GNTTAB: PowerPC patch for dynamic grant tables.

Grant table expansion is disabled for now, since we currently make assumptions
about grant table MFNs being contiguous.
Signed-off-by: Isaku Yamahata <yamahata@valinux.co.jp>
Signed-off-by: Hollis Blanchard <hollisb@us.ibm.com>

diff --git a/xen/arch/powerpc/mm.c b/xen/arch/powerpc/mm.c
index 5f257dcc8581e14ae6aff4c01e22c7abbbe45266..96fddd3d5cd0a1df9fc53e2bce380ea6ae86648e 100644 (file)
--- a/xen/arch/powerpc/mm.c
+++ b/xen/arch/powerpc/mm.c
@@ -416,7 +416,13 @@ ulong pfn2mfn(struct domain *d, ulong pfn, int *type)
     if (pfn & foreign_map_pfn) {
         t = PFN_TYPE_FOREIGN;
         mfn = foreign_to_mfn(d, pfn);
-    } else if (pfn >= max_page && pfn < (max_page + NR_GRANT_FRAMES)) {
+    } else if (pfn >= max_page && pfn <
+              (max_page + nr_grant_frames(d->grant_table))) {
+        /* XXX access d->grant_table->nr_grant_frames without lock.
+         * Currently on powerpc dynamic expanding grant table is
+         * inhibited by setting max_nr_grant_frames = INITIAL_NR_GRANT_FRAMES
+         * so that this access is safe.
+         */
         /* Its a grant table access */
         t = PFN_TYPE_GNTTAB;
         mfn = gnttab_shared_mfn(d, d->grant_table, (pfn - max_page));
@@ -494,9 +500,15 @@ unsigned long mfn_to_gmfn(struct domain *d, unsigned long mfn)
     ulong gnttab_mfn;
     ulong rma_mfn;
 
+    /* XXX access d->grant_table->nr_grant_frames without lock.
+     * Currently on powerpc dynamic expanding grant table is
+     * inhibited by setting max_nr_grant_frames = INITIAL_NR_GRANT_FRAMES
+     * so that this access is safe.
+     */
     /* grant? */
     gnttab_mfn = gnttab_shared_mfn(d, d->grant_table, 0);
-    if (mfn >= gnttab_mfn && mfn < (gnttab_mfn + NR_GRANT_FRAMES))
+    if (mfn >= gnttab_mfn && mfn <
+       (gnttab_mfn + nr_grant_frames(d->grant_table)))
         return max_page + (mfn - gnttab_mfn);
 
     /* IO? */

diff --git a/xen/common/grant_table.c b/xen/common/grant_table.c
index 642a3af4a9a6d7887d8adc2bd099296aa6d69dc5..1af842a52835380d41bfbd80d588c0aa6ff3cd85 100644 (file)
--- a/xen/common/grant_table.c
+++ b/xen/common/grant_table.c
@@ -35,8 +35,10 @@
 #include <xen/domain_page.h>
 #include <acm/acm_hooks.h>
 
+#ifndef max_nr_grant_frames
 unsigned int max_nr_grant_frames = DEFAULT_MAX_NR_GRANT_FRAMES;
 integer_param("gnttab_max_nr_frames", max_nr_grant_frames);
+#endif
 
 /* The maximum number of grant mappings is defined as a multiplier of the
  * maximum number of grant table entries. This defines the multiplier used.

diff --git a/xen/include/asm-powerpc/config.h b/xen/include/asm-powerpc/config.h
index 86366406f03f0e054387549b28d6fa601b1ec29e..02702b1489d10d1b10cb36fffad94544180f1ae3 100644 (file)
--- a/xen/include/asm-powerpc/config.h
+++ b/xen/include/asm-powerpc/config.h
@@ -73,4 +73,13 @@ extern char __bss_start[];
 
 #include <asm/powerpc64/config.h>
 
+/*
+ * Disallow grant table growing tempralily because pfn2mfn() and
+ * mfn_to_gmfn() depends on the fact that grant table is machine-address
+ * contiguous. Grant table growing breaks the assumption.
+ */
+#ifndef max_nr_grant_frames
+#define max_nr_grant_frames INITIAL_NR_GRANT_FRAMES
+#endif
+
 #endif

diff --git a/xen/include/asm-powerpc/grant_table.h b/xen/include/asm-powerpc/grant_table.h
index a50e51fca7d924b34b69ea50e8ac5fc7b0b4da4e..334a925cbb95302e17a8575ad991ea6a290c6d14 100644 (file)
--- a/xen/include/asm-powerpc/grant_table.h
+++ b/xen/include/asm-powerpc/grant_table.h
@@ -41,11 +41,11 @@ int destroy_grant_host_mapping(
 #define gnttab_create_shared_page(d, t, i)                               \
     do {                                                                 \
         share_xen_page_with_guest(                                       \
-            virt_to_page((char *)(t)->shared + ((i) * PAGE_SIZE)),       \
+            virt_to_page((t)->shared[(i)]),                       \
             (d), XENSHARE_writable);                                     \
     } while ( 0 )
 
-#define gnttab_shared_mfn(d, t, i) (((ulong)((t)->shared) >> PAGE_SHIFT) + (i))
+#define gnttab_shared_mfn(d, t, i) (virt_to_mfn((t)->shared[(i)]))
 
 #define gnttab_shared_gmfn(d, t, i)                     \
     (mfn_to_gmfn(d, gnttab_shared_mfn(d, t, i)))

diff --git a/xen/include/xen/grant_table.h b/xen/include/xen/grant_table.h
index 5ae9149bc1eed979e85cdfad60501552237ce931..0164668e2cc1f3f85316677e6c1e901258ee9edc 100644 (file)
--- a/xen/include/xen/grant_table.h
+++ b/xen/include/xen/grant_table.h
@@ -56,10 +56,14 @@ struct active_grant_entry {
 #define INITIAL_NR_GRANT_ENTRIES ((INITIAL_NR_GRANT_FRAMES << PAGE_SHIFT) / \
                                      sizeof(grant_entry_t))
 
+#ifndef DEFAULT_MAX_NR_GRANT_FRAMES /* to allow arch to override */
 /* Default maximum size of a grant table. [POLICY] */
 #define DEFAULT_MAX_NR_GRANT_FRAMES   32
+#endif
+#ifndef max_nr_grant_frames /* to allow arch to override */
 /* The maximum size of a grant table. */
 extern unsigned int max_nr_grant_frames;
+#endif
 
 /*
  * Tracks a mapping of another domain's grant reference. Each domain has a