From b52bdeda7653879d007bbd2ee776ec5201d0c786 Mon Sep 17 00:00:00 2001 From: Gerd Hoffmann Date: Tue, 4 Jun 2019 05:12:43 +0100 Subject: [PATCH 1/5] Introduce new "no_guest_reset" parameter for usb-host device RH-Author: Gerd Hoffmann Message-id: <20190604051246.11374-2-kraxel@redhat.com> Patchwork-id: 88470 O-Subject: [RHEL-8.1.0 qemu-kvm PATCH 1/4] Introduce new "no_guest_reset" parameter for usb-host device Bugzilla: 1719228 RH-Acked-by: Dr. David Alan Gilbert RH-Acked-by: Max Reitz RH-Acked-by: Danilo de Paula From: Alexander Kappner With certain USB devices passed through via usb-host, a guest attempting to reset a usb-host device can trigger a reset loop that renders the USB device unusable. In my use case, the device was an iPhone XR that was passed through to a Mac OS X Mojave guest. Upon connecting the device, the following happens: 1) Guest recognizes new device, sends reset to emulated USB host 2) QEMU's USB host sends reset to host kernel 3) Host kernel resets device 4) After reset, host kernel determines that some part of the device descriptor has changed ("device firmware changed" in dmesg), so host kernel decides to re-enumerate the device. 5) Re-enumeration causes QEMU to disconnect and reconnect the device in the guest. 6) goto 1) Here's from the host kernel (note the "device firmware changed" lines") [3677704.473050] usb 1-1.3: new high-speed USB device number 53 using ehci-pci [3677704.555594] usb 1-1.3: New USB device found, idVendor=05ac, idProduct=12a8, bcdDevice=11.08 [3677704.555599] usb 1-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [3677704.555602] usb 1-1.3: Product: iPhone [3677704.555605] usb 1-1.3: Manufacturer: Apple Inc. [3677704.555607] usb 1-1.3: SerialNumber: [[removed]] [3677709.401040] usb 1-1.3: reset high-speed USB device number 53 using ehci-pci [3677709.479486] usb 1-1.3: device firmware changed [3677709.479842] usb 1-1.3: USB disconnect, device number 53 [3677709.546039] usb 1-1.3: new high-speed USB device number 54 using ehci-pci [3677709.627471] usb 1-1.3: New USB device found, idVendor=05ac, idProduct=12a8, bcdDevice=11.08 [3677709.627476] usb 1-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [3677709.627479] usb 1-1.3: Product: iPhone [3677709.627481] usb 1-1.3: Manufacturer: Apple Inc. [3677709.627483] usb 1-1.3: SerialNumber: [[removed]] [3677762.320044] usb 1-1.3: reset high-speed USB device number 54 using ehci-pci [3677762.615630] usb 1-1.3: USB disconnect, device number 54 [3677762.787043] usb 1-1.3: new high-speed USB device number 55 using ehci-pci [3677762.869016] usb 1-1.3: New USB device found, idVendor=05ac, idProduct=12a8, bcdDevice=11.08 [3677762.869024] usb 1-1.3: New USB device strings: Mfr=1, Product=2, SerialNumber=3 [3677762.869028] usb 1-1.3: Product: iPhone [3677762.869032] usb 1-1.3: Manufacturer: Apple Inc. [3677762.869035] usb 1-1.3: SerialNumber: [[removed]] [3677815.662036] usb 1-1.3: reset high-speed USB device number 55 using ehci-pci Here's from QEMU: libusb: error [_get_usbfs_fd] libusb couldn't open USB device /dev/bus/usb/005/022: No such file or directory libusb: error [udev_hotplug_event] ignoring udev action bind libusb: error [udev_hotplug_event] ignoring udev action bind libusb: error [_open_sysfs_attr] open /sys/bus/usb/devices/5-1/bConfigurationValue failed ret=-1 errno=2 libusb: error [_get_usbfs_fd] File doesn't exist, wait 10 ms and try again libusb: error [_get_usbfs_fd] libusb couldn't open USB device /dev/bus/usb/005/024: No such file or directory libusb: error [udev_hotplug_event] ignoring udev action bind libusb: error [udev_hotplug_event] ignoring udev action bind libusb: error [_open_sysfs_attr] open /sys/bus/usb/devices/5-1/bConfigurationValue failed ret=-1 errno=2 libusb: error [_get_usbfs_fd] File doesn't exist, wait 10 ms and try again libusb: error [_get_usbfs_fd] libusb couldn't open USB device /dev/bus/usb/005/026: No such file or directory The result of this is that the device remains permanently unusable in the guest. The same problem has been previously reported for an iPad: https://stackoverflow.com/questions/52617634/how-do-i-get-qemu-usb-passthrough-to-work-for-ipad-iphone This problem can be elegantly solved by interrupting step 2) above. Instead of passing through the reset, QEMU simply ignores it. To allow this to be configured on a per-device level, a new parameter "no_guest_reset" is introduced for the usb-host device. I can confirm that the configuration described above (iPhone XS + Mojave guest) works flawlessly with no_guest_reset=True specified. Working command line for my scenario: device_add usb-host,vendorid=0x05ac,productid=0x12a8,no_guest_reset=True,id=iphone Best regards Alexander Signed-off-by: Alexander Kappner Signed-off-by: Gerd Hoffmann Message-id: 20190128140027.9448-1-kraxel@redhat.com [ kraxel: rename parameter to "guest-reset" ] Signed-off-by: Gerd Hoffmann (cherry picked from commit ba4c735b4fc74e309ce4b2551d258e442ef513a5) Signed-off-by: Danilo C. L. de Paula --- hw/usb/host-libusb.c | 7 ++++++- 1 file changed, 6 insertions(+), 1 deletion(-) diff --git a/hw/usb/host-libusb.c b/hw/usb/host-libusb.c index f31e9cb..d82a10a 100644 --- a/hw/usb/host-libusb.c +++ b/hw/usb/host-libusb.c @@ -82,7 +82,7 @@ struct USBHostDevice { uint32_t options; uint32_t loglevel; bool needs_autoscan; - + bool allow_guest_reset; /* state */ QTAILQ_ENTRY(USBHostDevice) next; int seen, errcount; @@ -1451,6 +1451,10 @@ static void usb_host_handle_reset(USBDevice *udev) USBHostDevice *s = USB_HOST_DEVICE(udev); int rc; + if (!s->allow_guest_reset) { + return; + } + trace_usb_host_reset(s->bus_num, s->addr); rc = libusb_reset_device(s->dh); @@ -1568,6 +1572,7 @@ static Property usb_host_dev_properties[] = { DEFINE_PROP_UINT32("productid", USBHostDevice, match.product_id, 0), DEFINE_PROP_UINT32("isobufs", USBHostDevice, iso_urb_count, 4), DEFINE_PROP_UINT32("isobsize", USBHostDevice, iso_urb_frames, 32), + DEFINE_PROP_BOOL("guest-reset", USBHostDevice, allow_guest_reset, true), DEFINE_PROP_UINT32("loglevel", USBHostDevice, loglevel, LIBUSB_LOG_LEVEL_WARNING), DEFINE_PROP_BIT("pipeline", USBHostDevice, options, -- 1.8.3.1