| Message ID | 3d655be73ce220f176b2c163839d83699f8faf43.1720611677.git.mst@redhat.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | None | expand |
On Wed, 10 Jul 2024 at 05:43, Michael S. Tsirkin <mst@redhat.com> wrote: > > 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. > > Message-ID: <cover.1720173841.git.mst@redhat.com> > Fixes: b0c504f15471 ("virtio-balloon: add support for providing free page reports to host") > Cc: "Alexander Duyck" <alexander.h.duyck@linux.intel.com> > Signed-off-by: Michael S. Tsirkin <mst@redhat.com> > --- > arch/um/drivers/virtio_uml.c | 4 ++-- > drivers/remoteproc/remoteproc_virtio.c | 4 ++-- Reviewed-by: Mathieu Poirier <mathieu.poirier@linaro.org> > drivers/s390/virtio/virtio_ccw.c | 4 ++-- > drivers/virtio/virtio_mmio.c | 4 ++-- > drivers/virtio/virtio_pci_common.c | 11 ++++++++--- > drivers/virtio/virtio_vdpa.c | 4 ++-- > 6 files changed, 18 insertions(+), 13 deletions(-) > > diff --git a/arch/um/drivers/virtio_uml.c b/arch/um/drivers/virtio_uml.c > index 2b6e701776b6..c903e4959f51 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 */ > @@ -1038,7 +1038,7 @@ static int vu_find_vqs(struct virtio_device *vdev, unsigned nvqs, > continue; > } > > - vqs[i] = vu_setup_vq(vdev, queue_idx++, vqi->callback, > + vqs[i] = vu_setup_vq(vdev, i, vqi->callback, > vqi->name, vqi->ctx); > 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 d3f39009b28e..1019b2825c26 100644 > --- a/drivers/remoteproc/remoteproc_virtio.c > +++ b/drivers/remoteproc/remoteproc_virtio.c > @@ -185,7 +185,7 @@ static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned int nvqs, > struct virtqueue_info vqs_info[], > struct irq_affinity *desc) > { > - int i, ret, queue_idx = 0; > + int i, ret; > > for (i = 0; i < nvqs; ++i) { > struct virtqueue_info *vqi = &vqs_info[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++, vqi->callback, > + vqs[i] = rp_find_vq(vdev, i, vqi->callback, > vqi->name, vqi->ctx); > 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 62eca9419ad7..82a3440bbabb 100644 > --- a/drivers/s390/virtio/virtio_ccw.c > +++ b/drivers/s390/virtio/virtio_ccw.c > @@ -694,7 +694,7 @@ 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++, vqi->callback, > + vqs[i] = virtio_ccw_setup_vq(vdev, i, vqi->callback, > vqi->name, vqi->ctx, ccw); > if (IS_ERR(vqs[i])) { > ret = PTR_ERR(vqs[i]); > diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c > index 90e784e7b721..db6a0366f082 100644 > --- a/drivers/virtio/virtio_mmio.c > +++ b/drivers/virtio/virtio_mmio.c > @@ -494,7 +494,7 @@ 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++, vqi->callback, > + vqs[i] = vm_setup_vq(vdev, i, vqi->callback, > vqi->name, vqi->ctx); > 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 7d82facafd75..fa606e7321ad 100644 > --- a/drivers/virtio/virtio_pci_common.c > +++ b/drivers/virtio/virtio_pci_common.c > @@ -293,7 +293,7 @@ static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned int nvqs, > struct virtio_pci_device *vp_dev = to_vp_device(vdev); > struct virtqueue_info *vqi; > 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) > @@ -332,7 +332,7 @@ 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++, vqi->callback, > + vqs[i] = vp_setup_vq(vdev, i, vqi->callback, > vqi->name, vqi->ctx, msix_vec); > if (IS_ERR(vqs[i])) { > err = PTR_ERR(vqs[i]); > @@ -368,7 +368,7 @@ static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned int nvqs, > struct virtqueue_info vqs_info[]) > { > 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) > @@ -388,8 +388,13 @@ static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned int nvqs, > vqs[i] = NULL; > continue; > } > +<<<<<<< HEAD > vqs[i] = vp_setup_vq(vdev, queue_idx++, vqi->callback, > vqi->name, vqi->ctx, > +======= > + vqs[i] = vp_setup_vq(vdev, i, callbacks[i], names[i], > + ctx ? ctx[i] : false, > +>>>>>>> f814759f80b7... virtio: fix vq # for balloon > VIRTIO_MSI_NO_VECTOR); > if (IS_ERR(vqs[i])) { > err = PTR_ERR(vqs[i]); > diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c > index 7364bd53e38d..149e893583e9 100644 > --- a/drivers/virtio/virtio_vdpa.c > +++ b/drivers/virtio/virtio_vdpa.c > @@ -368,7 +368,7 @@ 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++, vqi->callback, > + vqs[i] = virtio_vdpa_setup_vq(vdev, i, vqi->callback, > vqi->name, vqi->ctx); > if (IS_ERR(vqs[i])) { > err = PTR_ERR(vqs[i]); > -- > MST >
