diff options
| author | Nadav Amit <namit@vmware.com> | 2021-07-23 02:32:04 -0700 |
|---|---|---|
| committer | Joerg Roedel <jroedel@suse.de> | 2021-08-02 11:26:05 +0200 |
| commit | 6664340cf1d541c2a44d588002893f795ab4143f (patch) | |
| tree | 3148d661d25ade14c30d3ce67eb16fa3bfd77d97 /drivers/iommu/amd | |
| parent | fc65d0acaf23179b94de399c204328fa259acb90 (diff) | |
iommu/amd: Do not use flush-queue when NpCache is on
Do not use flush-queue on virtualized environments, where the NpCache
capability of the IOMMU is set. This is required to reduce
virtualization overheads.
This change follows a similar change to Intel's VT-d and a detailed
explanation as for the rationale is described in commit 29b32839725f
("iommu/vt-d: Do not use flush-queue when caching-mode is on").
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>
Link: https://lore.kernel.org/r/20210723093209.714328-3-namit@vmware.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Diffstat (limited to 'drivers/iommu/amd')
| -rw-r--r-- | drivers/iommu/amd/init.c | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/drivers/iommu/amd/init.c b/drivers/iommu/amd/init.c index 46280e6e1535..1c7ae7d3c55d 100644 --- a/drivers/iommu/amd/init.c +++ b/drivers/iommu/amd/init.c @@ -1850,8 +1850,13 @@ static int __init iommu_init_pci(struct amd_iommu *iommu) if (ret) return ret; - if (iommu->cap & (1UL << IOMMU_CAP_NPCACHE)) + if (iommu->cap & (1UL << IOMMU_CAP_NPCACHE)) { + if (!amd_iommu_unmap_flush) + pr_info("IOMMU batching is disabled due to virtualization\n"); + amd_iommu_np_cache = true; + amd_iommu_unmap_flush = true; + } init_iommu_perf_ctr(iommu); |