From f1c48c1ec73538a8e49695445a0fbc52156aac42 Mon Sep 17 00:00:00 2001 From: Chao Du Date: Tue, 2 Apr 2024 06:26:28 +0000 Subject: [PATCH] RISC-V: KVM: selftests: Add ebreak test support Initial support for RISC-V KVM ebreak test. Check the exit reason and the PC when guest debug is enabled. Also to make sure the guest could handle the ebreak exception without exiting to the VMM when guest debug is not enabled. Signed-off-by: Chao Du Reviewed-by: Andrew Jones Link: https://lore.kernel.org/r/20240402062628.5425-4-duchao@eswincomputing.com Signed-off-by: Anup Patel --- tools/testing/selftests/kvm/Makefile | 1 + .../testing/selftests/kvm/riscv/ebreak_test.c | 82 +++++++++++++++++++ 2 files changed, 83 insertions(+) create mode 100644 tools/testing/selftests/kvm/riscv/ebreak_test.c diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile index 741c7dc16afc7..7f4430242c9eb 100644 --- a/tools/testing/selftests/kvm/Makefile +++ b/tools/testing/selftests/kvm/Makefile @@ -189,6 +189,7 @@ TEST_GEN_PROGS_s390x += rseq_test TEST_GEN_PROGS_s390x += set_memory_region_test TEST_GEN_PROGS_s390x += kvm_binary_stats_test +TEST_GEN_PROGS_riscv += riscv/ebreak_test TEST_GEN_PROGS_riscv += arch_timer TEST_GEN_PROGS_riscv += demand_paging_test TEST_GEN_PROGS_riscv += dirty_log_test diff --git a/tools/testing/selftests/kvm/riscv/ebreak_test.c b/tools/testing/selftests/kvm/riscv/ebreak_test.c new file mode 100644 index 0000000000000..823c132069b46 --- /dev/null +++ b/tools/testing/selftests/kvm/riscv/ebreak_test.c @@ -0,0 +1,82 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * RISC-V KVM ebreak test. + * + * Copyright 2024 Beijing ESWIN Computing Technology Co., Ltd. + * + */ +#include "kvm_util.h" + +#define LABEL_ADDRESS(v) ((uint64_t)&(v)) + +extern unsigned char sw_bp_1, sw_bp_2; +static uint64_t sw_bp_addr; + +static void guest_code(void) +{ + asm volatile( + ".option push\n" + ".option norvc\n" + "sw_bp_1: ebreak\n" + "sw_bp_2: ebreak\n" + ".option pop\n" + ); + GUEST_ASSERT_EQ(READ_ONCE(sw_bp_addr), LABEL_ADDRESS(sw_bp_2)); + + GUEST_DONE(); +} + +static void guest_breakpoint_handler(struct ex_regs *regs) +{ + WRITE_ONCE(sw_bp_addr, regs->epc); + regs->epc += 4; +} + +int main(void) +{ + struct kvm_vm *vm; + struct kvm_vcpu *vcpu; + uint64_t pc; + struct kvm_guest_debug debug = { + .control = KVM_GUESTDBG_ENABLE, + }; + + TEST_REQUIRE(kvm_has_cap(KVM_CAP_SET_GUEST_DEBUG)); + + vm = vm_create_with_one_vcpu(&vcpu, guest_code); + + vm_init_vector_tables(vm); + vcpu_init_vector_tables(vcpu); + vm_install_exception_handler(vm, EXC_BREAKPOINT, + guest_breakpoint_handler); + + /* + * Enable the guest debug. + * ebreak should exit to the VMM with KVM_EXIT_DEBUG reason. + */ + vcpu_guest_debug_set(vcpu, &debug); + vcpu_run(vcpu); + + TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_DEBUG); + + vcpu_get_reg(vcpu, RISCV_CORE_REG(regs.pc), &pc); + TEST_ASSERT_EQ(pc, LABEL_ADDRESS(sw_bp_1)); + + /* skip sw_bp_1 */ + vcpu_set_reg(vcpu, RISCV_CORE_REG(regs.pc), pc + 4); + + /* + * Disable all debug controls. + * Guest should handle the ebreak without exiting to the VMM. + */ + memset(&debug, 0, sizeof(debug)); + vcpu_guest_debug_set(vcpu, &debug); + + vcpu_run(vcpu); + + TEST_ASSERT_EQ(get_ucall(vcpu, NULL), UCALL_DONE); + + kvm_vm_free(vm); + + return 0; +} -- 2.30.2