[PATCH XEN v2 13/15] tools: Implement xc_map_foreign_range(s) in terms of common helper

[Ian Campbell <ian.campbell@citrix.com>]

Both Linux and FreeBSD already implemented these functions using
identical helpers based on xc_map_foreign_pages. Make one copy of
these common helpers and switch all OSes to use them, even those which
previously had a specific lower level implementation of this
functionality.

This is makes two fewer low level interfaces to think about.

Signed-off-by: Ian Campbell <ian.campbell@citrix.com>
---
 docs/misc/toolstack-library-abis.pandoc | 35 +++++------------
 tools/libxc/xc_foreign_memory.c         | 50 +++++++++++++++++++++++
 tools/libxc/xc_freebsd_osdep.c          | 50 -----------------------
 tools/libxc/xc_linux_osdep.c            | 49 -----------------------
 tools/libxc/xc_minios.c                 | 43 --------------------
 tools/libxc/xc_netbsd.c                 | 70 ---------------------------------
 tools/libxc/xc_solaris.c                | 67 -------------------------------
 7 files changed, 60 insertions(+), 304 deletions(-)

diff --git a/docs/misc/toolstack-library-abis.pandoc b/docs/misc/toolstack-library-abis.pandoc
index 4ad6c7d..35674cc 100644
--- a/docs/misc/toolstack-library-abis.pandoc
+++ b/docs/misc/toolstack-library-abis.pandoc
@@ -876,36 +876,25 @@ functionality areas:
 
 # Foreign memory mapping functions
 
-The `xc_map_foreign_*` functions are a bit of a twisty maze.
+The `xc_map_foreign_*` functions were once a bit of a twisty maze, but
+now all are implemented in terms of a single underlying per-OS
+function.
 
 osdep level interfaces:
 
 Interface            Linux Minios Netbsd Freebsd Solaris
 -------------------- ----- ------ ------ ------- -------
 `map_foreign_bulk`   Y     Y      compat Y       compat
-`map_foreign_range`  Y     Y      Y      Y       Y
-`map_foreign_ranges` Y     Y      Y      Y       Y
 
-_compat_ means using `xc_map_foreign_bulk_compat`
-
-`xc_map_foreign_pages` is common and implemented using
-`xc_map_foreign_bulk`.
-
-Some osdep call other `xc_map_foreign_*` recursivley:
-
-Interface            Linux                        FreeBSD
--------------------- ---------------------------- -------------------------
-`map_foreign_bulk`   `IOCTL_PRIVCMD_MMAPBATCH_V2` `IOCTL_PRIVCMD_MMAPBATCH`
-`map_foreign_range`  `xc_map_foreign_pages`       `xc_map_foreign_pages`
-`map_foreign_ranges` `xc_map_foreign_pages`       `xc_map_foreign_pages`
+_compat_ means using `osdep_map_foreign_batch` layer
 
 libxenctrl level interfaces:
 
 Interface               Underlying interface
 ----------------------  ---------------------------
 `xc_map_foreign_pages`  `xc_map_foreign_bulk`
-`xc_map_foreign_range`  `osdep: map_foreign_range`
-`xc_map_foreign_ranges` `osdep: map_foreign_ranges`
+`xc_map_foreign_range`  `xc_map_foreign_pages`
+`xc_map_foreign_ranges` `xc_map_foreign_pages`
 `xc_map_foreign_bulk`   `osdep: map_foreign_bulk`
 
 `osdep: *` have been collapsed since osdep layer was removed.
@@ -915,17 +904,13 @@ which have not implemented their own version. It used to use
 `xc_map_foreign_batch` which is now an osdep for those OSes which need
 it.
 
-Interface               Internal users               External users
-----------------------  --------------               --------------
+Interface               In-tree users                External users
+----------------------  -------------                --------------
 `xc_map_foreign_pages`  xenpaging                    qemu-pv
 `xc_map_foreign_range`  xenconsole, kdd, libxl,      qemu-dm, qemu-pv
                         mfndump, memshrtool, xenmon,
                         xenstored, xentrace
-`xc_map_foreign_ranges` NONE
+`xc_map_foreign_ranges` libxc internal
 `xc_map_foreign_bulk`   used recursively             qemu-dm
 
-Only one interface should become a stable API. Something based on
-`xc_map_foreign_bulk` seems most appropriate (it is used by
-`xc_map_foreign_pages` as well as by xc_map_foreign_range` and
-`xc_map_foreign_ranges` on Linux + FreeBSD. A compat version exists in
-terms of `xc_map_foreign_batch` for other OSes.
+`xc_map_foreign_bulk` should become an underlying stable API.
diff --git a/tools/libxc/xc_foreign_memory.c b/tools/libxc/xc_foreign_memory.c
index ae133a1..c96489d 100644
--- a/tools/libxc/xc_foreign_memory.c
+++ b/tools/libxc/xc_foreign_memory.c
@@ -51,6 +51,56 @@ void *xc_map_foreign_pages(xc_interface *xch, uint32_t dom, int prot,
     return res;
 }
 
