From: Jason Gunthorpe <jgg@nvidia.com>
To: iommu@lists.linux.dev, Kevin Tian <kevin.tian@intel.com>,
linux-kselftest@vger.kernel.org
Cc: Lu Baolu <baolu.lu@linux.intel.com>,
kvm@vger.kernel.org, Nicolin Chen <nicolinc@nvidia.com>,
Yi Liu <yi.l.liu@intel.com>
Subject: [PATCH v3 11/17] iommu: Introduce a new iommu_group_replace_domain() API
Date: Tue, 21 Mar 2023 16:14:45 -0300 [thread overview]
Message-ID: <11-v3-61d41fd9e13e+1f5-iommufd_alloc_jgg@nvidia.com> (raw)
In-Reply-To: <0-v3-61d41fd9e13e+1f5-iommufd_alloc_jgg@nvidia.com>
From: Nicolin Chen <nicolinc@nvidia.com>
qemu has a need to replace the translations associated with a domain
when the guest does large-scale operations like switching between an
IDENTITY domain and, say, dma-iommu.c.
Currently, it does this by replacing all the mappings in a single
domain, but this is very inefficient and means that domains have to be
per-device rather than per-translation.
Provide a high-level API to allow replacements of one domain with
another. This is similar to a detach/attach cycle except it doesn't
force the group to go to the blocking domain in-between.
By removing this forced blocking domain the iommu driver has the
opportunity to implement a non-disruptive replacement of the domain to the
greatest extent its hardware allows. This allows the qemu emulation of the
vIOMMU to be more complete, as real hardware often has a non-distruptive
replacement capability.
It could be possible to address this by simply removing the protection
from the iommu_attach_group(), but it is not so clear if that is safe for
the few users. Thus, add a new API to serve this new purpose.
All drivers are already required to support changing between active
UNMANAGED domains when using their attach_dev ops.
This API is expected to be used only by IOMMUFD, so add to the iommu-priv
header and mark it as IOMMUFD_INTERNAL.
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
drivers/iommu/iommu-priv.h | 10 ++++++++++
drivers/iommu/iommu.c | 30 ++++++++++++++++++++++++++++++
2 files changed, 40 insertions(+)
create mode 100644 drivers/iommu/iommu-priv.h
diff --git a/drivers/iommu/iommu-priv.h b/drivers/iommu/iommu-priv.h
new file mode 100644
index 00000000000000..7c8011bfd15374
--- /dev/null
+++ b/drivers/iommu/iommu-priv.h
@@ -0,0 +1,10 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+#ifndef __LINUX_IOMMU_PRIV_H
+#define __LINUX_IOMMU_PRIV_H
+
+#include <linux/iommu.h>
+
+int iommu_group_replace_domain(struct iommu_group *group,
+ struct iommu_domain *new_domain);
+
+#endif /* __LINUX_IOMMU_PRIV_H */
diff --git a/drivers/iommu/iommu.c b/drivers/iommu/iommu.c
index 76969904b93af4..91a948a76db5ee 100644
--- a/drivers/iommu/iommu.c
+++ b/drivers/iommu/iommu.c
@@ -33,6 +33,7 @@
#include <linux/msi.h>
#include "dma-iommu.h"
+#include "iommu-priv.h"
#include "iommu-sva.h"
@@ -2191,6 +2192,35 @@ int iommu_attach_group(struct iommu_domain *domain, struct iommu_group *group)
}
EXPORT_SYMBOL_GPL(iommu_attach_group);
+/**
+ * iommu_group_replace_domain - replace the domain that a group is attached to
+ * @new_domain: new IOMMU domain to replace with
+ * @group: IOMMU group that will be attached to the new domain
+ *
+ * This API allows the group to switch domains without being forced to go to
+ * the blocking domain in-between.
+ *
+ * If the currently attached domain is a core domain (e.g. a default_domain),
+ * it will act just like the iommu_attach_group().
