[Xen-devel] [PATCH 1 of 3 V6] tools/libxc: introduce page_aligned_alloc in xc_{minios, linux, solaris, netbsd}.c

[rshriram@xxxxxxxxx]

# HG changeset patch
# User Shriram Rajagopalan <rshriram@xxxxxxxxx>
# Date 1320791162 28800
# Node ID 58a24a7d4b87540692363b081dd72f62a6d380dd
# Parent  54a5e994a241a506900ee0e197bb42e5f1d8e759
tools/libxc: introduce page_aligned_alloc in xc_{minios,linux,solaris,netbsd}.c

Move (page aligned) buffer allocations in {os}_privcmd_alloc_hypercall_buffer
into a global function page_aligned_alloc. This API is also used by Remus
compression code to allocate compression caches that need to be page aligned.

Signed-off-by: Shriram Rajagopalan <rshriram@xxxxxxxxx>

diff -r 54a5e994a241 -r 58a24a7d4b87 tools/libxc/xc_linux.c
--- a/tools/libxc/xc_linux.c    Wed Nov 02 17:09:09 2011 +0000
+++ b/tools/libxc/xc_linux.c    Tue Nov 08 14:26:02 2011 -0800
@@ -55,6 +55,18 @@
     errno = saved_errno;
 }
 
+void *page_aligned_alloc(xc_interface *xch, size_t size)
+{
+    int ret;
+    void *ptr;
+
+    ret = posix_memalign(&ptr, XC_PAGE_SIZE, size);
+    if (ret != 0 || !ptr)
+        return NULL;
+
+    return ptr;
+}
+
 /*
  * Local variables:
  * mode: C
diff -r 54a5e994a241 -r 58a24a7d4b87 tools/libxc/xc_linux_osdep.c
--- a/tools/libxc/xc_linux_osdep.c      Wed Nov 02 17:09:09 2011 +0000
+++ b/tools/libxc/xc_linux_osdep.c      Tue Nov 08 14:26:02 2011 -0800
@@ -36,9 +36,17 @@
 #include <xen/sys/gntdev.h>
 #include <xen/sys/gntalloc.h>
 
+#include "xc_private.h"
 #include "xenctrl.h"
 #include "xenctrlosdep.h"
 
+/* We need xc_private.h for page_aligned_alloc().
+ * xc_private.h already defines ERROR and PERROR.
+ * So we undef it and redefine it here.
+ */
+#undef ERROR
+#undef PERROR
+
 #define ERROR(_m, _a...)  xc_osdep_log(xch,XTL_ERROR,XC_INTERNAL_ERROR,_m , ## 
_a )
 #define PERROR(_m, _a...) xc_osdep_log(xch,XTL_ERROR,XC_INTERNAL_ERROR,_m \
                   " (%d = %s)", ## _a , errno, xc_strerror(xch, errno))
@@ -91,10 +99,9 @@
 {
     size_t size = npages * XC_PAGE_SIZE;
     void *p;
-    int ret;
 
-    ret = posix_memalign(&p, XC_PAGE_SIZE, size);
-    if (ret != 0 || !p)
+    p = page_aligned_alloc(xch, size);
+    if (!p)
         return NULL;
 
     if ( mlock(p, size) < 0 )
diff -r 54a5e994a241 -r 58a24a7d4b87 tools/libxc/xc_minios.c
--- a/tools/libxc/xc_minios.c   Wed Nov 02 17:09:09 2011 +0000
+++ b/tools/libxc/xc_minios.c   Tue Nov 08 14:26:02 2011 -0800
@@ -73,7 +73,7 @@
 
 static void *minios_privcmd_alloc_hypercall_buffer(xc_interface *xch, 
xc_osdep_handle h, int npages)
 {
-    return memalign(PAGE_SIZE, npages * PAGE_SIZE);
+    return page_aligned_alloc(xch, npages * PAGE_SIZE);
 }
 
 static void minios_privcmd_free_hypercall_buffer(xc_interface *xch, 
xc_osdep_handle h, void *ptr, int npages)
@@ -437,6 +437,11 @@
         fsync(fd);
 }
 
+void *page_aligned_alloc(xc_interface *xch, size_t size)
+{
+    return memalign(PAGE_SIZE, size);
+}
+
 static xc_osdep_handle minios_gnttab_open(xc_gnttab *xcg)
 {
     int fd = alloc_fd(FTYPE_GNTMAP);
diff -r 54a5e994a241 -r 58a24a7d4b87 tools/libxc/xc_netbsd.c
--- a/tools/libxc/xc_netbsd.c   Wed Nov 02 17:09:09 2011 +0000
+++ b/tools/libxc/xc_netbsd.c   Tue Nov 08 14:26:02 2011 -0800
@@ -71,8 +71,9 @@
 static void *netbsd_privcmd_alloc_hypercall_buffer(xc_interface *xch, 
xc_osdep_handle h, int npages)
 {
     size_t size = npages * XC_PAGE_SIZE;
-    void *p = valloc(size);
+    void *p;
 
+    p = page_aligned_alloc(xch, size);
     if (!p)
         return NULL;
 
@@ -378,6 +379,11 @@
     errno = saved_errno;
 }
 
+void *page_aligned_alloc(xc_interface *xch, size_t size)
+{
+    return valloc(size);
+}
+
 static struct xc_osdep_ops *netbsd_osdep_init(xc_interface *xch, enum 
xc_osdep_type type)
 {
     switch ( type )
diff -r 54a5e994a241 -r 58a24a7d4b87 tools/libxc/xc_private.h
--- a/tools/libxc/xc_private.h  Wed Nov 02 17:09:09 2011 +0000
+++ b/tools/libxc/xc_private.h  Tue Nov 08 14:26:02 2011 -0800
@@ -302,6 +302,9 @@
 /* Optionally flush file to disk and discard page cache */
 void discard_file_cache(xc_interface *xch, int fd, int flush);
 
+/* Encapsulates memalign style calls for different OSes. */
+void *page_aligned_alloc(xc_interface *xch, size_t size);
+
 #define MAX_MMU_UPDATES 1024
 struct xc_mmu {
     mmu_update_t updates[MAX_MMU_UPDATES];
diff -r 54a5e994a241 -r 58a24a7d4b87 tools/libxc/xc_solaris.c
--- a/tools/libxc/xc_solaris.c  Wed Nov 02 17:09:09 2011 +0000
+++ b/tools/libxc/xc_solaris.c  Tue Nov 08 14:26:02 2011 -0800
@@ -70,7 +70,7 @@
 
 static void *solaris_privcmd_alloc_hypercall_buffer(xc_interface *xch, 
xc_osdep_handle h, int npages)
 {
-    return memalign(XC_PAGE_SIZE, npages * XC_PAGE_SIZE);
+    return page_aligned_alloc(xch, npages * XC_PAGE_SIZE);
 }
 
 static void solaris_privcmd_free_hypercall_buffer(xc_interface *xch, 
xc_osdep_handle h, void *ptr, int npages)
@@ -314,6 +314,11 @@
     // TODO: Implement for Solaris!
 }
 
+void *page_aligned_alloc(xc_interface *xch, size_t size)
+{
+    return memalign(XC_PAGE_SIZE, size);
+}
+
 static struct xc_osdep_ops *solaris_osdep_init(xc_interface *xch, enum 
xc_osdep_type type)
 {
     switch ( type )

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