[PATCH 6.4 280/800] iommu/virtio: Return size mapped for a detached domain

Greg Kroah-Hartman
2023-07-16T20:07:38Z

From: Jean-Philippe Brucker <jean-philippe@linaro.org>

[ Upstream commit 7061b6af34686e7e2364b7240cfb061293218f2d ]

When map() is called on a detached domain, the domain does not exist in
the device so we do not send a MAP request, but we do update the
internal mapping tree, to be replayed on the next attach. Since this
constitutes a successful iommu_map() call, return *mapped in this case
too.

Fixes: 7e62edd7a33a ("iommu/virtio: Add map/unmap_pages() callbacks implementation")
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Link: https://lore.kernel.org/r/20230515113946.1017624-3-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/iommu/virtio-iommu.c | 33 +++++++++++++++++----------------
1 file changed, 17 insertions(+), 16 deletions(-)

diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
index fd316a37d7562..3551ed057774e 100644
--- a/drivers/iommu/virtio-iommu.c
+++ b/drivers/iommu/virtio-iommu.c
@@ -833,25 +833,26 @@ static int viommu_map_pages(struct iommu_domain *domain, unsigned long iova,
if (ret)
return ret;

- map = (struct virtio_iommu_req_map) {
- .head.type = VIRTIO_IOMMU_T_MAP,
- .domain = cpu_to_le32(vdomain->id),
- .virt_start = cpu_to_le64(iova),
- .phys_start = cpu_to_le64(paddr),
- .virt_end = cpu_to_le64(end),
- .flags = cpu_to_le32(flags),
- };
-
- if (!vdomain->nr_endpoints)
- return 0;
+ if (vdomain->nr_endpoints) {
+ map = (struct virtio_iommu_req_map) {
+ .head.type = VIRTIO_IOMMU_T_MAP,
+ .domain = cpu_to_le32(vdomain->id),
+ .virt_start = cpu_to_le64(iova),
+ .phys_start = cpu_to_le64(paddr),
+ .virt_end = cpu_to_le64(end),
+ .flags = cpu_to_le32(flags),
+ };

- ret = viommu_send_req_sync(vdomain->viommu, &map, sizeof(map));
- if (ret)
- viommu_del_mappings(vdomain, iova, end);
- else if (mapped)
+ ret = viommu_send_req_sync(vdomain->viommu, &map, sizeof(map));
+ if (ret) {
+ viommu_del_mappings(vdomain, iova, end);
+ return ret;
+ }
+ }
+ if (mapped)
*mapped = size;

- return ret;
+ return 0;
}

static size_t viommu_unmap_pages(struct iommu_domain *domain, unsigned long iova,
--
2.39.2