On Wed, Jul 10, 2024 at 4:43 AM Michael S. Tsirkin <mst@redhat.com> wrote: > > 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. Thanks for fixing this - I think the overall approach of the patch looks good. > 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. In addition to virtio-balloon, I believe the same problem also affects the virtio-fs device, since queue 1 is only supposed to be present if VIRTIO_FS_F_NOTIFICATION is negotiated, and the request queues are meant to be queue indexes 2 and up. From a look at the Linux driver (virtio_fs.c), it appears like it never acks VIRTIO_FS_F_NOTIFICATION and assumes that request queues start at index 1 rather than 2, which looks out of spec to me, but the current device implementations (that I am aware of, anyway) are also broken in the same way, so it ends up working today. Queue numbering in a spec-compliant device and the current Linux driver would mismatch; what the driver considers to be the first request queue (index 1) would be ignored by the device since queue index 1 has no function if F_NOTIFICATION isn't negotiated. [...] > diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c > index 7d82facafd75..fa606e7321ad 100644 > --- a/drivers/virtio/virtio_pci_common.c > +++ b/drivers/virtio/virtio_pci_common.c > @@ -293,7 +293,7 @@ static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned int nvqs, > struct virtio_pci_device *vp_dev = to_vp_device(vdev); > struct virtqueue_info *vqi; > 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) > @@ -332,7 +332,7 @@ 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++, vqi->callback, > + vqs[i] = vp_setup_vq(vdev, i, vqi->callback, > vqi->name, vqi->ctx, msix_vec); > if (IS_ERR(vqs[i])) { > err = PTR_ERR(vqs[i]); > @@ -368,7 +368,7 @@ static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned int nvqs, > struct virtqueue_info vqs_info[]) > { > 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) > @@ -388,8 +388,13 @@ static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned int nvqs, > vqs[i] = NULL; > continue; > } > +<<<<<<< HEAD > vqs[i] = vp_setup_vq(vdev, queue_idx++, vqi->callback, > vqi->name, vqi->ctx, > +======= > + vqs[i] = vp_setup_vq(vdev, i, callbacks[i], names[i], > + ctx ? ctx[i] : false, > +>>>>>>> f814759f80b7... virtio: fix vq # for balloon This still has merge markers in it. Thanks, -- Daniel
On Wed, Jul 10, 2024 at 11:12:34AM -0700, Daniel Verkamp wrote: > On Wed, Jul 10, 2024 at 4:43 AM Michael S. Tsirkin <mst@redhat.com> wrote: > > > > 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. > > Thanks for fixing this - I think the overall approach of the patch looks good. > > > 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. > > In addition to virtio-balloon, I believe the same problem also affects > the virtio-fs device, since queue 1 is only supposed to be present if > VIRTIO_FS_F_NOTIFICATION is negotiated, and the request queues are > meant to be queue indexes 2 and up. From a look at the Linux driver > (virtio_fs.c), it appears like it never acks VIRTIO_FS_F_NOTIFICATION > and assumes that request queues start at index 1 rather than 2, which > looks out of spec to me, but the current device implementations (that > I am aware of, anyway) are also broken in the same way, so it ends up > working today. Queue numbering in a spec-compliant device and the > current Linux driver would mismatch; what the driver considers to be > the first request queue (index 1) would be ignored by the device since > queue index 1 has no function if F_NOTIFICATION isn't negotiated. Oh, thanks a lot for pointing this out! I see so this patch is no good as is, we need to add a workaround for virtio-fs first. QEMU workaround is simple - just add an extra queue. But I did not reasearch how this would interact with vhost-user. From driver POV, I guess we could just ignore queue # 1 - would that be ok or does it have performance implications? Or do what I did for balloon here: try with spec compliant #s first, if that fails then assume it's the spec issue and shift by 1. > [...] > > diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c > > index 7d82facafd75..fa606e7321ad 100644 > > --- a/drivers/virtio/virtio_pci_common.c > > +++ b/drivers/virtio/virtio_pci_common.c > > @@ -293,7 +293,7 @@ static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned int nvqs, > > struct virtio_pci_device *vp_dev = to_vp_device(vdev); > > struct virtqueue_info *vqi; > > 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) > > @@ -332,7 +332,7 @@ 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++, vqi->callback, > > + vqs[i] = vp_setup_vq(vdev, i, vqi->callback, > > vqi->name, vqi->ctx, msix_vec); > > if (IS_ERR(vqs[i])) { > > err = PTR_ERR(vqs[i]); > > @@ -368,7 +368,7 @@ static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned int nvqs, > > struct virtqueue_info vqs_info[]) > > { > > 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) > > @@ -388,8 +388,13 @@ static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned int nvqs, > > vqs[i] = NULL; > > continue; > > } > > +<<<<<<< HEAD > > vqs[i] = vp_setup_vq(vdev, queue_idx++, vqi->callback, > > vqi->name, vqi->ctx, > > +======= > > + vqs[i] = vp_setup_vq(vdev, i, callbacks[i], names[i], > > + ctx ? ctx[i] : false, > > +>>>>>>> f814759f80b7... virtio: fix vq # for balloon > > This still has merge markers in it. > > Thanks, > -- Daniel
