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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [PATCH v2 3/3] docs/doxygen: doxygen documentation for grant_table.h
Modification to include/public/grant_table.h:
1) Add doxygen tags to:
- Create Grant tables section
- include variables in the generated documentation
2) Add .rst file for grant table for Arm64
Signed-off-by: Luca Fancellu <luca.fancellu@xxxxxxx>
---
v2 changes:
- Revert back to anonymous union/struct
- add doxygen tags to skip anonymous union/struct
---
docs/hypercall-interfaces/arm64.rst | 1 +
.../arm64/grant_tables.rst | 8 ++
docs/xen-doxygen/doxy_input.list | 1 +
xen/include/public/grant_table.h | 97 ++++++++++++-------
4 files changed, 73 insertions(+), 34 deletions(-)
create mode 100644 docs/hypercall-interfaces/arm64/grant_tables.rst
diff --git a/docs/hypercall-interfaces/arm64.rst
b/docs/hypercall-interfaces/arm64.rst
index 5e701a2adc..c30a7142b1 100644
--- a/docs/hypercall-interfaces/arm64.rst
+++ b/docs/hypercall-interfaces/arm64.rst
@@ -8,6 +8,7 @@ Starting points
.. toctree::
:maxdepth: 2
+ arm64/grant_tables
Functions
diff --git a/docs/hypercall-interfaces/arm64/grant_tables.rst
b/docs/hypercall-interfaces/arm64/grant_tables.rst
new file mode 100644
index 0000000000..8955ec5812
--- /dev/null
+++ b/docs/hypercall-interfaces/arm64/grant_tables.rst
@@ -0,0 +1,8 @@
+.. SPDX-License-Identifier: CC-BY-4.0
+
+Grant Tables
+============
+
+.. doxygengroup:: grant_table
+ :project: Xen
+ :members:
diff --git a/docs/xen-doxygen/doxy_input.list b/docs/xen-doxygen/doxy_input.list
index e69de29bb2..233d692fa7 100644
--- a/docs/xen-doxygen/doxy_input.list
+++ b/docs/xen-doxygen/doxy_input.list
@@ -0,0 +1 @@
+xen/include/public/grant_table.h
diff --git a/xen/include/public/grant_table.h b/xen/include/public/grant_table.h
index 84b1d26b36..51c8d85822 100644
--- a/xen/include/public/grant_table.h
+++ b/xen/include/public/grant_table.h
@@ -25,15 +25,19 @@
* Copyright (c) 2004, K A Fraser
*/
-#ifndef __XEN_PUBLIC_GRANT_TABLE_H__
+/**
+ * @file
+ * @brief Interface for granting foreign access to page frames, and receiving
+ * page-ownership transfers.
+ */
+
+#if !defined(__XEN_PUBLIC_GRANT_TABLE_H__) || defined(DOXYGEN)
#define __XEN_PUBLIC_GRANT_TABLE_H__
#include "xen.h"
-/*
- * `incontents 150 gnttab Grant Tables
- *
- * Xen's grant tables provide a generic mechanism to memory sharing
+/**
+ * @brief Xen's grant tables provide a generic mechanism to memory sharing
* between domains. This shared memory interface underpins the split
* device drivers for block and network IO.
*
@@ -51,13 +55,10 @@
* know the real machine address of a page it is sharing. This makes
* it possible to share memory correctly with domains running in
* fully virtualised memory.
- */
-
-/***********************************
+ *
* GRANT TABLE REPRESENTATION
- */
-
-/* Some rough guidelines on accessing and updating grant-table entries
+ *
+ * Some rough guidelines on accessing and updating grant-table entries
* in a concurrency-safe manner. For more information, Linux contains a
* reference implementation for guest OSes (drivers/xen/grant_table.c, see
*
http://git.kernel.org/?p=linux/kernel/git/torvalds/linux.git;a=blob;f=drivers/xen/grant-table.c;hb=HEAD
@@ -66,6 +67,7 @@
* compiler barrier will still be required.
