On Tue, Jul 20, 2021 at 05:46:30AM -0400, Michael S. Tsirkin wrote: > On Mon, Jul 19, 2021 at 11:41:03PM -0700, Taylor Stark wrote: > > On Mon, Jul 19, 2021 at 05:17:00PM -0400, Michael S. Tsirkin wrote: > > > 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] > > > > Absolutely! I tried looking on the virtio-spec repo on github but > > I couldn't find a spec for virtio-pmem to update. There is this > > issue (https://github.com/oasis-tcs/virtio-spec/issues/78) which > > seems to indicate the virtio-pmem spec hasn't been added yet. > > Any suggestions for where to send a patch? > > > > Thanks, > > Taylor > > Just apply that patch (whichever you think is right) > and do yours on top and indicate this in the email. > Send it to virtio-comments.
Posted the patch here for those that want to follow along: https://lists.oasis-open.org/archives/virtio-comment/202107/msg00111.html > > > > --- > > > > 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
