[PATCH 2/2] virtio: fix vq # when vq skipped

Michael S. Tsirkin
2024-07-05T10:09:13Z

virtio balloon communicates to the core that in some
configurations vq #s are non-contiguous by setting name
pointer to NULL.

Unfortunately, core then turned around and just made them
contiguous again. Result is that driver is out of spec.

Implement what the API was supposed to do
in the 1st place. Compatibility with buggy hypervisors
is handled inside virtio-balloon, which is the only driver
making use of this facility, so far.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
arch/um/drivers/virtio_uml.c | 4 ++--
drivers/remoteproc/remoteproc_virtio.c | 4 ++--
drivers/s390/virtio/virtio_ccw.c | 4 ++--
drivers/virtio/virtio_mmio.c | 4 ++--
drivers/virtio/virtio_pci_common.c | 8 ++++----
drivers/virtio/virtio_vdpa.c | 4 ++--
6 files changed, 14 insertions(+), 14 deletions(-)

diff --git a/arch/um/drivers/virtio_uml.c b/arch/um/drivers/virtio_uml.c
index 77faa2cf3a13..d65346cd340e 100644
--- a/arch/um/drivers/virtio_uml.c
+++ b/arch/um/drivers/virtio_uml.c
@@ -1019,7 +1019,7 @@ static int vu_find_vqs(struct virtio_device *vdev, unsigned nvqs,
struct irq_affinity *desc)
{
struct virtio_uml_device *vu_dev = to_virtio_uml_device(vdev);
- int i, queue_idx = 0, rc;
+ int i, rc;
struct virtqueue *vq;

/* not supported for now */
@@ -1036,7 +1036,7 @@ static int vu_find_vqs(struct virtio_device *vdev, unsigned nvqs,
continue;
}

- vqs[i] = vu_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
+ vqs[i] = vu_setup_vq(vdev, i, callbacks[i], names[i],
ctx ? ctx[i] : false);
if (IS_ERR(vqs[i])) {
rc = PTR_ERR(vqs[i]);
diff --git a/drivers/remoteproc/remoteproc_virtio.c b/drivers/remoteproc/remoteproc_virtio.c
index 25b66b113b69..2d17135abb66 100644
--- a/drivers/remoteproc/remoteproc_virtio.c
+++ b/drivers/remoteproc/remoteproc_virtio.c
@@ -187,7 +187,7 @@ static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
const bool * ctx,
struct irq_affinity *desc)
{
- int i, ret, queue_idx = 0;
+ int i, ret;

for (i = 0; i < nvqs; ++i) {
if (!names[i]) {
@@ -195,7 +195,7 @@ static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
continue;
}

- vqs[i] = rp_find_vq(vdev, queue_idx++, callbacks[i], names[i],
+ vqs[i] = rp_find_vq(vdev, i, callbacks[i], names[i],
ctx ? ctx[i] : false);
if (IS_ERR(vqs[i])) {
ret = PTR_ERR(vqs[i]);
diff --git a/drivers/s390/virtio/virtio_ccw.c b/drivers/s390/virtio/virtio_ccw.c
index d6491fc84e8c..64541b3bb8a2 100644
--- a/drivers/s390/virtio/virtio_ccw.c
+++ b/drivers/s390/virtio/virtio_ccw.c
@@ -696,7 +696,7 @@ static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
{
struct virtio_ccw_device *vcdev = to_vc_device(vdev);
dma64_t *indicatorp = NULL;
- int ret, i, queue_idx = 0;
+ int ret, i;
struct ccw1 *ccw;
dma32_t indicatorp_dma = 0;

@@ -710,7 +710,7 @@ static int virtio_ccw_find_vqs(struct virtio_device *vdev, unsigned nvqs,
continue;
}

- vqs[i] = virtio_ccw_setup_vq(vdev, queue_idx++, callbacks[i],
+ vqs[i] = virtio_ccw_setup_vq(vdev, i, callbacks[i],
names[i], ctx ? ctx[i] : false,
ccw);
if (IS_ERR(vqs[i])) {
diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c
index 173596589c71..a3a66a0b7cb1 100644
--- a/drivers/virtio/virtio_mmio.c
+++ b/drivers/virtio/virtio_mmio.c
@@ -496,7 +496,7 @@ static int vm_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
{
struct virtio_mmio_device *vm_dev = to_virtio_mmio_device(vdev);
int irq = platform_get_irq(vm_dev->pdev, 0);
- int i, err, queue_idx = 0;
+ int i, err;

if (irq < 0)
return irq;
@@ -515,7 +515,7 @@ static int vm_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
continue;
}

- vqs[i] = vm_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
+ vqs[i] = vm_setup_vq(vdev, i, callbacks[i], names[i],
ctx ? ctx[i] : false);
if (IS_ERR(vqs[i])) {
vm_del_vqs(vdev);
diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c
index f6b0b00e4599..eeff060cacec 100644
--- a/drivers/virtio/virtio_pci_common.c
+++ b/drivers/virtio/virtio_pci_common.c
@@ -292,7 +292,7 @@ static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned int nvqs,
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
u16 msix_vec;
- int i, err, nvectors, allocated_vectors, queue_idx = 0;
+ int i, err, nvectors, allocated_vectors;

vp_dev->vqs = kcalloc(nvqs, sizeof(*vp_dev->vqs), GFP_KERNEL);
if (!vp_dev->vqs)
@@ -328,7 +328,7 @@ static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned int nvqs,
msix_vec = allocated_vectors++;
else
msix_vec = VP_MSIX_VQ_VECTOR;
- vqs[i] = vp_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
+ vqs[i] = vp_setup_vq(vdev, i, callbacks[i], names[i],
ctx ? ctx[i] : false,
msix_vec);
if (IS_ERR(vqs[i])) {
@@ -365,7 +365,7 @@ static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned int nvqs,
const char * const names[], const bool *ctx)
{
struct virtio_pci_device *vp_dev = to_vp_device(vdev);
- int i, err, queue_idx = 0;
+ int i, err;

vp_dev->vqs = kcalloc(nvqs, sizeof(*vp_dev->vqs), GFP_KERNEL);
if (!vp_dev->vqs)
@@ -383,7 +383,7 @@ static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned int nvqs,
vqs[i] = NULL;
continue;
}
- vqs[i] = vp_setup_vq(vdev, queue_idx++, callbacks[i], names[i],
+ vqs[i] = vp_setup_vq(vdev, i, callbacks[i], names[i],
ctx ? ctx[i] : false,
VIRTIO_MSI_NO_VECTOR);
if (IS_ERR(vqs[i])) {
diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c
index e803db0da307..fe91a5d673dc 100644
--- a/drivers/virtio/virtio_vdpa.c
+++ b/drivers/virtio/virtio_vdpa.c
@@ -370,7 +370,7 @@ static int virtio_vdpa_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
struct cpumask *masks;
struct vdpa_callback cb;
bool has_affinity = desc && ops->set_vq_affinity;
- int i, err, queue_idx = 0;
+ int i, err;

if (has_affinity) {
masks = create_affinity_masks(nvqs, desc ? desc : &default_affd);
@@ -384,7 +384,7 @@ static int virtio_vdpa_find_vqs(struct virtio_device *vdev, unsigned int nvqs,
continue;
}

- vqs[i] = virtio_vdpa_setup_vq(vdev, queue_idx++,
+ vqs[i] = virtio_vdpa_setup_vq(vdev, i,
callbacks[i], names[i], ctx ?
ctx[i] : false);
if (IS_ERR(vqs[i])) {
--
MST