[Qemu-devel] [RFC V4 25/30] qcow2: Integrate SKEIN hash algorithm in deduplication.

["Benoît Canet" <benoit@irqsave.net>]

Signed-off-by: Benoit Canet <benoit@irqsave.net>
---
 block/qcow2-dedup.c |   14 ++++++++++++++
 block/qcow2.c       |    5 +++++
 configure           |   33 +++++++++++++++++++++++++++++++++
 3 files changed, 52 insertions(+)

diff --git a/block/qcow2-dedup.c b/block/qcow2-dedup.c
index 28001c6..bd8397e 100644
--- a/block/qcow2-dedup.c
+++ b/block/qcow2-dedup.c
@@ -30,6 +30,9 @@
 #include "block/block_int.h"
 #include "qemu-common.h"
 #include "qcow2.h"
+#ifdef CONFIG_SKEIN_DEDUP
+#include <skeinApi.h>
+#endif
 
 static int qcow2_dedup_read_write_hash(BlockDriverState *bs,
                                        QCowHash *hash,
@@ -202,6 +205,17 @@ static int qcow2_compute_cluster_hash(BlockDriverState *bs,
     case QCOW_HASH_SHA256:
         return gnutls_hash_fast(GNUTLS_DIG_SHA256, data,
                                 s->cluster_size, hash->data);
+#if defined(CONFIG_SKEIN_DEDUP)
+    case QCOW_HASH_SKEIN:
+        {
+        SkeinCtx_t ctx;
+        skeinCtxPrepare(&ctx, Skein256);
+        skeinInit(&ctx, Skein256);
+        skeinUpdate(&ctx, data, s->cluster_size);
+        skeinFinal(&ctx, hash->data);
+        }
+        return 0;
+#endif
     default:
         error_report("Invalid deduplication hash algorithm %i",
                      s->dedup_hash_algo);
diff --git a/block/qcow2.c b/block/qcow2.c
index 13f6a5c..0154d50 100644
--- a/block/qcow2.c
+++ b/block/qcow2.c
@@ -1540,6 +1540,11 @@ static int8_t qcow2_get_dedup_hash_algo(char *value)
     if (!strcmp(value, "sha256")) {
         return QCOW_HASH_SHA256;
     }
+#if defined(CONFIG_SKEIN_DEDUP)
+    if (!strcmp(value, "skein")) {
+        return QCOW_HASH_SKEIN;
+    }
+#endif
 
     error_printf("Unsupported deduplication hash algorithm.\n");
     return -EINVAL;
diff --git a/configure b/configure
index 390326e..97497af 100755
--- a/configure
+++ b/configure
@@ -223,6 +223,7 @@ libiscsi=""
 coroutine=""
 seccomp=""
 glusterfs=""
+skein_dedup="no"
 
 # parse CC options first
 for opt do
@@ -882,6 +883,8 @@ for opt do
   ;;
   --enable-glusterfs) glusterfs="yes"
   ;;
+  --enable-skein-dedup) skein_dedup="yes"
+  ;;
   *) echo "ERROR: unknown option $opt"; show_help="yes"
   ;;
   esac
@@ -1130,6 +1133,7 @@ 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 "  --enable-skein-dedup     enable computing dedup hashes with SKEIN"
 echo ""
 echo "NOTE: The object files are built at the place where configure is launched"
 exit 1
@@ -2412,6 +2416,30 @@ EOF
   fi
 fi
 
+##########################################
+# SKEIN dedup hash function probe
+if test "$skein_dedup" != "no" ; then
+  cat > $TMPC <<EOF
+#include <skeinApi.h>
+int main(void) {
+    SkeinCtx_t ctx;
+    skeinCtxPrepare(&ctx, 512);
+    return 0;
+}
+EOF
+  skein_libs="-lskein3fish"
+  if compile_prog "" "$skein_libs" ; then
+    skein_dedup=yes
+    libs_tools="$skein_libs $libs_tools"
+    libs_softmmu="$skein_libs $libs_softmmu"
+  else
+    if test "$skein_dedup" = "yes" ; then
+      feature_not_found "libskein3fish not found"
+    fi
+    skein_dedup=no
+  fi
+fi
+
 #
 # Check for xxxat() functions when we are building linux-user
 # emulator.  This is done because older glibc versions don't
@@ -3296,6 +3324,7 @@ echo "build guest agent $guest_agent"
 echo "seccomp support   $seccomp"
 echo "coroutine backend $coroutine_backend"
 echo "GlusterFS support $glusterfs"
+echo "SKEIN support     $skein_dedup"
 
 if test "$sdl_too_old" = "yes"; then
 echo "-> Your SDL version is too old - please upgrade to have SDL support"
@@ -3637,6 +3666,10 @@ if test "$glusterfs" = "yes" ; then
   echo "CONFIG_GLUSTERFS=y" >> $config_host_mak
 fi
 
+if test "$skein_dedup" = "yes" ; then
+  echo "CONFIG_SKEIN_DEDUP=y" >> $config_host_mak
+fi
+
 # USB host support
 case "$usb" in
 linux)
-- 
1.7.10.4