[PATCH v20210601 20/38] tools/guest: restore: move mfns array

[Olaf Hering <olaf@xxxxxxxxx>]

Remove allocation from hotpath, move mfns array into preallocated space.

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 96cd60e0d6..c7291bb5ca 100644
--- a/tools/libs/saverestore/common.h
+++ b/tools/libs/saverestore/common.h
@@ -239,6 +239,8 @@ struct xc_sr_restore_arrays {
     /* handle_page_data */
     xen_pfn_t pfns[MAX_BATCH_SIZE];
     uint32_t types[MAX_BATCH_SIZE];
+    /* process_page_data */
+    xen_pfn_t mfns[MAX_BATCH_SIZE];
 };
 
 struct xc_sr_context
diff --git a/tools/libs/saverestore/restore.c b/tools/libs/saverestore/restore.c
index 815a2d5a12..aadf322428 100644
--- a/tools/libs/saverestore/restore.c
+++ b/tools/libs/saverestore/restore.c
@@ -205,7 +205,7 @@ static int process_page_data(struct xc_sr_context *ctx, 
unsigned int count,
                              xen_pfn_t *pfns, uint32_t *types, void *page_data)
 {
     xc_interface *xch = ctx->xch;
-    xen_pfn_t *mfns = malloc(count * sizeof(*mfns));
+    xen_pfn_t *mfns = ctx->restore.m->mfns;
     int *map_errs = malloc(count * sizeof(*map_errs));
     int rc;
     void *mapping = NULL, *guest_page = NULL;
@@ -213,7 +213,7 @@ static int process_page_data(struct xc_sr_context *ctx, 
unsigned int count,
         j,          /* j indexes the subset of pfns we decide to map. */
         nr_pages = 0;
 
-    if ( !mfns || !map_errs )
+    if ( !map_errs )
     {
         rc = -1;
         ERROR("Failed to allocate %zu bytes to process page data",
@@ -299,7 +299,6 @@ static int process_page_data(struct xc_sr_context *ctx, 
unsigned int count,
         xenforeignmemory_unmap(xch->fmem, mapping, nr_pages);
 
     free(map_errs);
-    free(mfns);
 
     return rc;
 }