[Qemu-devel] [RFC V8 13/24] qcow2: Implement qcow2_compute_cluster_hash.

["Benoît Canet" <benoit@irqsave.net>]

Also factorize detection of libgnutls with vnc tls.

Signed-off-by: Benoit Canet <benoit@irqsave.net>
---
 block/qcow2-dedup.c |   17 +++++++++-
 configure           |   86 +++++++++++++++++++++++++++++++++++++--------------
 2 files changed, 79 insertions(+), 24 deletions(-)

diff --git a/block/qcow2-dedup.c b/block/qcow2-dedup.c
index ffbf866..2d2c15c 100644
--- a/block/qcow2-dedup.c
+++ b/block/qcow2-dedup.c
@@ -28,6 +28,10 @@
 #include "block/block_int.h"
 #include "qemu-common.h"
 #include "qcow2.h"
+#ifdef CONFIG_SHA256_DEDUP
+#include <gnutls/gnutls.h>
+#include <gnutls/crypto.h>
+#endif
 
 /*
  * Prepare a buffer containing everything required to compute cluster
@@ -142,7 +146,18 @@ static int qcow2_compute_cluster_hash(BlockDriverState *bs,
                                        QCowHash *hash,
                                        uint8_t *data)
 {
-    return 0;
+    BDRVQcowState *s = bs->opaque;
+    switch (s->dedup_hash_algo) {
+#ifdef CONFIG_SHA256_DEDUP
+    case QCOW_HASH_SHA256:
+        return gnutls_hash_fast(GNUTLS_DIG_SHA256, data,
+                                s->cluster_size, hash->data);
+#endif
+    default:
+        error_report("Invalid deduplication hash algorithm %i",
+                     s->dedup_hash_algo);
+        abort();
+    }
 }
 
 /*
diff --git a/configure b/configure
index e818e8b..34b26b2 100755
--- a/configure
+++ b/configure
@@ -240,6 +240,7 @@ gtk=""
 gtkabi="2.0"
 tpm="no"
 libssh2=""
+sha256_dedup="yes"
 
 # parse CC options first
 for opt do
@@ -930,6 +931,10 @@ for opt do
   ;;
   --enable-libssh2) libssh2="yes"
   ;;
+  --disable-sha256-dedup) sha256_dedup="no"
+  ;;
+  --enable-sha256-dedup) sha256_dedup="yes"
+  ;;
   *) echo "ERROR: unknown option $opt"; show_help="yes"
   ;;
   esac
@@ -1190,6 +1195,8 @@ echo "  --with-coroutine=BACKEND coroutine backend. Supported options:"
 echo "                           gthread, ucontext, sigaltstack, windows"
 echo "  --enable-glusterfs       enable GlusterFS backend"
 echo "  --disable-glusterfs      disable GlusterFS backend"
+echo "  --disable-sha256-dedup   disable sha256 dedup"
+echo "  --enable-sha256-dedup    enables sha256 dedup"
 echo "  --enable-gcov            enable test coverage analysis with gcov"
 echo "  --gcov=GCOV              use specified gcov [$gcov_tool]"
 echo "  --enable-tpm             enable TPM support"
@@ -1812,32 +1819,60 @@ EOF
 fi
 
