[Qemu-devel] [PATCH v3 8/9] Use qemu_put_buffer_no_copy for guest memory pages

[Orit Wasserman <owasserm@redhat.com>]

This will remove an unneeded copy of guest memory pages.
For the page header and device state we still copy the data to the
static buffer the other option is to allocate the memory on demand
which is more expensive.

Signed-off-by: Orit Wasserman <owasserm@redhat.com>
---
 arch_init.c | 2 +-
 savevm.c    | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/arch_init.c b/arch_init.c
index 98e2bc6..27b53eb 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -481,7 +481,7 @@ static int ram_save_block(QEMUFile *f, bool last_stage)
             /* XBZRLE overflow or normal page */
             if (bytes_sent == -1) {
                 bytes_sent = save_block_hdr(f, block, offset, cont, RAM_SAVE_FLAG_PAGE);
-                qemu_put_buffer(f, p, TARGET_PAGE_SIZE);
+                qemu_put_buffer_no_copy(f, p, TARGET_PAGE_SIZE);
                 bytes_sent += TARGET_PAGE_SIZE;
                 acct_info.norm_pages++;
             }
diff --git a/savevm.c b/savevm.c
index fbfb9e3..50e8fb2 100644
--- a/savevm.c
+++ b/savevm.c
@@ -634,7 +634,7 @@ void qemu_put_buffer_no_copy(QEMUFile *f, const uint8_t *buf, int size)
         abort();
     }
 
-    f->iov[f->iovcnt].iov_base = f->buf + f->buf_index;
+    f->iov[f->iovcnt].iov_base = (uint8_t *)buf;
     f->iov[f->iovcnt++].iov_len = size;
 
     f->is_write = 1;
-- 
1.7.11.7