From: Charlie Jenkins <[email protected]> Introduce a kvm test that uses the emulated test csr to validate that all emulated reads/writes to csrs function as expected.
Signed-off-by: Charlie Jenkins <[email protected]> --- tools/testing/selftests/kvm/Makefile.kvm | 1 + tools/testing/selftests/kvm/riscv/csr_test.c | 123 +++++++++++++++++++++++++++ 2 files changed, 124 insertions(+) diff --git a/tools/testing/selftests/kvm/Makefile.kvm b/tools/testing/selftests/kvm/Makefile.kvm index d402fb339bc0..2eadab48186b 100644 --- a/tools/testing/selftests/kvm/Makefile.kvm +++ b/tools/testing/selftests/kvm/Makefile.kvm @@ -202,6 +202,7 @@ TEST_GEN_PROGS_s390 += s390/user_operexec TEST_GEN_PROGS_s390 += rseq_test TEST_GEN_PROGS_riscv = $(TEST_GEN_PROGS_COMMON) +TEST_GEN_PROGS_riscv += riscv/csr_test TEST_GEN_PROGS_riscv += riscv/sbi_pmu_test TEST_GEN_PROGS_riscv += riscv/ebreak_test TEST_GEN_PROGS_riscv += riscv/mmio_test diff --git a/tools/testing/selftests/kvm/riscv/csr_test.c b/tools/testing/selftests/kvm/riscv/csr_test.c new file mode 100644 index 000000000000..432d043fa1ac --- /dev/null +++ b/tools/testing/selftests/kvm/riscv/csr_test.c @@ -0,0 +1,123 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * csr_test.c - Tests the csr functionality. + */ +#include "kvm_util.h" +#include "ucall_common.h" + +#define CSR_TEST 0x240 +#define FP 0x00006000 + +/* + * Use the fcsr as a U-mode accesible csr and compare against the custom 'test' + * hypervisor csr (currently using vsscratch) + */ +#define test_csr(write, initial, mode) \ +static void test_##write(void) \ +{ \ + unsigned long hypervisor_result, reference_result, old_hypervisor; \ + unsigned long mask = 0x15; \ + asm volatile ( \ + "csrs sstatus, %[enable_fp]\n" \ + "csrw fcsr, %[init]\n" \ + #write" zero, fcsr, %[mask]\n" \ + "csrr %[ref_res], fcsr\n" \ + : [ref_res] "=&r" (reference_result) \ + : [enable_fp] "r" (FP), [mask] #mode(mask), [init] "r" (initial) \ + : "memory" \ + ); \ + asm volatile ( \ + "csrw %[test_csr], %[init]\n" \ + #write" %[old], %[test_csr], %[mask]\n" \ + "csrr %[hyp_res], %[test_csr]\n" \ + : [hyp_res] "=&r" (hypervisor_result), [old] "=&r" (old_hypervisor) \ + : [test_csr] "i"(CSR_TEST), [mask] #mode(mask), [init] "r" (initial) \ + : "memory" \ + ); \ + /* Check that writing works */ \ + GUEST_ASSERT_EQ(reference_result, hypervisor_result); \ + /* Check that reading works */ \ + GUEST_ASSERT_EQ(old_hypervisor, initial); \ + GUEST_DONE(); \ +} + +test_csr(csrrw, 0x0, r) +test_csr(csrrs, 0x0, r) +test_csr(csrrc, 0x15, r) +test_csr(csrrwi, 0x0, i) +test_csr(csrrsi, 0x0, i) +test_csr(csrrci, 0x15, i) + +static void run(void *guest_code, char *instruction) +{ + struct ucall uc; + struct kvm_vm *vm; + struct kvm_vcpu *vcpu; + + vm = vm_create_with_one_vcpu(&vcpu, guest_code); + + kvm_create_device(vm, KVM_DEV_TYPE_TEST); + + vcpu_run(vcpu); + + TEST_ASSERT(get_ucall(vcpu, &uc) == UCALL_DONE, + "CSR instruction '%s' failed: '%s'", instruction, + uc.buffer); + + kvm_vm_free(vm); +} + +static void check_test_csr_guest(void) +{ + unsigned long scause, stvec; + + asm volatile( + "la %[stvec], 1f\n" + "csrw stvec, %[stvec]\n" + "csrwi %[test_csr], 0x0\n" + "1:\n" + "csrr %[scause], scause\n" + : [scause] "=&r" (scause), [stvec] "=&r" (stvec) + : [test_csr] "i" (CSR_TEST) + ); + + /* An illegal instruction will be generated if CONFIG_RISCV_KVM_TEST_CSR is not enabled. */ + if (scause == 2) + GUEST_FAIL("CONFIG_RISCV_KVM_TEST_CSR not enabled.\n"); + GUEST_DONE(); +} + +static int check_test_csr(void) +{ + struct ucall uc; + struct kvm_vm *vm; + struct kvm_vcpu *vcpu; + int success; + + vm = vm_create_with_one_vcpu(&vcpu, check_test_csr_guest); + kvm_create_device(vm, KVM_DEV_TYPE_TEST); + + vcpu_run(vcpu); + + success = get_ucall(vcpu, &uc) == UCALL_DONE; + + kvm_vm_free(vm); + + return success; +} + +int main(void) +{ + /* Skip if CONFIG_RISCV_KVM_TEST_CSR not enabled */ + if (!check_test_csr()) + exit(KSFT_SKIP); + + run(test_csrrw, "csrrw"); + run(test_csrrs, "csrrs"); + run(test_csrrc, "csrrc"); + run(test_csrrwi, "csrrwi"); + run(test_csrrsi, "csrrsi"); + run(test_csrrci, "csrrci"); + + return 0; +} -- 2.52.0
