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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v9 2/3] tools/libxc: add API for bitmap access for restore
Extend API for managing bitmaps. Each bitmap is now represented by a
generic struct xc_sr_bitmap.
Switch the existing populated_pfns to this API.
Signed-off-by: Olaf Hering <olaf@xxxxxxxxx>
Acked-by: Wei Liu <wei.liu2@xxxxxxxxxx>
---
tools/libxc/xc_sr_common.c | 41 ++++++++++++++++++++++++++
tools/libxc/xc_sr_common.h | 72 +++++++++++++++++++++++++++++++++++++++++++--
tools/libxc/xc_sr_restore.c | 66 ++---------------------------------------
3 files changed, 114 insertions(+), 65 deletions(-)
diff --git a/tools/libxc/xc_sr_common.c b/tools/libxc/xc_sr_common.c
index 79b9c3e940..4d221ca90c 100644
--- a/tools/libxc/xc_sr_common.c
+++ b/tools/libxc/xc_sr_common.c
@@ -155,6 +155,47 @@ static void __attribute__((unused)) build_assertions(void)
BUILD_BUG_ON(sizeof(struct xc_sr_rec_hvm_params) != 8);
}
+/*
+ * Expand the tracking structures as needed.
+ * To avoid realloc()ing too excessively, the size increased to the nearest
power
+ * of two large enough to contain the required number of bits.
+ */
+bool _xc_sr_bitmap_resize(struct xc_sr_bitmap *bm, unsigned long bits)
+{
+ if (bits > bm->bits)
+ {
+ size_t new_max;
+ size_t old_sz, new_sz;
+ void *p;
+
+ /* Round up to the nearest power of two larger than bit, less 1. */
+ new_max = bits;
+ new_max |= new_max >> 1;
+ new_max |= new_max >> 2;
+ new_max |= new_max >> 4;
+ new_max |= new_max >> 8;
+ new_max |= new_max >> 16;
+#ifdef __x86_64__
+ new_max |= new_max >> 32;
+#endif
+
+ old_sz = bitmap_size(bm->bits + 1);
+ new_sz = bitmap_size(new_max + 1);
+ p = realloc(bm->p, new_sz);
+ if (!p)
+ return false;
+
+ if (bm->p)
+ memset(p + old_sz, 0, new_sz - old_sz);
+ else
+ memset(p, 0, new_sz);
+
+ bm->p = p;
+ bm->bits = new_max;
+ }
+ return true;
+}
+
/*
* Local variables:
* mode: C
diff --git a/tools/libxc/xc_sr_common.h b/tools/libxc/xc_sr_common.h
index a83f22af4e..734320947a 100644
--- a/tools/libxc/xc_sr_common.h
+++ b/tools/libxc/xc_sr_common.h
@@ -172,6 +172,12 @@ struct xc_sr_x86_pv_restore_vcpu
size_t basicsz, extdsz, xsavesz, msrsz;
};
+struct xc_sr_bitmap
+{
+ void *p;
+ unsigned long bits;
+};
+
struct xc_sr_context
{
xc_interface *xch;
@@ -255,8 +261,7 @@ struct xc_sr_context
domid_t xenstore_domid, console_domid;
/* Bitmap of currently populated PFNs during restore. */
- unsigned long *populated_pfns;
- xen_pfn_t max_populated_pfn;
+ struct xc_sr_bitmap populated_pfns;
/* Sender has invoked verify mode on the stream. */
bool verify;
@@ -343,6 +348,69 @@ extern struct xc_sr_save_ops save_ops_x86_hvm;
extern struct xc_sr_restore_ops restore_ops_x86_pv;
extern struct xc_sr_restore_ops restore_ops_x86_hvm;
+extern bool _xc_sr_bitmap_resize(struct xc_sr_bitmap *bm, unsigned long bits);
+
+static inline bool xc_sr_bitmap_resize(struct xc_sr_bitmap *bm, unsigned long
bits)
+{
+ if (bits > bm->bits)
+ return _xc_sr_bitmap_resize(bm, bits);
+ return true;
+}
+
+static inline void xc_sr_bitmap_free(struct xc_sr_bitmap *bm)
+{
+ free(bm->p);
+ bm->p = NULL;
+}
+
+static inline bool xc_sr_set_bit(unsigned long bit, struct xc_sr_bitmap *bm)
+{
+ if (!xc_sr_bitmap_resize(bm, bit))
+ return false;
+
+ set_bit(bit, bm->p);
+ return true;
+}
+
+static inline bool xc_sr_test_bit(unsigned long bit, struct xc_sr_bitmap *bm)
+{
+ if (bit > bm->bits)
+ return false;
+ return !!test_bit(bit, bm->p);
+}
+