On Wed, Jul 10, 2024 at 11:12:34AM -0700, Daniel Verkamp wrote: > On Wed, Jul 10, 2024 at 4:43 AM Michael S. Tsirkin <mst@redhat.com> wrote: > > > > 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. > > Thanks for fixing this - I think the overall approach of the patch looks good. > > > 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. > > In addition to virtio-balloon, I believe the same problem also affects > the virtio-fs device, since queue 1 is only supposed to be present if > VIRTIO_FS_F_NOTIFICATION is negotiated, and the request queues are > meant to be queue indexes 2 and up. From a look at the Linux driver > (virtio_fs.c), it appears like it never acks VIRTIO_FS_F_NOTIFICATION > and assumes that request queues start at index 1 rather than 2, which > looks out of spec to me, but the current device implementations (that > I am aware of, anyway) are also broken in the same way, so it ends up > working today. Queue numbering in a spec-compliant device and the > current Linux driver would mismatch; what the driver considers to be > the first request queue (index 1) would be ignored by the device since > queue index 1 has no function if F_NOTIFICATION isn't negotiated. > > [...] > > diff --git a/drivers/virtio/virtio_pci_common.c b/drivers/virtio/virtio_pci_common.c > > index 7d82facafd75..fa606e7321ad 100644 > > --- a/drivers/virtio/virtio_pci_common.c > > +++ b/drivers/virtio/virtio_pci_common.c > > @@ -293,7 +293,7 @@ static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned int nvqs, > > struct virtio_pci_device *vp_dev = to_vp_device(vdev); > > struct virtqueue_info *vqi; > > 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) > > @@ -332,7 +332,7 @@ 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++, vqi->callback, > > + vqs[i] = vp_setup_vq(vdev, i, vqi->callback, > > vqi->name, vqi->ctx, msix_vec); > > if (IS_ERR(vqs[i])) { > > err = PTR_ERR(vqs[i]); > > @@ -368,7 +368,7 @@ static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned int nvqs, > > struct virtqueue_info vqs_info[]) > > { > > 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) > > @@ -388,8 +388,13 @@ static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned int nvqs, > > vqs[i] = NULL; > > continue; > > } > > +<<<<<<< HEAD > > vqs[i] = vp_setup_vq(vdev, queue_idx++, vqi->callback, > > vqi->name, vqi->ctx, > > +======= > > + vqs[i] = vp_setup_vq(vdev, i, callbacks[i], names[i], > > + ctx ? ctx[i] : false, > > +>>>>>>> f814759f80b7... virtio: fix vq # for balloon > > This still has merge markers in it. > > Thanks, > -- Daniel ouch forgot to commit ;)
On Wed, Jul 10, 2024 at 11:39 AM Michael S. Tsirkin <mst@redhat.com> wrote: > > On Wed, Jul 10, 2024 at 11:12:34AM -0700, Daniel Verkamp wrote: > > On Wed, Jul 10, 2024 at 4:43 AM Michael S. Tsirkin <mst@redhat.com> wrote: > > > > > > 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. > > > > Thanks for fixing this - I think the overall approach of the patch looks good. > > > > > 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. > > > > In addition to virtio-balloon, I believe the same problem also affects > > the virtio-fs device, since queue 1 is only supposed to be present if > > VIRTIO_FS_F_NOTIFICATION is negotiated, and the request queues are > > meant to be queue indexes 2 and up. From a look at the Linux driver > > (virtio_fs.c), it appears like it never acks VIRTIO_FS_F_NOTIFICATION > > and assumes that request queues start at index 1 rather than 2, which > > looks out of spec to me, but the current device implementations (that > > I am aware of, anyway) are also broken in the same way, so it ends up > > working today. Queue numbering in a spec-compliant device and the > > current Linux driver would mismatch; what the driver considers to be > > the first request queue (index 1) would be ignored by the device since > > queue index 1 has no function if F_NOTIFICATION isn't negotiated. > > > Oh, thanks a lot for pointing this out! > > I see so this patch is no good as is, we need to add a workaround for > virtio-fs first. > > QEMU workaround is simple - just add an extra queue. But I did not > reasearch how this would interact with vhost-user. > > From driver POV, I guess we could just ignore queue # 1 - would that be > ok or does it have performance implications? As a driver workaround for non-compliant devices, I think ignoring the first request queue would be a reasonable approach if the device's config advertises num_request_queues > 1. Unfortunately, both virtiofsd and crosvm's virtio-fs device have hard-coded num_request_queues =1, so this won't help with those existing devices. Maybe there are other devices that we would need to consider as well; commit 529395d2ae64 ("virtio-fs: add multi-queue support") quotes benchmarks that seem to be from a different virtio-fs implementation that does support multiple request queues, so the workaround could possibly be used there. > Or do what I did for balloon here: try with spec compliant #s first, > if that fails then assume it's the spec issue and shift by 1. If there is a way to "guess and check" without breaking spec-compliant devices, that sounds reasonable too; however, I'm not sure how this would work out in practice: an existing non-compliant device may fail to start if the driver tries to enable queue index 2 when it only supports one request queue, and a spec-compliant device would probably balk if the driver tries to enable queue 1 but does not negotiate VIRTIO_FS_F_NOTIFICATION. If there's a way to reset and retry the whole virtio device initialization process if a device fails like this, then maybe it's feasible. (Or can the driver tweak the virtqueue configuration and try to set DRIVER_OK repeatedly until it works? It's not clear to me if this is allowed by the spec, or what device implementations actually do in practice in this scenario.) Thanks, -- Daniel
