[v5,0/3] LoongArch: KVM: Add Binary Translation extension support

Message

Bibo Mao July 25, 2024, 3:34 a.m. UTC

Loongson Binary Translation (LBT) is used to accelerate binary
translation, which contains 4 scratch registers (scr0 to scr3), x86/ARM
eflags (eflags) and x87 fpu stack pointer (ftop).

Like FPU extension, here lately enabling method is used for LBT. LBT
context is saved/restored during vcpu context switch path.

Also this patch set LBT capability detection, and LBT register get/set
interface for userspace vmm, so that vm supports migration with BT
extension.

---
v4 ... v5:
  1. Add feature detection for LSX/LASX from vm side, previously
LSX/LASX feature is detected from vcpu ioctl command, now both methods
are supported.

v3 ... v4:
  1. Merge LBT feature detection for VM and VCPU into one patch.
  2. Move function declaration such as kvm_lose_lbt()/kvm_check_fcsr()/
kvm_enable_lbt_fpu() from header file to c file, since it is only
used in one c file.

v2 ... v3:
  1. Split KVM_LOONGARCH_VM_FEAT_LBT capability checking into three
sub-features, KVM_LOONGARCH_VM_FEAT_X86BT/KVM_LOONGARCH_VM_FEAT_ARMBT
and KVM_LOONGARCH_VM_FEAT_MIPSBT. Return success only if host supports
the sub-feature.

v1 ... v2:
  1. With LBT register read or write interface to userpace, replace
device attr method with KVM_GET_ONE_REG method, since lbt register is
vcpu register and can be added in kvm_reg_list in future.
  2. Add vm device attr ctrl marcro KVM_LOONGARCH_VM_FEAT_CTRL, it is
used to get supported LBT feature before vm or vcpu is created.
---

Bibo Mao (3):
  LoongArch: KVM: Add HW Binary Translation extension support
  LoongArch: KVM: Add LBT feature detection function
  LoongArch: KVM: Add vm migration support for LBT registers

 arch/loongarch/include/asm/kvm_host.h |   8 ++
 arch/loongarch/include/asm/kvm_vcpu.h |   6 ++
 arch/loongarch/include/uapi/asm/kvm.h |  17 ++++
 arch/loongarch/kvm/exit.c             |   9 ++
 arch/loongarch/kvm/vcpu.c             | 126 +++++++++++++++++++++++++-
 arch/loongarch/kvm/vm.c               |  52 ++++++++++-
 6 files changed, 216 insertions(+), 2 deletions(-)


base-commit: c33ffdb70cc6df4105160f991288e7d2567d7ffa