Messages in this thread | | | From | Bharat Bhushan <> | Subject | RE: [EXT] Re: [RFC PATCH v2] iommu/virtio: Use page size bitmap supported by endpoint | Date | Thu, 2 Apr 2020 03:53:40 +0000 |
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> -----Original Message----- > From: Jean-Philippe Brucker <jean-philippe@linaro.org> > Sent: Wednesday, April 1, 2020 9:20 PM > To: Robin Murphy <robin.murphy@arm.com> > Cc: Bharat Bhushan <bbhushan2@marvell.com>; joro@8bytes.org; > mst@redhat.com; jasowang@redhat.com; virtualization@lists.linux- > foundation.org; iommu@lists.linux-foundation.org; linux-kernel@vger.kernel.org; > eric.auger.pro@gmail.com; eric.auger@redhat.com > Subject: [EXT] Re: [RFC PATCH v2] iommu/virtio: Use page size bitmap supported by > endpoint > > External Email > > ---------------------------------------------------------------------- > On Wed, Apr 01, 2020 at 02:00:13PM +0100, Robin Murphy wrote: > > On 2020-04-01 12:38 pm, Bharat Bhushan wrote: > > > Different endpoint can support different page size, probe endpoint > > > if it supports specific page size otherwise use global page sizes. > > > > > > Signed-off-by: Bharat Bhushan <bbhushan2@marvell.com> > > > --- > > > drivers/iommu/virtio-iommu.c | 33 +++++++++++++++++++++++++++---- > > > include/uapi/linux/virtio_iommu.h | 7 +++++++ > > > 2 files changed, 36 insertions(+), 4 deletions(-) > > > > > > diff --git a/drivers/iommu/virtio-iommu.c > > > b/drivers/iommu/virtio-iommu.c index cce329d71fba..c794cb5b7b3e > > > 100644 > > > --- a/drivers/iommu/virtio-iommu.c > > > +++ b/drivers/iommu/virtio-iommu.c > > > @@ -78,6 +78,7 @@ struct viommu_endpoint { > > > struct viommu_dev *viommu; > > > struct viommu_domain *vdomain; > > > struct list_head resv_regions; > > > + u64 pgsize_bitmap; > > > }; > > > struct viommu_request { > > > @@ -415,6 +416,20 @@ static int viommu_replay_mappings(struct > viommu_domain *vdomain) > > > return ret; > > > } > > > +static int viommu_set_pgsize_bitmap(struct viommu_endpoint *vdev, > > > + struct virtio_iommu_probe_pgsize_mask *mask, > > > + size_t len) > > > + > > > +{ > > > + u64 pgsize_bitmap = le64_to_cpu(mask->pgsize_bitmap); > > > + > > > + if (len < sizeof(*mask)) > > > + return -EINVAL; > > > + > > > + vdev->pgsize_bitmap = pgsize_bitmap; > > > + return 0; > > > +} > > > + > > > static int viommu_add_resv_mem(struct viommu_endpoint *vdev, > > > struct virtio_iommu_probe_resv_mem *mem, > > > size_t len) > > > @@ -494,11 +509,13 @@ static int viommu_probe_endpoint(struct > viommu_dev *viommu, struct device *dev) > > > while (type != VIRTIO_IOMMU_PROBE_T_NONE && > > > cur < viommu->probe_size) { > > > len = le16_to_cpu(prop->length) + sizeof(*prop); > > > - > > Whitespace change > > > > switch (type) { > > > case VIRTIO_IOMMU_PROBE_T_RESV_MEM: > > > ret = viommu_add_resv_mem(vdev, (void *)prop, len); > > > break; > > > + case VIRTIO_IOMMU_PROBE_T_PAGE_SIZE_MASK: > > > + ret = viommu_set_pgsize_bitmap(vdev, (void *)prop, len); > > > + break; > > > default: > > > dev_err(dev, "unknown viommu prop 0x%x\n", type); > > > } > > > @@ -607,16 +624,23 @@ static struct iommu_domain > *viommu_domain_alloc(unsigned type) > > > return &vdomain->domain; > > > } > > > -static int viommu_domain_finalise(struct viommu_dev *viommu, > > > +static int viommu_domain_finalise(struct viommu_endpoint *vdev, > > > struct iommu_domain *domain) > > > { > > > int ret; > > > struct viommu_domain *vdomain = to_viommu_domain(domain); > > > + struct viommu_dev *viommu = vdev->viommu; > > > vdomain->viommu = viommu; > > > vdomain->map_flags = viommu->map_flags; > > > - domain->pgsize_bitmap = viommu->pgsize_bitmap; > > > + /* Devices in same domain must support same size pages */ > > > > AFAICS what the code appears to do is enforce that the first endpoint > > attached to any domain has the same pgsize_bitmap as the most recently > > probed viommu_dev instance, then ignore any subsequent endpoints > > attached to the same domain. Thus I'm not sure that comment is accurate. > > > > Yes viommu_domain_finalise() is only called once. What I had in mind is > something like:
