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-rw-r--r--drivers/virtio/virtio_pci_common.c244
-rw-r--r--drivers/virtio/virtio_pci_common.h16
2 files changed, 148 insertions, 112 deletions
diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index 3921b0a2439e..d99029d3892e 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -33,8 +33,10 @@ void vp_synchronize_vectors(struct virtio_device *vdev)
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
int i;
- synchronize_irq(pci_irq_vector(vp_dev->pci_dev, 0));
- for (i = 1; i < vp_dev->msix_vectors; i++)
+ if (vp_dev->intx_enabled)
+ synchronize_irq(vp_dev->pci_dev->irq);
+
+ for (i = 0; i < vp_dev->msix_vectors; ++i)
synchronize_irq(pci_irq_vector(vp_dev->pci_dev, i));
}
@@ -97,10 +99,79 @@ static irqreturn_t vp_interrupt(int irq, void *opaque)
return vp_vring_interrupt(irq, opaque);
}
-static void vp_remove_vqs(struct virtio_device *vdev)
+static int vp_request_msix_vectors(struct virtio_device *vdev, int nvectors,
+ bool per_vq_vectors, struct irq_affinity *desc)
+{
+ struct virtio_pci_device *vp_dev = to_vp_device(vdev);
+ const char *name = dev_name(&vp_dev->vdev.dev);
+ unsigned i, v;
+ int err = -ENOMEM;
+
+ vp_dev->msix_vectors = nvectors;
+
+ vp_dev->msix_names = kmalloc(nvectors * sizeof *vp_dev->msix_names,
+ 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;
+
+ err = pci_alloc_irq_vectors_affinity(vp_dev->pci_dev, nvectors,
+ nvectors, PCI_IRQ_MSIX |
+ (desc ? PCI_IRQ_AFFINITY : 0),
+ desc);
+ if (err < 0)
+ goto error;
+ vp_dev->msix_enabled = 1;
+
+ /* Set the vector used for configuration */
+ v = vp_dev->msix_used_vectors;
+ snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
+ "%s-config", name);
+ err = request_irq(pci_irq_vector(vp_dev->pci_dev, v),
+ vp_config_changed, 0, vp_dev->msix_names[v],
+ vp_dev);
+ if (err)
+ goto error;
+ ++vp_dev->msix_used_vectors;
+
+ v = vp_dev->config_vector(vp_dev, v);
+ /* Verify we had enough resources to assign the vector */
+ if (v == VIRTIO_MSI_NO_VECTOR) {
+ err = -EBUSY;
+ goto error;
+ }
+
+ if (!per_vq_vectors) {
+ /* Shared vector for all VQs */
+ v = vp_dev->msix_used_vectors;
+ snprintf(vp_dev->msix_names[v], sizeof *vp_dev->msix_names,
+ "%s-virtqueues", name);
+ err = request_irq(pci_irq_vector(vp_dev->pci_dev, v),
+ vp_vring_interrupt, 0, vp_dev->msix_names[v],
+ vp_dev);
+ if (err)
+ goto error;
+ ++vp_dev->msix_used_vectors;
+ }
+ return 0;
+error:
+ return err;
+}
+
+/* the config->del_vqs() implementation */
+void vp_del_vqs(struct virtio_device *vdev)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
struct virtqueue *vq, *n;
+ int i;
list_for_each_entry_safe(vq, n, &vdev->vqs, list) {
if (vp_dev->msix_vector_map) {
@@ -112,33 +183,35 @@ static void vp_remove_vqs(struct virtio_device *vdev)
}
vp_dev->del_vq(vq);
}
-}
-/* the config->del_vqs() implementation */
-void vp_del_vqs(struct virtio_device *vdev)
-{
- struct virtio_pci_device *vp_dev = to_vp_device(vdev);
- int i;
-
- if (WARN_ON_ONCE(list_empty_careful(&vdev->vqs)))
- return;
+ if (vp_dev->intx_enabled) {
+ free_irq(vp_dev->pci_dev->irq, vp_dev);
+ vp_dev->intx_enabled = 0;
+ }
- vp_remove_vqs(vdev);
+ for (i = 0; i < vp_dev->msix_used_vectors; ++i)
+ free_irq(pci_irq_vector(vp_dev->pci_dev, i), vp_dev);
- if (vp_dev->msix_enabled) {
- for (i = 0; i < vp_dev->msix_vectors; i++)
+ 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 */
vp_dev->config_vector(vp_dev, VIRTIO_MSI_NO_VECTOR);
