Merge tag 'kvmarm-6.1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD

KVM/arm64 updates for v6.1

- Fixes for single-stepping in the presence of an async
  exception as well as the preservation of PSTATE.SS

- Better handling of AArch32 ID registers on AArch64-only
  systems

- Fixes for the dirty-ring API, allowing it to work on
  architectures with relaxed memory ordering

- Advertise the new kvmarm mailing list

- Various minor cleanups and spelling fixes

7 files changed, 331 insertions, 12 deletions

diff --git a/tools/testing/selftests/kvm/.gitignore b/tools/testing/selftests/kvm/.gitignore
index 45d9aee1c0d8..2f0d705db9db 100644
--- a/tools/testing/selftests/kvm/.gitignore
+++ b/tools/testing/selftests/kvm/.gitignore
@@ -1,4 +1,5 @@
 # SPDX-License-Identifier: GPL-2.0-only
+/aarch64/aarch32_id_regs
 /aarch64/arch_timer
 /aarch64/debug-exceptions
 /aarch64/get-reg-list
diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index fde3ae8cfa4c..0172eb6cb6ee 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -147,6 +147,7 @@ TEST_GEN_PROGS_x86_64 += system_counter_offset_test
 # Compiled outputs used by test targets
 TEST_GEN_PROGS_EXTENDED_x86_64 += x86_64/nx_huge_pages_test
 
