[PATCH v3 01/21] xen: update grant_table.h

Juergen Gross
2022-05-05T08:20:34Z

Update include/xen/interface/grant_table.h to its newest version.

This allows to drop some private definitions in grant-table.c and
include/xen/grant_table.h.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
V3:
- new patch
---
drivers/xen/grant-table.c | 8 +-
include/xen/grant_table.h | 2 -
include/xen/interface/grant_table.h | 161 +++++++++++++++++-----------
3 files changed, 103 insertions(+), 68 deletions(-)

diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
index 8ccccace2a4f..6ea31ea26008 100644
--- a/drivers/xen/grant-table.c
+++ b/drivers/xen/grant-table.c
@@ -66,8 +66,6 @@

#include <asm/sync_bitops.h>

-/* External tools reserve first few grant table entries. */
-#define NR_RESERVED_ENTRIES 8
#define GNTTAB_LIST_END 0xffffffff

static grant_ref_t **gnttab_list;
@@ -1465,12 +1463,12 @@ int gnttab_init(void)
nr_init_grefs = nr_grant_frames *
gnttab_interface->grefs_per_grant_frame;

- for (i = NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++)
+ for (i = GNTTAB_NR_RESERVED_ENTRIES; i < nr_init_grefs - 1; i++)
gnttab_entry(i) = i + 1;

gnttab_entry(nr_init_grefs - 1) = GNTTAB_LIST_END;
- gnttab_free_count = nr_init_grefs - NR_RESERVED_ENTRIES;
- gnttab_free_head = NR_RESERVED_ENTRIES;
+ gnttab_free_count = nr_init_grefs - GNTTAB_NR_RESERVED_ENTRIES;
+ gnttab_free_head = GNTTAB_NR_RESERVED_ENTRIES;

printk("Grant table initialized\n");
return 0;
diff --git a/include/xen/grant_table.h b/include/xen/grant_table.h
index dfd5bf31cfb9..7d0f2f0037b8 100644
--- a/include/xen/grant_table.h
+++ b/include/xen/grant_table.h
@@ -57,8 +57,6 @@
#define INVALID_GRANT_REF ((grant_ref_t)-1)
#define INVALID_GRANT_HANDLE ((grant_handle_t)-1)

-#define GNTTAB_RESERVED_XENSTORE 1
-
/* NR_GRANT_FRAMES must be less than or equal to that configured in Xen */
#define NR_GRANT_FRAMES 4

diff --git a/include/xen/interface/grant_table.h b/include/xen/interface/grant_table.h
index 3eeabbc7ee09..cebbd99f1f84 100644
--- a/include/xen/interface/grant_table.h
+++ b/include/xen/interface/grant_table.h
@@ -19,7 +19,8 @@

/* 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 (arch/xen/kernel/grant_table.c).
+ * 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
*
* NB. WMB is a no-op on current-generation x86 processors. However, a
* compiler barrier will still be required.
@@ -80,8 +81,9 @@ typedef uint32_t grant_ref_t;
*/

/*
- * Version 1 of the grant table entry structure is maintained purely
- * for backwards compatibility. New guests should use version 2.
+ * Version 1 of the grant table entry structure is maintained largely for
+ * backwards compatibility. New guests are recommended to support using
+ * version 2 to overcome version 1 limitations, but to default to version 1.
*/
struct grant_entry_v1 {
/* GTF_xxx: various type and flag information. [XEN,GST] */
@@ -89,12 +91,21 @@ struct grant_entry_v1 {
/* The domain being granted foreign privileges. [GST] */
domid_t domid;
/*
- * GTF_permit_access: Frame that @domid is allowed to map and access. [GST]
- * GTF_accept_transfer: Frame whose ownership transferred by @domid. [XEN]
+ * 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]
*/
uint32_t frame;
};

+/* The first few grant table entries will be preserved across grant table
+ * version changes and may be pre-populated at domain creation by tools.
+ */
+#define GNTTAB_NR_RESERVED_ENTRIES 8
+#define GNTTAB_RESERVED_CONSOLE 0
+#define GNTTAB_RESERVED_XENSTORE 1
+
/*
* Type of grant entry.
* GTF_invalid: This grant entry grants no privileges.
@@ -111,10 +122,13 @@ struct grant_entry_v1 {
#define GTF_type_mask (3U<<0)

