[PATCH AUTOSEL 5.13 22/88] iommu/amd: Sync once for scatter-gather operations
From: Sasha Levin <sashal@kernel.org>
Date: 2021-09-10 00:49:50
Also in:
linux-iommu, lkml
Subsystem:
amd iommu (amd-vi), iommu subsystem, the rest · Maintainers:
Joerg Roedel, Will Deacon, Linus Torvalds
From: Nadav Amit <redacted>
[ Upstream commit 3b122a5666cb7c0bb9a439fba0c9a6cf59f999c3 ]
On virtual machines, software must flush the IOTLB after each page table
entry update.
The iommu_map_sg() code iterates through the given scatter-gather list
and invokes iommu_map() for each element in the scatter-gather list,
which calls into the vendor IOMMU driver through iommu_ops callback. As
the result, a single sg mapping may lead to multiple IOTLB flushes.
Fix this by adding amd_iotlb_sync_map() callback and flushing at this
point after all sg mappings we set.
This commit is followed and inspired by commit 933fcd01e97e2
("iommu/vt-d: Add iotlb_sync_map callback").
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Will Deacon <will@kernel.org>
Cc: Jiajun Cao <redacted>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Lu Baolu <baolu.lu@linux.intel.com>
Cc: iommu@lists.linux-foundation.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Nadav Amit <redacted>
Link: https://lore.kernel.org/r/20210723093209.714328-7-namit@vmware.com (local)
Signed-off-by: Joerg Roedel <redacted>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/iommu/amd/iommu.c | 15 ++++++++++++---
1 file changed, 12 insertions(+), 3 deletions(-)
diff --git a/drivers/iommu/amd/iommu.c b/drivers/iommu/amd/iommu.c
index 69d441fc1e32..d11386177301 100644
--- a/drivers/iommu/amd/iommu.c
+++ b/drivers/iommu/amd/iommu.c@@ -2028,6 +2028,16 @@ static int amd_iommu_attach_device(struct iommu_domain *dom, return ret; } +static void amd_iommu_iotlb_sync_map(struct iommu_domain *dom, + unsigned long iova, size_t size) +{ + struct protection_domain *domain = to_pdomain(dom); + struct io_pgtable_ops *ops = &domain->iop.iop.ops; + + if (ops->map) + domain_flush_np_cache(domain, iova, size); +} + static int amd_iommu_map(struct iommu_domain *dom, unsigned long iova, phys_addr_t paddr, size_t page_size, int iommu_prot, gfp_t gfp)
@@ -2046,10 +2056,8 @@ static int amd_iommu_map(struct iommu_domain *dom, unsigned long iova, if (iommu_prot & IOMMU_WRITE) prot |= IOMMU_PROT_IW; - if (ops->map) { + if (ops->map) ret = ops->map(ops, iova, paddr, page_size, prot, gfp); - domain_flush_np_cache(domain, iova, page_size); - } return ret; }
@@ -2197,6 +2205,7 @@ const struct iommu_ops amd_iommu_ops = { .attach_dev = amd_iommu_attach_device, .detach_dev = amd_iommu_detach_device, .map = amd_iommu_map, + .iotlb_sync_map = amd_iommu_iotlb_sync_map, .unmap = amd_iommu_unmap, .iova_to_phys = amd_iommu_iova_to_phys, .probe_device = amd_iommu_probe_device,
--
2.30.2