Ohh, I did not realized that viommu_domain_finalise(). I have included below suggested changes
> > ---- 8< ---- > diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c index > 750f69c49b95..8303b7b513ff 100644 > --- a/drivers/iommu/virtio-iommu.c > +++ b/drivers/iommu/virtio-iommu.c > @@ -639,6 +639,29 @@ static int viommu_domain_finalise(struct > viommu_endpoint *vdev, > return 0; > } > > +/* > + * Check whether the endpoint's capabilities are compatible with other > +endpoints > + * in the domain. Report any inconsistency. > + */ > +static bool viommu_endpoint_is_compatible(struct viommu_endpoint *vdev, > + struct viommu_domain *vdomain) > +{ > + struct device *dev = vdev->dev; > + > + if (vdomain->viommu != vdev->viommu) { > + dev_err(dev, "cannot attach to foreign vIOMMU\n"); > + return false; > + } > + > + if (vdomain->domain.pgsize_bitmap != vdev->pgsize_bitmap) { > + dev_err(dev, "incompatible domain bitmap 0x%lx != 0x%lx\n", > + vdomain->domain.pgsize_bitmap, vdev->pgsize_bitmap); > + return false; > + } > + > + return true; > +} > + > static void viommu_domain_free(struct iommu_domain *domain) { > struct viommu_domain *vdomain = to_viommu_domain(domain); @@ - > 670,9 +693,8 @@ static int viommu_attach_dev(struct iommu_domain *domain, > struct device *dev) > * owns it. > */ > ret = viommu_domain_finalise(vdev, domain); > - } else if (vdomain->viommu != vdev->viommu) { > - dev_err(dev, "cannot attach to foreign vIOMMU\n"); > - ret = -EXDEV; > + } else if (!viommu_endpoint_is_compatible(vdev, vdomain)) { > + ret = -EINVAL; > } > mutex_unlock(&vdomain->mutex); > ---- >8 ---- > > > > > > + if ((domain->pgsize_bitmap != viommu->pgsize_bitmap) && > > > + (domain->pgsize_bitmap != vdev->pgsize_bitmap)) > > > + return -EINVAL; > > > + > > > + domain->pgsize_bitmap = vdev->pgsize_bitmap; > > > + > > > domain->geometry = viommu->geometry; > > > ret = ida_alloc_range(&viommu->domain_ids, viommu->first_domain, > > > @@ -657,7 +681,7 @@ static int viommu_attach_dev(struct iommu_domain > *domain, struct device *dev) > > > * Properly initialize the domain now that we know which viommu > > > * owns it. > > > */ > > > - ret = viommu_domain_finalise(vdev->viommu, domain); > > > + ret = viommu_domain_finalise(vdev, domain); > > > } else if (vdomain->viommu != vdev->viommu) { > > > dev_err(dev, "cannot attach to foreign vIOMMU\n"); > > > ret = -EXDEV; > > > @@ -875,6 +899,7 @@ static int viommu_add_device(struct device *dev) > > > vdev->dev = dev; > > > vdev->viommu = viommu; > > > + vdev->pgsize_bitmap = viommu->pgsize_bitmap; > > > INIT_LIST_HEAD(&vdev->resv_regions); > > > fwspec->iommu_priv = vdev; > > > diff --git a/include/uapi/linux/virtio_iommu.h > > > b/include/uapi/linux/virtio_iommu.h > > > index 237e36a280cb..dc9d3f40bcd8 100644 > > > --- a/include/uapi/linux/virtio_iommu.h > > > +++ b/include/uapi/linux/virtio_iommu.h > > > @@ -111,6 +111,7 @@ struct virtio_iommu_req_unmap { > > > #define VIRTIO_IOMMU_PROBE_T_NONE 0 > > > #define VIRTIO_IOMMU_PROBE_T_RESV_MEM 1 > > > +#define VIRTIO_IOMMU_PROBE_T_PAGE_SIZE_MASK 2 > > > #define VIRTIO_IOMMU_PROBE_T_MASK 0xfff > > > @@ -119,6 +120,12 @@ struct virtio_iommu_probe_property { > > > __le16 length; > > > }; > > > +struct virtio_iommu_probe_pgsize_mask { > > > + struct virtio_iommu_probe_property head; > > > + __u8 reserved[4]; > > > + __u64 pgsize_bitmap; > > Should be __le64
Based on" iommu/virtio: Fix sparse warning" patch https://www.spinics.net/lists/linux-virtualization/msg41944.html changed to __u64 (not __le64)
Will keep __le64.
Thanks -Bharat
> > Thanks, > Jean > > > > +}; > > > + > > > #define VIRTIO_IOMMU_RESV_MEM_T_RESERVED 0 > > > #define VIRTIO_IOMMU_RESV_MEM_T_MSI 1 > > >
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