; err = vmem_add_mapping(config->address, diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index 008bf58bdaae..5d7fee385b70 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -306,6 +306,9 @@ static struct virtqueue *vm_setup_vq(struct virtio_device *vdev, unsigned index, unsigned long flags, size; int err; + if (!name) + return NULL; + /* Select the queue we're interested in */ writel(index, vm_dev->base + VIRTIO_MMIO_QUEUE_SEL); diff --git a/drivers/virtio/virtio_pci.c b/drivers/virtio/virtio_pci.c index f5dfe6bdb959..42b20769d122 100644 --- a/drivers/virtio/virtio_pci.c +++ b/drivers/virtio/virtio_pci.c @@ -555,7 +555,10 @@ static int vp_try_to_find_vqs(struct virtio_device *vdev, unsigned nvqs, vp_dev->per_vq_vectors = per_vq_vectors; allocated_vectors = vp_dev->msix_used_vectors; for (i = 0; i < nvqs; ++i) { - if (!callbacks[i] || !vp_dev->msix_enabled) + if (!names[i]) { + vqs[i] = NULL; + continue; + } else if (!callbacks[i] || !vp_dev->msix_enabled) msix_vec = VIRTIO_MSI_NO_VECTOR; else if (vp_dev->per_vq_vectors) msix_vec = allocated_vectors++; diff --git a/include/linux/virtio_config.h b/include/linux/virtio_config.h index 2c4a9895379d..e2850a7ea276 100644 --- a/include/linux/virtio_config.h +++ b/include/linux/virtio_config.h @@ -84,7 +84,9 @@ * nvqs: the number of virtqueues to find * vqs: on success, includes new virtqueues * callbacks: array of callbacks, for each virtqueue + * include a NULL entry for vqs that do not need a callback * names: array of virtqueue names (mainly for debugging) + * include a NULL entry for vqs unused by driver * Returns 0 on success or error status * @del_vqs: free virtqueues found by find_vqs(). * @get_features: get the array of feature bits for this device. -- cgit v1.2.3