/*
- * Subflags for GTF_permit_access.
+ * Subflags for GTF_permit_access and GTF_transitive.
* GTF_readonly: Restrict @domid to read-only mappings and accesses. [GST]
* GTF_reading: Grant entry is currently mapped for reading by @domid. [XEN]
* GTF_writing: Grant entry is currently mapped for writing by @domid. [XEN]
+ * Further subflags for GTF_permit_access only.
+ * GTF_PAT, GTF_PWT, GTF_PCD: (x86) cache attribute flags to be used for
+ * mappings of the grant [GST]
* GTF_sub_page: Grant access to only a subrange of the page. @domid
* will only be allowed to copy from the grant, and not
* map it. [GST]
@@ -125,6 +139,12 @@ struct grant_entry_v1 {
#define GTF_reading (1U<<_GTF_reading)
#define _GTF_writing (4)
#define GTF_writing (1U<<_GTF_writing)
+#define _GTF_PWT (5)
+#define GTF_PWT (1U<<_GTF_PWT)
+#define _GTF_PCD (6)
+#define GTF_PCD (1U<<_GTF_PCD)
+#define _GTF_PAT (7)
+#define GTF_PAT (1U<<_GTF_PAT)
#define _GTF_sub_page (8)
#define GTF_sub_page (1U<<_GTF_sub_page)

@@ -164,8 +184,7 @@ struct grant_entry_header {
};

/*
- * Version 2 of the grant entry structure, here is a union because three
- * different types are suppotted: full_page, sub_page and transitive.
+ * Version 2 of the grant entry structure.
*/
union grant_entry_v2 {
struct grant_entry_header hdr;
@@ -180,9 +199,9 @@ union grant_entry_v2 {
* field of the same name in the V1 entry structure.
*/
struct {
- struct grant_entry_header hdr;
- uint32_t pad0;
- uint64_t frame;
+ struct grant_entry_header hdr;
+ uint32_t pad0;
+ uint64_t frame;
} full_page;

/*
@@ -191,10 +210,10 @@ union grant_entry_v2 {
* in frame @frame.
*/
struct {
- struct grant_entry_header hdr;
- uint16_t page_off;
- uint16_t length;
- uint64_t frame;
+ struct grant_entry_header hdr;
+ uint16_t page_off;
+ uint16_t length;
+ uint64_t frame;
} sub_page;

/*
@@ -202,12 +221,15 @@ union grant_entry_v2 {
* grant @gref in domain @trans_domid, as if it was the local
* domain. Obviously, the transitive access must be compatible
* with the original grant.
+ *
+ * The current version of Xen does not allow transitive grants
+ * to be mapped.
*/
struct {
- struct grant_entry_header hdr;
- domid_t trans_domid;
- uint16_t pad0;
- grant_ref_t gref;
+ struct grant_entry_header hdr;
+ domid_t trans_domid;
+ uint16_t pad0;
+ grant_ref_t gref;
} transitive;

uint32_t __spacer[4]; /* Pad to a power of two */
@@ -219,6 +241,21 @@ typedef uint16_t grant_status_t;
* GRANT TABLE QUERIES AND USES
*/

