On 1/4/22 11:22 PM, Philippe Mathieu-Daudé wrote:
On 27/12/21 15:27, zhenwei pi wrote:
A device of USB video class usually uses larger desc structure, so
use larger buffer to avoid failure.
Signed-off-by: zhenwei pi <pizhen...@bytedance.com>
---
hw/usb/desc.c | 15 ++++++++-------
hw/usb/desc.h | 1 +
2 files changed, 9 insertions(+), 7 deletions(-)
diff --git a/hw/usb/desc.c b/hw/usb/desc.c
index 8b6eaea407..7f6cc2f99b 100644
--- a/hw/usb/desc.c
+++ b/hw/usb/desc.c
@@ -632,7 +632,8 @@ int usb_desc_get_descriptor(USBDevice *dev,
USBPacket *p,
bool msos = (dev->flags & (1 << USB_DEV_FLAG_MSOS_DESC_IN_USE));
const USBDesc *desc = usb_device_get_usb_desc(dev);
const USBDescDevice *other_dev;
- uint8_t buf[256];
+ size_t buflen = USB_DESC_MAX_LEN;
+ g_autofree uint8_t *buf = g_malloc(buflen);
Do we want to have a per-device desc_size (in USBDevice, default to
256, video devices set it to 8K)?
How "hot" is this path? Could we keep 8K on the stack?
It's an unlikely code path:
1, During guest startup, guest tries to probe device.
2, run 'lsusb' command in guest
Keeping 8K on the stack also seems OK.
diff --git a/hw/usb/desc.h b/hw/usb/desc.h
index 3ac604ecfa..35babdeff6 100644
--- a/hw/usb/desc.h
+++ b/hw/usb/desc.h
@@ -199,6 +199,7 @@ struct USBDesc {
const USBDescMSOS *msos;
};
+#define USB_DESC_MAX_LEN 8192
#define USB_DESC_FLAG_SUPER (1 << 1)
/* little helpers */
--
zhenwei pi
