[PULL 18/31] hw/misc/aspeed_hace: skip automatic zero-init of large array

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[PULL 18/31] hw/misc/aspeed_hace: skip automatic zero-init of large array
Posted by Stefan Hajnoczi 5 months ago
From: Daniel P. Berrangé <berrange@redhat.com>

The 'do_hash_operation' method has a 256 element iovec array used for
holding pointers to data that is to be hashed. Skip the automatic
zero-init of this array to eliminate the performance overhead in the
I/O hot path.

The 'iovec' array will be selectively initialized based on data that
needs to be hashed.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Message-id: 20250610123709.835102-19-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
---
 hw/misc/aspeed_hace.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/hw/misc/aspeed_hace.c b/hw/misc/aspeed_hace.c
index 8924a30eff..726368fbbc 100644
--- a/hw/misc/aspeed_hace.c
+++ b/hw/misc/aspeed_hace.c
@@ -419,7 +419,7 @@ static void hash_execute_acc_mode(AspeedHACEState *s, int algo,
 static void do_hash_operation(AspeedHACEState *s, int algo, bool sg_mode,
                               bool acc_mode)
 {
-    struct iovec iov[ASPEED_HACE_MAX_SG];
+    QEMU_UNINITIALIZED struct iovec iov[ASPEED_HACE_MAX_SG];
     bool acc_final_request = false;
     int iov_idx = -1;
 
-- 
2.49.0