+void *xc_map_foreign_range(xc_interface *xch,
+                           uint32_t dom, int size, int prot,
+                           unsigned long mfn)
+{
+    xen_pfn_t *arr;
+    int num;
+    int i;
+    void *ret;
+
+    num = (size + XC_PAGE_SIZE - 1) >> XC_PAGE_SHIFT;
+    arr = calloc(num, sizeof(xen_pfn_t));
+    if ( arr == NULL )
+        return NULL;
+
+    for ( i = 0; i < num; i++ )
+        arr[i] = mfn + i;
+
+    ret = xc_map_foreign_pages(xch, dom, prot, arr, num);
+    free(arr);
+    return ret;
+}
+
+void *xc_map_foreign_ranges(xc_interface *xch,
+                            uint32_t dom, size_t size,
+                            int prot, size_t chunksize,
+                            privcmd_mmap_entry_t entries[],
+                            int nentries)
+{
+    xen_pfn_t *arr;
+    int num_per_entry;
+    int num;
+    int i;
+    int j;
+    void *ret;
+
+    num_per_entry = chunksize >> XC_PAGE_SHIFT;
+    num = num_per_entry * nentries;
+    arr = calloc(num, sizeof(xen_pfn_t));
+    if ( arr == NULL )
+        return NULL;
+
+    for ( i = 0; i < nentries; i++ )
+        for ( j = 0; j < num_per_entry; j++ )
+            arr[i * num_per_entry + j] = entries[i].mfn + j;
+
+    ret = xc_map_foreign_pages(xch, dom, prot, arr, num);
+    free(arr);
+    return ret;
+}
+
 /*
  * stub for all not yet converted OSes (NetBSD and Solaris). New OSes should
  * just implement xc_map_foreign_bulk.
diff --git a/tools/libxc/xc_freebsd_osdep.c b/tools/libxc/xc_freebsd_osdep.c
index b0ec965..d09e0da 100644
--- a/tools/libxc/xc_freebsd_osdep.c
+++ b/tools/libxc/xc_freebsd_osdep.c
@@ -126,56 +126,6 @@ void *xc_map_foreign_bulk(xc_interface *xch,
     return addr;
 }
 
-void *xc_map_foreign_range(xc_interface *xch,
-                           uint32_t dom, int size, int prot,
-                           unsigned long mfn)
-{
-    xen_pfn_t *arr;
-    int num;
-    int i;
-    void *ret;
-
-    num = (size + XC_PAGE_SIZE - 1) >> XC_PAGE_SHIFT;
-    arr = calloc(num, sizeof(xen_pfn_t));
-    if ( arr == NULL )
-        return NULL;
-
-    for ( i = 0; i < num; i++ )
-        arr[i] = mfn + i;
-
-    ret = xc_map_foreign_pages(xch, dom, prot, arr, num);
-    free(arr);
-    return ret;
-}
-
-void *xc_map_foreign_ranges(xc_interface *xch,
-                            uint32_t dom, size_t size,
-                            int prot, size_t chunksize,
-                            privcmd_mmap_entry_t entries[],
-                            int nentries)
-{
-    xen_pfn_t *arr;
-    int num_per_entry;
-    int num;
-    int i;
-    int j;
-    void *ret;
-
-    num_per_entry = chunksize >> XC_PAGE_SHIFT;
-    num = num_per_entry * nentries;
-    arr = calloc(num, sizeof(xen_pfn_t));
-    if ( arr == NULL )
-        return NULL;
-
-    for ( i = 0; i < nentries; i++ )
-        for ( j = 0; j < num_per_entry; j++ )
-            arr[i * num_per_entry + j] = entries[i].mfn + j;
-
-    ret = xc_map_foreign_pages(xch, dom, prot, arr, num);
-    free(arr);
-    return ret;
-}
-
 /*
  * Local variables:
  * mode: C
diff --git a/tools/libxc/xc_linux_osdep.c b/tools/libxc/xc_linux_osdep.c
index 6641bd1..9f8805a 100644
--- a/tools/libxc/xc_linux_osdep.c
+++ b/tools/libxc/xc_linux_osdep.c
@@ -285,55 +285,6 @@ void *xc_map_foreign_bulk(xc_interface *xch,
     return addr;
 }
 
