[PATCH 2/2] KVM: selftests: Filter out DEMUX registers

[Andrew Jones <drjones@xxxxxxxxxx>]

DEMUX register presence depends on the host's hardware (the
CLIDR_EL1 register to be precise). This means there's no set
of them that we can bless and that it's possible to encounter
new ones when running on different hardware (which would
generate "Consider adding them ..." messages, but we'll never
want to add them.)

Remove the ones we have in the blessed list and filter them
out of the new list, but also provide a new command line switch
to list them if one so desires.

Signed-off-by: Andrew Jones <drjones@xxxxxxxxxx>
---
 .../selftests/kvm/aarch64/get-reg-list.c      | 39 ++++++++++++++-----
 1 file changed, 30 insertions(+), 9 deletions(-)

diff --git a/tools/testing/selftests/kvm/aarch64/get-reg-list.c b/tools/testing/selftests/kvm/aarch64/get-reg-list.c
index 33218a395d9f..486932164cf2 100644
--- a/tools/testing/selftests/kvm/aarch64/get-reg-list.c
+++ b/tools/testing/selftests/kvm/aarch64/get-reg-list.c
@@ -42,12 +42,16 @@
 #define for_each_reg(i)								\
 	for ((i) = 0; (i) < reg_list->n; ++(i))
 
+#define for_each_reg_filtered(i)						\
+	for_each_reg(i)								\
+		if (!filter_reg(reg_list->reg[i]))
+
 #define for_each_missing_reg(i)							\
 	for ((i) = 0; (i) < blessed_n; ++(i))					\
 		if (!find_reg(reg_list->reg, reg_list->n, blessed_reg[i]))
 
 #define for_each_new_reg(i)							\
-	for ((i) = 0; (i) < reg_list->n; ++(i))					\
+	for_each_reg_filtered(i)						\
 		if (!find_reg(blessed_reg, blessed_n, reg_list->reg[i]))
 
 
@@ -57,6 +61,18 @@ static __u64 base_regs[], vregs[], sve_regs[], rejects_set[];
 static __u64 base_regs_n, vregs_n, sve_regs_n, rejects_set_n;
 static __u64 *blessed_reg, blessed_n;
 
+static bool filter_reg(__u64 reg)
+{
+	/*
+	 * DEMUX register presence depends on the host's CLIDR_EL1.
+	 * This means there's no set of them that we can bless.
+	 */
+	if ((reg & KVM_REG_ARM_COPROC_MASK) == KVM_REG_ARM_DEMUX)
+		return true;
+
+	return false;
+}
+
 static bool find_reg(__u64 regs[], __u64 nr_regs, __u64 reg)
 {
 	int i;
@@ -325,7 +341,7 @@ int main(int ac, char **av)
 	struct kvm_vcpu_init init = { .target = -1, };
 	int new_regs = 0, missing_regs = 0, i;
 	int failed_get = 0, failed_set = 0, failed_reject = 0;
-	bool print_list = false, fixup_core_regs = false;
+	bool print_list = false, print_filtered = false, fixup_core_regs = false;
 	struct kvm_vm *vm;
 	__u64 *vec_regs;
 
@@ -336,8 +352,10 @@ int main(int ac, char **av)
 			fixup_core_regs = true;
 		else if (strcmp(av[i], "--list") == 0)
 			print_list = true;
+		else if (strcmp(av[i], "--list-filtered") == 0)
+			print_filtered = true;
 		else
-			fprintf(stderr, "Ignoring unknown option: %s\n", av[i]);
+			TEST_FAIL("Unknown option: %s\n", av[i]);
 	}
 
 	vm = vm_create(VM_MODE_DEFAULT, DEFAULT_GUEST_PHY_PAGES, O_RDWR);
@@ -350,10 +368,14 @@ int main(int ac, char **av)
 	if (fixup_core_regs)
 		core_reg_fixup();
 
-	if (print_list) {
+	if (print_list || print_filtered) {
 		putchar('\n');
-		for_each_reg(i)
-			print_reg(reg_list->reg[i]);
+		for_each_reg(i) {
+			__u64 id = reg_list->reg[i];
+			if ((print_list && !filter_reg(id)) ||
+			    (print_filtered && filter_reg(id)))
+				print_reg(id);
+		}
 		putchar('\n');
 		return 0;
 	}
@@ -458,6 +480,8 @@ int main(int ac, char **av)
 /*
  * The current blessed list was primed with the output of kernel version
  * v4.15 with --core-reg-fixup and then later updated with new registers.
+ *
+ * The blessed list is up to date with kernel version v5.10-rc5
  */
 static __u64 base_regs[] = {
 	KVM_REG_ARM64 | KVM_REG_SIZE_U64 | KVM_REG_ARM_CORE | KVM_REG_ARM_CORE_REG(regs.regs[0]),
@@ -736,9 +760,6 @@ static __u64 base_regs[] = {
 	ARM64_SYS_REG(3, 4, 3, 0, 0),	/* DACR32_EL2 */
 	ARM64_SYS_REG(3, 4, 5, 0, 1),	/* IFSR32_EL2 */
 	ARM64_SYS_REG(3, 4, 5, 3, 0),	/* FPEXC32_EL2 */
-	KVM_REG_ARM64 | KVM_REG_SIZE_U32 | KVM_REG_ARM_DEMUX | KVM_REG_ARM_DEMUX_ID_CCSIDR | 0,
-	KVM_REG_ARM64 | KVM_REG_SIZE_U32 | KVM_REG_ARM_DEMUX | KVM_REG_ARM_DEMUX_ID_CCSIDR | 1,
-	KVM_REG_ARM64 | KVM_REG_SIZE_U32 | KVM_REG_ARM_DEMUX | KVM_REG_ARM_DEMUX_ID_CCSIDR | 2,
 };
 static __u64 base_regs_n = ARRAY_SIZE(base_regs);
 
-- 
2.26.2