On Sun, 14 Apr 2013, Gonglei (Arei) wrote: > > > Hi Alan, > > > We pass-throughed USB 2.0 disk to guest using usb-host (qemu option: > > -device usb-ehci,id=ehci -device usb-host,bus=ehci.0,hostbus=2,hostport=1) > > on > > KVM(on linux-3.8.3 or linux-3.0.13) and qemu 1.4.0 , > > > > Are you sure this disk was using EHCI? The attached log shows bulk > > packet sizes that aren't multiples of 512, which isn't possible in the > > middle of a high-speed transfer. > > Yes, this disk was using EHCI, since guest QEMU and Linux kernel both > prints matching EHCI logs, such as transfer types and transfer sizes. > There are many buck-out URBs whose sizes are 31 or 4064 that are not > multiples of 512. Since URB size 31 does occur without guest format > USB 2.0 disk sceneiro, did you mean that buck-out size 4064 should > not occur? /* EHCI spec version 1.0 Section 4.10.6 */
That's right; it should not occur. It's okay to have an URB size that isn't a multiple of 512 if that URB is the last one in a transfer. For example, the 31-byte URBs were the only URBs in their transfers, so they were okay. But the 4064-byte URBs occurred at the start and in the middle of their transfers, so they were wrong. > > What kernel version did you use while recording this log? > > We tested KVM on Linux 3.8.3 and Linux 3.0.13, and the problem exists > on both kernels. But which kernel version did you use while recording the log that you posted? Also, what type of computer is your host? > This time we attached a usbmon USB disk format failed log and > USBlyzer' logs for another test. Would you give us some advice, > thanks a lot! > > Something look like: > > ffff88180b974600 480512312 S Bo:6:009:2 -115 31 = 55534243 50599784 00000100 > 00000a2a 00000008 de000080 00000000 000000 > ffff88180b974600 480512375 C Bo:6:009:2 0 31 > > ffff88180b974600 480513372 S Bo:6:009:2 -115 4064 = f8ffff0f ffffff0f > ffffff0f 00000000 00000000 00000000 00000000 00000000 This is a lot more concise than the other log, but it still shows the same problem: the 4064-byte URB. Can you post the contents of the /sys/kernel/debug/usb/devices file? Alan Stern