On Wed, Jul 10, 2024 at 12:58:11PM -0700, Daniel Verkamp wrote: > On Wed, Jul 10, 2024 at 11:39 AM Michael S. Tsirkin <mst@redhat.com> wrote: > > > > On Wed, Jul 10, 2024 at 11:12:34AM -0700, Daniel Verkamp wrote: > > > On Wed, Jul 10, 2024 at 4:43 AM Michael S. Tsirkin <mst@redhat.com> wrote: > > > > > > > > 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. > > > > > > Thanks for fixing this - I think the overall approach of the patch looks good. > > > > > > > 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. > > > > > > In addition to virtio-balloon, I believe the same problem also affects > > > the virtio-fs device, since queue 1 is only supposed to be present if > > > VIRTIO_FS_F_NOTIFICATION is negotiated, and the request queues are > > > meant to be queue indexes 2 and up. From a look at the Linux driver > > > (virtio_fs.c), it appears like it never acks VIRTIO_FS_F_NOTIFICATION > > > and assumes that request queues start at index 1 rather than 2, which > > > looks out of spec to me, but the current device implementations (that > > > I am aware of, anyway) are also broken in the same way, so it ends up > > > working today. Queue numbering in a spec-compliant device and the > > > current Linux driver would mismatch; what the driver considers to be > > > the first request queue (index 1) would be ignored by the device since > > > queue index 1 has no function if F_NOTIFICATION isn't negotiated. > > > > > > Oh, thanks a lot for pointing this out! > > > > I see so this patch is no good as is, we need to add a workaround for > > virtio-fs first. > > > > QEMU workaround is simple - just add an extra queue. But I did not > > reasearch how this would interact with vhost-user. > > > > From driver POV, I guess we could just ignore queue # 1 - would that be > > ok or does it have performance implications? > > As a driver workaround for non-compliant devices, I think ignoring the > first request queue would be a reasonable approach if the device's > config advertises num_request_queues > 1. Unfortunately, both > virtiofsd and crosvm's virtio-fs device have hard-coded > num_request_queues =1, so this won't help with those existing devices. Do they care what the vq # is though? We could do some magic to translate VQ #s in qemu. > Maybe there are other devices that we would need to consider as well; > commit 529395d2ae64 ("virtio-fs: add multi-queue support") quotes > benchmarks that seem to be from a different virtio-fs implementation > that does support multiple request queues, so the workaround could > possibly be used there. > > > Or do what I did for balloon here: try with spec compliant #s first, > > if that fails then assume it's the spec issue and shift by 1. > > If there is a way to "guess and check" without breaking spec-compliant > devices, that sounds reasonable too; however, I'm not sure how this > would work out in practice: an existing non-compliant device may fail > to start if the driver tries to enable queue index 2 when it only > supports one request queue, You don't try to enable queue - driver starts by checking queue size. The way my patch works is that it assumes a non existing queue has size 0 if not available. This was actually a documented way to check for PCI and MMIO: Read the virtqueue size from queue_size. This controls how big the virtqueue is (see 2.6 Virtqueues). If this field is 0, the virtqueue does not exist. MMIO: If the returned value is zero (0x0) the queue is not available. unfortunately not for CCW, but I guess CCW implementations outside of QEMU are uncommon enough that we can assume it's the same? To me the above is also a big hint that drivers are allowed to query size for queues that do not exist. > and a spec-compliant device would probably > balk if the driver tries to enable queue 1 but does not negotiate > VIRTIO_FS_F_NOTIFICATION. If there's a way to reset and retry the > whole virtio device initialization process if a device fails like > this, then maybe it's feasible. (Or can the driver tweak the virtqueue > configuration and try to set DRIVER_OK repeatedly until it works? It's > not clear to me if this is allowed by the spec, or what device > implementations actually do in practice in this scenario.) > > Thanks, > -- Daniel My patch starts with a spec compliant behaviour. If that fails, try non-compliant one as a fallback.
