From: Nadav Amit <nadav.amit@gmail.com> To: Joerg Roedel <joro@8bytes.org> Cc: John Garry <john.garry@huawei.com>, Nadav Amit <namit@vmware.com>, Will Deacon <will@kernel.org>, Jiajun Cao <caojiajun@vmware.com>, Robin Murphy <robin.murphy@arm.com>, Lu Baolu <baolu.lu@linux.intel.com>, iommu@lists.linux-foundation.org, linux-kernel@vger.kernel.org Subject: [PATCH v6 6/7] iommu/amd: Sync once for scatter-gather operations Date: Fri, 23 Jul 2021 02:32:08 -0700 [thread overview] Message-ID: <20210723093209.714328-7-namit@vmware.com> (raw) In-Reply-To: <20210723093209.714328-1-namit@vmware.com> From: Nadav Amit <namit@vmware.com> 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 <caojiajun@vmware.com> 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 <namit@vmware.com> --- 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 f5d5f2124391..7846fcb1e92b 100644 --- a/drivers/iommu/amd/iommu.c +++ b/drivers/iommu/amd/iommu.c @@ -2022,6 +2022,16 @@ 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) @@ -2040,10 +2050,8 @@ 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; } @@ -2223,6 +2231,7 @@ 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, -- 2.25.1
next prev parent reply other threads:[~2021-07-23 17:02 UTC|newest] Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top 2021-07-23 9:32 [PATCH v6 0/7] iommu/amd: Enable page-selective flushes Nadav Amit 2021-07-23 9:32 ` [PATCH v6 1/7] iommu/amd: Selective flush on unmap Nadav Amit 2021-07-23 9:32 ` [PATCH v6 2/7] iommu/amd: Do not use flush-queue when NpCache is on Nadav Amit 2021-07-23 9:32 ` [PATCH v6 3/7] iommu: Improve iommu_iotlb_gather helpers Nadav Amit 2021-07-23 9:32 ` [PATCH v6 4/7] iommu: Factor iommu_iotlb_gather_is_disjoint() out Nadav Amit 2021-07-23 9:32 ` [PATCH v6 5/7] iommu/amd: Tailored gather logic for AMD Nadav Amit 2021-07-23 9:32 ` Nadav Amit [this message] 2021-07-23 9:32 ` [PATCH v6 7/7] iommu/amd: Use only natural aligned flushes in a VM Nadav Amit 2021-07-26 12:31 ` [PATCH v6 0/7] iommu/amd: Enable page-selective flushes Joerg Roedel 2021-08-02 9:26 ` Joerg Roedel
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