- kfree(vp_dev->msix_affinity_masks);
- kfree(vp_dev->msix_names);
- kfree(vp_dev->msix_vector_map);
+ pci_free_irq_vectors(vp_dev->pci_dev);
+ vp_dev->msix_enabled = 0;
}
- free_irq(pci_irq_vector(vp_dev->pci_dev, 0), vp_dev);
- pci_free_irq_vectors(vp_dev->pci_dev);
+ vp_dev->msix_vectors = 0;
+ vp_dev->msix_used_vectors = 0;
+ kfree(vp_dev->msix_names);
+ vp_dev->msix_names = NULL;
+ kfree(vp_dev->msix_affinity_masks);
+ vp_dev->msix_affinity_masks = NULL;
+ kfree(vp_dev->msix_vector_map);
+ vp_dev->msix_vector_map = NULL;
}
static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs,
@@ -147,128 +220,80 @@ static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned nvqs,
struct irq_affinity *desc)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
- const char *name = dev_name(&vp_dev->vdev.dev);
- int i, err = -ENOMEM, allocated_vectors, nvectors;
- unsigned flags = PCI_IRQ_MSIX;
u16 msix_vec;
-
- if (desc) {
- flags |= PCI_IRQ_AFFINITY;
- desc->pre_vectors++; /* virtio config vector */
- }
-
- nvectors = 1;
- for (i = 0; i < nvqs; i++)
- if (callbacks[i])
- nvectors++;
+ int i, err, nvectors, allocated_vectors;
if (per_vq_vectors) {
- err = pci_alloc_irq_vectors_affinity(vp_dev->pci_dev, nvectors,
- nvectors, flags, desc);
+ /* Best option: one for change interrupt, one per vq. */
+ nvectors = 1;
+ for (i = 0; i < nvqs; ++i)
+ if (callbacks[i])
+ ++nvectors;
} else {
- err = pci_alloc_irq_vectors(vp_dev->pci_dev, 2, 2,
- PCI_IRQ_MSIX);
- }
- if (err < 0)
- return err;
-
- vp_dev->msix_vectors = nvectors;
- vp_dev->msix_names = kmalloc_array(nvectors,
- sizeof(*vp_dev->msix_names), GFP_KERNEL);
- if (!vp_dev->msix_names)
- goto out_free_irq_vectors;
-
- vp_dev->msix_affinity_masks = kcalloc(nvectors,
- sizeof(*vp_dev->msix_affinity_masks), GFP_KERNEL);
- if (!vp_dev->msix_affinity_masks)
- goto out_free_msix_names;
-
- for (i = 0; i < nvectors; ++i) {
- if (!alloc_cpumask_var(&vp_dev->msix_affinity_masks[i],
- GFP_KERNEL))
- goto out_free_msix_affinity_masks;
+ /* Second best: one for change, shared for all vqs. */
+ nvectors = 2;
}
- /* Set the vector used for configuration */
- snprintf(vp_dev->msix_names[0], sizeof(*vp_dev->msix_names),
- "%s-config", name);
- err = request_irq(pci_irq_vector(vp_dev->pci_dev, 0), vp_config_changed,
- 0, vp_dev->msix_names[0], vp_dev);
+ err = vp_request_msix_vectors(vdev, nvectors, per_vq_vectors,
+ per_vq_vectors ? desc : NULL);
if (err)
- goto out_free_irq_vectors;
+ goto error_find;
- /* Verify we had enough resources to assign the vector */
- if (vp_dev->config_vector(vp_dev, 0) == VIRTIO_MSI_NO_VECTOR) {
- err = -EBUSY;
- goto out_free_config_irq;
+ if (per_vq_vectors) {
+ vp_dev->msix_vector_map = kmalloc_array(nvqs,
+ sizeof(*vp_dev->msix_vector_map), GFP_KERNEL);
+ if (!vp_dev->msix_vector_map)
+ goto error_find;
}
- vp_dev->msix_vector_map = kmalloc_array(nvqs,
- sizeof(*vp_dev->msix_vector_map), GFP_KERNEL);
- if (!vp_dev->msix_vector_map)
- goto out_disable_config_irq;
-
- allocated_vectors = 1; /* vector 0 is the config interrupt */
+ allocated_vectors = vp_dev->msix_used_vectors;
for (i = 0; i < nvqs; ++i) {
if (!names[i]) {
vqs[i] = NULL;
continue;
}
- if (callbacks[i])
- msix_vec = allocated_vectors;
- else
+ if (!callbacks[i])
msix_vec = VIRTIO_MSI_NO_VECTOR;
-
+ else if (per_vq_vectors)
+ msix_vec = allocated_vectors++;
+ else
+ msix_vec = VP_MSIX_VQ_VECTOR;
