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authorDaniel P. Berrangé <berrange@redhat.com>2025-06-10 13:37:04 +0100
committerStefan Hajnoczi <stefanha@redhat.com>2025-06-12 13:40:16 -0400
commit14997d521d1cd0bb36c902ef1032f0d3f2a3c912 (patch)
treee643170eb6e7b2c5f20fbb53ae663b0f08d090c0 /hw/usb/hcd-ohci.c
parent5dd9087fff74b5672526cad254e76f790fb35c7a (diff)
downloadfocaccia-qemu-14997d521d1cd0bb36c902ef1032f0d3f2a3c912.tar.gz
focaccia-qemu-14997d521d1cd0bb36c902ef1032f0d3f2a3c912.zip
hw/usb/hcd-ohci: skip automatic zero-init of large array
The 'ohci_service_iso_td' method has a 8k byte array used for copying
data between guest and host. 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 reading data from guest
memory.

Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Reviewed-by: Harsh Prateek Bora <harshpb@linux.ibm.com>
Message-id: 20250610123709.835102-27-berrange@redhat.com
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Diffstat (limited to 'hw/usb/hcd-ohci.c')
-rw-r--r--hw/usb/hcd-ohci.c2
1 files changed, 1 insertions, 1 deletions
diff --git a/hw/usb/hcd-ohci.c b/hw/usb/hcd-ohci.c
index 71b54914d3..72a9f9f474 100644
--- a/hw/usb/hcd-ohci.c
+++ b/hw/usb/hcd-ohci.c
@@ -577,7 +577,7 @@ static int ohci_service_iso_td(OHCIState *ohci, struct ohci_ed *ed)
     USBDevice *dev;
     USBEndpoint *ep;
     USBPacket *pkt;
-    uint8_t buf[8192];
+    QEMU_UNINITIALIZED uint8_t buf[8192];
     bool int_req;
     struct ohci_iso_td iso_td;
     uint32_t addr;