On Tue, Dec 13, 2016 at 01:44:36PM +0100, Thomas Huth wrote: > When passing through a USB storage device to a pseries guest, it > is currently not possible to automatically boot from the device > if the "bootindex" property has been specified, too (e.g. when using > "-device nec-usb-xhci -device usb-host,hostbus=1,hostaddr=2,bootindex=0" > at the command line). The problem is that QEMU builds a device tree path > like "/pci@800000020000000/usb@0/usb-host@1" and passes it to SLOF > in the /chosen/qemu,boot-list property. SLOF, however, probes the > USB device, recognizes that it is a storage device and thus changes > its name to "storage", and additionally adds a child node for the > SCSI LUN, so the correct boot path in SLOF is something like > "/pci@800000020000000/usb@0/storage@1/disk@101000000000000" instead. > So when we detect an USB mass storage device with SCSI interface, > we've got to adjust the firmware boot-device path properly, so that > SLOF can automatically boot from the device. > > Buglink: https://bugzilla.redhat.com/show_bug.cgi?id=1354177 > Signed-off-by: Thomas Huth <th...@redhat.com> > --- > hw/ppc/spapr.c | 9 +++++++++ > hw/usb/host-libusb.c | 29 +++++++++++++++++++++++++++++ > hw/usb/host-stub.c | 5 +++++ > include/hw/usb.h | 1 + > 4 files changed, 44 insertions(+) > > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index 208ef7b..fe315b5 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -2185,6 +2185,15 @@ static char *spapr_get_fw_dev_path(FWPathProvider *p, > BusState *bus, > } > }
I think a chunk of your commit message needs to go into a comment
here. Anticipating the guest firmware behaviour is kind of a hack - I
think it's worth it in this case, but we do need to make it clear to
someone reading the code what the rationale is.
> + if (strcmp("usb-host", qdev_fw_name(dev)) == 0) {
> + USBDevice *usbdev = CAST(USBDevice, dev, TYPE_USB_DEVICE);
> +
> + /* SLOF scans USB storage and adds a "disk" node for the SCSI LUN */
> + if (usb_host_dev_is_scsi_storage(usbdev)) {
> + return g_strdup_printf("storage@%s/disk", usbdev->port->path);
> + }
> + }
> +
> if (phb) {
> /* Replace "pci" with "pci@800000020000000" */
> return g_strdup_printf("pci@%"PRIX64, phb->buid);
> diff --git a/hw/usb/host-libusb.c b/hw/usb/host-libusb.c
> index bd81d71..7791c6d 100644
> --- a/hw/usb/host-libusb.c
> +++ b/hw/usb/host-libusb.c
> @@ -1707,6 +1707,35 @@ static void usb_host_auto_check(void *unused)
> timer_mod(usb_auto_timer, qemu_clock_get_ms(QEMU_CLOCK_REALTIME) + 2000);
> }
>
> +/**
> + * Check whether USB host device has a USB mass storage SCSI interface
> + */
> +bool usb_host_dev_is_scsi_storage(USBDevice *ud)
> +{
> + USBHostDevice *uhd = USB_HOST_DEVICE(ud);
> + struct libusb_config_descriptor *conf;
> + const struct libusb_interface_descriptor *intf;
> + bool is_scsi_storage = false;
> + int i;
> +
> + if (!uhd || libusb_get_active_config_descriptor(uhd->dev, &conf) != 0) {
> + return false;
> + }
> +
> + for (i = 0; i < conf->bNumInterfaces; i++) {
> + intf = &conf->interface[i].altsetting[ud->altsetting[i]];
> + if (intf->bInterfaceClass == LIBUSB_CLASS_MASS_STORAGE &&
> + intf->bInterfaceSubClass == 6) { /* 6 means SCSI
> */
> + is_scsi_storage = true;
> + break;
> + }
> + }
> +
> + libusb_free_config_descriptor(conf);
> +
> + return is_scsi_storage;
> +}
> +
> void hmp_info_usbhost(Monitor *mon, const QDict *qdict)
> {
> libusb_device **devs = NULL;
> diff --git a/hw/usb/host-stub.c b/hw/usb/host-stub.c
> index 6ba65a1..d0268ba 100644
> --- a/hw/usb/host-stub.c
> +++ b/hw/usb/host-stub.c
> @@ -46,3 +46,8 @@ USBDevice *usb_host_device_open(USBBus *bus, const char
> *devname)
> {
> return NULL;
> }
> +
> +bool usb_host_dev_is_scsi_storage(USBDevice *ud)
> +{
> + return false;
> +}
> diff --git a/include/hw/usb.h b/include/hw/usb.h
> index 847c9de..43838c9 100644
> --- a/include/hw/usb.h
> +++ b/include/hw/usb.h
> @@ -471,6 +471,7 @@ void usb_generic_async_ctrl_complete(USBDevice *s,
> USBPacket *p);
> /* usb-linux.c */
> USBDevice *usb_host_device_open(USBBus *bus, const char *devname);
> void hmp_info_usbhost(Monitor *mon, const QDict *qdict);
> +bool usb_host_dev_is_scsi_storage(USBDevice *usbdev);
>
> /* usb ports of the VM */
>
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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