[Qemu-devel] [PATCH 0/9] S390x KVM support v3

[Alexander Graf]

While S390x was one of the first targets that were supported by KVM it always
lacked qemu system emulation support.

In order to change that sad fact, I figured I'd just take on the task myself,
taking kuli (http://www.ibm.com/developerworks/linux/linux390/kuli.html),
Documentation/s390/kvm.txt and lguest as starting points to write a clean,
qemu'ish S390x Virtio machine emulation.

So now you can run Linux VMs on Linux on z/VM on LPAR on zSeries!

This is the resulting code. Please comment on things you like and also on the
ones you don't :-).

The patchset is based on Uli's S390x userspace emulation patches. There's not
really that much shared functionality, but I didn't want to reimplement the
configure wheels. So make sure to have his patches applied first.

Please only run S390x system virtualization using io threads. S390x has very
few intercepts and even less that actually reach userspace. So you'll end up
with a non-responsive VM without a dedicated IO thread.

Use: $ ./configure --target-list=s390x-softmmu --enable-io-thread

Currently only -kernel, -initrd and friends work. Booting from a real dasd
device is not supported.

Also to actually run this code you need a patch for an ugly bug in the kernel
module that Carsten sent a patch to on the ML.

I verified that the userspace actually works on a 2.6.27 (SLES11) kernel, so
if it doesn't work on current git, please tell me! I'm too afraid that I might
end up in a 3270 terminal to update the kernel on my z/VM instance :-).

v1 -> v2:

  - use new kvm_run variables
  - use DO_UPCAST
  - add bridge device for "info qtree"

v2 -> v3:

  - move memory allocation logic to qemu_ram_alloc

Alexander Graf (9):
  Add KVM support for S390x
  Allocate physical memory in low virtual address space
  Add support for S390x system emulation
  Add S390x virtio machine bus
  Add S390x virtio machine description
  S390 GDB stub
  Implement early printk in virtio-console
  Set default console to virtio on S390x
  Move mp_state to CPU_COMMON

 Makefile.target          |    2 +
 configure                |    4 +-
 cpu-defs.h               |    1 +
 exec.c                   |    6 +
 gdbstub.c                |   52 ++++++
 hw/s390-virtio-bus.c     |  384 ++++++++++++++++++++++++++++++++++++++
 hw/s390-virtio-bus.h     |   64 +++++++
 hw/s390-virtio.c         |  243 ++++++++++++++++++++++++
 hw/virtio-console.c      |    7 +
 hw/virtio-console.h      |    2 +
 target-i386/cpu.h        |    1 -
 target-s390x/cpu.h       |   86 +++++++++-
 target-s390x/exec.h      |    5 +
 target-s390x/helper.c    |   26 +++-
 target-s390x/kvm.c       |  457 ++++++++++++++++++++++++++++++++++++++++++++++
 target-s390x/machine.c   |   30 +++
 target-s390x/op_helper.c |   53 ++++++
 vl.c                     |   26 +++
 18 files changed, 1443 insertions(+), 6 deletions(-)
 create mode 100644 hw/s390-virtio-bus.c
 create mode 100644 hw/s390-virtio-bus.h
 create mode 100644 hw/s390-virtio.c
 create mode 100644 target-s390x/kvm.c
 create mode 100644 target-s390x/machine.c