[PATCH v2 0/3] KVM: riscv: Add KVM_PRE_FAULT_MEMORY support

[Jinyu Tang]

This series adds RISC-V support for the generic KVM_PRE_FAULT_MEMORY
vcpu ioctl and enables the existing generic KVM selftest for RISC-V.

KVM_PRE_FAULT_MEMORY lets userspace ask KVM to populate stage-2 mappings
for a GPA range before running a vCPU that is expected to access that
range.  x86 already supports the ioctl; RISC-V currently falls back to
normal first-touch G-stage faults.

Patch 1 implements the RISC-V arch hook using the existing G-stage map
path.  Patch 2 fixes the RISC-V selftest page-table walker for Sv57,
which can be selected as the default guest mode.  Patch 3 enables
pre_fault_memory_test for RISC-V.

Tested with pre_fault_memory_test on a RISC-V KVM host.

Changes in v2:
- Drop the per-test guest_modes_append_default() call from
  pre_fault_memory_test.c.  RISC-V already initializes supported and
  default guest modes from kvm_selftest_arch_init(), which is called by
  the common kvm_selftest_init() constructor, as suggested by Sean.

Jinyu Tang (3):
  KVM: riscv: Implement KVM_PRE_FAULT_MEMORY
  KVM: selftests: Add RISC-V Sv57 page table indexing
  KVM: selftests: Enable pre_fault_memory_test for RISC-V

 arch/riscv/kvm/Kconfig                        |  1 +
 arch/riscv/kvm/gstage.c                       |  3 ++
 arch/riscv/kvm/mmu.c                          | 33 +++++++++++++++++++
 arch/riscv/kvm/vm.c                           |  1 +
 tools/testing/selftests/kvm/Makefile.kvm      |  1 +
 .../selftests/kvm/include/riscv/processor.h   |  6 ++++
 .../selftests/kvm/lib/riscv/processor.c       |  2 ++
 7 files changed, 47 insertions(+)

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2.43.0