+ */
+int iommu_group_replace_domain(struct iommu_group *group,
+ struct iommu_domain *new_domain)
+{
+ int ret;
+
+ if (!new_domain)
+ return -EINVAL;
+
+ mutex_lock(&group->mutex);
+ ret = __iommu_group_set_domain(group, new_domain);
+ if (ret)
+ __iommu_group_for_each_dev(group, group->domain,
+ iommu_group_do_attach_device);
+ mutex_unlock(&group->mutex);
+ return ret;
+}
+EXPORT_SYMBOL_NS_GPL(iommu_group_replace_domain, IOMMUFD_INTERNAL);
+
static int iommu_group_do_set_platform_dma(struct device *dev, void *data)
{
const struct iommu_ops *ops = dev_iommu_ops(dev);
--
2.40.0
next prev parent reply other threads:[~2023-03-21 19:15 UTC|newest]
Thread overview: 46+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-03-21 19:14 [PATCH v3 00/17] Add iommufd physical device operations for replace and alloc hwpt Jason Gunthorpe
2023-03-21 19:14 ` [PATCH v3 01/17] iommufd: Move isolated msi enforcement to iommufd_device_bind() Jason Gunthorpe
2023-03-21 19:14 ` [PATCH v3 02/17] iommufd: Add iommufd_group Jason Gunthorpe
2023-03-21 19:14 ` [PATCH v3 03/17] iommufd: Replace the hwpt->devices list with iommufd_group Jason Gunthorpe
2023-03-23 7:21 ` Tian, Kevin
2023-03-23 14:23 ` Jason Gunthorpe
2023-03-24 1:37 ` Tian, Kevin
2023-03-24 15:02 ` Jason Gunthorpe
2023-03-28 2:32 ` Tian, Kevin
2023-03-28 11:38 ` Jason Gunthorpe
2023-03-29 3:03 ` Tian, Kevin
2023-04-11 14:31 ` Jason Gunthorpe
2023-04-12 8:27 ` Tian, Kevin
2023-04-12 11:17 ` Jason Gunthorpe
2023-04-13 2:52 ` Tian, Kevin
2023-04-14 13:31 ` Jason Gunthorpe
2023-04-20 6:15 ` Tian, Kevin
2023-04-20 15:34 ` Jason Gunthorpe
2023-03-21 19:14 ` [PATCH v3 04/17] iommu: Export iommu_get_resv_regions() Jason Gunthorpe
2023-03-21 19:14 ` [PATCH v3 05/17] iommufd: Keep track of each device's reserved regions instead of groups Jason Gunthorpe
2023-03-21 19:14 ` [PATCH v3 06/17] iommufd: Use the iommufd_group to avoid duplicate MSI setup Jason Gunthorpe
2023-03-21 19:14 ` [PATCH v3 07/17] iommufd: Make sw_msi_start a group global Jason Gunthorpe
2023-03-21 19:14 ` [PATCH v3 08/17] iommufd: Move putting a hwpt to a helper function Jason Gunthorpe
2023-03-21 19:14 ` [PATCH v3 09/17] iommufd: Add enforced_cache_coherency to iommufd_hw_pagetable_alloc() Jason Gunthorpe
2023-03-21 19:14 ` [PATCH v3 10/17] iommufd: Reorganize iommufd_device_attach into iommufd_device_change_pt Jason Gunthorpe
2023-03-23 7:25 ` Tian, Kevin
2023-03-23 14:26 ` Jason Gunthorpe
2023-03-21 19:14 ` Jason Gunthorpe [this message]
2023-03-21 19:14 ` [PATCH v3 12/17] iommufd: Add iommufd_device_replace() Jason Gunthorpe
2023-03-23 7:31 ` Tian, Kevin
2023-03-23 14:30 ` Jason Gunthorpe
2023-03-24 1:42 ` Tian, Kevin
2023-03-24 15:03 ` Jason Gunthorpe
2023-03-21 19:14 ` [PATCH v3 13/17] iommufd: Make destroy_rwsem use a lock class per object type Jason Gunthorpe
2023-03-23 7:54 ` Tian, Kevin
2023-03-21 19:14 ` [PATCH v3 14/17] iommufd/selftest: Test iommufd_device_replace() Jason Gunthorpe
2023-03-23 7:57 ` Tian, Kevin
2023-03-23 14:32 ` Jason Gunthorpe
2023-03-21 19:14 ` [PATCH v3 15/17] iommufd: Add IOMMU_HWPT_ALLOC Jason Gunthorpe
2023-03-23 8:00 ` Tian, Kevin
2023-03-21 19:14 ` [PATCH v3 16/17] iommufd/selftest: Return the real idev id from selftest mock_domain Jason Gunthorpe
2023-03-23 8:02 ` Tian, Kevin
2023-03-21 19:14 ` [PATCH v3 17/17] iommufd/selftest: Add a selftest for IOMMU_HWPT_ALLOC Jason Gunthorpe
2023-03-23 8:03 ` Tian, Kevin
2023-03-23 8:04 ` [PATCH v3 00/17] Add iommufd physical device operations for replace and alloc hwpt Tian, Kevin
2023-03-23 14:35 ` Jason Gunthorpe
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