-void *xc_map_foreign_range(xc_interface *xch,
-                           uint32_t dom, int size, int prot,
-                           unsigned long mfn)
-{
-    xen_pfn_t *arr;
-    int num;
-    int i;
-    void *ret;
-
-    num = (size + XC_PAGE_SIZE - 1) >> XC_PAGE_SHIFT;
-    arr = calloc(num, sizeof(xen_pfn_t));
-    if ( arr == NULL )
-        return NULL;
-
-    for ( i = 0; i < num; i++ )
-        arr[i] = mfn + i;
-
-    ret = xc_map_foreign_pages(xch, dom, prot, arr, num);
-    free(arr);
-    return ret;
-}
-
-void *xc_map_foreign_ranges(xc_interface *xch,
-                            uint32_t dom, size_t size, int prot,
-                            size_t chunksize, privcmd_mmap_entry_t entries[],
-                            int nentries)
-{
-    xen_pfn_t *arr;
-    int num_per_entry;
-    int num;
-    int i;
-    int j;
-    void *ret;
-
-    num_per_entry = chunksize >> XC_PAGE_SHIFT;
-    num = num_per_entry * nentries;
-    arr = calloc(num, sizeof(xen_pfn_t));
-    if ( arr == NULL )
-        return NULL;
-
-    for ( i = 0; i < nentries; i++ )
-        for ( j = 0; j < num_per_entry; j++ )
-            arr[i * num_per_entry + j] = entries[i].mfn + j;
-
-    ret = xc_map_foreign_pages(xch, dom, prot, arr, num);
-    free(arr);
-    return ret;
-}
-
 /*
  * Local variables:
  * mode: C
diff --git a/tools/libxc/xc_minios.c b/tools/libxc/xc_minios.c
index ed20652..1616c58 100644
--- a/tools/libxc/xc_minios.c
+++ b/tools/libxc/xc_minios.c
@@ -74,49 +74,6 @@ void *xc_map_foreign_bulk(xc_interface *xch,
     return map_frames_ex(arr, num, 1, 0, 1, dom, err, pt_prot);
 }
 
-void *xc_map_foreign_range(xc_interface *xch,
-                           uint32_t dom,
-                           int size, int prot,
-                           unsigned long mfn)
-{
-    unsigned long pt_prot = 0;
-
-    if (prot & PROT_READ)
-	pt_prot = L1_PROT_RO;
-    if (prot & PROT_WRITE)
-	pt_prot = L1_PROT;
-
-    assert(!(size % getpagesize()));
-    return map_frames_ex(&mfn, size / getpagesize(), 0, 1, 1, dom, NULL, pt_prot);
-}
-
-void *xc_map_foreign_ranges(xc_interface *xch,
-                            uint32_t dom,
-                            size_t size, int prot, size_t chunksize,
-                            privcmd_mmap_entry_t entries[], int nentries)
-{
-    unsigned long *mfns;
-    int i, j, n;
-    unsigned long pt_prot = 0;
-    void *ret;
-
-    if (prot & PROT_READ)
-	pt_prot = L1_PROT_RO;
-    if (prot & PROT_WRITE)
-	pt_prot = L1_PROT;
-
-    mfns = malloc((size / XC_PAGE_SIZE) * sizeof(*mfns));
-
-    n = 0;
-    for (i = 0; i < nentries; i++)
-        for (j = 0; j < chunksize / XC_PAGE_SIZE; j++)
-            mfns[n++] = entries[i].mfn + j;
-
-    ret = map_frames_ex(mfns, n, 1, 0, 1, dom, NULL, pt_prot);
-    free(mfns);
-    return ret;
-}
-
 /* Optionally flush file to disk and discard page cache */
 void discard_file_cache(xc_interface *xch, int fd, int flush)
 {
diff --git a/tools/libxc/xc_netbsd.c b/tools/libxc/xc_netbsd.c
index f02015c..2654d18 100644
--- a/tools/libxc/xc_netbsd.c
+++ b/tools/libxc/xc_netbsd.c
@@ -97,76 +97,6 @@ void *osdep_map_foreign_batch(xc_interface *xch,
 