+TEST_GEN_PROGS_aarch64 += aarch64/aarch32_id_regs
 TEST_GEN_PROGS_aarch64 += aarch64/arch_timer
 TEST_GEN_PROGS_aarch64 += aarch64/debug-exceptions
 TEST_GEN_PROGS_aarch64 += aarch64/get-reg-list
diff --git a/tools/testing/selftests/kvm/aarch64/aarch32_id_regs.c b/tools/testing/selftests/kvm/aarch64/aarch32_id_regs.c
new file mode 100644
index 000000000000..6f9c1f19c7f6
--- /dev/null
+++ b/tools/testing/selftests/kvm/aarch64/aarch32_id_regs.c
@@ -0,0 +1,169 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * aarch32_id_regs - Test for ID register behavior on AArch64-only systems
+ *
+ * Copyright (c) 2022 Google LLC.
+ *
+ * Test that KVM handles the AArch64 views of the AArch32 ID registers as RAZ
+ * and WI from userspace.
+ */
+
+#include <stdint.h>
+
+#include "kvm_util.h"
+#include "processor.h"
+#include "test_util.h"
+
+#define BAD_ID_REG_VAL	0x1badc0deul
+
+#define GUEST_ASSERT_REG_RAZ(reg)	GUEST_ASSERT_EQ(read_sysreg_s(reg), 0)
+
+static void guest_main(void)
+{
+	GUEST_ASSERT_REG_RAZ(SYS_ID_PFR0_EL1);
+	GUEST_ASSERT_REG_RAZ(SYS_ID_PFR1_EL1);
+	GUEST_ASSERT_REG_RAZ(SYS_ID_DFR0_EL1);
+	GUEST_ASSERT_REG_RAZ(SYS_ID_AFR0_EL1);
+	GUEST_ASSERT_REG_RAZ(SYS_ID_MMFR0_EL1);
+	GUEST_ASSERT_REG_RAZ(SYS_ID_MMFR1_EL1);
+	GUEST_ASSERT_REG_RAZ(SYS_ID_MMFR2_EL1);
+	GUEST_ASSERT_REG_RAZ(SYS_ID_MMFR3_EL1);
+	GUEST_ASSERT_REG_RAZ(SYS_ID_ISAR0_EL1);
+	GUEST_ASSERT_REG_RAZ(SYS_ID_ISAR1_EL1);
+	GUEST_ASSERT_REG_RAZ(SYS_ID_ISAR2_EL1);
+	GUEST_ASSERT_REG_RAZ(SYS_ID_ISAR3_EL1);
+	GUEST_ASSERT_REG_RAZ(SYS_ID_ISAR4_EL1);
+	GUEST_ASSERT_REG_RAZ(SYS_ID_ISAR5_EL1);
+	GUEST_ASSERT_REG_RAZ(SYS_ID_MMFR4_EL1);
+	GUEST_ASSERT_REG_RAZ(SYS_ID_ISAR6_EL1);
+	GUEST_ASSERT_REG_RAZ(SYS_MVFR0_EL1);
+	GUEST_ASSERT_REG_RAZ(SYS_MVFR1_EL1);
+	GUEST_ASSERT_REG_RAZ(SYS_MVFR2_EL1);
+	GUEST_ASSERT_REG_RAZ(sys_reg(3, 0, 0, 3, 3));
+	GUEST_ASSERT_REG_RAZ(SYS_ID_PFR2_EL1);
+	GUEST_ASSERT_REG_RAZ(SYS_ID_DFR1_EL1);
+	GUEST_ASSERT_REG_RAZ(SYS_ID_MMFR5_EL1);
+	GUEST_ASSERT_REG_RAZ(sys_reg(3, 0, 0, 3, 7));
+
+	GUEST_DONE();
+}
+
+static void test_guest_raz(struct kvm_vcpu *vcpu)
+{
+	struct ucall uc;
+
+	vcpu_run(vcpu);
+
+	switch (get_ucall(vcpu, &uc)) {
+	case UCALL_ABORT:
+		REPORT_GUEST_ASSERT(uc);
+		break;
+	case UCALL_DONE:
+		break;
+	default:
+		TEST_FAIL("Unexpected ucall: %lu", uc.cmd);
+	}
+}
+
+static uint64_t raz_wi_reg_ids[] = {
+	KVM_ARM64_SYS_REG(SYS_ID_PFR0_EL1),
+	KVM_ARM64_SYS_REG(SYS_ID_PFR1_EL1),
+	KVM_ARM64_SYS_REG(SYS_ID_DFR0_EL1),
+	KVM_ARM64_SYS_REG(SYS_ID_MMFR0_EL1),
+	KVM_ARM64_SYS_REG(SYS_ID_MMFR1_EL1),
+	KVM_ARM64_SYS_REG(SYS_ID_MMFR2_EL1),
+	KVM_ARM64_SYS_REG(SYS_ID_MMFR3_EL1),
+	KVM_ARM64_SYS_REG(SYS_ID_ISAR0_EL1),
+	KVM_ARM64_SYS_REG(SYS_ID_ISAR1_EL1),
+	KVM_ARM64_SYS_REG(SYS_ID_ISAR2_EL1),
+	KVM_ARM64_SYS_REG(SYS_ID_ISAR3_EL1),
+	KVM_ARM64_SYS_REG(SYS_ID_ISAR4_EL1),
+	KVM_ARM64_SYS_REG(SYS_ID_ISAR5_EL1),
+	KVM_ARM64_SYS_REG(SYS_ID_MMFR4_EL1),
+	KVM_ARM64_SYS_REG(SYS_ID_ISAR6_EL1),
+	KVM_ARM64_SYS_REG(SYS_MVFR0_EL1),
+	KVM_ARM64_SYS_REG(SYS_MVFR1_EL1),
+	KVM_ARM64_SYS_REG(SYS_MVFR2_EL1),
+	KVM_ARM64_SYS_REG(SYS_ID_PFR2_EL1),
+	KVM_ARM64_SYS_REG(SYS_ID_MMFR5_EL1),
+};
+
+static void test_user_raz_wi(struct kvm_vcpu *vcpu)
+{
+	int i;
+
+	for (i = 0; i < ARRAY_SIZE(raz_wi_reg_ids); i++) {
+		uint64_t reg_id = raz_wi_reg_ids[i];
+		uint64_t val;
+
+		vcpu_get_reg(vcpu, reg_id, &val);
+		ASSERT_EQ(val, 0);
+
+		/*
+		 * Expect the ioctl to succeed with no effect on the register
+		 * value.
+		 */
+		vcpu_set_reg(vcpu, reg_id, BAD_ID_REG_VAL);
+
+		vcpu_get_reg(vcpu, reg_id, &val);
+		ASSERT_EQ(val, 0);
+	}
+}
+
+static uint64_t raz_invariant_reg_ids[] = {
+	KVM_ARM64_SYS_REG(SYS_ID_AFR0_EL1),
+	KVM_ARM64_SYS_REG(sys_reg(3, 0, 0, 3, 3)),
+	KVM_ARM64_SYS_REG(SYS_ID_DFR1_EL1),
+	KVM_ARM64_SYS_REG(sys_reg(3, 0, 0, 3, 7)),
+};
+
+static void test_user_raz_invariant(struct kvm_vcpu *vcpu)
+{
+	int i, r;
+
+	for (i = 0; i < ARRAY_SIZE(raz_invariant_reg_ids); i++) {
+		uint64_t reg_id = raz_invariant_reg_ids[i];
+		uint64_t val;
+
+		vcpu_get_reg(vcpu, reg_id, &val);
+		ASSERT_EQ(val, 0);
+
+		r = __vcpu_set_reg(vcpu, reg_id, BAD_ID_REG_VAL);
+		TEST_ASSERT(r < 0 && errno == EINVAL,
+			    "unexpected KVM_SET_ONE_REG error: r=%d, errno=%d", r, errno);
+
+		vcpu_get_reg(vcpu, reg_id, &val);
+		ASSERT_EQ(val, 0);
+	}
+}
+
+
+
+static bool vcpu_aarch64_only(struct kvm_vcpu *vcpu)
+{
+	uint64_t val, el0;
+
+	vcpu_get_reg(vcpu, KVM_ARM64_SYS_REG(SYS_ID_AA64PFR0_EL1), &val);
+
+	el0 = (val & ARM64_FEATURE_MASK(ID_AA64PFR0_EL0)) >> ID_AA64PFR0_EL0_SHIFT;
+	return el0 == ID_AA64PFR0_ELx_64BIT_ONLY;
+}
+
+int main(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+
+	vm = vm_create_with_one_vcpu(&vcpu, guest_main);
+
+	TEST_REQUIRE(vcpu_aarch64_only(vcpu));
+
+	ucall_init(vm, NULL);
+
+	test_user_raz_wi(vcpu);
+	test_user_raz_invariant(vcpu);
+	test_guest_raz(vcpu);
+
+	ucall_uninit(vm);
+	kvm_vm_free(vm);
+}
diff --git a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
index 2ee35cf9801e..947bd201435c 100644
--- a/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
+++ b/tools/testing/selftests/kvm/aarch64/debug-exceptions.c
@@ -22,6 +22,7 @@
 #define SPSR_SS		(1 << 21)
 
