Subject: [PATCH 14/46] rdma: introduce ram_handle_compressed()

From: Nigel Croxon <[email-masked]>
Date: Thu, 14 Nov 2013 22:52:50 +0100

RH-Author: Nigel Croxon <[email-masked]>
Message-id: <[email-masked]>
Patchwork-id: 55706
O-Subject: [RHEL7.0 PATCH 14/42] rdma: introduce ram_handle_compressed()
Bugzilla: 1011720
RH-Acked-by: Orit Wasserman <[email-masked]>
RH-Acked-by: Amit Shah <[email-masked]>
RH-Acked-by: Paolo Bonzini <[email-masked]>

Bugzilla: 1011720
https://bugzilla.redhat.com/show_bug.cgi?id=1011720

>From commit ID:
commit 44c3b58cf9b2c91a38363f0b45d20f3f40b8f2b3
Author: Michael R. Hines <[email-masked]>
Date:   Mon Jul 22 10:01:53 2013 -0400

    rdma: introduce ram_handle_compressed()

    This gives RDMA shared access to madvise() on the destination side
    when an entire chunk is found to be zero.

    Reviewed-by: Juan Quintela <[email-masked]>
    Reviewed-by: Paolo Bonzini <[email-masked]>
    Reviewed-by: Chegu Vinod <[email-masked]>
    Tested-by: Chegu Vinod <[email-masked]>
    Tested-by: Michael R. Hines <[email-masked]>
    Signed-off-by: Michael R. Hines <[email-masked]>
    Signed-off-by: Juan Quintela <[email-masked]>
---
 arch_init.c                   |   29 +++++++++++++++++++----------
 include/migration/migration.h |    2 ++
 2 files changed, 21 insertions(+), 10 deletions(-)

Signed-off-by: Michal Novotny <[email-masked]>
---
 arch_init.c                   | 29 +++++++++++++++++++----------
 include/migration/migration.h |  2 ++
 2 files changed, 21 insertions(+), 10 deletions(-)

diff --git a/arch_init.c b/arch_init.c
index e940ede..e7da520 100644
--- a/arch_init.c
+++ b/arch_init.c
@@ -809,6 +809,24 @@ static inline void *host_from_stream_offset(QEMUFile *f,
     return NULL;
 }
 
+/*
+ * If a page (or a whole RDMA chunk) has been
+ * determined to be zero, then zap it.
+ */
+void ram_handle_compressed(void *host, uint8_t ch, uint64_t size)
+{
+    if (ch != 0 || !is_zero_page(host)) {
+        memset(host, ch, size);
+#ifndef _WIN32
+        if (ch == 0 &&
+            (!kvm_enabled() || kvm_has_sync_mmu()) &&
+            getpagesize() <= TARGET_PAGE_SIZE) {
+            qemu_madvise(host, TARGET_PAGE_SIZE, QEMU_MADV_DONTNEED);
+        }
+#endif
+    }
+}
+
 static int ram_load(QEMUFile *f, void *opaque, int version_id)
 {
     ram_addr_t addr;
@@ -876,16 +894,7 @@ static int ram_load(QEMUFile *f, void *opaque, int version_id)
             }
 
             ch = qemu_get_byte(f);
-            if (ch != 0 || !is_zero_page(host)) {
-                memset(host, ch, TARGET_PAGE_SIZE);
-#ifndef _WIN32
-                if (ch == 0 &&
-                    (!kvm_enabled() || kvm_has_sync_mmu()) &&
-                    getpagesize() <= TARGET_PAGE_SIZE) {
-                    qemu_madvise(host, TARGET_PAGE_SIZE, QEMU_MADV_DONTNEED);
-                }
-#endif
-            }
+            ram_handle_compressed(host, ch, TARGET_PAGE_SIZE);
         } else if (flags & RAM_SAVE_FLAG_PAGE) {
             void *host;
 
diff --git a/include/migration/migration.h b/include/migration/migration.h
index 701709a..90b5021 100644
--- a/include/migration/migration.h
+++ b/include/migration/migration.h
@@ -109,6 +109,8 @@ uint64_t xbzrle_mig_pages_transferred(void);
 uint64_t xbzrle_mig_pages_overflow(void);
 uint64_t xbzrle_mig_pages_cache_miss(void);
 
+void ram_handle_compressed(void *host, uint8_t ch, uint64_t size);
+
 /**
  * @migrate_add_blocker - prevent migration from proceeding
  *
-- 
1.7.11.7