[Qemu-devel] [PATCH v4 1/2] Interface for grant copy operation in libs.

[Paulina Szubarczyk <paulinaszubarczyk@gmail.com>]

In a linux part an ioctl(gntdev, IOCTL_GNTDEV_GRANT_COPY, ..)
system call is invoked. In mini-os the operation is yet not
implemented. For the OSs that does not implement gnttab the
call of the grant copy operation causes abort.

Signed-off-by: Paulina Szubarczyk <paulinaszubarczyk@gmail.com>
---
Changes since v3:
- revert to cast from xengnttab_grant_copy_segment_t
  to ioctl_gntdev_grant_copy.
- added compile-time check to compare the libs
  xengnttab_grant_copy_segment_t with the ioctl structure.
  The patch relies on Wei patch introducing XENGNTTAB_BUILD_BUG_ON  
  in libs/gnttab.
---
 tools/include/xen-sys/Linux/gntdev.h  | 21 ++++++++++
 tools/libs/gnttab/Makefile            |  2 +-
 tools/libs/gnttab/gnttab_core.c       |  6 +++
 tools/libs/gnttab/gnttab_unimp.c      |  6 +++
 tools/libs/gnttab/include/xengnttab.h | 28 +++++++++++++
 tools/libs/gnttab/libxengnttab.map    |  5 +++
 tools/libs/gnttab/linux.c             | 79 +++++++++++++++++++++++++++++++++++
 tools/libs/gnttab/minios.c            |  6 +++
 tools/libs/gnttab/private.h           |  4 ++
 9 files changed, 156 insertions(+), 1 deletion(-)

diff --git a/tools/include/xen-sys/Linux/gntdev.h b/tools/include/xen-sys/Linux/gntdev.h
index caf6fb4..0ca07c9 100644
--- a/tools/include/xen-sys/Linux/gntdev.h
+++ b/tools/include/xen-sys/Linux/gntdev.h
@@ -147,4 +147,25 @@ struct ioctl_gntdev_unmap_notify {
 /* Send an interrupt on the indicated event channel */
 #define UNMAP_NOTIFY_SEND_EVENT 0x2
 
+struct ioctl_gntdev_grant_copy_segment {
+    union {
+        void *virt;
+        struct {
+            uint32_t ref;
+            uint16_t offset;
+            uint16_t domid;
+        } foreign;
+    } source, dest;
+    uint16_t len;
+    uint16_t flags;
+    int16_t status;
+};
+
+#define IOCTL_GNTDEV_GRANT_COPY \
+_IOC(_IOC_NONE, 'G', 8, sizeof(struct ioctl_gntdev_grant_copy))
+struct ioctl_gntdev_grant_copy {
+    unsigned int count;
+    struct ioctl_gntdev_grant_copy_segment *segments;
+};
+
 #endif /* __LINUX_PUBLIC_GNTDEV_H__ */
diff --git a/tools/libs/gnttab/Makefile b/tools/libs/gnttab/Makefile
index af64542..95c2cd8 100644
--- a/tools/libs/gnttab/Makefile
+++ b/tools/libs/gnttab/Makefile
@@ -2,7 +2,7 @@ XEN_ROOT = $(CURDIR)/../../..
 include $(XEN_ROOT)/tools/Rules.mk
 
 MAJOR    = 1
-MINOR    = 0
+MINOR    = 1
 SHLIB_LDFLAGS += -Wl,--version-script=libxengnttab.map
 
 CFLAGS   += -Werror -Wmissing-prototypes
diff --git a/tools/libs/gnttab/gnttab_core.c b/tools/libs/gnttab/gnttab_core.c
index 5d0474d..968c833 100644
--- a/tools/libs/gnttab/gnttab_core.c
+++ b/tools/libs/gnttab/gnttab_core.c
@@ -113,6 +113,12 @@ int xengnttab_unmap(xengnttab_handle *xgt, void *start_address, uint32_t count)
     return osdep_gnttab_unmap(xgt, start_address, count);
 }
 
+int xengnttab_grant_copy(xengnttab_handle *xgt,
+                         uint32_t count,
+                         xengnttab_grant_copy_segment_t *segs)
+{
+    return osdep_gnttab_grant_copy(xgt, count, segs);
+}
 /*
  * Local variables:
  * mode: C
diff --git a/tools/libs/gnttab/gnttab_unimp.c b/tools/libs/gnttab/gnttab_unimp.c
index b3a4a20..829eced 100644
--- a/tools/libs/gnttab/gnttab_unimp.c
+++ b/tools/libs/gnttab/gnttab_unimp.c
@@ -78,6 +78,12 @@ int xengnttab_unmap(xengnttab_handle *xgt, void *start_address, uint32_t count)
     abort();
 }
 
