[PATCH 4/4] KVM: selftests: aarch64: add tool to dump registers

[Sebastian Ott]

Iterate over registers obtained via KVM_GET_REG_LIST, dump
their values and writable masks.

Signed-off-by: Sebastian Ott <sebott at redhat.com>
---
 tools/testing/selftests/kvm/Makefile          |  1 +
 .../testing/selftests/kvm/aarch64/dump_regs.c | 72 +++++++++++++++++++
 2 files changed, 73 insertions(+)
 create mode 100644 tools/testing/selftests/kvm/aarch64/dump_regs.c

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index 492e937fab00..3bbb163abb1e 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -145,6 +145,7 @@ 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/dump_regs
 TEST_GEN_PROGS_aarch64 += aarch64/hypercalls
 TEST_GEN_PROGS_aarch64 += aarch64/page_fault_test
 TEST_GEN_PROGS_aarch64 += aarch64/psci_test
diff --git a/tools/testing/selftests/kvm/aarch64/dump_regs.c b/tools/testing/selftests/kvm/aarch64/dump_regs.c
new file mode 100644
index 000000000000..390b4629ca12
--- /dev/null
+++ b/tools/testing/selftests/kvm/aarch64/dump_regs.c
@@ -0,0 +1,72 @@
+#include <stdint.h>
+#include "kvm_util.h"
+#include "processor.h"
+#include "test_util.h"
+#include <linux/bitfield.h>
+
+static uint64_t masks[KVM_ARM_FEATURE_ID_RANGE_SIZE];
+
+static void guest_code(void)
+{
+}
+
+static void get_writable_masks(struct kvm_vm *vm)
+{
+	struct reg_mask_range range = {
+		.addr = (__u64)masks,
+	};
+
+	memset(range.reserved, 0, sizeof(range.reserved));
+	vm_ioctl(vm, KVM_ARM_GET_REG_WRITABLE_MASKS, &range);
+}
+
+#define kvm_sys_reg_Op0(id) (((id) & KVM_REG_ARM64_SYSREG_OP0_MASK) >> KVM_REG_ARM64_SYSREG_OP0_SHIFT)
+#define kvm_sys_reg_Op1(id) (((id) & KVM_REG_ARM64_SYSREG_OP1_MASK) >> KVM_REG_ARM64_SYSREG_OP1_SHIFT)
+#define kvm_sys_reg_CRn(id) (((id) & KVM_REG_ARM64_SYSREG_CRN_MASK) >> KVM_REG_ARM64_SYSREG_CRN_SHIFT)
+#define kvm_sys_reg_CRm(id) (((id) & KVM_REG_ARM64_SYSREG_CRM_MASK) >> KVM_REG_ARM64_SYSREG_CRM_SHIFT)
+#define kvm_sys_reg_Op2(id) (((id) & KVM_REG_ARM64_SYSREG_OP2_MASK) >> KVM_REG_ARM64_SYSREG_OP2_SHIFT)
+
+static bool reg_in_feature_id_range(uint64_t reg)
+{
+	return kvm_sys_reg_Op0(reg) == 3 &&
+	       kvm_sys_reg_Op1(reg) >= 0 && kvm_sys_reg_Op1(reg) <= 3 &&
+	       kvm_sys_reg_CRn(reg) == 0 &&
+	       kvm_sys_reg_CRm(reg) >= 0 && kvm_sys_reg_CRm(reg) <= 7 &&
+	       kvm_sys_reg_Op2(reg) >= 0 && kvm_sys_reg_Op2(reg) <= 7;
+}
+
+static uint64_t reg_get_mask(uint64_t reg)
+{
+	int idx = KVM_ARM_FEATURE_ID_RANGE_IDX(kvm_sys_reg_Op0(reg), kvm_sys_reg_Op1(reg),
+					       kvm_sys_reg_CRn(reg), kvm_sys_reg_CRm(reg),
+					       kvm_sys_reg_Op2(reg));
+
+	return reg_in_feature_id_range(reg) ? masks[idx] : 0;
+}
+
+static void dump_regs(struct kvm_vcpu *vcpu)
+{
+	struct kvm_reg_list *reg_list = vcpu_get_reg_list(vcpu);
+	uint64_t reg, val[8];
+	int i, ret;
+
+	for (i = 0; i < reg_list->n; i++) {
+		reg = reg_list->reg[i];
+		ret = __vcpu_get_reg(vcpu, reg, val);
+		if (!ret)
+			pr_info("%lx : %16lx %lx\n", reg, val[0], reg_get_mask(reg));
+	}
+
+	free(reg_list);
+}
+
+int main(void)
+{
+	struct kvm_vcpu *vcpu;
+	struct kvm_vm *vm;
+
+	vm = vm_create_with_one_vcpu(&vcpu, guest_code);
+	get_writable_masks(vm);
+	dump_regs(vcpu);
+	kvm_vm_free(vm);
+}
-- 
2.42.0