[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-Id: <20230825-viommu-sync-map-v1-2-56bdcfaa29ec@linux.ibm.com>
Date: Fri, 25 Aug 2023 17:21:26 +0200
From: Niklas Schnelle <schnelle@...ux.ibm.com>
To: Jean-Philippe Brucker <jean-philippe@...aro.org>,
Joerg Roedel <joro@...tes.org>, Will Deacon <will@...nel.org>,
Robin Murphy <robin.murphy@....com>
Cc: virtualization@...ts.linux-foundation.org, iommu@...ts.linux.dev,
linux-kernel@...r.kernel.org,
Niklas Schnelle <schnelle@...ux.ibm.com>
Subject: [PATCH 2/2] iommu/virtio: Add ops->flush_iotlb_all and enable
deferred flush
Add ops->flush_iotlb_all operation to enable virtio-iommu for the
dma-iommu deferred flush scheme. This results inn a significant increase
in performance in exchange for a window in which devices can still
access previously IOMMU mapped memory. To get back to the prior behavior
iommu.strict=1 may be set on the kernel command line.
Link: https://lore.kernel.org/lkml/20230802123612.GA6142@myrica/
Signed-off-by: Niklas Schnelle <schnelle@...ux.ibm.com>
---
drivers/iommu/virtio-iommu.c | 12 ++++++++++++
1 file changed, 12 insertions(+)
diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
index fb73dec5b953..1b7526494490 100644
--- a/drivers/iommu/virtio-iommu.c
+++ b/drivers/iommu/virtio-iommu.c
@@ -924,6 +924,15 @@ static int viommu_iotlb_sync_map(struct iommu_domain *domain,
return viommu_sync_req(vdomain->viommu);
}
+static void viommu_flush_iotlb_all(struct iommu_domain *domain)
+{
+ struct viommu_domain *vdomain = to_viommu_domain(domain);
+
+ if (!vdomain->nr_endpoints)
+ return;
+ viommu_sync_req(vdomain->viommu);
+}
+
static void viommu_get_resv_regions(struct device *dev, struct list_head *head)
{
struct iommu_resv_region *entry, *new_entry, *msi = NULL;
@@ -1049,6 +1058,8 @@ static bool viommu_capable(struct device *dev, enum iommu_cap cap)
switch (cap) {
case IOMMU_CAP_CACHE_COHERENCY:
return true;
+ case IOMMU_CAP_DEFERRED_FLUSH:
+ return true;
default:
return false;
}
@@ -1069,6 +1080,7 @@ static struct iommu_ops viommu_ops = {
.map_pages = viommu_map_pages,
.unmap_pages = viommu_unmap_pages,
.iova_to_phys = viommu_iova_to_phys,
+ .flush_iotlb_all = viommu_flush_iotlb_all,
.iotlb_sync = viommu_iotlb_sync,
.iotlb_sync_map = viommu_iotlb_sync_map,
.free = viommu_domain_free,
--
2.39.2
Powered by blists - more mailing lists