 ##########################################
-# VNC TLS/WS detection
-if test "$vnc" = "yes" -a \( "$vnc_tls" != "no" -o "$vnc_ws" != "no" \) ; then
-  cat > $TMPC <<EOF
+# gnutls detection (factorize the VNC TLS and SHA256 deduplication test)
+cat > $TMPC <<EOF
 #include <gnutls/gnutls.h>
-int main(void) { gnutls_session_t s; gnutls_init(&s, GNUTLS_SERVER); return 0; }
+#include <gnutls/crypto.h>
+int main(void) {char data[4096], digest[32];
+gnutls_hash_fast(GNUTLS_DIG_SHA256, data, 4096, digest);
+return 0;
+}
 EOF
-  vnc_tls_cflags=`$pkg_config --cflags gnutls 2> /dev/null`
-  vnc_tls_libs=`$pkg_config --libs gnutls 2> /dev/null`
-  if compile_prog "$vnc_tls_cflags" "$vnc_tls_libs" ; then
-    if test "$vnc_tls" != "no" ; then
-      vnc_tls=yes
-    fi
-    if test "$vnc_ws" != "no" ; then
-      vnc_ws=yes
-    fi
-    libs_softmmu="$vnc_tls_libs $libs_softmmu"
-    QEMU_CFLAGS="$QEMU_CFLAGS $vnc_tls_cflags"
+gnu_tls_cflags=`$pkg_config --cflags gnutls 2> /dev/null`
+gnu_tls_libs=`$pkg_config --libs gnutls 2> /dev/null`
+if compile_prog "$gnu_tls_cflags" "$gnu_tls_libs" ; then
+  gnu_tls=yes
+else
+  gnu_tls=no
+fi
+
+##########################################
+# VNC TLS/WS
+if test "$vnc" = "yes" -a "$gnu_tls" != "no"; then
+  if test "$vnc_tls" != "no" ; then
+    libs_softmmu="$gnu_tls_libs $libs_softmmu"
+    libs_tools="$gnu_tls_libs $libs_softmmu"
+    QEMU_CFLAGS="$QEMU_CFLAGS $gnu_tls_cflags"
+    vnc_tls=yes
+  fi
+  if test "$vnc_ws" != "no" ; then
+    libs_softmmu="$gnu_tls_libs $libs_softmmu"
+    libs_tools="$gnu_tls_libs $libs_softmmu"
+    QEMU_CFLAGS="$QEMU_CFLAGS $gnu_tls_cflags"
+    vnc_ws=yes
+  fi
+else
+  if test "$vnc_tls" = "yes" ; then
+    feature_not_found "vnc-tls"
+  fi
+  if test "$vnc_ws" = "yes" ; then
+    feature_not_found "vnc-ws"
+  fi
+  vnc_tls=no
+  vnc_ws=no
+fi
+
+##########################################
+# SHA256 deduplication
+if test "$sha256_dedup" = "yes"; then
+  if test "$gnu_tls" = "yes"; then
+    libs_softmmu="$gnu_tls_libs $libs_softmmu"
+    libs_tools="$gnu_tls_libs $libs_softmmu"
+    QEMU_CFLAGS="$QEMU_CFLAGS $gnu_tls_cflags"
+    sha256_dedup=yes
   else
-    if test "$vnc_tls" = "yes" ; then
-      feature_not_found "vnc-tls"
-    fi
-    if test "$vnc_ws" = "yes" ; then
-      feature_not_found "vnc-ws"
-    fi
-    vnc_tls=no
-    vnc_ws=no
+    echo "gnutls > 2.10.0 required to compile QEMU with sha256 deduplication"
+    exit 1
   fi
 fi
 
@@ -3562,6 +3597,7 @@ echo "seccomp support   $seccomp"
 echo "coroutine backend $coroutine"
 echo "GlusterFS support $glusterfs"
 echo "virtio-blk-data-plane $virtio_blk_data_plane"
+echo "sha256-dedup      $sha256_dedup"
 echo "gcov              $gcov_tool"
 echo "gcov enabled      $gcov"
 echo "TPM support       $tpm"
@@ -3951,6 +3987,10 @@ if test "$virtio_blk_data_plane" = "yes" ; then
   echo 'CONFIG_VIRTIO_BLK_DATA_PLANE=$(CONFIG_VIRTIO)' >> $config_host_mak
 fi
 
+if test "$sha256_dedup" = "yes" ; then
+  echo "CONFIG_SHA256_DEDUP=y" >> $config_host_mak
+fi
+
 # USB host support
 case "$usb" in
 linux)
-- 
1.7.10.4