From: Nicolin Chen <nicolinc@nvidia.com>
To: <jgg@nvidia.com>, <kevin.tian@intel.com>, <joro@8bytes.org>,
<will@kernel.org>, <robin.murphy@arm.com>,
<alex.williamson@redhat.com>, <shuah@kernel.org>
Cc: <yi.l.liu@intel.com>, <linux-kernel@vger.kernel.org>,
<iommu@lists.linux.dev>, <kvm@vger.kernel.org>,
<linux-kselftest@vger.kernel.org>, <mjrosato@linux.ibm.com>,
<farman@linux.ibm.com>
Subject: [PATCH v5 4/4] vfio: Support IO page table replacement
Date: Thu, 23 Mar 2023 01:33:05 -0700 [thread overview]
Message-ID: <29023644817002345ab94d8916a8447debb45a95.1679559476.git.nicolinc@nvidia.com> (raw)
In-Reply-To: <cover.1679559476.git.nicolinc@nvidia.com>
Now both the physical path and the emulated path should support an IO page
table replacement. Call iommufd_device_replace/iommufd_access_replace(),
when vdev->iommufd_attached is true.
Also update the VFIO_DEVICE_ATTACH_IOMMUFD_PT kdoc in the uAPI header.
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
---
drivers/vfio/iommufd.c | 11 ++++++-----
include/uapi/linux/vfio.h | 6 ++++++
2 files changed, 12 insertions(+), 5 deletions(-)
diff --git a/drivers/vfio/iommufd.c b/drivers/vfio/iommufd.c
index f3fa03495a41..861e10a6b198 100644
--- a/drivers/vfio/iommufd.c
+++ b/drivers/vfio/iommufd.c
@@ -113,9 +113,9 @@ int vfio_iommufd_physical_attach_ioas(struct vfio_device *vdev, u32 *pt_id)
return -EINVAL;
if (vdev->iommufd_attached)
- return -EBUSY;
-
- rc = iommufd_device_attach(vdev->iommufd_device, pt_id);
+ rc = iommufd_device_replace(vdev->iommufd_device, pt_id);
+ else
+ rc = iommufd_device_attach(vdev->iommufd_device, pt_id);
if (rc)
return rc;
vdev->iommufd_attached = true;
@@ -192,8 +192,9 @@ int vfio_iommufd_emulated_attach_ioas(struct vfio_device *vdev, u32 *pt_id)
if (WARN_ON(!vdev->iommufd_access))
return -ENOENT;
if (vdev->iommufd_attached)
- return -EBUSY;
- rc = iommufd_access_attach(vdev->iommufd_access, *pt_id);
+ rc = iommufd_access_replace(vdev->iommufd_access, *pt_id);
+ else
+ rc = iommufd_access_attach(vdev->iommufd_access, *pt_id);
if (rc)
return rc;
vdev->iommufd_attached = true;
diff --git a/include/uapi/linux/vfio.h b/include/uapi/linux/vfio.h
index 53c72e26ecd3..3f2548a5e847 100644
--- a/include/uapi/linux/vfio.h
+++ b/include/uapi/linux/vfio.h
@@ -243,6 +243,12 @@ struct vfio_device_bind_iommufd {
*
* Undo by VFIO_DEVICE_DETACH_IOMMUFD_PT or device fd close.
*
+ * If a vfio device is currently attached to a valid hw_pagetable, without doing
+ * a VFIO_DEVICE_DETACH_IOMMUFD_PT, a second VFIO_DEVICE_ATTACH_IOMMUFD_PT ioctl
+ * passing in another hw_pagetable (hwpt) id is allowed. This action, also known
+ * as a hw_pagetable replacement, will replace the device's currently attached
+ * hw_pagetable with a new hw_pagetable corresponding to the given pt_id.
+ *
* @argsz: user filled size of this data.
* @flags: must be 0.
* @pt_id: Input the target id which can represent an ioas or a hwpt
--
2.40.0
next prev parent reply other threads:[~2023-03-23 8:33 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-23 8:33 [PATCH v5 0/4] cover-letter: Add IO page table replacement support Nicolin Chen
2023-03-23 8:33 ` [PATCH v5 1/4] vfio: Do not allow !ops->dma_unmap in vfio_pin/unpin_pages() Nicolin Chen
2023-03-23 8:33 ` [PATCH v5 2/4] iommufd: Add iommufd_access_replace() API Nicolin Chen
2023-03-24 3:02 ` Tian, Kevin
2023-03-24 17:02 ` Nicolin Chen
2023-03-23 8:33 ` [PATCH v5 3/4] iommufd/selftest: Add IOMMU_TEST_OP_ACCESS_REPLACE_IOAS coverage Nicolin Chen
2023-03-23 8:33 ` Nicolin Chen [this message]
2023-03-24 3:04 ` [PATCH v5 4/4] vfio: Support IO page table replacement Tian, Kevin
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