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-rw-r--r--drivers/virtio/virtio_pci.c46
-rw-r--r--include/linux/virtio_config.h21
2 files changed, 67 insertions, 0 deletions
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 */
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