From: Jason Gunthorpe <jgg@nvidia.com>
To: iommu@lists.linux.dev, Kevin Tian <kevin.tian@intel.com>,
linux-kselftest@vger.kernel.org
Cc: kvm@vger.kernel.org, Nicolin Chen <nicolinc@nvidia.com>,
Yi Liu <yi.l.liu@intel.com>
Subject: [PATCH 10/14] iommufd: Make destroy_rwsem use a lock class per object type
Date: Fri, 24 Feb 2023 20:27:55 -0400 [thread overview]
Message-ID: <10-v1-7612f88c19f5+2f21-iommufd_alloc_jgg@nvidia.com> (raw)
In-Reply-To: <0-v1-7612f88c19f5+2f21-iommufd_alloc_jgg@nvidia.com>
The selftest invokes things like replace under the object lock of its
idev which protects the idev in a similar way to a real user.
Unfortunately this triggers lockdep. A lock class per type will solve the
problem.
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
---
drivers/iommu/iommufd/iommufd_private.h | 1 +
drivers/iommu/iommufd/main.c | 11 ++++++++++-
2 files changed, 11 insertions(+), 1 deletion(-)
diff --git a/drivers/iommu/iommufd/iommufd_private.h b/drivers/iommu/iommufd/iommufd_private.h
index 8921761ff98980..cfcda73942b533 100644
--- a/drivers/iommu/iommufd/iommufd_private.h
+++ b/drivers/iommu/iommufd/iommufd_private.h
@@ -119,6 +119,7 @@ enum iommufd_object_type {
#ifdef CONFIG_IOMMUFD_TEST
IOMMUFD_OBJ_SELFTEST,
#endif
+ IOMMUFD_OBJ_MAX,
};
/* Base struct for all objects with a userspace ID handle. */
diff --git a/drivers/iommu/iommufd/main.c b/drivers/iommu/iommufd/main.c
index 8597f2fb88da3a..9cba592d0482e7 100644
--- a/drivers/iommu/iommufd/main.c
+++ b/drivers/iommu/iommufd/main.c
@@ -32,6 +32,7 @@ struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
size_t size,
enum iommufd_object_type type)
{
+ static struct lock_class_key obj_keys[IOMMUFD_OBJ_MAX];
struct iommufd_object *obj;
int rc;
@@ -39,7 +40,15 @@ struct iommufd_object *_iommufd_object_alloc(struct iommufd_ctx *ictx,
if (!obj)
return ERR_PTR(-ENOMEM);
obj->type = type;
- init_rwsem(&obj->destroy_rwsem);
+ /*
+ * In most cases the destroy_rwsem is obtained with try so it doesn't
+ * interact with lockdep, however on destroy we have to sleep. This
+ * means if we have to destroy an object while holding a get on another
+ * object it triggers lockdep. Using one locking class per object type
+ * is a simple and reasonable way to avoid this.
+ */
+ __init_rwsem(&obj->destroy_rwsem, "iommufd_object::destroy_rwsem",
+ &obj_keys[type]);
refcount_set(&obj->users, 1);
/*
--
2.39.1
next prev parent reply other threads:[~2023-02-25 0:28 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-02-25 0:27 [PATCH 00/14] Add iommufd physical device operations for replace and alloc hwpt Jason Gunthorpe
2023-02-25 0:27 ` [PATCH 01/14] iommufd: Move isolated msi enforcement to iommufd_device_bind() Jason Gunthorpe
2023-03-02 7:45 ` Tian, Kevin
2023-02-25 0:27 ` [PATCH 02/14] iommufd: Add iommufd_group Jason Gunthorpe
2023-03-02 7:55 ` Tian, Kevin
2023-03-02 12:51 ` Jason Gunthorpe
2023-03-03 2:13 ` Tian, Kevin
2023-03-06 19:16 ` Jason Gunthorpe
2023-03-07 2:32 ` Tian, Kevin