 extern unsigned char sw_bp, sw_bp2, hw_bp, hw_bp2, bp_svc, bp_brk, hw_wp, ss_start;
+extern unsigned char iter_ss_begin, iter_ss_end;
 static volatile uint64_t sw_bp_addr, hw_bp_addr;
 static volatile uint64_t wp_addr, wp_data_addr;
 static volatile uint64_t svc_addr;
@@ -238,6 +239,46 @@ static void guest_svc_handler(struct ex_regs *regs)
 	svc_addr = regs->pc;
 }
 
+enum single_step_op {
+	SINGLE_STEP_ENABLE = 0,
+	SINGLE_STEP_DISABLE = 1,
+};
+
+static void guest_code_ss(int test_cnt)
+{
+	uint64_t i;
+	uint64_t bvr, wvr, w_bvr, w_wvr;
+
+	for (i = 0; i < test_cnt; i++) {
+		/* Bits [1:0] of dbg{b,w}vr are RES0 */
+		w_bvr = i << 2;
+		w_wvr = i << 2;
+
+		/* Enable Single Step execution */
+		GUEST_SYNC(SINGLE_STEP_ENABLE);
+
+		/*
+		 * The userspace will veriry that the pc is as expected during
+		 * single step execution between iter_ss_begin and iter_ss_end.
+		 */
+		asm volatile("iter_ss_begin:nop\n");
+
+		write_sysreg(w_bvr, dbgbvr0_el1);
+		write_sysreg(w_wvr, dbgwvr0_el1);
+		bvr = read_sysreg(dbgbvr0_el1);
+		wvr = read_sysreg(dbgwvr0_el1);
+
+		asm volatile("iter_ss_end:\n");
+
+		/* Disable Single Step execution */
+		GUEST_SYNC(SINGLE_STEP_DISABLE);
+
+		GUEST_ASSERT(bvr == w_bvr);
+		GUEST_ASSERT(wvr == w_wvr);
+	}
+	GUEST_DONE();
+}
+
 static int debug_version(struct kvm_vcpu *vcpu)
 {
 	uint64_t id_aa64dfr0;
@@ -246,7 +287,7 @@ static int debug_version(struct kvm_vcpu *vcpu)
 	return id_aa64dfr0 & 0xf;
 }
 