+#define GNTTABOP_map_grant_ref 0
+#define GNTTABOP_unmap_grant_ref 1
+#define GNTTABOP_setup_table 2
+#define GNTTABOP_dump_table 3
+#define GNTTABOP_transfer 4
+#define GNTTABOP_copy 5
+#define GNTTABOP_query_size 6
+#define GNTTABOP_unmap_and_replace 7
+#define GNTTABOP_set_version 8
+#define GNTTABOP_get_status_frames 9
+#define GNTTABOP_get_version 10
+#define GNTTABOP_swap_grant_ref 11
+#define GNTTABOP_cache_flush 12
+/* ` } */
+
/*
* Handle to track a mapping created via a grant reference.
*/
@@ -227,7 +264,7 @@ typedef uint32_t grant_handle_t;
/*
* GNTTABOP_map_grant_ref: Map the grant entry (<dom>,<ref>) for access
* by devices and/or host CPUs. If successful, <handle> is a tracking number
- * that must be presented later to destroy the mapping(s). On error, <handle>
+ * that must be presented later to destroy the mapping(s). On error, <status>
* is a negative status code.
* NOTES:
* 1. If GNTMAP_device_map is specified then <dev_bus_addr> is the address
@@ -241,7 +278,6 @@ typedef uint32_t grant_handle_t;
* host mapping is destroyed by other means then it is *NOT* guaranteed
* to be accounted to the correct grant reference!
*/
-#define GNTTABOP_map_grant_ref 0
struct gnttab_map_grant_ref {
/* IN parameters. */
uint64_t host_addr;
@@ -266,7 +302,6 @@ DEFINE_GUEST_HANDLE_STRUCT(gnttab_map_grant_ref);
* 3. After executing a batch of unmaps, it is guaranteed that no stale
* mappings will remain in the device or host TLBs.
*/
-#define GNTTABOP_unmap_grant_ref 1
struct gnttab_unmap_grant_ref {
/* IN parameters. */
uint64_t host_addr;
@@ -286,7 +321,6 @@ DEFINE_GUEST_HANDLE_STRUCT(gnttab_unmap_grant_ref);
* 2. Only a sufficiently-privileged domain may specify <dom> != DOMID_SELF.
* 3. Xen may not support more than a single grant-table page per domain.
*/
-#define GNTTABOP_setup_table 2
struct gnttab_setup_table {
/* IN parameters. */
domid_t dom;
@@ -301,7 +335,6 @@ DEFINE_GUEST_HANDLE_STRUCT(gnttab_setup_table);
* GNTTABOP_dump_table: Dump the contents of the grant table to the
* xen console. Debugging use only.
*/
-#define GNTTABOP_dump_table 3
struct gnttab_dump_table {
/* IN parameters. */
domid_t dom;
@@ -311,17 +344,17 @@ struct gnttab_dump_table {
DEFINE_GUEST_HANDLE_STRUCT(gnttab_dump_table);

/*
- * GNTTABOP_transfer_grant_ref: Transfer to a foreign domain. The
- * foreign domain has previously registered its interest in the transfer via
- * <domid, ref>.
+ * GNTTABOP_transfer: Transfer to a foreign domain. The foreign domain
+ * has previously registered its interest in the transfer via <domid, ref>.
*
* Note that, even if the transfer fails, the specified page no longer belongs
* to the calling domain *unless* the error is GNTST_bad_page.
+ *
+ * Note further that only PV guests can use this operation.
*/
-#define GNTTABOP_transfer 4
struct gnttab_transfer {
/* IN parameters. */
- xen_pfn_t mfn;
+ xen_pfn_t mfn;
domid_t domid;
grant_ref_t ref;
/* OUT parameters. */
@@ -352,21 +385,20 @@ DEFINE_GUEST_HANDLE_STRUCT(gnttab_transfer);
#define _GNTCOPY_dest_gref (1)
#define GNTCOPY_dest_gref (1<<_GNTCOPY_dest_gref)

-#define GNTTABOP_copy 5
struct gnttab_copy {
- /* IN parameters. */
- struct {
- union {
- grant_ref_t ref;
- xen_pfn_t gmfn;
- } u;
- domid_t domid;
- uint16_t offset;
- } source, dest;
- uint16_t len;
- uint16_t flags; /* GNTCOPY_* */
- /* OUT parameters. */
- int16_t status;
+ /* IN parameters. */
+ struct gnttab_copy_ptr {
+ union {
+ grant_ref_t ref;
+ xen_pfn_t gmfn;
+ } u;
+ domid_t domid;
+ uint16_t offset;
+ } source, dest;
+ uint16_t len;
+ uint16_t flags; /* GNTCOPY_* */
+ /* OUT parameters. */
+ int16_t status;
};
DEFINE_GUEST_HANDLE_STRUCT(gnttab_copy);

