[PATCH v2] Support runtime configuration for per-VM's HGATP mode

[fangyu.yu at linux.alibaba.com]

From: Fangyu Yu <fangyu.yu at linux.alibaba.com>

Currently, RISC-V KVM hardcodes the G-stage page table format (HGATP mode)
to the maximum mode detected at boot time (e.g., SV57x4 if supported). but
often such a wide GPA is unnecessary, just as a host sometimes doesn't need
sv57.

This patch introduces per-VM configurability of the G-stage mode via a new
KVM capability: KVM_CAP_RISCV_SET_HGATP_MODE. User-space can now explicitly
request a specific HGATP mode (SV39x4, SV48x4, or SV57x4 on 64-bit) during
VM creation.

Fangyu Yu (2):
  RISC-V: KVM: Support runtime configuration for per-VM's HGATP mode
  RISC-V: KVM: add KVM_CAP_RISCV_SET_HGATP_MODE

 Documentation/virt/kvm/api.rst      | 14 +++++
 arch/riscv/include/asm/kvm_gstage.h | 12 ++---
 arch/riscv/include/asm/kvm_host.h   |  4 ++
 arch/riscv/kvm/gstage.c             | 82 +++++++++++++++++------------
 arch/riscv/kvm/main.c               |  4 +-
 arch/riscv/kvm/mmu.c                | 18 +++++--
 arch/riscv/kvm/vm.c                 | 28 ++++++++--
 arch/riscv/kvm/vmid.c               |  2 +-
 include/uapi/linux/kvm.h            |  1 +
 9 files changed, 113 insertions(+), 52 deletions(-)

-- 
2.50.1