Re: [libvirt] [PATCH] device-assignment: Reset device on system reset

* Alex Williamson (alex.williamson(a)redhat.com) wrote: > static void reset_assigned_device(DeviceState *dev) > { > - PCIDevice *d = DO_UPCAST(PCIDevice, qdev, dev); > + PCIDevice *pci_dev = DO_UPCAST(PCIDevice, qdev, dev); > + AssignedDevice *adev = DO_UPCAST(AssignedDevice, dev, pci_dev); > + char reset_file[64]; > + const char reset[] = "1"; > + int fd, ret; > + > + snprintf(reset_file, sizeof(reset_file), > + "/sys/bus/pci/devices/0000:%02x:%02x.%01x/reset", > + adev->host.bus, adev->host.dev, adev->host.func); need to consider segment: %04x:..., adev->host.seg, ...

> + /* > + * Issue a device reset via pci-sysfs. Note that we use write(2) here > + * and ignore the return value because some kernels have a bug that > + * returns 0 rather than bytes written on success, sending us into an > + * infinite retry loop using other write mechanisms. > + */ > + fd = open(reset_file, O_WRONLY); > + if (fd != -1) { > + ret = write(fd, reset, strlen(reset)); > + close(fd); > + } This will probably fail when it's managed by libvirt. I expect it will need some file ownership and security label mgmt added to device assignement path I expect.