@@ -377,7 +409,6 @@ DEFINE_GUEST_HANDLE_STRUCT(gnttab_copy);
* 1. <dom> may be specified as DOMID_SELF.
* 2. Only a sufficiently-privileged domain may specify <dom> != DOMID_SELF.
*/
-#define GNTTABOP_query_size 6
struct gnttab_query_size {
/* IN parameters. */
domid_t dom;
@@ -399,7 +430,6 @@ DEFINE_GUEST_HANDLE_STRUCT(gnttab_query_size);
* 2. After executing a batch of unmaps, it is guaranteed that no stale
* mappings will remain in the device or host TLBs.
*/
-#define GNTTABOP_unmap_and_replace 7
struct gnttab_unmap_and_replace {
/* IN parameters. */
uint64_t host_addr;
@@ -412,14 +442,12 @@ DEFINE_GUEST_HANDLE_STRUCT(gnttab_unmap_and_replace);

/*
* GNTTABOP_set_version: Request a particular version of the grant
- * table shared table structure. This operation can only be performed
- * once in any given domain. It must be performed before any grants
- * are activated; otherwise, the domain will be stuck with version 1.
- * The only defined versions are 1 and 2.
+ * table shared table structure. This operation may be used to toggle
+ * between different versions, but must be performed while no grants
+ * are active. The only defined versions are 1 and 2.
*/
-#define GNTTABOP_set_version 8
struct gnttab_set_version {
- /* IN parameters */
+ /* IN/OUT parameters */
uint32_t version;
};
DEFINE_GUEST_HANDLE_STRUCT(gnttab_set_version);
@@ -436,7 +464,6 @@ DEFINE_GUEST_HANDLE_STRUCT(gnttab_set_version);
* 1. <dom> may be specified as DOMID_SELF.
* 2. Only a sufficiently-privileged domain may specify <dom> != DOMID_SELF.
*/
-#define GNTTABOP_get_status_frames 9
struct gnttab_get_status_frames {
/* IN parameters. */
uint32_t nr_frames;
@@ -451,7 +478,6 @@ DEFINE_GUEST_HANDLE_STRUCT(gnttab_get_status_frames);
* GNTTABOP_get_version: Get the grant table version which is in
* effect for domain <dom>.
*/
-#define GNTTABOP_get_version 10
struct gnttab_get_version {
/* IN parameters */
domid_t dom;
@@ -461,27 +487,38 @@ struct gnttab_get_version {
};
DEFINE_GUEST_HANDLE_STRUCT(gnttab_get_version);

+/*
+ * GNTTABOP_swap_grant_ref: Swap the contents of two grant entries.
+ */
+struct gnttab_swap_grant_ref {
+ /* IN parameters */
+ grant_ref_t ref_a;
+ grant_ref_t ref_b;
+ /* OUT parameters */
+ int16_t status; /* GNTST_* */
+};
+DEFINE_GUEST_HANDLE_STRUCT(gnttab_swap_grant_ref);
+
/*
* Issue one or more cache maintenance operations on a portion of a
* page granted to the calling domain by a foreign domain.
*/
-#define GNTTABOP_cache_flush 12
struct gnttab_cache_flush {
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 */
-#define GNTTAB_CACHE_CLEAN (1<<0)
-#define GNTTAB_CACHE_INVAL (1<<1)
-#define GNTTAB_CACHE_SOURCE_GREF (1<<31)
+ 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)
uint32_t op;
};
DEFINE_GUEST_HANDLE_STRUCT(gnttab_cache_flush);

/*
- * Bitfield values for update_pin_status.flags.
+ * Bitfield values for gnttab_map_grant_ref.flags.
*/
/* Map the grant entry for access by I/O devices. */
#define _GNTMAP_device_map (0)
@@ -531,6 +568,7 @@ DEFINE_GUEST_HANDLE_STRUCT(gnttab_cache_flush);
#define GNTST_bad_copy_arg (-10) /* copy arguments cross page boundary. */
#define GNTST_address_too_big (-11) /* transfer page address too large. */
#define GNTST_eagain (-12) /* Operation not done; try again. */
+#define GNTST_no_space (-13) /* Out of space (handles etc). */

#define GNTTABOP_error_msgs { \
"okay", \
@@ -545,7 +583,8 @@ DEFINE_GUEST_HANDLE_STRUCT(gnttab_cache_flush);
"bad page", \
"copy arguments cross page boundary", \
"page address size too large", \
- "operation not done; try again" \
+ "operation not done; try again", \
+ "out of space", \
}

#endif /* __XEN_PUBLIC_GRANT_TABLE_H__ */
--
2.35.3