On Thu, Jul 15, 2021 at 03:35:05PM -0700, Taylor Stark wrote: > Update virtio-pmem to allow for the pmem region to be specified in either > guest absolute terms or as a PCI BAR-relative address. This is required > to support virtio-pmem in Hyper-V, since Hyper-V only allows PCI devices > to operate on PCI memory ranges defined via BARs. > > Virtio-pmem will check for a shared memory window and use that if found, > else it will fallback to using the guest absolute addresses in > virtio_pmem_config. This was chosen over defining a new feature bit, > since it's similar to how virtio-fs is configured. > > Signed-off-by: Taylor Stark <[email protected]>
This needs to be added to the device spec too. Can you send a spec patch please? It's a subscriber-only list [email protected] > --- > drivers/nvdimm/virtio_pmem.c | 21 +++++++++++++++++---- > drivers/nvdimm/virtio_pmem.h | 3 +++ > 2 files changed, 20 insertions(+), 4 deletions(-) > > diff --git a/drivers/nvdimm/virtio_pmem.c b/drivers/nvdimm/virtio_pmem.c > index 726c7354d465..43c1d835a449 100644 > --- a/drivers/nvdimm/virtio_pmem.c > +++ b/drivers/nvdimm/virtio_pmem.c > @@ -37,6 +37,8 @@ static int virtio_pmem_probe(struct virtio_device *vdev) > struct virtio_pmem *vpmem; > struct resource res; > int err = 0; > + bool have_shm_region; > + struct virtio_shm_region pmem_region; > > if (!vdev->config->get) { > dev_err(&vdev->dev, "%s failure: config access disabled\n", > @@ -58,10 +60,21 @@ static int virtio_pmem_probe(struct virtio_device *vdev) > goto out_err; > } > > - virtio_cread_le(vpmem->vdev, struct virtio_pmem_config, > - start, &vpmem->start); > - virtio_cread_le(vpmem->vdev, struct virtio_pmem_config, > - size, &vpmem->size); > + /* Retrieve the pmem device's address and size. It may have been > supplied > + * as a PCI BAR-relative shared memory region, or as a guest absolute > address. > + */ > + have_shm_region = virtio_get_shm_region(vpmem->vdev, &pmem_region, > + > VIRTIO_PMEM_SHMCAP_ID_PMEM_REGION); > + > + if (have_shm_region) { > + vpmem->start = pmem_region.addr; > + vpmem->size = pmem_region.len; > + } else { > + virtio_cread_le(vpmem->vdev, struct virtio_pmem_config, > + start, &vpmem->start); > + virtio_cread_le(vpmem->vdev, struct virtio_pmem_config, > + size, &vpmem->size); > + } > > res.start = vpmem->start; > res.end = vpmem->start + vpmem->size - 1; > diff --git a/drivers/nvdimm/virtio_pmem.h b/drivers/nvdimm/virtio_pmem.h > index 0dddefe594c4..62bb564e81cb 100644 > --- a/drivers/nvdimm/virtio_pmem.h > +++ b/drivers/nvdimm/virtio_pmem.h > @@ -50,6 +50,9 @@ struct virtio_pmem { > __u64 size; > }; > > +/* For the id field in virtio_pci_shm_cap */ > +#define VIRTIO_PMEM_SHMCAP_ID_PMEM_REGION 0 > + > void virtio_pmem_host_ack(struct virtqueue *vq); > int async_pmem_flush(struct nd_region *nd_region, struct bio *bio); > #endif > -- > 2.32.0 > >
