From: Jacob Pan <jacob.jun.pan@linux.intel.com>
To: iommu@lists.linux-foundation.org,
LKML <linux-kernel@vger.kernel.org>,
"Lu Baolu" <baolu.lu@linux.intel.com>,
Joerg Roedel <joro@8bytes.org>,
David Woodhouse <dwmw2@infradead.org>
Cc: "Yi Liu" <yi.l.liu@intel.com>,
"Tian, Kevin" <kevin.tian@intel.com>,
Raj Ashok <ashok.raj@intel.com>,
Alex Williamson <alex.williamson@redhat.com>,
"Christoph Hellwig" <hch@infradead.org>,
Jean-Philippe Brucker <jean-philippe@linaro.com>,
Jonathan Cameron <jic23@kernel.org>,
Eric Auger <eric.auger@redhat.com>,
Jacob Pan <jacob.jun.pan@linux.intel.com>
Subject: [PATCH 1/3] iommu/uapi: Define uapi version and capabilities
Date: Tue, 28 Jan 2020 22:02:02 -0800 [thread overview]
Message-ID: <1580277724-66994-2-git-send-email-jacob.jun.pan@linux.intel.com> (raw)
In-Reply-To: <1580277724-66994-1-git-send-email-jacob.jun.pan@linux.intel.com>
Define a unified UAPI version to be used for compatibility
checks between user and kernel.
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
---
include/uapi/linux/iommu.h | 48 ++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 48 insertions(+)
diff --git a/include/uapi/linux/iommu.h b/include/uapi/linux/iommu.h
index fcafb6401430..65a26c2519ee 100644
--- a/include/uapi/linux/iommu.h
+++ b/include/uapi/linux/iommu.h
@@ -8,6 +8,54 @@
#include <linux/types.h>
+/**
+ * Current version of the IOMMU user API. This is intended for query
+ * between user and kernel to determine compatible data structures.
+ *
+ * Having a single UAPI version to govern the user-kernel data structures
+ * makes compatibility check straightforward. On the contrary, supporting
+ * combinations of multiple versions of the data can be a nightmare.
+ *
+ * UAPI version can be bumped up with the following rules:
+ * 1. All data structures passed between user and kernel space share
+ * the same version number. i.e. any extension to to any structure
+ * results in version bump up.
+ *
+ * 2. Data structures are open to extension but closed to modification.
+ * New fields must be added at the end of each data structure with
+ * 64bit alignment. Flag bits can be added without size change but
+ * existing ones cannot be altered.
+ *
+ * 3. Versions are backward compatible.
+ *
+ * 4. Version to size lookup is supported by kernel internal API for each
+ * API function type. @version is mandatory for new data structures
+ * and must be at the beginning with type of __u32.
+ */
+#define IOMMU_UAPI_VERSION 1
+static inline int iommu_get_uapi_version(void)
+{
+ return IOMMU_UAPI_VERSION;
+}
+
+/*
+ * Supported UAPI features that can be reported to user space.
+ * These types represent the capability available in the kernel.
+ *
+ * REVISIT: UAPI version also implies the capabilities. Should we
+ * report them explicitly?
+ */
+enum IOMMU_UAPI_DATA_TYPES {
+ IOMMU_UAPI_BIND_GPASID,
+ IOMMU_UAPI_CACHE_INVAL,
+ IOMMU_UAPI_PAGE_RESP,
+ NR_IOMMU_UAPI_TYPE,
+};
+
+#define IOMMU_UAPI_CAP_MASK ((1 << IOMMU_UAPI_BIND_GPASID) | \
+ (1 << IOMMU_UAPI_CACHE_INVAL) | \
+ (1 << IOMMU_UAPI_PAGE_RESP))
+
#define IOMMU_FAULT_PERM_READ (1 << 0) /* read */
#define IOMMU_FAULT_PERM_WRITE (1 << 1) /* write */
#define IOMMU_FAULT_PERM_EXEC (1 << 2) /* exec */
--
2.7.4
next prev parent reply other threads:[~2020-01-29 5:56 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-29 6:02 [PATCH 0/3] IOMMU user API enhancement Jacob Pan
2020-01-29 6:02 ` Jacob Pan [this message]
2020-02-06 10:14 ` [PATCH 1/3] iommu/uapi: Define uapi version and capabilities Auger Eric
2020-02-06 18:22 ` Jacob Pan
2020-01-29 6:02 ` [PATCH 2/3] iommu/uapi: Use unified UAPI version Jacob Pan
2020-01-29 6:02 ` [PATCH 3/3] iommu/uapi: Add helper function for size lookup Jacob Pan
2020-01-29 21:40 ` Alex Williamson
2020-01-29 22:19 ` Alex Williamson
2020-01-31 19:51 ` Jacob Pan
2020-01-31 23:51 ` Jacob Pan
2020-02-03 18:27 ` Alex Williamson
2020-02-03 20:41 ` Jacob Pan
2020-02-03 21:12 ` Alex Williamson
2020-02-03 22:41 ` Jacob Pan
2020-02-06 10:14 ` Auger Eric
2020-02-07 8:47 ` Jean-Philippe Brucker
2020-01-31 17:56 ` Jacob Pan
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