1 files changed, 330 insertions, 0 deletions
diff --git a/tools/testing/selftests/kvm/arm64/external_aborts.c b/tools/testing/selftests/kvm/arm64/external_aborts.c
new file mode 100644
index 000000000000..062bf84cced1
--- /dev/null
+++ b/tools/testing/selftests/kvm/arm64/external_aborts.c
@@ -0,0 +1,330 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * external_abort - Tests for userspace external abort injection
+ *
+ * Copyright (c) 2024 Google LLC
+ */
+#include "processor.h"
+#include "test_util.h"
+
+#define MMIO_ADDR		0x8000000ULL
+#define EXPECTED_SERROR_ISS	(ESR_ELx_ISV | 0x1d1ed)
+
+static u64 expected_abort_pc;
+
+static void expect_sea_handler(struct ex_regs *regs)
+{
+	u64 esr = read_sysreg(esr_el1);
+
+	GUEST_ASSERT_EQ(regs->pc, expected_abort_pc);
+	GUEST_ASSERT_EQ(ESR_ELx_EC(esr), ESR_ELx_EC_DABT_CUR);
+	GUEST_ASSERT_EQ(esr & ESR_ELx_FSC_TYPE, ESR_ELx_FSC_EXTABT);
+
+	GUEST_DONE();
+}
+
+static void unexpected_dabt_handler(struct ex_regs *regs)
+{
+	GUEST_FAIL("Unexpected data abort at PC: %lx\n", regs->pc);
+}
+
+static struct kvm_vm *vm_create_with_dabt_handler(struct kvm_vcpu **vcpu, void *guest_code,
+						  handler_fn dabt_handler)
+{
+	struct kvm_vm *vm = vm_create_with_one_vcpu(vcpu, guest_code);
+
+	vm_init_descriptor_tables(vm);
+	vcpu_init_descriptor_tables(*vcpu);
+	vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT, ESR_ELx_EC_DABT_CUR, dabt_handler);
+
+	virt_map(vm, MMIO_ADDR, MMIO_ADDR, 1);
+
+	return vm;
+}
+
+static void vcpu_inject_sea(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_events events = {};
+
+	events.exception.ext_dabt_pending = true;
+	vcpu_events_set(vcpu, &events);
+}
+
+static bool vcpu_has_ras(struct kvm_vcpu *vcpu)
+{
+	u64 pfr0 = vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64PFR0_EL1));
+
+	return SYS_FIELD_GET(ID_AA64PFR0_EL1, RAS, pfr0);
+}
+
+static bool guest_has_ras(void)
+{
+	return SYS_FIELD_GET(ID_AA64PFR0_EL1, RAS, read_sysreg(id_aa64pfr0_el1));
+}
+
+static void vcpu_inject_serror(struct kvm_vcpu *vcpu)
+{
+	struct kvm_vcpu_events events = {};
+
+	events.exception.serror_pending = true;
+	if (vcpu_has_ras(vcpu)) {
+		events.exception.serror_has_esr = true;
+		events.exception.serror_esr = EXPECTED_SERROR_ISS;
+	}
+
+	vcpu_events_set(vcpu, &events);
+}
+
+static void __vcpu_run_expect(struct kvm_vcpu *vcpu, unsigned int cmd)
+{
+	struct ucall uc;
+
+	vcpu_run(vcpu);
+	switch (get_ucall(vcpu, &uc)) {
+	case UCALL_ABORT:
+		REPORT_GUEST_ASSERT(uc);
+		break;
+	default:
+		if (uc.cmd == cmd)
+			return;
+
+		TEST_FAIL("Unexpected ucall: %lu", uc.cmd);
+	}
+}
+
+static void vcpu_run_expect_done(struct kvm_vcpu *vcpu)
+{
+	__vcpu_run_expect(vcpu, UCALL_DONE);
+}
+
+static void vcpu_run_expect_sync(struct kvm_vcpu *vcpu)
+{
+	__vcpu_run_expect(vcpu, UCALL_SYNC);
+}
+
+extern char test_mmio_abort_insn;
+
+static noinline void test_mmio_abort_guest(void)
+{
+	WRITE_ONCE(expected_abort_pc, (u64)&test_mmio_abort_insn);
+
+	asm volatile("test_mmio_abort_insn:\n\t"
+		     "ldr x0, [%0]\n\t"
+		     : : "r" (MMIO_ADDR) : "x0", "memory");
+
+	GUEST_FAIL("MMIO instruction should not retire");
+}
+
+/*
+ * Test that KVM doesn't complete MMIO emulation when userspace has made an
+ * external abort pending for the instruction.
