Re: [PATCH 00/31] KVM/MIPS: Implement hardware virtualization viathe MIPS-VZ extensions.

From: David Daney
Date: Fri Jun 07 2013 - 19:15:12 EST

I should also add that I will shortly send patches for the kvm tool required to drive this VM as well as a small set of patches that create a para-virtualized MIPS/Linux guest kernel.

The idea is that because there is no standard SMP linux system, we create a standard para-virtualized system that uses a handful of hypercalls, but mostly just uses virtio devices. It has no emulated real hardware (no 8250 UART, no emulated legacy anything...)

David Daney

On 06/07/2013 04:03 PM, David Daney wrote:
From: David Daney <david.daney@xxxxxxxxxx>

These patches take a somewhat different approach to MIPS
virtualization via the MIPS-VZ extensions than the patches previously
sent by Sanjay Lal.

Several facts about the code:

o Existing exception handlers are modified to hook in to KVM instead
of intercepting all exceptions via the EBase register, and then
chaining to real exception handlers.

o Able to boot 64-bit SMP guests that use the FPU (I have booted 4-way
SMP 64-bit MIPS/Linux).

o Additional overhead on every exception even when *no* vCPU is running.

o Lower interrupt overhead, than the EBase interception method, when
vCPU *is* running.

o This code is somewhat smaller than the existing trap/emulate
implementation (about 2100 lines vs. about 5300 lines)

o Currently probably only usable on the OCTEON III CPU model, as some
MIPS-VZ implementation-defined behaviors were assumed to have the
OCTEON III behavior.

Note: I think Ralf already has the 17/31 (MIPS: Quit exposing Kconfig
symbols in uapi headers.) queued, but I also include it here.

David Daney (31):
MIPS: Move allocate_kscratch to cpu-probe.c and make it public.
MIPS: Save and restore K0/K1 when CONFIG_KVM_MIPSVZ
mips/kvm: Fix 32-bitisms in kvm_locore.S
mips/kvm: Add casts to avoid pointer width mismatch build failures.
mips/kvm: Use generic cache flushing functions.
mips/kvm: Rename kvm_vcpu_arch.pc to kvm_vcpu_arch.epc
mips/kvm: Rename VCPU_registername to KVM_VCPU_ARCH_registername
mips/kvm: Fix code formatting in arch/mips/kvm/kvm_locore.S
mips/kvm: Factor trap-and-emulate support into a pluggable
mips/kvm: Implement ioctls to get and set FPU registers.
MIPS: Rearrange branch.c so it can be used by kvm code.
MIPS: Add instruction format information for WAIT, MTC0, MFC0, et al.
mips/kvm: Add accessors for MIPS VZ registers.
mips/kvm: Add thread_info flag to indicate operation in MIPS VZ Guest
mips/kvm: Exception handling to leave and reenter guest mode.
mips/kvm: Add exception handler for MIPSVZ Guest exceptions.
MIPS: Quit exposing Kconfig symbols in uapi headers.
mips/kvm: Add pt_regs slots for BadInstr and BadInstrP
mips/kvm: Add host definitions for MIPS VZ based host.
mips/kvm: Hook into TLB fault handlers.
mips/kvm: Allow set_except_vector() to be used from MIPSVZ code.
mips/kvm: Split get_new_mmu_context into two parts.
mips/kvm: Hook into CP unusable exception handler.
mips/kvm: Add thread_struct fields used by MIPSVZ hosts.
mips/kvm: Add some asm-offsets constants used by MIPSVZ.
mips/kvm: Split up Kconfig and Makefile definitions in preperation
mips/kvm: Gate the use of kvm_local_flush_tlb_all() by KVM_MIPSTE
mips/kvm: Add MIPSVZ support.
mips/kvm: Enable MIPSVZ in Kconfig/Makefile
mips/kvm: Allow for upto 8 KVM vcpus per vm.

arch/mips/Kconfig | 1 +
arch/mips/include/asm/branch.h | 7 +
arch/mips/include/asm/kvm_host.h | 622 +-----------
arch/mips/include/asm/kvm_mips_te.h | 589 +++++++++++
arch/mips/include/asm/kvm_mips_vz.h | 29 +
arch/mips/include/asm/mipsregs.h | 264 +++++
arch/mips/include/asm/mmu_context.h | 12 +-
arch/mips/include/asm/processor.h | 6 +
arch/mips/include/asm/ptrace.h | 36 +
arch/mips/include/asm/stackframe.h | 150 ++-
arch/mips/include/asm/thread_info.h | 2 +
arch/mips/include/asm/uasm.h | 2 +-
arch/mips/include/uapi/asm/inst.h | 23 +-
arch/mips/include/uapi/asm/ptrace.h | 17 +-
arch/mips/kernel/asm-offsets.c | 124 ++-
arch/mips/kernel/branch.c | 63 +-
arch/mips/kernel/cpu-probe.c | 34 +
arch/mips/kernel/genex.S | 8 +
arch/mips/kernel/scall64-64.S | 12 +
arch/mips/kernel/scall64-n32.S | 12 +
arch/mips/kernel/traps.c | 15 +-
arch/mips/kvm/Kconfig | 23 +-
arch/mips/kvm/Makefile | 15 +-
arch/mips/kvm/kvm_locore.S | 980 +++++++++---------
arch/mips/kvm/kvm_mips.c | 768 ++------------
arch/mips/kvm/kvm_mips_comm.h | 1 +
arch/mips/kvm/kvm_mips_commpage.c | 9 +-
arch/mips/kvm/kvm_mips_dyntrans.c | 4 +-
arch/mips/kvm/kvm_mips_emul.c | 312 +++---
arch/mips/kvm/kvm_mips_int.c | 53 +-
arch/mips/kvm/kvm_mips_int.h | 2 -
arch/mips/kvm/kvm_mips_stats.c | 6 +-
arch/mips/kvm/kvm_mipsvz.c | 1894 +++++++++++++++++++++++++++++++++++
arch/mips/kvm/kvm_mipsvz_guest.S | 234 +++++
arch/mips/kvm/kvm_tlb.c | 140 +--
arch/mips/kvm/kvm_trap_emul.c | 932 +++++++++++++++--
arch/mips/mm/fault.c | 8 +
arch/mips/mm/tlbex-fault.S | 6 +
arch/mips/mm/tlbex.c | 45 +-
39 files changed, 5299 insertions(+), 2161 deletions(-)
create mode 100644 arch/mips/include/asm/kvm_mips_te.h
create mode 100644 arch/mips/include/asm/kvm_mips_vz.h
create mode 100644 arch/mips/kvm/kvm_mipsvz.c
create mode 100644 arch/mips/kvm/kvm_mipsvz_guest.S

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