On Wed, Jul 10, 2024 at 1:39 PM Michael S. Tsirkin <mst@redhat.com> wrote: > > On Wed, Jul 10, 2024 at 12:58:11PM -0700, Daniel Verkamp wrote: > > On Wed, Jul 10, 2024 at 11:39 AM Michael S. Tsirkin <mst@redhat.com> wrote: > > > > > > On Wed, Jul 10, 2024 at 11:12:34AM -0700, Daniel Verkamp wrote: > > > > On Wed, Jul 10, 2024 at 4:43 AM Michael S. Tsirkin <mst@redhat.com> wrote: > > > > > > > > > > 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. > > > > > > > > Thanks for fixing this - I think the overall approach of the patch looks good. > > > > > > > > > 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. > > > > > > > > In addition to virtio-balloon, I believe the same problem also affects > > > > the virtio-fs device, since queue 1 is only supposed to be present if > > > > VIRTIO_FS_F_NOTIFICATION is negotiated, and the request queues are > > > > meant to be queue indexes 2 and up. From a look at the Linux driver > > > > (virtio_fs.c), it appears like it never acks VIRTIO_FS_F_NOTIFICATION > > > > and assumes that request queues start at index 1 rather than 2, which > > > > looks out of spec to me, but the current device implementations (that > > > > I am aware of, anyway) are also broken in the same way, so it ends up > > > > working today. Queue numbering in a spec-compliant device and the > > > > current Linux driver would mismatch; what the driver considers to be > > > > the first request queue (index 1) would be ignored by the device since > > > > queue index 1 has no function if F_NOTIFICATION isn't negotiated. > > > > > > > > > Oh, thanks a lot for pointing this out! > > > > > > I see so this patch is no good as is, we need to add a workaround for > > > virtio-fs first. > > > > > > QEMU workaround is simple - just add an extra queue. But I did not > > > reasearch how this would interact with vhost-user. > > > > > > From driver POV, I guess we could just ignore queue # 1 - would that be > > > ok or does it have performance implications? > > > > As a driver workaround for non-compliant devices, I think ignoring the > > first request queue would be a reasonable approach if the device's > > config advertises num_request_queues > 1. Unfortunately, both > > virtiofsd and crosvm's virtio-fs device have hard-coded > > num_request_queues =1, so this won't help with those existing devices. > > Do they care what the vq # is though? > We could do some magic to translate VQ #s in qemu. > > > > Maybe there are other devices that we would need to consider as well; > > commit 529395d2ae64 ("virtio-fs: add multi-queue support") quotes > > benchmarks that seem to be from a different virtio-fs implementation > > that does support multiple request queues, so the workaround could > > possibly be used there. > > > > > Or do what I did for balloon here: try with spec compliant #s first, > > > if that fails then assume it's the spec issue and shift by 1. > > > > If there is a way to "guess and check" without breaking spec-compliant > > devices, that sounds reasonable too; however, I'm not sure how this > > would work out in practice: an existing non-compliant device may fail > > to start if the driver tries to enable queue index 2 when it only > > supports one request queue, > > You don't try to enable queue - driver starts by checking queue size. > The way my patch works is that it assumes a non existing queue has > size 0 if not available. > > This was actually a documented way to check for PCI and MMIO: > Read the virtqueue size from queue_size. This controls how big the virtqueue is (see 2.6 Virtqueues). > If this field is 0, the virtqueue does not exist. > MMIO: > If the returned value is zero (0x0) the queue is not available. > > unfortunately not for CCW, but I guess CCW implementations outside > of QEMU are uncommon enough that we can assume it's the same? > > > To me the above is also a big hint that drivers are allowed to > query size for queues that do not exist. Ah, that makes total sense - detecting queue presence by non-zero queue size sounds good to me, and it should work in the normal virtio device case. I am not sure about vhost-user, since there is no way for the front-end to ask the back-end for a queue's size; the confusingly named VHOST_USER_SET_VRING_NUM allows the front-end to configure the size of a queue, but there's no corresponding GET message. > > and a spec-compliant device would probably > > balk if the driver