Re: [PATCH v7 6/8] hw/usb/redirect-server: Implement bulk and interrupt transfers

[Junjie Cao <junjie.cao@linux.dev>]

Hi Jamin,

On Wed, Oct 28, 2026 at 03:41:48AM +0000, Jamin Lin wrote:
> +    int actual = rp->pkt.actual_length;
> +    /* Only an IN transfer carries data back. */
> +    int len = is_in ? actual : 0;

For OUT this also zeroes the length in the reply header, and redirect.c
copies that length into p->actual_length.

With usb-storage exported and qemu-xhci on the client side, the device
enumerates, but the Debian guest keeps resetting it and no sda shows
up. A usb-ehci client works, because EHCI ignores the OUT length.

Keeping actual in the header and sending no payload for OUT, as
usbredirhost does, fixes it here: sda appears on xHCI and a 1 MiB
write/read compares equal. The control and interrupt OUT replies drop
the length the same way.

The endpoint checks from v6 work now, including start_interrupt_receiving
on a bulk endpoint, thanks.

Junjie