+ */
+static void test_mmio_abort(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm = vm_create_with_dabt_handler(&vcpu, test_mmio_abort_guest,
+							expect_sea_handler);
+	struct kvm_run *run = vcpu->run;
+
+	vcpu_run(vcpu);
+	TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_MMIO);
+	TEST_ASSERT_EQ(run->mmio.phys_addr, MMIO_ADDR);
+	TEST_ASSERT_EQ(run->mmio.len, sizeof(unsigned long));
+	TEST_ASSERT(!run->mmio.is_write, "Expected MMIO read");
+
+	vcpu_inject_sea(vcpu);
+	vcpu_run_expect_done(vcpu);
+	kvm_vm_free(vm);
+}
+
+extern char test_mmio_nisv_insn;
+
+static void test_mmio_nisv_guest(void)
+{
+	WRITE_ONCE(expected_abort_pc, (u64)&test_mmio_nisv_insn);
+
+	asm volatile("test_mmio_nisv_insn:\n\t"
+		     "ldr x0, [%0], #8\n\t"
+		     : : "r" (MMIO_ADDR) : "x0", "memory");
+
+	GUEST_FAIL("MMIO instruction should not retire");
+}
+
+/*
+ * Test that the KVM_RUN ioctl fails for ESR_EL2.ISV=0 MMIO aborts if userspace
+ * hasn't enabled KVM_CAP_ARM_NISV_TO_USER.
+ */
+static void test_mmio_nisv(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm = vm_create_with_dabt_handler(&vcpu, test_mmio_nisv_guest,
+							unexpected_dabt_handler);
+
+	TEST_ASSERT(_vcpu_run(vcpu), "Expected nonzero return code from KVM_RUN");
+	TEST_ASSERT_EQ(errno, ENOSYS);
+
+	kvm_vm_free(vm);
+}
+
+/*
+ * Test that ESR_EL2.ISV=0 MMIO aborts reach userspace and that an injected SEA
+ * reaches the guest.
+ */
+static void test_mmio_nisv_abort(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm = vm_create_with_dabt_handler(&vcpu, test_mmio_nisv_guest,
+							expect_sea_handler);
+	struct kvm_run *run = vcpu->run;
+
+	vm_enable_cap(vm, KVM_CAP_ARM_NISV_TO_USER, 1);
+
+	vcpu_run(vcpu);
+	TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_ARM_NISV);
+	TEST_ASSERT_EQ(run->arm_nisv.fault_ipa, MMIO_ADDR);
+
+	vcpu_inject_sea(vcpu);
+	vcpu_run_expect_done(vcpu);
+	kvm_vm_free(vm);
+}
+
+static void unexpected_serror_handler(struct ex_regs *regs)
+{
+	GUEST_FAIL("Took unexpected SError exception");
+}
+
+static void test_serror_masked_guest(void)
+{
+	GUEST_ASSERT(read_sysreg(isr_el1) & ISR_EL1_A);
+
+	isb();
+
+	GUEST_DONE();
+}
+
+static void test_serror_masked(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm = vm_create_with_dabt_handler(&vcpu, test_serror_masked_guest,
+							unexpected_dabt_handler);
+
+	vm_install_exception_handler(vm, VECTOR_ERROR_CURRENT, unexpected_serror_handler);
+
+	vcpu_inject_serror(vcpu);
+	vcpu_run_expect_done(vcpu);
+	kvm_vm_free(vm);
+}
+
+static void expect_serror_handler(struct ex_regs *regs)
+{
+	u64 esr = read_sysreg(esr_el1);
+
+	GUEST_ASSERT_EQ(ESR_ELx_EC(esr), ESR_ELx_EC_SERROR);
+	if (guest_has_ras())