tries to enable queue 1 but does not negotiate > > VIRTIO_FS_F_NOTIFICATION. If there's a way to reset and retry the > > whole virtio device initialization process if a device fails like > > this, then maybe it's feasible. (Or can the driver tweak the virtqueue > > configuration and try to set DRIVER_OK repeatedly until it works? It's > > not clear to me if this is allowed by the spec, or what device > > implementations actually do in practice in this scenario.) > > > > Thanks, > > -- Daniel > > My patch starts with a spec compliant behaviour. If that fails, > try non-compliant one as a fallback. Got it, that sounds reasonable to me given the explanation above. Thanks, -- Daniel
On Wed, Jul 10, 2024 at 03:54:22PM -0700, Daniel Verkamp wrote: > On Wed, Jul 10, 2024 at 1:39 PM Michael S. Tsirkin <mst@redhat.com> wrote: > > > > On Wed, Jul 10, 2024 at 12:58:11PM -0700, Daniel Verkamp wrote: > > > On Wed, Jul 10, 2024 at 11:39 AM Michael S. Tsirkin <mst@redhat.com> wrote: > > > > > > > > On Wed, Jul 10, 2024 at 11:12:34AM -0700, Daniel Verkamp wrote: > > > > > On Wed, Jul 10, 2024 at 4:43 AM Michael S. Tsirkin <mst@redhat.com> wrote: > > > > > > > > > > > > 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. > > > > > > > > > > Thanks for fixing this - I think the overall approach of the patch looks good. > > > > > > > > > > > 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. > > > > > > > > > > In addition to virtio-balloon, I believe the same problem also affects > > > > > the virtio-fs device, since queue 1 is only supposed to be present if > > > > > VIRTIO_FS_F_NOTIFICATION is negotiated, and the request queues are > > > > > meant to be queue indexes 2 and up. From a look at the Linux driver > > > > > (virtio_fs.c), it appears like it never acks VIRTIO_FS_F_NOTIFICATION > > > > > and assumes that request queues start at index 1 rather than 2, which > > > > > looks out of spec to me, but the current device implementations (that > > > > > I am aware of, anyway) are also broken in the same way, so it ends up > > > > > working today. Queue numbering in a spec-compliant device and the > > > > > current Linux driver would mismatch; what the driver considers to be > > > > > the first request queue (index 1) would be ignored by the device since > > > > > queue index 1 has no function if F_NOTIFICATION isn't negotiated. > > > > > > > > > > > > Oh, thanks a lot for pointing this out! > > > > > > > > I see so this patch is no good as is, we need to add a workaround for > > > > virtio-fs first. > > > > > > > > QEMU workaround is simple - just add an extra queue. But I did not > > > > reasearch how this would interact with vhost-user. > > > > > > > > From driver POV, I guess we could just ignore queue # 1 - would that be > > > > ok or does it have performance implications? > > > > > > As a driver workaround for non-compliant devices, I think ignoring the > > > first request queue would be a reasonable approach if the device's > > > config advertises num_request_queues > 1. Unfortunately, both > > > virtiofsd and crosvm's virtio-fs device have hard-coded > > > num_request_queues =1, so this won't help with those existing devices. > > > > Do they care what the vq # is though? > > We could do some magic to translate VQ #s in qemu. > > > > > > > Maybe there are other devices that we would need to consider as well; > > > commit 529395d2ae64 ("virtio-fs: add multi-queue support") quotes > > > benchmarks that seem to be from a different virtio-fs implementation > > > that does support multiple request queues, so the workaround could > > > possibly be used there. > > > > > > > Or do what I did for balloon here: try with spec compliant #s first, > > > > if that fails then assume it's the spec issue and shift by 1. > > > > > > If there is a way to "guess and check" without breaking spec-compliant > > > devices, that sounds reasonable too; however, I'm not sure how this > > > would work out in practice: an existing non-compliant device may fail > > > to start if the driver tries to enable queue index 2 when it only > > > supports one request queue, > > > > You don't try to enable queue - driver starts by checking queue size. > > The way my patch works is that it assumes a non existing queue has > > size 0 if not available. > > > > This was actually a documented way to check for PCI and MMIO: > > Read the virtqueue size from queue_size. This controls