+int xengnttab_copy_grant(xengnttab_handle *xgt,
+                         uint32_t count,
+                         xengnttab_copy_grant_segment_t *segs)
+{
+    abort();
+}
 /*
  * Local variables:
  * mode: C
diff --git a/tools/libs/gnttab/include/xengnttab.h b/tools/libs/gnttab/include/xengnttab.h
index 0431dcf..949fd9e 100644
--- a/tools/libs/gnttab/include/xengnttab.h
+++ b/tools/libs/gnttab/include/xengnttab.h
@@ -258,6 +258,34 @@ int xengnttab_unmap(xengnttab_handle *xgt, void *start_address, uint32_t count);
 int xengnttab_set_max_grants(xengnttab_handle *xgt,
                              uint32_t nr_grants);
 
+struct xengnttab_grant_copy_segment {
+    union xengnttab_copy_ptr {
+        void *virt;
+        struct {
+            uint32_t ref;
+            uint16_t offset;
+            uint16_t domid;
+        } foreign;
+    } source, dest;
+    uint16_t len;
+    uint16_t flags;
+    int16_t status;
+};
+
+typedef struct xengnttab_grant_copy_segment xengnttab_grant_copy_segment_t;
+
+/**
+ * Copy memory from or to grant references. The information of each operations
+ * are contained in 'xengnttab_grant_copy_segment_t'. The @flag value indicate
+ * the direction of an operation (GNTCOPY_source_gref\GNTCOPY_dest_gref).
+ *
+ * The sum of fields @offset[i] and @len[i] of 'xengnttab_grant_copy_segment_t'
+ * should not exceed XEN_PAGE_SIZE
+ */
+int xengnttab_grant_copy(xengnttab_handle *xgt,
+                         uint32_t count,
+                         xengnttab_grant_copy_segment_t *segs);
+
 /*
  * Grant Sharing Interface (allocating and granting pages to others)
  */
diff --git a/tools/libs/gnttab/libxengnttab.map b/tools/libs/gnttab/libxengnttab.map
index dc737ac..f78da22 100644
--- a/tools/libs/gnttab/libxengnttab.map
+++ b/tools/libs/gnttab/libxengnttab.map
@@ -21,3 +21,8 @@ VERS_1.0 {
 		xengntshr_unshare;
 	local: *; /* Do not expose anything by default */
 };
+
+VERS_1.1 {
+    global:
+        xengnttab_grant_copy;
+} VERS_1.0;
diff --git a/tools/libs/gnttab/linux.c b/tools/libs/gnttab/linux.c
index 7b0fba4..56dff57 100644
--- a/tools/libs/gnttab/linux.c
+++ b/tools/libs/gnttab/linux.c
@@ -23,6 +23,7 @@
 #include <stdlib.h>
 #include <stdint.h>
 #include <string.h>
+#include <stddef.h>
 
 #include <sys/ioctl.h>
 #include <sys/mman.h>
@@ -235,6 +236,84 @@ int osdep_gnttab_unmap(xengnttab_handle *xgt,
     return 0;
 }
 