-int main(int argc, char *argv[])
+static void test_guest_debug_exceptions(void)
 {
 	struct kvm_vcpu *vcpu;
 	struct kvm_vm *vm;
@@ -259,9 +300,6 @@ int main(int argc, char *argv[])
 	vm_init_descriptor_tables(vm);
 	vcpu_init_descriptor_tables(vcpu);
 
-	__TEST_REQUIRE(debug_version(vcpu) >= 6,
-		       "Armv8 debug architecture not supported.");
-
 	vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT,
 				ESR_EC_BRK_INS, guest_sw_bp_handler);
 	vm_install_sync_handler(vm, VECTOR_SYNC_CURRENT,
@@ -294,5 +332,108 @@ int main(int argc, char *argv[])
 
 done:
 	kvm_vm_free(vm);
+}
+
+void test_single_step_from_userspace(int test_cnt)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+	struct ucall uc;
+	struct kvm_run *run;
+	uint64_t pc, cmd;
+	uint64_t test_pc = 0;
+	bool ss_enable = false;
+	struct kvm_guest_debug debug = {};
+
+	vm = vm_create_with_one_vcpu(&vcpu, guest_code_ss);
+	ucall_init(vm, NULL);
+	run = vcpu->run;
+	vcpu_args_set(vcpu, 1, test_cnt);
+
+	while (1) {
+		vcpu_run(vcpu);
+		if (run->exit_reason != KVM_EXIT_DEBUG) {
+			cmd = get_ucall(vcpu, &uc);
+			if (cmd == UCALL_ABORT) {
+				REPORT_GUEST_ASSERT(uc);
+				/* NOT REACHED */
+			} else if (cmd == UCALL_DONE) {
+				break;
+			}
+
+			TEST_ASSERT(cmd == UCALL_SYNC,
+				    "Unexpected ucall cmd 0x%lx", cmd);
+
+			if (uc.args[1] == SINGLE_STEP_ENABLE) {
+				debug.control = KVM_GUESTDBG_ENABLE |
+						KVM_GUESTDBG_SINGLESTEP;
+				ss_enable = true;
+			} else {
+				debug.control = SINGLE_STEP_DISABLE;
+				ss_enable = false;
+			}
+
+			vcpu_guest_debug_set(vcpu, &debug);
+			continue;
+		}
+
+		TEST_ASSERT(ss_enable, "Unexpected KVM_EXIT_DEBUG");
+
+		/* Check if the current pc is expected. */
+		vcpu_get_reg(vcpu, ARM64_CORE_REG(regs.pc), &pc);
+		TEST_ASSERT(!test_pc || pc == test_pc,
+			    "Unexpected pc 0x%lx (expected 0x%lx)",
+			    pc, test_pc);
+
+		/*
+		 * If the current pc is between iter_ss_bgin and
+		 * iter_ss_end, the pc for the next KVM_EXIT_DEBUG should
+		 * be the current pc + 4.
+		 */
+		if ((pc >= (uint64_t)&iter_ss_begin) &&
+		    (pc < (uint64_t)&iter_ss_end))
+			test_pc = pc + 4;
+		else
+			test_pc = 0;
+	}
+
+	kvm_vm_free(vm);
+}
+
+static void help(char *name)
+{
+	puts("");
+	printf("Usage: %s [-h] [-i iterations of the single step test]\n", name);
+	puts("");
+	exit(0);
+}
+
+int main(int argc, char *argv[])
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+	int opt;
+	int ss_iteration = 10000;
+
+	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
+	__TEST_REQUIRE(debug_version(vcpu) >= 6,
+		       "Armv8 debug architecture not supported.");
+	kvm_vm_free(vm);
+
+	while ((opt = getopt(argc, argv, "i:")) != -1) {
+		switch (opt) {
+		case 'i':
+			ss_iteration = atoi(optarg);
+			break;
+		case 'h':
+		default:
+			help(argv[0]);
+			break;
+		}
+	}
+
+	test_guest_debug_exceptions();
+	test_single_step_from_userspace(ss_iteration);
+
 	return 0;
 }
diff --git a/tools/testing/selftests/kvm/aarch64/psci_test.c b/tools/testing/selftests/kvm/aarch64/psci_test.c
index f7621f6e938e..e0b9e81a3e09 100644
--- a/tools/testing/selftests/kvm/aarch64/psci_test.c
+++ b/tools/testing/selftests/kvm/aarch64/psci_test.c
@@ -1,12 +1,14 @@
 // SPDX-License-Identifier: GPL-2.0-only
 /*
- * psci_cpu_on_test - Test that the observable state of a vCPU targeted by the
- * CPU_ON PSCI call matches what the caller requested.
+ * psci_test - Tests relating to KVM's PSCI implementation.
  *
  * Copyright (c) 2021 Google LLC.
  *
- * This is a regression test for a race between KVM servicing the PSCI call and
- * userspace reading the vCPUs registers.
+ * This test includes:
+ *  - A regression test for a race between KVM servicing the PSCI CPU_ON call
+ *    and userspace reading the targeted vCPU's registers.
+ *  - A test for KVM's handling of PSCI SYSTEM_SUSPEND and the associated
+ *    KVM_SYSTEM_EVENT_SUSPEND UAPI.
  */
 