2023-02-25 0:27 ` [PATCH 03/14] iommufd: Replace the hwpt->devices list with iommufd_group Jason Gunthorpe
2023-03-02 8:01 ` Tian, Kevin
2023-03-06 20:22 ` Jason Gunthorpe
2023-03-07 2:38 ` Tian, Kevin
2023-03-07 13:53 ` Jason Gunthorpe
2023-03-08 7:29 ` Tian, Kevin
2023-03-08 19:00 ` Jason Gunthorpe
2023-02-25 0:27 ` [PATCH 04/14] iommufd: Use the iommufd_group to avoid duplicate reserved groups and msi setup Jason Gunthorpe
2023-03-02 8:06 ` Tian, Kevin
2023-03-02 12:55 ` Jason Gunthorpe
2023-03-03 2:16 ` Tian, Kevin
2023-02-25 0:27 ` [PATCH 05/14] iommufd: Make sw_msi_start a group global Jason Gunthorpe
2023-03-02 8:09 ` Tian, Kevin
2023-03-06 20:27 ` Jason Gunthorpe
2023-02-25 0:27 ` [PATCH 06/14] iommufd: Move putting a hwpt to a helper function Jason Gunthorpe
2023-03-02 8:12 ` Tian, Kevin
2023-03-06 20:29 ` Jason Gunthorpe
2023-02-25 0:27 ` [PATCH 07/14] iommufd: Add enforced_cache_coherency to iommufd_hw_pagetable_alloc() Jason Gunthorpe
2023-03-02 8:14 ` Tian, Kevin
2023-02-25 0:27 ` [PATCH 08/14] iommu: Introduce a new iommu_group_replace_domain() API Jason Gunthorpe
2023-03-02 8:16 ` Tian, Kevin
2023-02-25 0:27 ` [PATCH 09/14] iommufd: Add iommufd_device_replace() Jason Gunthorpe
2023-02-26 3:01 ` Baolu Lu
2023-02-27 13:58 ` Jason Gunthorpe
2023-02-28 1:50 ` Baolu Lu
2023-02-28 13:51 ` Jason Gunthorpe
2023-03-01 1:55 ` Baolu Lu
2023-02-26 3:13 ` Baolu Lu
2023-02-27 14:00 ` Jason Gunthorpe
2023-02-28 2:10 ` Baolu Lu
2023-02-28 13:52 ` Jason Gunthorpe
2023-03-01 2:23 ` Baolu Lu
2023-03-02 8:20 ` Tian, Kevin
2023-03-06 20:44 ` Jason Gunthorpe
2023-03-07 2:42 ` Tian, Kevin
2023-03-07 13:54 ` Jason Gunthorpe
2023-02-25 0:27 ` Jason Gunthorpe [this message]
2023-02-25 0:27 ` [PATCH 11/14] iommufd/selftest: Test iommufd_device_replace() Jason Gunthorpe
2023-02-25 0:27 ` [PATCH 12/14] iommufd: Add IOMMU_HWPT_ALLOC Jason Gunthorpe
2023-03-06 1:42 ` Nicolin Chen
2023-03-06 20:31 ` Jason Gunthorpe
2023-03-17 3:02 ` Tian, Kevin
2023-03-17 4:02 ` Nicolin Chen
2023-03-17 10:20 ` Tian, Kevin
2023-03-21 17:16 ` Jason Gunthorpe
2023-02-25 0:27 ` [PATCH 13/14] iommufd/selftest: Return the real idev id from selftest mock_domain Jason Gunthorpe
2023-02-25 0:27 ` [PATCH 14/14] iommufd/selftest: Add a selftest for IOMMU_HWPT_ALLOC Jason Gunthorpe
2023-02-26 19:29 ` Nicolin Chen
2023-02-27 15:02 ` Jason Gunthorpe
2023-02-28 0:17 ` Nicolin Chen
2023-03-07 8:42 ` [PATCH 00/14] Add iommufd physical device operations for replace and alloc hwpt Tian, Kevin
2023-03-07 12:46 ` Jason Gunthorpe
2023-03-08 2:08 ` Baolu Lu
2023-03-08 7:38 ` Tian, Kevin
2023-03-08 18:59 ` Jason Gunthorpe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=10-v1-7612f88c19f5+2f21-iommufd_alloc_jgg@nvidia.com \
--to=jgg@nvidia.com \
--cc=iommu@lists.linux.dev \
--cc=kevin.tian@intel.com \
--cc=kvm@vger.kernel.org \
--cc=linux-kselftest@vger.kernel.org \
--cc=nicolinc@nvidia.com \
--cc=yi.l.liu@intel.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).