diff options
| -rw-r--r-- | docs/system/s390x/bootdevices.rst | 82 | ||||
| -rw-r--r-- | docs/system/target-s390x.rst | 1 | ||||
| -rw-r--r-- | hw/s390x/virtio-ccw-input.c | 2 | ||||
| -rw-r--r-- | hw/vfio/ap.c | 1 |
4 files changed, 85 insertions, 1 deletions
diff --git a/docs/system/s390x/bootdevices.rst b/docs/system/s390x/bootdevices.rst new file mode 100644 index 0000000..9e591cb --- /dev/null +++ b/docs/system/s390x/bootdevices.rst @@ -0,0 +1,82 @@ +Boot devices on s390x +===================== + +Booting with bootindex parameter +-------------------------------- + +For classical mainframe guests (i.e. LPAR or z/VM installations), you always +have to explicitly specify the disk where you want to boot from (or "IPL" from, +in s390x-speak -- IPL means "Initial Program Load"). In particular, there can +also be only one boot device according to the architecture specification, thus +specifying multiple boot devices is not possible (yet). + +So for booting an s390x guest in QEMU, you should always mark the +device where you want to boot from with the ``bootindex`` property, for +example:: + + qemu-system-s390x -drive if=none,id=dr1,file=guest.qcow2 \ + -device virtio-blk,drive=dr1,bootindex=1 + +For booting from a CD-ROM ISO image (which needs to include El-Torito boot +information in order to be bootable), it is recommended to specify a ``scsi-cd`` +device, for example like this:: + + qemu-system-s390x -blockdev file,node-name=c1,filename=... \ + -device virtio-scsi \ + -device scsi-cd,drive=c1,bootindex=1 + +Note that you really have to use the ``bootindex`` property to select the +boot device. The old-fashioned ``-boot order=...`` command of QEMU (and +also ``-boot once=...``) is not supported on s390x. + + +Booting without bootindex parameter +----------------------------------- + +The QEMU guest firmware (the so-called s390-ccw bios) has also some rudimentary +support for scanning through the available block devices. So in case you did +not specify a boot device with the ``bootindex`` property, there is still a +chance that it finds a bootable device on its own and starts a guest operating +system from it. However, this scanning algorithm is still very rough and may +be incomplete, so that it might fail to detect a bootable device in many cases. +It is really recommended to always specify the boot device with the +``bootindex`` property instead. + +This also means that you should avoid the classical short-cut commands like +``-hda``, ``-cdrom`` or ``-drive if=virtio``, since it is not possible to +specify the ``bootindex`` with these commands. Note that the convenience +``-cdrom`` option even does not give you a real (virtio-scsi) CD-ROM device on +s390x. Due to technical limitations in the QEMU code base, you will get a +virtio-blk device with this parameter instead, which might not be the right +device type for installing a Linux distribution via ISO image. It is +recommended to specify a CD-ROM device via ``-device scsi-cd`` (as mentioned +above) instead. + + +Booting from a network device +----------------------------- + +Beside the normal guest firmware (which is loaded from the file ``s390-ccw.img`` +in the data directory of QEMU, or via the ``-bios`` option), QEMU ships with +a small TFTP network bootloader firmware for virtio-net-ccw devices, too. This +firmware is loaded from a file called ``s390-netboot.img`` in the QEMU data +directory. In case you want to load it from a different filename instead, +you can specify it via the ``-global s390-ipl.netboot_fw=filename`` +command line option. + +The ``bootindex`` property is especially important for booting via the network. +If you don't specify the the ``bootindex`` property here, the network bootloader +firmware code won't get loaded into the guest memory so that the network boot +will fail. For a successful network boot, try something like this:: + + qemu-system-s390x -netdev user,id=n1,tftp=...,bootfile=... \ + -device virtio-net-ccw,netdev=n1,bootindex=1 + +The network bootloader firmware also has basic support for pxelinux.cfg-style +configuration files. See the `PXELINUX Configuration page +<https://wiki.syslinux.org/wiki/index.php?title=PXELINUX#Configuration>`__ +for details how to set up the configuration file on your TFTP server. +The supported configuration file entries are ``DEFAULT``, ``LABEL``, +``KERNEL``, ``INITRD`` and ``APPEND`` (see the `Syslinux Config file syntax +<https://wiki.syslinux.org/wiki/index.php?title=Config>`__ for more +information). diff --git a/docs/system/target-s390x.rst b/docs/system/target-s390x.rst index 644e404..c636f64 100644 --- a/docs/system/target-s390x.rst +++ b/docs/system/target-s390x.rst @@ -31,4 +31,5 @@ Architectural features ====================== .. toctree:: + s390x/bootdevices s390x/protvirt diff --git a/hw/s390x/virtio-ccw-input.c b/hw/s390x/virtio-ccw-input.c index 5601e25..83136fb 100644 --- a/hw/s390x/virtio-ccw-input.c +++ b/hw/s390x/virtio-ccw-input.c @@ -1,5 +1,5 @@ /* - * virtio ccw scsi implementation + * virtio ccw input implementation * * Copyright 2012, 2015 IBM Corp. * diff --git a/hw/vfio/ap.c b/hw/vfio/ap.c index b9330a8..cec6fe1 100644 --- a/hw/vfio/ap.c +++ b/hw/vfio/ap.c @@ -71,6 +71,7 @@ static VFIOGroup *vfio_ap_get_group(VFIOAPDevice *vapdev, Error **errp) if (!group_path) { error_setg(errp, "%s: no iommu_group found for %s: %s", VFIO_AP_DEVICE_TYPE, vapdev->vdev.sysfsdev, gerror->message); + g_error_free(gerror); return NULL; } |