Hi Jacob, Kevin,


On 3/4/21 11:28 AM, Tian, Kevin wrote:

quoted

From: Jacob Pan <redacted>
Sent: Thursday, March 4, 2021 2:29 AM

Hi Vivek,

On Fri, 15 Jan 2021 17:43:39 +0530, Vivek Gautam [off-list ref]
wrote:

quoted

From: Jean-Philippe Brucker <redacted>

Add support for tlb invalidation ops that can send invalidation
requests to back-end virtio-iommu when stage-1 page tables are
supported.

Just curious if it possible to reuse the iommu uapi for invalidation and others.
When we started out designing the iommu uapi, the intention was to support
both emulated and virtio iommu.

IIUC this patch is about the protocol between virtio-iommu frontend and backend.
After the virtio-iommu backend receives invalidation ops, it then needs to
forward the request to the host IOMMU driver through the existing iommu
uapi that you referred to, as a emulated VT-d or SMMU would do.

Thanks a lot for looking at the patch.

Yes this patch is to provide the front-end virtio interface for 
invalidation requests during map/unmap and when flushing the pasid 
tables when virtio-iommu requested pasid table (in other words cd tables 
for arm-smmu-v3) from the iommu-pasid-table library.
The kvmtool back-end virtio driver forwards these requests to vfio 
driver which then makes use of iommu uapi to finally request host iommu 
driver for handling these invalidations.

Regards
Vivek

Thanks
Kevin

quoted

quoted

Signed-off-by: Jean-Philippe Brucker <redacted>
[Vivek: Refactoring the iommu_flush_ops, and adding only one pasid sync
         op that's needed with current iommu-pasid-table infrastructure.
	Also updating uapi defines as required by latest changes]
Signed-off-by: Vivek Gautam <redacted>
Cc: Joerg Roedel <joro@8bytes.org>
Cc: Will Deacon <redacted>
Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Robin Murphy <robin.murphy@arm.com>
Cc: Jean-Philippe Brucker <redacted>
Cc: Eric Auger <eric.auger@redhat.com>
Cc: Alex Williamson <redacted>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Jacob Pan <redacted>
Cc: Liu Yi L <redacted>
Cc: Lorenzo Pieralisi <redacted>
Cc: Shameerali Kolothum Thodi <redacted>
---
  drivers/iommu/virtio-iommu.c | 95

++++++++++++++++++++++++++++++++++++

quoted

  1 file changed, 95 insertions(+)

diff --git a/drivers/iommu/virtio-iommu.c b/drivers/iommu/virtio-iommu.c
index ae5dfd3f8269..004ea94e3731 100644
--- a/drivers/iommu/virtio-iommu.c
+++ b/drivers/iommu/virtio-iommu.c

@@ -13,6 +13,7 @@
  #include <linux/freezer.h>
  #include <linux/interval_tree.h>
  #include <linux/iommu.h>
+#include <linux/io-pgtable.h>
  #include <linux/module.h>
  #include <linux/of_iommu.h>
  #include <linux/of_platform.h>

@@ -63,6 +64,8 @@ struct viommu_mapping {
  };

  struct viommu_mm {
+	int				pasid;
+	u64				archid;
  	struct io_pgtable_ops		*ops;
  	struct viommu_domain		*domain;
  };

@@ -692,6 +695,98 @@ static void viommu_event_handler(struct

virtqueue

quoted

*vq) virtqueue_kick(vq);
  }

+/* PASID and pgtable APIs */
+
+static void __viommu_flush_pasid_tlb_all(struct viommu_domain