how big the virtqueue is (see 2.6 Virtqueues). > > If this field is 0, the virtqueue does not exist. > > MMIO: > > If the returned value is zero (0x0) the queue is not available. > > > > unfortunately not for CCW, but I guess CCW implementations outside > > of QEMU are uncommon enough that we can assume it's the same? > > > > > > To me the above is also a big hint that drivers are allowed to > > query size for queues that do not exist. > > Ah, that makes total sense - detecting queue presence by non-zero > queue size sounds good to me, and it should work in the normal virtio > device case. > > I am not sure about vhost-user, since there is no way for the > front-end to ask the back-end for a queue's size; the confusingly > named VHOST_USER_SET_VRING_NUM allows the front-end to configure the > size of a queue, but there's no corresponding GET message. So for vhost user I would assume it is non spec compliant and qemu remaps queue numbers? And can add a backend feature for supporting VHOST_USER_GET_VRING_NUM and with that, also require that backends are spec compliant? And again, qemu can remap queue numbers. > > > and a spec-compliant device would probably > > > balk if the driver tries to enable queue 1 but does not negotiate > > > VIRTIO_FS_F_NOTIFICATION. If there's a way to reset and retry the > > > whole virtio device initialization process if a device fails like > > > this, then maybe it's feasible. (Or can the driver tweak the virtqueue > > > configuration and try to set DRIVER_OK repeatedly until it works? It's > > > not clear to me if this is allowed by the spec, or what device > > > implementations actually do in practice in this scenario.) > > > > > > Thanks, > > > -- Daniel > > > > My patch starts with a spec compliant behaviour. If that fails, > > try non-compliant one as a fallback. > > Got it, that sounds reasonable to me given the explanation above. > > Thanks, > -- Daniel
Hi Michael, kernel test robot noticed the following build errors: [auto build test ERROR on next-20240710] [cannot apply to uml/next remoteproc/rproc-next s390/features linus/master uml/fixes v6.10-rc7 v6.10-rc6 v6.10-rc5 v6.10-rc7] [If your patch is applied to the wrong git tree, kindly drop us a note. And when submitting patch, we suggest to use '--base' as documented in https://git-scm.com/docs/git-format-patch#_base_tree_information] url: https://github.com/intel-lab-lkp/linux/commits/Michael-S-Tsirkin/virtio_balloon-add-work-around-for-out-of-spec-QEMU/20240711-004346 base: next-20240710 patch link: https://lore.kernel.org/r/3d655be73ce220f176b2c163839d83699f8faf43.1720611677.git.mst%40redhat.com patch subject: [PATCH v2 2/2] virtio: fix vq # for balloon config: i386-randconfig-014-20240711 (https://download.01.org/0day-ci/archive/20240711/202407112113.SzSpdDLK-lkp@intel.com/config) compiler: clang version 18.1.5 (https://github.com/llvm/llvm-project 617a15a9eac96088ae5e9134248d8236e34b91b1) reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20240711/202407112113.SzSpdDLK-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202407112113.SzSpdDLK-lkp@intel.com/ All errors (new ones prefixed by >>): >> drivers/virtio/virtio_pci_common.c:391:1: error: version control conflict marker in file 391 | <<<<<<< HEAD | ^ >> drivers/virtio/virtio_pci_common.c:392:30: error: use of undeclared identifier 'queue_idx' 392 | vqs[i] = vp_setup_vq(vdev, queue_idx++, vqi->callback, | ^ 2 errors generated. vim +391 drivers/virtio/virtio_pci_common.c 365 366 static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned int nvqs, 367 struct virtqueue *vqs[], 368 struct virtqueue_info vqs_info[]) 369 { 370 struct virtio_pci_device *vp_dev = to_vp_device(vdev); 371 int i, err; 372 373 vp_dev->vqs = kcalloc(nvqs, sizeof(*vp_dev->vqs), GFP_KERNEL); 374 if (!vp_dev->vqs) 375 return -ENOMEM; 376 377 err = request_irq(vp_dev->pci_dev->irq, vp_interrupt, IRQF_SHARED, 378 dev_name(&vdev->dev), vp_dev); 379 if (err) 380 goto out_del_vqs; 381 382 vp_dev->intx_enabled = 1; 383 vp_dev->per_vq_vectors = false; 384 for (i = 0; i < nvqs; ++i) { 385 struct virtqueue_info *vqi = &vqs_info[i]; 386 387 if (!vqi->name) { 388 vqs[i] = NULL; 389 continue; 390 } > 391 <<<<<<< HEAD > 392 vqs[i] = vp_setup_vq(vdev, queue_idx++, vqi->callback, 393 vqi->name, vqi->ctx, 394 ======= 395 vqs[i] = vp_setup_vq(vdev, i, callbacks[i], names[i], 396 ctx ? ctx[i] : false, 397 >>>>>>> f814759f80b7... virtio: fix vq # for balloon 398 VIRTIO_MSI_NO_VECTOR); 399 if (IS_ERR(vqs[i])) { 400 err = PTR_ERR(vqs[i]); 401 goto out_del_vqs; 402 } 403 } 404 405 return 0; 406 out_del_vqs: 407 vp_del_vqs(vdev); 408 return err; 409 } 410
