This series implements the “KVM Guset Debug” feature on RISC-V. This is an existing feature which is already supported by some other arches. It allows us to debug a RISC-V KVM guest from GDB in host side. As the first stage, the software breakpoints (ebreak instruction) is implemented. HW breakpoints support will come later after a synthetically consideration with the SBI debug trigger extension. A selftest case was added in this series. Manual test was done on QEMU RISC-V hypervisor emulator. (add '-s' to enable the gdbserver in QEMU) This series is based on Linux 6.8-rc6 and also available at: https://github.com/Du-Chao/kvm-riscv/tree/guest_debug_sw_v2 The matched QEMU is available at: https://github.com/Du-Chao/qemu/tree/riscv_gd_sw Please note that if Paolo's change https://lore.kernel.org/kvm/20240131233056.10845-8-pbonzini@xxxxxxxxxx/ is adopted, then we can keep 'arch/riscv/include/uapi/asm/kvm.h' untouched. Changes from v1->v2: - Rebased on Linux 6.8-rc6. - Maintain a hedeleg in "struct kvm_vcpu_config" for each VCPU. - Update the HEDELEG csr in kvm_arch_vcpu_load(). Changes from RFC->v1: - Rebased on Linux 6.8-rc2. - Merge PATCH1 and PATCH2 into one patch. - kselftest case added. v1 link: https://lore.kernel.org/kvm/20240206074931.22930-1-duchao@xxxxxxxxxxxxxxxxxx RFC link: https://lore.kernel.org/kvm/20231221095002.7404-1-duchao@xxxxxxxxxxxxxxxxxx Chao Du (3): RISC-V: KVM: Implement kvm_arch_vcpu_ioctl_set_guest_debug() RISC-V: KVM: Handle breakpoint exits for VCPU RISC-V: KVM: selftests: Add breakpoints test support arch/riscv/include/asm/kvm_host.h | 17 +++++++ arch/riscv/include/uapi/asm/kvm.h | 1 + arch/riscv/kvm/main.c | 18 +------ arch/riscv/kvm/vcpu.c | 15 +++++- arch/riscv/kvm/vcpu_exit.c | 4 ++ arch/riscv/kvm/vm.c | 1 + tools/testing/selftests/kvm/Makefile | 1 + .../testing/selftests/kvm/riscv/breakpoints.c | 49 +++++++++++++++++++ 8 files changed, 88 insertions(+), 18 deletions(-) create mode 100644 tools/testing/selftests/kvm/riscv/breakpoints.c -- 2.17.1
