[Qemu-devel] [PATCH v4 00/10] KVM Support for MIPS32 Processors

[James Hogan]

I'd like to have this squeezed into 2.0 (if at all possible), so any
final review from KVM people would be much appreciated. 

Thanks to everybody who has already taken part in review.

This patchset implements KVM support for MIPS32 processors, using Trap &
Emulation.

In KVM mode, CPU virtualization is handled via the kvm kernel module,
while system and I/O virtualization leverage the Malta model already
present in QEMU.

Both Guest kernel and Guest Userspace execute in UM. The Guest address
space is as folows:
Guest User address space:   0x00000000 -> 0x40000000
Guest Kernel Unmapped:      0x40000000 -> 0x60000000
Guest Kernel Mapped:        0x60000000 -> 0x80000000

As a result, Guest Usermode virtual memory is limited to 1GB.

KVM support (by trap and emulate) was added to the Linux kernel in
v3.10.

Changes in v4:

Changes mostly addressing a few review comments from v3 patchset.

A git tag for this version of the patchset can also be found on github:
https://github.com/jahogan/qemu-kvm-mips.git kvm-mips-v4

 - Rebase on v2.0.0-rc0.
 - Use int32_t instead of int32 (which is for softfloat) in kvm register
   accessors (Andreas Färber).
 - Use uint64_t instead of __u64 (which is really just for kernel
   headers) in the kvm register accessors (Andreas Färber).
 - Cast pointer to uintptr_t rather than target_ulong in kvm register
   accessors.
 - Remove some redundant casts in kvm register accessors.
 - Add MAINTAINERS entry for MIPS KVM.

Changes in v3:

Changes mostly addressing review comments from v2 patchset.

A git tag for this version of the patchset can also be found on github:
https://github.com/jahogan/qemu-kvm-mips.git kvm-mips-v3

 - Remove "target-mips: Set target page size to 16K in KVM mode". It
   should actually work fine with 4k TARGET_PAGE_SIZE as long as there
   is no cache aliasing or both host and guest kernels are configured to
   a sufficient page size to avoid aliasing (which the kernel
   arch/mips/kvm/00README.txt alludes to anyway).
 - Rewrote kvm sigmask patch to allow sigmask length to be set by
   kvm_arch_init(), so that MIPS can set it to 16 as it has 128 signals.
   This is better than cluttering kvm-all.c with TARGET_* ifdefs (Peter
   Maydell).
 - Set sigmask length to 16 from kvm_arch_init() since MIPS Linux has
   128 signals. This is better than cluttering kvm_all.c with TARGET_*
   ifdefs (Peter Maydell).
 - s/dprintf/DPRINTF/ (Andreas Färber).
 - Use "cs" rather than "cpu" or "env" for CPUState variable names
   (Andreas Färber).
 - Use CPUMIPSState rather than CPUArchState (Andreas Färber).
 - Pass MIPSCPU to cpu_mips_io_interrupts_pending() rather than
   CPUMIPSState (Andreas Färber).
 - Remove spurious parentheses around cpu_mips_io_interrupts_pending()
   call (Andreas Färber).
 - Pass MIPSCPU to kvm_mips_set_[ipi_]interrupt (Andreas Färber).
 - Make use of error_report (Andreas Färber) and clean up error messages
   a little to include __func__.
 - Remove inline kvm_mips_{put,get}_one_[ul]reg() declarations from
   kvm_mips.h. They're only used in target-mips/kvm.c anyway.
 - Make kvm_arch_{put,get}_registers static within target-mips/kvm.c and
   remove from kvm_mips.h.
 - Remove unnecessary includes from Malta patch, especially linux/kvm.h
   which isn't a good idea on non-Linux (Peter Maydell).

Changes in v2:

This patchset is based on Sanjay Lal's V1 patchset from 2nd March 2013:
https://patchwork.kernel.org/project/kvm/list/?submitter=51991&state=*&q=qemu-devel

I think I've addressed all the V1 feedback. The other main change is the
removal of the boot-CPS ROM code binary blob and GIC/SMP support since
it's all slightly orthogonal to KVM support. Instead the existing
minimal bootloader code for Malta has been updated to work with KVM T&E.

A git tag for this version of the patchset can also be found on github:
https://github.com/jahogan/qemu-kvm-mips.git kvm-mips-v2

 - Expand commit messages
 - Rebase on v1.7.0
 - Misc checkpatch and other cleanups
 - Some interrupt bug fixes from Yann Le Du <address@hidden>
 - Add get/set register functionality from Yann Le Du <address@hidden>
 - Use new 64 bit compatible ABI from Cavium from Sanjay Lal
   <address@hidden>
 - Add dummy kvm_arch_init_irq_routing()
   The common KVM code insists on calling kvm_arch_init_irq_routing() as
   soon as it sees kernel header support for it (regardless of whether
   QEMU supports it). Provide a dummy function to satisfy this.
 - Remove request_interrupt_window code (Peter Maydell)
 - Remove #ifdef CONFIG_KVM where guarded by kvm_enabled() already
 - Removal of cps / GIC / SMP support
 - Minimal bootloader modified to execute safely from RAM
 - Create asm-mips symlink using generic code and move above default
   case (Peter Maydell)
 - Remove redundant check of target_name = cpu = mips
 - Remove mipsel cross compilation fix, which is now fixed by commit
   61cc919f73ea (configure: detect endian via compile test)
 - Add translation of guest kernel segments to allow an attached gdb to
   see kernel memory correctly

James Hogan (5):
  target-mips: get_physical_address: Add defines for segment bases
  target-mips: get_physical_address: Add KVM awareness
  kvm: Allow arch to set sigmask length
  hw/mips: malta: Add KVM support
  MAINTAINERS: Add entry for MIPS KVM

Sanjay Lal (5):
  hw/mips/cputimer: Don't start periodic timer in KVM mode
  hw/mips: Add API to convert KVM guest KSEG0 <-> GPA
  target-mips: kvm: Add main KVM support for MIPS
  hw/mips: In KVM mode, inject IRQ2 (I/O) interupts via ioctls
  target-mips: Enable KVM support in build system

 MAINTAINERS               |   5 +
 configure                 |   6 +-
 hw/mips/addr.c            |  10 +
 hw/mips/cputimer.c        |  13 +-
 hw/mips/mips_int.c        |  11 ++
 hw/mips/mips_malta.c      |  82 +++++---
 include/hw/mips/cpudevs.h |   4 +
 include/sysemu/kvm.h      |   2 +
 kvm-all.c                 |  11 +-
 target-mips/Makefile.objs |   1 +
 target-mips/helper.c      |  51 +++--
 target-mips/kvm.c         | 472 ++++++++++++++++++++++++++++++++++++++++++++++
 target-mips/kvm_mips.h    |  19 ++
 13 files changed, 647 insertions(+), 40 deletions(-)
 create mode 100644 target-mips/kvm.c
 create mode 100644 target-mips/kvm_mips.h

-- 
1.8.1.2