+static inline bool xc_sr_test_and_clear_bit(unsigned long bit, struct
xc_sr_bitmap *bm)
+{
+ if (bit > bm->bits)
+ return false;
+ return !!test_and_clear_bit(bit, bm->p);
+}
+
+static inline bool xc_sr_test_and_set_bit(unsigned long bit, struct
xc_sr_bitmap *bm)
+{
+ if (bit > bm->bits)
+ return false;
+ return !!test_and_set_bit(bit, bm->p);
+}
+
+static inline bool pfn_is_populated(struct xc_sr_context *ctx, xen_pfn_t pfn)
+{
+ return xc_sr_test_bit(pfn, &ctx->restore.populated_pfns);
+}
+
+static inline int pfn_set_populated(struct xc_sr_context *ctx, xen_pfn_t pfn)
+{
+ xc_interface *xch = ctx->xch;
+
+ if ( !xc_sr_set_bit(pfn, &ctx->restore.populated_pfns) )
+ {
+ ERROR("Failed to realloc populated_pfns bitmap");
+ errno = ENOMEM;
+ return -1;
+ }
+ return 0;
+}
+
struct xc_sr_record
{
uint32_t type;
diff --git a/tools/libxc/xc_sr_restore.c b/tools/libxc/xc_sr_restore.c
index a016678332..d53948e1a6 100644
--- a/tools/libxc/xc_sr_restore.c
+++ b/tools/libxc/xc_sr_restore.c
@@ -68,64 +68,6 @@ static int read_headers(struct xc_sr_context *ctx)
return 0;
}
-/*
- * Is a pfn populated?
- */
-static bool pfn_is_populated(const struct xc_sr_context *ctx, xen_pfn_t pfn)
-{
- if ( pfn > ctx->restore.max_populated_pfn )
- return false;
- return test_bit(pfn, ctx->restore.populated_pfns);
-}
-
-/*
- * Set a pfn as populated, expanding the tracking structures if needed. To
- * avoid realloc()ing too excessively, the size increased to the nearest power
- * of two large enough to contain the required pfn.
- */
-static int pfn_set_populated(struct xc_sr_context *ctx, xen_pfn_t pfn)
-{
- xc_interface *xch = ctx->xch;
-
- if ( pfn > ctx->restore.max_populated_pfn )
- {
- xen_pfn_t new_max;
- size_t old_sz, new_sz;
- unsigned long *p;
-
- /* Round up to the nearest power of two larger than pfn, less 1. */
- new_max = pfn;
- new_max |= new_max >> 1;
- new_max |= new_max >> 2;
- new_max |= new_max >> 4;
- new_max |= new_max >> 8;
- new_max |= new_max >> 16;
-#ifdef __x86_64__
- new_max |= new_max >> 32;
-#endif
-
- old_sz = bitmap_size(ctx->restore.max_populated_pfn + 1);
- new_sz = bitmap_size(new_max + 1);
- p = realloc(ctx->restore.populated_pfns, new_sz);
- if ( !p )
- {
- ERROR("Failed to realloc populated bitmap");
- errno = ENOMEM;
- return -1;
- }
-
- memset((uint8_t *)p + old_sz, 0x00, new_sz - old_sz);
-
- ctx->restore.populated_pfns = p;
- ctx->restore.max_populated_pfn = new_max;
- }
-
- assert(!test_bit(pfn, ctx->restore.populated_pfns));
- set_bit(pfn, ctx->restore.populated_pfns);
-
- return 0;
-}
-
/*
* Given a set of pfns, obtain memory from Xen to fill the physmap for the
* unpopulated subset. If types is NULL, no page type checking is performed
@@ -684,10 +626,8 @@ static int setup(struct xc_sr_context *ctx)
if ( rc )
goto err;
- ctx->restore.max_populated_pfn = (32 * 1024 / 4) - 1;
- ctx->restore.populated_pfns = bitmap_alloc(
- ctx->restore.max_populated_pfn + 1);
- if ( !ctx->restore.populated_pfns )
+ rc = !xc_sr_bitmap_resize(&ctx->restore.populated_pfns, 32 * 1024 / 4);
+ if ( rc )
{
ERROR("Unable to allocate memory for populated_pfns bitmap");
rc = -1;
@@ -722,7 +662,7 @@ static void cleanup(struct xc_sr_context *ctx)
xc_hypercall_buffer_free_pages(xch, dirty_bitmap,
NRPAGES(bitmap_size(ctx->restore.p2m_size)));
free(ctx->restore.buffered_records);
- free(ctx->restore.populated_pfns);
+ xc_sr_bitmap_free(&ctx->restore.populated_pfns);
if ( ctx->restore.ops.cleanup(ctx) )
PERROR("Failed to clean up");
}
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