From ce14f24611aa0469b464a9512e192b4fd51dca2b Mon Sep 17 00:00:00 2001 From: =?utf8?q?Daniel=20P=2E=20Berrang=C3=A9?= Date: Tue, 10 Jun 2025 13:36:53 +0100 Subject: [PATCH] hw/dma/xlnx_csu_dma: skip automatic zero-init of large array MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit The 'xlnx_csu_dma_src_notify' method has a 4k byte array used for copying DMA data. Skip the automatic zero-init of this array to eliminate the performance overhead in the I/O hot path. The 'buf' array will be fully initialized when data is copied. Signed-off-by: Daniel P. Berrangé Reviewed-by: Stefan Hajnoczi Message-id: 20250610123709.835102-16-berrange@redhat.com Signed-off-by: Stefan Hajnoczi --- hw/dma/xlnx_csu_dma.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/hw/dma/xlnx_csu_dma.c b/hw/dma/xlnx_csu_dma.c index 3db3904d83..d8c7da1a50 100644 --- a/hw/dma/xlnx_csu_dma.c +++ b/hw/dma/xlnx_csu_dma.c @@ -287,7 +287,7 @@ static uint32_t xlnx_csu_dma_advance(XlnxCSUDMA *s, uint32_t len) static void xlnx_csu_dma_src_notify(void *opaque) { XlnxCSUDMA *s = XLNX_CSU_DMA(opaque); - unsigned char buf[4 * 1024]; + QEMU_UNINITIALIZED unsigned char buf[4 * 1024]; size_t rlen = 0; ptimer_transaction_begin(s->src_timer); -- 2.39.5