From: Daniel P. Berrangé Date: Tue, 10 Jun 2025 12:37:02 +0000 (+0100) Subject: hw/ppc/pnv_occ: skip automatic zero-init of large struct X-Git-Tag: v10.1.0-rc0~51^2~7 X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=3438eabaf4f8ae58b6c47f1727938d1d7dac4823;p=thirdparty%2Fqemu.git hw/ppc/pnv_occ: skip automatic zero-init of large struct The 'occ_model_tick' method has a 12k struct used for copying data between guest and host. Skip the automatic zero-init of this struct to eliminate the performance overhead in the I/O hot path. The 'dynamic_data' buffer will be fully initialized when reading data from the guest. Signed-off-by: Daniel P. Berrangé Reviewed-by: Stefan Hajnoczi Reviewed-by: Klaus Jensen Reviewed-by: Harsh Prateek Bora Message-id: 20250610123709.835102-25-berrange@redhat.com Signed-off-by: Stefan Hajnoczi --- diff --git a/hw/ppc/pnv_occ.c b/hw/ppc/pnv_occ.c index fa6f31cb8d8..24b789c191c 100644 --- a/hw/ppc/pnv_occ.c +++ b/hw/ppc/pnv_occ.c @@ -789,7 +789,7 @@ static bool occ_opal_process_command(PnvOCC *occ, static bool occ_model_tick(PnvOCC *occ) { - struct occ_dynamic_data dynamic_data; + QEMU_UNINITIALIZED struct occ_dynamic_data dynamic_data; if (!occ_read_dynamic_data(occ, &dynamic_data, NULL)) { /* Can't move OCC state field to safe because we can't map it! */