 #define _GNU_SOURCE
diff --git a/tools/testing/selftests/kvm/dirty_log_test.c b/tools/testing/selftests/kvm/dirty_log_test.c
index 9c883c94d478..b5234d6efbe1 100644
--- a/tools/testing/selftests/kvm/dirty_log_test.c
+++ b/tools/testing/selftests/kvm/dirty_log_test.c
@@ -17,6 +17,7 @@
 #include <linux/bitmap.h>
 #include <linux/bitops.h>
 #include <linux/atomic.h>
+#include <asm/barrier.h>
 
 #include "kvm_util.h"
 #include "test_util.h"
@@ -264,7 +265,8 @@ static void default_after_vcpu_run(struct kvm_vcpu *vcpu, int ret, int err)
 
 static bool dirty_ring_supported(void)
 {
-	return kvm_has_cap(KVM_CAP_DIRTY_LOG_RING);
+	return (kvm_has_cap(KVM_CAP_DIRTY_LOG_RING) ||
+		kvm_has_cap(KVM_CAP_DIRTY_LOG_RING_ACQ_REL));
 }
 
 static void dirty_ring_create_vm_done(struct kvm_vm *vm)
@@ -279,12 +281,12 @@ static void dirty_ring_create_vm_done(struct kvm_vm *vm)
 
 static inline bool dirty_gfn_is_dirtied(struct kvm_dirty_gfn *gfn)
 {
-	return gfn->flags == KVM_DIRTY_GFN_F_DIRTY;
+	return smp_load_acquire(&gfn->flags) == KVM_DIRTY_GFN_F_DIRTY;
 }
 
 static inline void dirty_gfn_set_collected(struct kvm_dirty_gfn *gfn)
 {
-	gfn->flags = KVM_DIRTY_GFN_F_RESET;
+	smp_store_release(&gfn->flags, KVM_DIRTY_GFN_F_RESET);
 }
 
 static uint32_t dirty_ring_collect_one(struct kvm_dirty_gfn *dirty_gfns,
diff --git a/tools/testing/selftests/kvm/lib/kvm_util.c b/tools/testing/selftests/kvm/lib/kvm_util.c
index 504c1e1355c3..f1cb1627161f 100644
--- a/tools/testing/selftests/kvm/lib/kvm_util.c
+++ b/tools/testing/selftests/kvm/lib/kvm_util.c
@@ -121,7 +121,10 @@ unsigned int kvm_check_cap(long cap)
 
 void vm_enable_dirty_ring(struct kvm_vm *vm, uint32_t ring_size)
 {
-	vm_enable_cap(vm, KVM_CAP_DIRTY_LOG_RING, ring_size);
+	if (vm_check_cap(vm, KVM_CAP_DIRTY_LOG_RING_ACQ_REL))
+		vm_enable_cap(vm, KVM_CAP_DIRTY_LOG_RING_ACQ_REL, ring_size);
+	else
+		vm_enable_cap(vm, KVM_CAP_DIRTY_LOG_RING, ring_size);
 	vm->dirty_ring_size = ring_size;
 }