This patchset primarily adds guest Floating Point Unit (FPU) and MIPS
SIMD Architecture (MSA) support to MIPS KVM, by enabling the host
FPU/MSA while in guest mode.
This patchset depends on Paul Burton's FP/MSA fixes patchset, which will
hopefully make it into 4.0. I'd like to get this into 4.1, so all review
comments welcome. Corresponding QEMU patches will follow soon.
- Adds KVM_CAP_MIPS_FPU and KVM_CAP_MIPS_MSA capabilities which must be
enabled to add FPU/MSA to the guest.
- Supports FR=0, FR=1, FRE=1 floating point register modes and 128-bit
vector registers.
- Does not support UFR/UFE (guest user control of FR/FRE bits), or MSA
vector partitioning.
- Context restore is lazy: done on first actual use.
- Context save is lazy: once restored, host FPU/MSA gets
enabled/disabled when guest enables/disables it, with registers left
loaded as long as possible.
- So the state that can be loaded at any one time is:
- No FPRs/vector state
- FR=0 FPRs (change of FR discards FP state)
- FR=1 FPRs
- Vector state (includes FR=1 FPRs)
- Vector state only (when guest CU1=0, FR=0)
- FCSR/MSACSR status registers are saved/restored around guest
execution, since care must be taken to handle FP exceptions when
writing these registers.
The patches are arranged roughly in groups:
- Patch 1 is a related minimal stable fix which can be applied in
advance of the others (patch 18 fills it out a bit).
- Patch 2 is a generic MIPS change required to be able to restore
FCSR/MSACSR registers with exceptions pending.
- Patches 3..10 add various misc KVM improvements and cleanups, most of
which the later patches depend on.
- Patches 11..15 add the main guest FPU support.
- Patches 16..20 add the main guest MSA support (structured like 11.15).
James Hogan (20):
MIPS: KVM: Handle MSA Disabled exceptions from guest
MIPS: Clear [MSA]FPE CSR.Cause after notify_die()
MIPS: KVM: Handle TRAP exceptions from guest kernel
MIPS: KVM: Implement PRid CP0 register access
MIPS: KVM: Sort kvm_mips_get_reg() registers
MIPS: KVM: Drop pr_info messages on init/exit
MIPS: KVM: Clean up register definitions a little
MIPS: KVM: Simplify default guest Config registers
MIPS: KVM: Add Config4/5 and writing of Config registers
MIPS: KVM: Add vcpu_get_regs/vcpu_set_regs callback
MIPS: KVM: Add base guest FPU support
MIPS: KVM: Emulate FPU bits in COP0 interface
MIPS: KVM: Add FP exception handling
MIPS: KVM: Expose FPU registers
MIPS: KVM: Wire up FPU capability
MIPS: KVM: Add base guest MSA support
MIPS: KVM: Emulate MSA bits in COP0 interface
MIPS: KVM: Add MSA exception handling
MIPS: KVM: Expose MSA registers
MIPS: KVM: Wire up MSA capability
Documentation/virtual/kvm/api.txt | 47 ++++
arch/mips/include/asm/kdebug.h | 3 +-
arch/mips/include/asm/kvm_host.h | 125 +++++++---
arch/mips/include/uapi/asm/kvm.h | 160 ++++++++-----
arch/mips/kernel/asm-offsets.c | 39 ++++
arch/mips/kernel/genex.S | 14 +-
arch/mips/kernel/traps.c | 16 +-
arch/mips/kvm/Makefile | 8 +-
arch/mips/kvm/emulate.c | 332 +++++++++++++++++++++++++-
arch/mips/kvm/fpu.S | 122 ++++++++++
arch/mips/kvm/locore.S | 38 +++
arch/mips/kvm/mips.c | 478 +++++++++++++++++++++++++++++++++++++-
arch/mips/kvm/msa.S | 161 +++++++++++++
arch/mips/kvm/stats.c | 4 +
arch/mips/kvm/tlb.c | 6 +
arch/mips/kvm/trap_emul.c | 199 +++++++++++++++-
include/uapi/linux/kvm.h | 2 +
17 files changed, 1630 insertions(+), 124 deletions(-)
create mode 100644 arch/mips/kvm/fpu.S
create mode 100644 arch/mips/kvm/msa.S
Cc: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Cc: Paul Burton <paul.burton@xxxxxxxxxx>
Cc: Ralf Baechle <ralf@xxxxxxxxxxxxxx>
Cc: Gleb Natapov <gleb@xxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: linux-mips@xxxxxxxxxxxxxx
Cc: kvm@xxxxxxxxxxxxxxx
Cc: linux-api@xxxxxxxxxxxxxxx
Cc: linux-doc@xxxxxxxxxxxxxxx
--
2.0.5