+int osdep_gnttab_grant_copy(xengnttab_handle *xgt,
+                            uint32_t count,
+                            xengnttab_grant_copy_segment_t *segs)
+{
+    int rc;
+    int fd = xgt->fd;
+    struct ioctl_gntdev_grant_copy copy;
+
+    XENGNTTAB_BUILD_BUG_ON(sizeof(struct ioctl_gntdev_grant_copy_segment) !=
+                           sizeof(xengnttab_grant_copy_segment_t));
+
+    XENGNTTAB_BUILD_BUG_ON(__alignof__(struct ioctl_gntdev_grant_copy_segment) !=
+                           __alignof__(xengnttab_grant_copy_segment_t));
+
+    XENGNTTAB_BUILD_BUG_ON(offsetof(struct ioctl_gntdev_grant_copy_segment,
+                                    source.virt) !=
+                           offsetof(xengnttab_grant_copy_segment_t,
+                                    source.virt));
+    XENGNTTAB_BUILD_BUG_ON(offsetof(struct ioctl_gntdev_grant_copy_segment,
+                                    source.foreign) !=
+                           offsetof(xengnttab_grant_copy_segment_t,
+                                    source.foreign));
+    XENGNTTAB_BUILD_BUG_ON(offsetof(struct ioctl_gntdev_grant_copy_segment,
+                                    source.foreign.ref) !=
+                           offsetof(xengnttab_grant_copy_segment_t,
+                                    source.foreign));
+    XENGNTTAB_BUILD_BUG_ON(offsetof(struct ioctl_gntdev_grant_copy_segment,
+                                    source.foreign.offset) !=
+                           offsetof(xengnttab_grant_copy_segment_t,
+                                    source.foreign.offset));
+    XENGNTTAB_BUILD_BUG_ON(offsetof(struct ioctl_gntdev_grant_copy_segment,
+                                    source.foreign.domid) !=
+                           offsetof(xengnttab_grant_copy_segment_t,
+                                    source.foreign.domid));
+
+    XENGNTTAB_BUILD_BUG_ON(offsetof(struct ioctl_gntdev_grant_copy_segment,
+                                    dest.virt) !=
+                           offsetof(xengnttab_grant_copy_segment_t,
+                                    dest.virt));
+    XENGNTTAB_BUILD_BUG_ON(offsetof(struct ioctl_gntdev_grant_copy_segment,
+                                    dest.foreign) !=
+                           offsetof(xengnttab_grant_copy_segment_t,
+                                    dest.foreign));
+    XENGNTTAB_BUILD_BUG_ON(offsetof(struct ioctl_gntdev_grant_copy_segment,
+                                    dest.foreign.ref) !=
+                           offsetof(xengnttab_grant_copy_segment_t,
+                                    dest.foreign));
+    XENGNTTAB_BUILD_BUG_ON(offsetof(struct ioctl_gntdev_grant_copy_segment, 
+                                    dest.foreign.offset) !=
+                           offsetof(xengnttab_grant_copy_segment_t,
+                                    dest.foreign.offset));
+    XENGNTTAB_BUILD_BUG_ON(offsetof(struct ioctl_gntdev_grant_copy_segment,
+                                    dest.foreign.domid) !=
+                           offsetof(xengnttab_grant_copy_segment_t,
+                                    dest.foreign.domid));
+
+    XENGNTTAB_BUILD_BUG_ON(offsetof(struct ioctl_gntdev_grant_copy_segment, 
+                                    len) !=
+                           offsetof(xengnttab_grant_copy_segment_t, len));
+    XENGNTTAB_BUILD_BUG_ON(offsetof(struct ioctl_gntdev_grant_copy_segment,
+                                    flags) !=
+                           offsetof(xengnttab_grant_copy_segment_t, flags));
+    XENGNTTAB_BUILD_BUG_ON(offsetof(struct ioctl_gntdev_grant_copy_segment,
+                                    status) !=
+                           offsetof(xengnttab_grant_copy_segment_t, status));
+
+    copy.segments = (struct ioctl_gntdev_grant_copy_segment *)segs;
+    copy.count = count;
+
+    rc = ioctl(fd, IOCTL_GNTDEV_GRANT_COPY, &copy);
+    if (rc) 
+    {
+        GTERROR(xgt->logger, "ioctl GRANT COPY failed %d ", errno);
+    }
+
+    return rc;
+}
+
 int osdep_gntshr_open(xengntshr_handle *xgs)
 {
     int fd = open(DEVXEN "gntalloc", O_RDWR);
diff --git a/tools/libs/gnttab/minios.c b/tools/libs/gnttab/minios.c
index 7e04174..0951bc9 100644
--- a/tools/libs/gnttab/minios.c
+++ b/tools/libs/gnttab/minios.c
@@ -106,6 +106,12 @@ int osdep_gnttab_set_max_grants(xengnttab_handle *xgt, uint32_t count)
     return ret;
 }
 
+int osdep_gnttab_grant_copy(xengnttab_handle *xgt,
+                            uint32_t count,
+                            xengnttab_grant_copy_segment_t *segs)
+{
+    return -1;
+}
 /*
  * Local variables:
  * mode: C
diff --git a/tools/libs/gnttab/private.h b/tools/libs/gnttab/private.h
index 2bdc0f2..f8d234a 100644
--- a/tools/libs/gnttab/private.h
+++ b/tools/libs/gnttab/private.h
@@ -30,6 +30,10 @@ void *osdep_gnttab_grant_map(xengnttab_handle *xgt,
 int osdep_gnttab_unmap(xengnttab_handle *xgt,
                        void *start_address,
                        uint32_t count);
+int osdep_gnttab_grant_copy(xengnttab_handle *xgt,
+                            uint32_t count,
+                            xengnttab_grant_copy_segment_t *segs);
+
 int osdep_gntshr_open(xengntshr_handle *xgs);
 int osdep_gntshr_close(xengntshr_handle *xgs);
 
-- 
1.9.1