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

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);

+ /* + * 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); + }