[libvirt] [PATCH v2 08/11] qemu: handle host usb device plug/unplug when libvirtd is down

[Daniel Henrique Barboza]

On 9/9/19 8:33 AM, Nikolay Shirokovskiy wrote:
> Somebody can easily unplug usb device from host while libvirtd is being
> stopped. Also usb device can be plugged or unplugged/plugged back and so
> forth. Let's handle such cases.
>
> Signed-off-by: Nikolay Shirokovskiy <nshirokovskiy at virtuozzo.com>
> ---

Reviewed-by: Daniel Henrique Barboza <danielhb413 at gmail.com>

>   src/qemu/qemu_process.c | 55 +++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 55 insertions(+)
>
> diff --git a/src/qemu/qemu_process.c b/src/qemu/qemu_process.c
> index c9921646e9..8bec36fe2c 100644
> --- a/src/qemu/qemu_process.c
> +++ b/src/qemu/qemu_process.c
> @@ -3749,6 +3749,58 @@ qemuProcessUpdateDevices(virQEMUDriverPtr driver,
>       return ret;
>   }
>   
> +
> +static int
> +qemuProcessReattachUSBDevices(virQEMUDriverPtr driver,
> +                              virDomainObjPtr vm)
> +{
> +    size_t i;
> +
> +    for (i = 0; i < vm->def->nhostdevs; i++) {
> +        virDomainHostdevDefPtr hostdev = vm->def->hostdevs[i];
> +        virDomainHostdevSubsysUSBPtr usbsrc = &hostdev->source.subsys.u.usb;
> +
> +        if (hostdev->source.subsys.type != VIR_DOMAIN_HOSTDEV_SUBSYS_TYPE_USB)
> +            continue;
> +
> +        /* don't mess with devices that don't use stable host addressing
> +         * with respect to unplug/plug to host
> +         */
> +        if (!usbsrc->vendor || !usbsrc->product)
> +            continue;
> +
> +        if (!usbsrc->bus && !usbsrc->device) {
> +            int num;
> +
> +            if ((num = virUSBDeviceFindByVendor(usbsrc->vendor, usbsrc->product,
> +                                                NULL, false, NULL)) < 0)
> +                return -1;
> +
> +            if (num > 0 &&
> +                qemuDomainAttachHostDevice(driver, vm, hostdev) < 0)
> +                return -1;
> +        } else {
> +            virUSBDevicePtr usb;
> +
> +            if (virUSBDeviceFindByBus(usbsrc->bus, usbsrc->device,
> +                                      NULL, false, &usb) < 0)
> +                return -1;
> +
> +            if (!usb) {
> +                virDomainDeviceDef dev = { .type = VIR_DOMAIN_DEVICE_HOSTDEV };
> +
> +                dev.data.hostdev = hostdev;
> +                if (qemuDomainDetachDeviceLive(vm, &dev, driver, true, true) < 0)
> +                    return -1;
> +            }
> +            virUSBDeviceFree(usb);
> +        }
> +    }
> +
> +    return 0;
> +}
> +
> +
>   static int
>   qemuDomainPerfRestart(virDomainObjPtr vm)
>   {
> @@ -8206,6 +8258,9 @@ qemuProcessReconnect(void *opaque)
>       if (qemuProcessUpdateDevices(driver, obj) < 0)
>           goto error;
>   
> +    if (qemuProcessReattachUSBDevices(driver, obj) < 0)
> +        goto error;
> +
>       if (qemuRefreshPRManagerState(driver, obj) < 0)
>           goto error;
>