[PATCH v20210601 22/38] tools/guest: restore: move mfns array in populate_pfns

[Olaf Hering <olaf@xxxxxxxxx>]

Remove allocation from hotpath, move populate_pfns mfns array into preallocated 
space.
Use some prefix to avoid conflict with an array used in handle_page_data.

Signed-off-by: Olaf Hering <olaf@xxxxxxxxx>
---
 tools/libs/saverestore/common.h  | 2 ++
 tools/libs/saverestore/restore.c | 5 ++---
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/tools/libs/saverestore/common.h b/tools/libs/saverestore/common.h
index cea549d129..6ed213e14f 100644
--- a/tools/libs/saverestore/common.h
+++ b/tools/libs/saverestore/common.h
@@ -242,6 +242,8 @@ struct xc_sr_restore_arrays {
     /* process_page_data */
     xen_pfn_t mfns[MAX_BATCH_SIZE];
     int map_errs[MAX_BATCH_SIZE];
+    /* populate_pfns */
+    xen_pfn_t pp_mfns[MAX_BATCH_SIZE];
 };
 
 struct xc_sr_context
diff --git a/tools/libs/saverestore/restore.c b/tools/libs/saverestore/restore.c
index b534d80cbc..2ab9f792ef 100644
--- a/tools/libs/saverestore/restore.c
+++ b/tools/libs/saverestore/restore.c
@@ -138,12 +138,12 @@ int populate_pfns(struct xc_sr_context *ctx, unsigned int 
count,
                   const xen_pfn_t *original_pfns, const uint32_t *types)
 {
     xc_interface *xch = ctx->xch;
-    xen_pfn_t *mfns = malloc(count * sizeof(*mfns)),
+    xen_pfn_t *mfns = ctx->restore.m->pp_mfns,
         *pfns = malloc(count * sizeof(*pfns));
     unsigned int i, nr_pfns = 0;
     int rc = -1;
 
-    if ( !mfns || !pfns )
+    if ( !pfns )
     {
         ERROR("Failed to allocate %zu bytes for populating the physmap",
               2 * count * sizeof(*mfns));
@@ -191,7 +191,6 @@ int populate_pfns(struct xc_sr_context *ctx, unsigned int 
count,
 
  err:
     free(pfns);
-    free(mfns);
 
     return rc;
 }