+		GUEST_ASSERT_EQ(ESR_ELx_ISS(esr), EXPECTED_SERROR_ISS);
+
+	GUEST_DONE();
+}
+
+static void test_serror_guest(void)
+{
+	GUEST_ASSERT(read_sysreg(isr_el1) & ISR_EL1_A);
+
+	local_serror_enable();
+	isb();
+	local_serror_disable();
+
+	GUEST_FAIL("Should've taken pending SError exception");
+}
+
+static void test_serror(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm = vm_create_with_dabt_handler(&vcpu, test_serror_guest,
+							unexpected_dabt_handler);
+
+	vm_install_exception_handler(vm, VECTOR_ERROR_CURRENT, expect_serror_handler);
+
+	vcpu_inject_serror(vcpu);
+	vcpu_run_expect_done(vcpu);
+	kvm_vm_free(vm);
+}
+
+static void test_serror_emulated_guest(void)
+{
+	GUEST_ASSERT(!(read_sysreg(isr_el1) & ISR_EL1_A));
+
+	local_serror_enable();
+	GUEST_SYNC(0);
+	local_serror_disable();
+
+	GUEST_FAIL("Should've taken unmasked SError exception");
+}
+
+static void test_serror_emulated(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm = vm_create_with_dabt_handler(&vcpu, test_serror_emulated_guest,
+							unexpected_dabt_handler);
+
+	vm_install_exception_handler(vm, VECTOR_ERROR_CURRENT, expect_serror_handler);
+
+	vcpu_run_expect_sync(vcpu);
+	vcpu_inject_serror(vcpu);
+	vcpu_run_expect_done(vcpu);
+	kvm_vm_free(vm);
+}
+
+static void test_mmio_ease_guest(void)
+{
+	sysreg_clear_set_s(SYS_SCTLR2_EL1, 0, SCTLR2_EL1_EASE);
+	isb();
+
+	test_mmio_abort_guest();
+}
+
+/*
+ * Test that KVM doesn't complete MMIO emulation when userspace has made an
+ * external abort pending for the instruction.
+ */
+static void test_mmio_ease(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm = vm_create_with_dabt_handler(&vcpu, test_mmio_ease_guest,
+							unexpected_dabt_handler);
+	struct kvm_run *run = vcpu->run;
+	u64 pfr1;
+
+	pfr1 = vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64PFR1_EL1));
+	if (!SYS_FIELD_GET(ID_AA64PFR1_EL1, DF2, pfr1)) {
+		pr_debug("Skipping %s\n", __func__);
+		return;
+	}
+
+	/*
+	 * SCTLR2_ELx.EASE changes the exception vector to the SError vector but
+	 * doesn't further modify the exception context (e.g. ESR_ELx, FAR_ELx).
+	 */
+	vm_install_exception_handler(vm, VECTOR_ERROR_CURRENT, expect_sea_handler);
+
+	vcpu_run(vcpu);
+	TEST_ASSERT_KVM_EXIT_REASON(vcpu, KVM_EXIT_MMIO);
+	TEST_ASSERT_EQ(run->mmio.phys_addr, MMIO_ADDR);
+	TEST_ASSERT_EQ(run->mmio.len, sizeof(unsigned long));
+	TEST_ASSERT(!run->mmio.is_write, "Expected MMIO read");
+
+	vcpu_inject_sea(vcpu);
+	vcpu_run_expect_done(vcpu);
+	kvm_vm_free(vm);
+}
+
+int main(void)
+{
+	test_mmio_abort();
+	test_mmio_nisv();
+	test_mmio_nisv_abort();
+	test_serror();
+	test_serror_masked();
+	test_serror_emulated();
+	test_mmio_ease();
+}