*
* Introducing a valid entry into the grant table:
+ * @code
* 1. Write ent->domid.
* 2. Write ent->frame:
* GTF_permit_access: Frame to which access is permitted.
@@ -73,20 +75,25 @@
* frame, or zero if none.
* 3. Write memory barrier (WMB).
* 4. Write ent->flags, inc. valid type.
+ * @endcode
*
* Invalidating an unused GTF_permit_access entry:
+ * @code
* 1. flags = ent->flags.
* 2. Observe that !(flags & (GTF_reading|GTF_writing)).
* 3. Check result of SMP-safe CMPXCHG(&ent->flags, flags, 0).
* NB. No need for WMB as reuse of entry is control-dependent on success of
* step 3, and all architectures guarantee ordering of ctrl-dep writes.
+ * @endcode
*
* Invalidating an in-use GTF_permit_access entry:
+ *
* This cannot be done directly. Request assistance from the domain controller
* which can set a timeout on the use of a grant entry and take necessary
* action. (NB. This is not yet implemented!).
*
* Invalidating an unused GTF_accept_transfer entry:
+ * @code
* 1. flags = ent->flags.
* 2. Observe that !(flags & GTF_transfer_committed). [*]
* 3. Check result of SMP-safe CMPXCHG(&ent->flags, flags, 0).
@@ -97,47 +104,55 @@
* transferred frame is written. It is safe for the guest to spin waiting
* for this to occur (detect by observing GTF_transfer_completed in
* ent->flags).
+ * @endcode
*
* Invalidating a committed GTF_accept_transfer entry:
* 1. Wait for (ent->flags & GTF_transfer_completed).
*
* Changing a GTF_permit_access from writable to read-only:
+ *
* Use SMP-safe CMPXCHG to set GTF_readonly, while checking !GTF_writing.
*
* Changing a GTF_permit_access from read-only to writable:
+ *
* Use SMP-safe bit-setting instruction.
- */
-
-/*
- * Reference to a grant entry in a specified domain's grant table.
- */
-typedef uint32_t grant_ref_t;
-
-/*
+ *
* A grant table comprises a packed array of grant entries in one or more
* page frames shared between Xen and a guest.
+ *
* [XEN]: This field is written by Xen and read by the sharing guest.
+ *
* [GST]: This field is written by the guest and read by Xen.
+ *
+ * @addtogroup grant_table Grant Tables
+ * @{
*/
-/*
- * Version 1 of the grant table entry structure is maintained purely
- * for backwards compatibility. New guests should use version 2.
+/**
+ * Reference to a grant entry in a specified domain's grant table.
*/
+typedef uint32_t grant_ref_t;
+
#if __XEN_INTERFACE_VERSION__ < 0x0003020a
#define grant_entry_v1 grant_entry
#define grant_entry_v1_t grant_entry_t
#endif
+/**
+ * Version 1 of the grant table entry structure is maintained purely
+ * for backwards compatibility. New guests should use version 2.
+ */
struct grant_entry_v1 {
- /* GTF_xxx: various type and flag information. [XEN,GST] */
+ /** GTF_xxx: various type and flag information. [XEN,GST] */
uint16_t flags;
- /* The domain being granted foreign privileges. [GST] */
+ /** The domain being granted foreign privileges. [GST] */
domid_t domid;
- /*
+ /**
+ * @code
* GTF_permit_access: GFN that @domid is allowed to map and access. [GST]
* GTF_accept_transfer: GFN that @domid is allowed to transfer into. [GST]
* GTF_transfer_completed: MFN whose ownership transferred by @domid
* (non-translated guests only). [XEN]
+ * @endcode
*/
uint32_t frame;
};
@@ -243,23 +258,27 @@ union grant_entry_v2 {
* In that case, the frame field has the same semantics as the
* field of the same name in the V1 entry structure.