 }
 
-void *xc_map_foreign_range(xc_interface *xch,
-                           uint32_t dom,
-                           int size, int prot,
-                           unsigned long mfn)
-{
-    int fd = xch->privcmdfd;
-    privcmd_mmap_t ioctlx;
-    privcmd_mmap_entry_t entry;
-    void *addr;
-    addr = mmap(NULL, size, prot, MAP_ANON | MAP_SHARED, -1, 0);
-    if ( addr == MAP_FAILED ) {
-        PERROR("xc_map_foreign_range: mmap failed");
-        return NULL;
-    }
-
-    ioctlx.num=1;
-    ioctlx.dom=dom;
-    ioctlx.entry=&entry;
-    entry.va=(unsigned long) addr;
-    entry.mfn=mfn;
-    entry.npages=(size+XC_PAGE_SIZE-1)>>XC_PAGE_SHIFT;
-    if ( ioctl(fd, IOCTL_PRIVCMD_MMAP, &ioctlx) < 0 )
-    {
-        int saved_errno = errno;
-        PERROR("xc_map_foreign_range: ioctl failed");
-        (void)munmap(addr, size);
-        errno = saved_errno;
-        return NULL;
-    }
-    return addr;
-}
-
-void *xc_map_foreign_ranges(xc_interface *xch,
-                            uint32_t dom,
-                            size_t size, int prot, size_t chunksize,
-                            privcmd_mmap_entry_t entries[], int nentries)
-{
-    int fd = xch->privcmdfd;
-	privcmd_mmap_t ioctlx;
-	int i, rc;
-	void *addr;
-
-	addr = mmap(NULL, size, prot, MAP_ANON | MAP_SHARED, -1, 0);
-	if (addr == MAP_FAILED)
-		goto mmap_failed;
-
-	for (i = 0; i < nentries; i++) {
-		entries[i].va = (uintptr_t)addr + (i * chunksize);
-		entries[i].npages = chunksize >> XC_PAGE_SHIFT;
-	}
-
-	ioctlx.num   = nentries;
-	ioctlx.dom   = dom;
-	ioctlx.entry = entries;
-
-	rc = ioctl(fd, IOCTL_PRIVCMD_MMAP, &ioctlx);
-	if (rc)
-		goto ioctl_failed;
-
-	return addr;
-
-ioctl_failed:
-	rc = munmap(addr, size);
-	if (rc == -1)
-		ERROR("%s: error in error path\n", __FUNCTION__);
-
-mmap_failed:
-	return NULL;
-}
-
 /* Optionally flush file to disk and discard page cache */
 void discard_file_cache(xc_interface *xch, int fd, int flush) 
 {
diff --git a/tools/libxc/xc_solaris.c b/tools/libxc/xc_solaris.c
index 0a0fd14..e1e126d 100644
--- a/tools/libxc/xc_solaris.c
+++ b/tools/libxc/xc_solaris.c
@@ -95,73 +95,6 @@ void *osdep_map_foreign_batch(xc_interface *xch,
 
 }
 
-void *xc_map_foreign_range(xc_interface *xch,
-                           uint32_t dom,
-                           int size, int prot,
-                           unsigned long mfn)
-{
-    int fd = xch->privcmdfd;
-    privcmd_mmap_t ioctlx;
-    privcmd_mmap_entry_t entry;
-    void *addr;
-    addr = mmap(NULL, size, prot, MAP_SHARED, fd, 0);
-    if ( addr == MAP_FAILED )
-        return NULL;
-
-    ioctlx.num=1;
-    ioctlx.dom=dom;
-    ioctlx.entry=&entry;
-    entry.va=(unsigned long) addr;
-    entry.mfn=mfn;
-    entry.npages=(size+XC_PAGE_SIZE-1)>>XC_PAGE_SHIFT;
-    if ( ioctl(fd, IOCTL_PRIVCMD_MMAP, &ioctlx) < 0 )
-    {
-        int saved_errno = errno;
-        (void)munmap(addr, size);
-        errno = saved_errno;
-        return NULL;
-    }
-    return addr;
-}
-
-void *xc_map_foreign_ranges(xc_interface *xch,
-                            uint32_t dom,
-                            size_t size, int prot, size_t chunksize,
-                            privcmd_mmap_entry_t entries[], int nentries)
-{
-    int fd = xch->privcmdfd;
-    privcmd_mmap_t ioctlx;
-    int i, rc;
-    void *addr;
-
-    addr = mmap(NULL, size, prot, MAP_SHARED, fd, 0);
-    if (addr == MAP_FAILED)
-        goto mmap_failed;
-
-    for (i = 0; i < nentries; i++) {
-        entries[i].va = (uintptr_t)addr + (i * chunksize);
-        entries[i].npages = chunksize >> XC_PAGE_SHIFT;
-    }
-
-    ioctlx.num   = nentries;
-    ioctlx.dom   = dom;
-    ioctlx.entry = entries;
-
-    rc = ioctl(fd, IOCTL_PRIVCMD_MMAP, &ioctlx);
-    if (rc)
-        goto ioctl_failed;
-
-    return addr;
-
-ioctl_failed:
-    rc = munmap(addr, size);
-    if (rc == -1)
-        PERROR("%s: error in error path", __FUNCTION__);
-
-mmap_failed:
-    return NULL;
-}
-
 /* Optionally flush file to disk and discard page cache */
 void discard_file_cache(xc_interface *xch, int fd, int flush) 
 {
-- 
2.1.4