*vdomain,

quoted

+					 int pasid, u64 arch_id, int
type) +{
+	struct virtio_iommu_req_invalidate req = {
+		.head.type	= VIRTIO_IOMMU_T_INVALIDATE,
+		.inv_gran	=
cpu_to_le32(VIRTIO_IOMMU_INVAL_G_PASID),
+		.flags		=
cpu_to_le32(VIRTIO_IOMMU_INVAL_F_PASID),
+		.inv_type	= cpu_to_le32(type),
+
+		.domain		= cpu_to_le32(vdomain->id),
+		.pasid		= cpu_to_le32(pasid),
+		.archid		= cpu_to_le64(arch_id),
+	};
+
+	if (viommu_send_req_sync(vdomain->viommu, &req, sizeof(req)))
+		pr_debug("could not send invalidate request\n");
+}
+
+static void viommu_flush_tlb_add(struct iommu_iotlb_gather *gather,
+				 unsigned long iova, size_t granule,
+				 void *cookie)
+{
+	struct viommu_mm *viommu_mm = cookie;
+	struct viommu_domain *vdomain = viommu_mm->domain;
+	struct iommu_domain *domain = &vdomain->domain;
+
+	iommu_iotlb_gather_add_page(domain, gather, iova, granule);
+}
+
+static void viommu_flush_tlb_walk(unsigned long iova, size_t size,
+				  size_t granule, void *cookie)
+{
+	struct viommu_mm *viommu_mm = cookie;
+	struct viommu_domain *vdomain = viommu_mm->domain;
+	struct virtio_iommu_req_invalidate req = {
+		.head.type	= VIRTIO_IOMMU_T_INVALIDATE,
+		.inv_gran	= cpu_to_le32(VIRTIO_IOMMU_INVAL_G_VA),
+		.inv_type	=

cpu_to_le32(VIRTIO_IOMMU_INV_T_IOTLB),

quoted

+		.flags		=
cpu_to_le32(VIRTIO_IOMMU_INVAL_F_ARCHID), +
+		.domain		= cpu_to_le32(vdomain->id),
+		.pasid		= cpu_to_le32(viommu_mm->pasid),
+		.archid		= cpu_to_le64(viommu_mm->archid),
+		.virt_start	= cpu_to_le64(iova),
+		.nr_pages	= cpu_to_le64(size / granule),
+		.granule	= ilog2(granule),
+	};
+
+	if (viommu_add_req(vdomain->viommu, &req, sizeof(req)))
+		pr_debug("could not add invalidate request\n");
+}
+
+static void viommu_flush_tlb_all(void *cookie)
+{
+	struct viommu_mm *viommu_mm = cookie;
+
+	if (!viommu_mm->archid)
+		return;
+
+	__viommu_flush_pasid_tlb_all(viommu_mm->domain,

viommu_mm->pasid,

quoted

+				     viommu_mm->archid,
+				     VIRTIO_IOMMU_INV_T_IOTLB);
+}
+
+static struct iommu_flush_ops viommu_flush_ops = {
+	.tlb_flush_all		= viommu_flush_tlb_all,
+	.tlb_flush_walk		= viommu_flush_tlb_walk,
+	.tlb_add_page		= viommu_flush_tlb_add,
+};
+
+static void viommu_flush_pasid(void *cookie, int pasid, bool leaf)
+{
+	struct viommu_domain *vdomain = cookie;
+	struct virtio_iommu_req_invalidate req = {
+		.head.type	= VIRTIO_IOMMU_T_INVALIDATE,
+		.inv_gran	=
cpu_to_le32(VIRTIO_IOMMU_INVAL_G_PASID),
+		.inv_type	=

cpu_to_le32(VIRTIO_IOMMU_INV_T_PASID),

quoted

+		.flags		=
cpu_to_le32(VIRTIO_IOMMU_INVAL_F_PASID), +
+		.domain		= cpu_to_le32(vdomain->id),
+		.pasid		= cpu_to_le32(pasid),
+	};
+
+	if (leaf)
+		req.flags	|=
cpu_to_le32(VIRTIO_IOMMU_INVAL_F_LEAF); +
+	if (viommu_send_req_sync(vdomain->viommu, &req, sizeof(req)))
+		pr_debug("could not send invalidate request\n");
+}
+
  /* IOMMU API */

  static struct iommu_domain *viommu_domain_alloc(unsigned type)

Thanks,

Jacob

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