*/
+ /** @cond skip anonymous struct/union for doxygen */
struct {
grant_entry_header_t hdr;
uint32_t pad0;
uint64_t frame;
} full_page;
+ /** @endcond */
/*
* If the grant type is GTF_grant_access and GTF_sub_page is set,
* @domid is allowed to access bytes [@page_off,@page_off+@length)
* in frame @frame.
*/
+ /** @cond skip anonymous struct/union for doxygen */
struct {
grant_entry_header_t hdr;
uint16_t page_off;
uint16_t length;
uint64_t frame;
} sub_page;
+ /** @endcond */
/*
* If the grant is GTF_transitive, @domid is allowed to use the
@@ -270,12 +289,14 @@ union grant_entry_v2 {
* The current version of Xen does not allow transitive grants
* to be mapped.
*/
+ /** @cond skip anonymous struct/union for doxygen */
struct {
grant_entry_header_t hdr;
domid_t trans_domid;
uint16_t pad0;
grant_ref_t gref;
} transitive;
+ /** @endcond */
uint32_t __spacer[4]; /* Pad to a power of two */
};
@@ -433,7 +454,12 @@ typedef struct gnttab_transfer gnttab_transfer_t;
DEFINE_XEN_GUEST_HANDLE(gnttab_transfer_t);
-/*
+#define _GNTCOPY_source_gref (0)
+#define GNTCOPY_source_gref (1<<_GNTCOPY_source_gref)
+#define _GNTCOPY_dest_gref (1)
+#define GNTCOPY_dest_gref (1<<_GNTCOPY_dest_gref)
+
+/**
* GNTTABOP_copy: Hypervisor based copy
* source and destinations can be eithers MFNs or, for foreign domains,
* grant references. the foreign domain has to grant read/write access
@@ -451,18 +477,15 @@ DEFINE_XEN_GUEST_HANDLE(gnttab_transfer_t);
* bytes to be copied.
*/
-#define _GNTCOPY_source_gref (0)
-#define GNTCOPY_source_gref (1<<_GNTCOPY_source_gref)
-#define _GNTCOPY_dest_gref (1)
-#define GNTCOPY_dest_gref (1<<_GNTCOPY_dest_gref)
-
struct gnttab_copy {
/* IN parameters. */
struct gnttab_copy_ptr {
+ /** @cond skip anonymous struct/union for doxygen */
union {
grant_ref_t ref;
xen_pfn_t gmfn;
} u;
+ /** @endcond */
domid_t domid;
uint16_t offset;
} source, dest;
@@ -579,17 +602,19 @@ struct gnttab_swap_grant_ref {
typedef struct gnttab_swap_grant_ref gnttab_swap_grant_ref_t;
DEFINE_XEN_GUEST_HANDLE(gnttab_swap_grant_ref_t);
-/*
+/**
* Issue one or more cache maintenance operations on a portion of a
* page granted to the calling domain by a foreign domain.
*/
struct gnttab_cache_flush {
+ /** @cond skip anonymous struct/union for doxygen */
union {
uint64_t dev_bus_addr;
grant_ref_t ref;
} a;
- uint16_t offset; /* offset from start of grant */
- uint16_t length; /* size within the grant */
+ /** @endcond */
+ uint16_t offset; /**< offset from start of grant */
+ uint16_t length; /**< size within the grant */
#define GNTTAB_CACHE_CLEAN (1u<<0)
#define GNTTAB_CACHE_INVAL (1u<<1)
#define GNTTAB_CACHE_SOURCE_GREF (1u<<31)
@@ -673,6 +698,10 @@ DEFINE_XEN_GUEST_HANDLE(gnttab_cache_flush_t);
"operation not done; try again" \
}
+/**
+ * @}
+*/
+
#endif /* __XEN_PUBLIC_GRANT_TABLE_H__ */
/*
--
2.17.1
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