From: Daniel P. Berrangé Date: Tue, 10 Jun 2025 12:36:55 +0000 (+0100) Subject: hw/hyperv/syndbg: skip automatic zero-init of large array X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=5a1f614d0cd0bcc8e84e0b7ab6af63d56bd348a2;p=thirdparty%2Fqemu.git hw/hyperv/syndbg: skip automatic zero-init of large array The 'handle_recv_msg' method has a 4k byte array used for copying data between the network socket and guest memory. Skip the automatic zero-init of this array to eliminate the performance overhead in the I/O hot path. The 'data_buf' array will be fully initialized when data is read off the network socket. Signed-off-by: Daniel P. Berrangé Reviewed-by: Stefan Hajnoczi Message-id: 20250610123709.835102-18-berrange@redhat.com Signed-off-by: Stefan Hajnoczi --- diff --git a/hw/hyperv/syndbg.c b/hw/hyperv/syndbg.c index 8b8a14750d..ac7e15f6f1 100644 --- a/hw/hyperv/syndbg.c +++ b/hw/hyperv/syndbg.c @@ -192,7 +192,7 @@ static uint16_t handle_recv_msg(HvSynDbg *syndbg, uint64_t outgpa, { uint16_t ret; g_assert(MSG_BUFSZ >= qemu_target_page_size()); - uint8_t data_buf[MSG_BUFSZ]; + QEMU_UNINITIALIZED uint8_t data_buf[MSG_BUFSZ]; hwaddr out_len; void *out_data; ssize_t recv_byte_count;