xen/libxc-sr-xg_sr_bitmap-populated_pfns.patch

From: Olaf Hering <olaf@aepfle.de>
Date: Fri, 5 Feb 2021 20:16:02 +0100
Subject: libxc sr xg_sr_bitmap populated_pfns

tools: use xg_sr_bitmap for populated_pfns

Signed-off-by: Olaf Hering <olaf@aepfle.de>
---
 tools/libs/guest/xg_sr_common.h          | 20 ++++++-
 tools/libs/guest/xg_sr_restore.c         | 69 ------------------------
 tools/libs/guest/xg_sr_restore_x86_hvm.c |  9 ++++
 tools/libs/guest/xg_sr_restore_x86_pv.c  |  7 +++
 4 files changed, 34 insertions(+), 71 deletions(-)

--- a/tools/libs/guest/xg_sr_common.h
+++ b/tools/libs/guest/xg_sr_common.h
@@ -375,8 +375,7 @@ struct xc_sr_context
             uint32_t     xenstore_domid,  console_domid;
 
             /* Bitmap of currently populated PFNs during restore. */
-            unsigned long *populated_pfns;
-            xen_pfn_t max_populated_pfn;
+            struct sr_bitmap populated_pfns;
 
             /* Sender has invoked verify mode on the stream. */
             bool verify;
@@ -632,6 +631,23 @@ static inline bool page_type_has_stream_
     }
 }
 
+static inline bool pfn_is_populated(struct xc_sr_context *ctx, xen_pfn_t pfn)
+{
+    return 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 ( sr_set_bit(pfn, &ctx->restore.populated_pfns) == false )
+    {
+        PERROR("Failed to realloc populated_pfns bitmap");
+        errno = ENOMEM;
+        return -1;
+    }
+    return 0;
+}
 #endif
 /*
  * Local variables:
--- a/tools/libs/guest/xg_sr_restore.c
+++ b/tools/libs/guest/xg_sr_restore.c
@@ -72,64 +72,6 @@ static int read_headers(struct xc_sr_con
 }
 
 /*
- * 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
  * and all unpopulated pfns are populated.
@@ -911,16 +853,6 @@ static int setup(struct xc_sr_context *c
     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 )
-    {
-        ERROR("Unable to allocate memory for populated_pfns bitmap");
-        rc = -1;
-        goto err;
-    }
-
     ctx->restore.pfns = malloc(MAX_BATCH_SIZE * sizeof(*ctx->restore.pfns));
     ctx->restore.types = malloc(MAX_BATCH_SIZE * sizeof(*ctx->restore.types));
     ctx->restore.mfns = malloc(MAX_BATCH_SIZE * sizeof(*ctx->restore.mfns));
@@ -969,7 +901,6 @@ static void cleanup(struct xc_sr_context
             xch, dirty_bitmap, NRPAGES(bitmap_size(ctx->restore.p2m_size)));
 
     free(ctx->restore.buffered_records);
-    free(ctx->restore.populated_pfns);
     free(ctx->restore.pages);
     free(ctx->restore.iov);
     free(ctx->restore.guest_data);
--- a/tools/libs/guest/xg_sr_restore_x86_hvm.c
+++ b/tools/libs/guest/xg_sr_restore_x86_hvm.c
@@ -136,6 +136,7 @@ static int x86_hvm_localise_page(struct
 static int x86_hvm_setup(struct xc_sr_context *ctx)
 {
     xc_interface *xch = ctx->xch;
+    unsigned long max_pfn, max_pages = ctx->dominfo.max_pages;
 
     if ( ctx->restore.guest_type != DHDR_TYPE_X86_HVM )
     {
@@ -161,6 +162,13 @@ static int x86_hvm_setup(struct xc_sr_co
     }
 #endif
 
+    max_pfn = max(ctx->restore.p2m_size, max_pages);
+    if ( !sr_bitmap_expand(&ctx->restore.populated_pfns, max_pfn) )
+    {
+        PERROR("Unable to allocate memory for populated_pfns bitmap");
+        return -1;
+    }
+
     return 0;
 }
 
@@ -241,6 +249,7 @@ static int x86_hvm_stream_complete(struc
 
 static int x86_hvm_cleanup(struct xc_sr_context *ctx)
 {
+    sr_bitmap_free(&ctx->restore.populated_pfns);
     free(ctx->x86.hvm.restore.context.ptr);
 
     free(ctx->x86.restore.cpuid.ptr);
--- a/tools/libs/guest/xg_sr_restore_x86_pv.c
+++ b/tools/libs/guest/xg_sr_restore_x86_pv.c
@@ -1060,6 +1060,12 @@ static int x86_pv_setup(struct xc_sr_con
     if ( rc )
         return rc;
 
+    if ( !sr_bitmap_expand(&ctx->restore.populated_pfns, 32 * 1024 / 4) )
+    {
+        PERROR("Unable to allocate memory for populated_pfns bitmap");
+        return -1;
+    }
+
     ctx->x86.pv.restore.nr_vcpus = ctx->dominfo.max_vcpu_id + 1;
     ctx->x86.pv.restore.vcpus = calloc(sizeof(struct xc_sr_x86_pv_restore_vcpu),
                                        ctx->x86.pv.restore.nr_vcpus);
@@ -1153,6 +1159,7 @@ static int x86_pv_stream_complete(struct
  */
 static int x86_pv_cleanup(struct xc_sr_context *ctx)
 {
+    sr_bitmap_free(&ctx->restore.populated_pfns);
     free(ctx->x86.pv.p2m);
     free(ctx->x86.pv.p2m_pfns);