vqs[i] = vp_dev->setup_vq(vp_dev, i, callbacks[i], names[i],
msix_vec);
if (IS_ERR(vqs[i])) {
err = PTR_ERR(vqs[i]);
- goto out_remove_vqs;
+ goto error_find;
}
+ if (!per_vq_vectors)
+ continue;
+
if (msix_vec == VIRTIO_MSI_NO_VECTOR) {
vp_dev->msix_vector_map[i] = VIRTIO_MSI_NO_VECTOR;
continue;
}
- snprintf(vp_dev->msix_names[i + 1],
- sizeof(*vp_dev->msix_names), "%s-%s",
+ /* allocate per-vq irq if available and necessary */
+ snprintf(vp_dev->msix_names[msix_vec],
+ sizeof *vp_dev->msix_names,
+ "%s-%s",
dev_name(&vp_dev->vdev.dev), names[i]);
err = request_irq(pci_irq_vector(vp_dev->pci_dev, msix_vec),
- vring_interrupt, IRQF_SHARED,
- vp_dev->msix_names[i + 1], vqs[i]);
+ vring_interrupt, 0,
+ vp_dev->msix_names[msix_vec],
+ vqs[i]);
if (err) {
/* don't free this irq on error */
vp_dev->msix_vector_map[i] = VIRTIO_MSI_NO_VECTOR;
- goto out_remove_vqs;
+ goto error_find;
}
vp_dev->msix_vector_map[i] = msix_vec;
-
- if (per_vq_vectors)
- allocated_vectors++;
}
-
- vp_dev->msix_enabled = 1;
return 0;
-out_remove_vqs:
- vp_remove_vqs(vdev);
- kfree(vp_dev->msix_vector_map);
-out_disable_config_irq:
- vp_dev->config_vector(vp_dev, VIRTIO_MSI_NO_VECTOR);
-out_free_config_irq:
- free_irq(pci_irq_vector(vp_dev->pci_dev, 0), vp_dev);
-out_free_msix_affinity_masks:
- for (i = 0; i < nvectors; i++) {
- if (vp_dev->msix_affinity_masks[i])
- free_cpumask_var(vp_dev->msix_affinity_masks[i]);
- }
- kfree(vp_dev->msix_affinity_masks);
-out_free_msix_names:
- kfree(vp_dev->msix_names);
-out_free_irq_vectors:
- pci_free_irq_vectors(vp_dev->pci_dev);
+error_find:
+ vp_del_vqs(vdev);
return err;
}
@@ -282,8 +307,9 @@ static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned nvqs,
err = request_irq(vp_dev->pci_dev->irq, vp_interrupt, IRQF_SHARED,
dev_name(&vdev->dev), vp_dev);
if (err)
- return err;
+ goto out_del_vqs;
+ vp_dev->intx_enabled = 1;
for (i = 0; i < nvqs; ++i) {
if (!names[i]) {
vqs[i] = NULL;
@@ -293,15 +319,13 @@ static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned nvqs,
VIRTIO_MSI_NO_VECTOR);
if (IS_ERR(vqs[i])) {
err = PTR_ERR(vqs[i]);
- goto out_remove_vqs;
+ goto out_del_vqs;
}
}
return 0;
-
-out_remove_vqs:
- vp_remove_vqs(vdev);
- free_irq(pci_irq_vector(vp_dev->pci_dev, 0), vp_dev);
+out_del_vqs:
+ vp_del_vqs(vdev);
return err;
}
diff --git a/drivers/virtio/virtio_pci_common.h b/drivers/virtio/virtio_pci_common.h
index c8074997fd28..3cdabba8415e 100644
--- a/drivers/virtio/virtio_pci_common.h
+++ b/drivers/virtio/virtio_pci_common.h
@@ -66,12 +66,16 @@ struct virtio_pci_device {
/* MSI-X support */
int msix_enabled;
+ int intx_enabled;
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];
- /* Total Number of MSI-X vectors (including per-VQ ones). */
- int msix_vectors;
+ /* Number of available vectors */
+ unsigned msix_vectors;
+ /* Vectors allocated, excluding per-vq vectors if any */
+ unsigned msix_used_vectors;
+
/* Map of per-VQ MSI-X vectors, may be NULL */
unsigned *msix_vector_map;
@@ -85,6 +89,14 @@ struct virtio_pci_device {
u16 (*config_vector)(struct virtio_pci_device *vp_dev, u16 vector);
};
+/* Constants for MSI-X */
+/* Use first vector for configuration changes, second and the rest for
+ * virtqueues Thus, we need at least 2 vectors for MSI. */
+enum {
+ VP_MSIX_CONFIG_VECTOR = 0,
+ VP_MSIX_VQ_VECTOR = 1,
+};
+
/* Convert a generic virtio device to our structure */
static struct virtio_pci_device *to_vp_device(struct virtio_device *vdev)
{