On Wed, 10 Jul 2024 07:42:46 -0400 "Michael S. Tsirkin" <mst@redhat.com> wrote: > --- a/drivers/s390/virtio/virtio_ccw.c > +++ b/drivers/s390/virtio/virtio_ccw.c > @@ -694,7 +694,7 @@ 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++, vqi->callback, > + vqs[i] = virtio_ccw_setup_vq(vdev, i, vqi->callback, > vqi->name, vqi->ctx, ccw); > if (IS_ERR(vqs[i])) { > ret = PTR_ERR(vqs[i]); Acked-by: Halil Pasic <pasic@linux.ibm.com> #s390
diff --git a/arch/um/drivers/virtio_uml.c b/arch/um/drivers/virtio_uml.c index 2b6e701776b6..c903e4959f51 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 */ @@ -1038,7 +1038,7 @@ static int vu_find_vqs(struct virtio_device *vdev, unsigned nvqs, continue; } - vqs[i] = vu_setup_vq(vdev, queue_idx++, vqi->callback, + vqs[i] = vu_setup_vq(vdev, i, vqi->callback, vqi->name, vqi->ctx); 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 d3f39009b28e..1019b2825c26 100644 --- a/drivers/remoteproc/remoteproc_virtio.c +++ b/drivers/remoteproc/remoteproc_virtio.c @@ -185,7 +185,7 @@ static int rproc_virtio_find_vqs(struct virtio_device *vdev, unsigned int nvqs, struct virtqueue_info vqs_info[], struct irq_affinity *desc) { - int i, ret, queue_idx = 0; + int i, ret; for (i = 0; i < nvqs; ++i) { struct virtqueue_info *vqi = &vqs_info[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++, vqi->callback, + vqs[i] = rp_find_vq(vdev, i, vqi->callback, vqi->name, vqi->ctx); 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 62eca9419ad7..82a3440bbabb 100644 --- a/drivers/s390/virtio/virtio_ccw.c +++ b/drivers/s390/virtio/virtio_ccw.c @@ -694,7 +694,7 @@ 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++, vqi->callback, + vqs[i] = virtio_ccw_setup_vq(vdev, i, vqi->callback, vqi->name, vqi->ctx, ccw); if (IS_ERR(vqs[i])) { ret = PTR_ERR(vqs[i]); diff --git a/drivers/virtio/virtio_mmio.c b/drivers/virtio/virtio_mmio.c index 90e784e7b721..db6a0366f082 100644 --- a/drivers/virtio/virtio_mmio.c +++ b/drivers/virtio/virtio_mmio.c @@ -494,7 +494,7 @@ 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++, vqi->callback, + vqs[i] = vm_setup_vq(vdev, i, vqi->callback, vqi->name, vqi->ctx); 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 7d82facafd75..fa606e7321ad 100644 --- a/drivers/virtio/virtio_pci_common.c +++ b/drivers/virtio/virtio_pci_common.c @@ -293,7 +293,7 @@ static int vp_find_vqs_msix(struct virtio_device *vdev, unsigned int nvqs, struct virtio_pci_device *vp_dev = to_vp_device(vdev); struct virtqueue_info *vqi; 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) @@ -332,7 +332,7 @@ 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++, vqi->callback, + vqs[i] = vp_setup_vq(vdev, i, vqi->callback, vqi->name, vqi->ctx, msix_vec); if (IS_ERR(vqs[i])) { err = PTR_ERR(vqs[i]); @@ -368,7 +368,7 @@ static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned int nvqs, struct virtqueue_info vqs_info[]) { 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) @@ -388,8 +388,13 @@ static int vp_find_vqs_intx(struct virtio_device *vdev, unsigned int nvqs, vqs[i] = NULL; continue; } +<<<<<<< HEAD vqs[i] = vp_setup_vq(vdev, queue_idx++, vqi->callback, vqi->name, vqi->ctx, +======= + vqs[i] = vp_setup_vq(vdev, i, callbacks[i], names[i], + ctx ? ctx[i] : false, +>>>>>>> f814759f80b7... virtio: fix vq # for balloon VIRTIO_MSI_NO_VECTOR); if (IS_ERR(vqs[i])) { err = PTR_ERR(vqs[i]); diff --git a/drivers/virtio/virtio_vdpa.c b/drivers/virtio/virtio_vdpa.c index 7364bd53e38d..149e893583e9 100644 --- a/drivers/virtio/virtio_vdpa.c +++ b/drivers/virtio/virtio_vdpa.c @@ -368,7 +368,7 @@ 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++, vqi->callback, + vqs[i] = virtio_vdpa_setup_vq(vdev, i, vqi->callback, vqi->name, vqi->ctx); if (IS_ERR(vqs[i])) { err = PTR_ERR(vqs[i]);
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. Message-ID: <cover.1720173841.git.mst@redhat.com> Fixes: b0c504f15471 ("virtio-balloon: add support for providing free page reports to host") Cc: "Alexander Duyck" <alexander.h.duyck@linux.intel.com> 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 | 11 ++++++++--- drivers/virtio/virtio_vdpa.c | 4 ++-- 6 files changed, 18 insertions(+), 13 deletions(-)