[PATCH v2 05/11] KVM: arm64: selftests: Delete core_reg_fixup

Haibo Xu
2023-05-25T07:36:22Z

From: Andrew Jones <ajones@ventanamicro.com>

core_reg_fixup() complicates sharing the get-reg-list test with
other architectures. Rather than work at keeping it, with plenty
of #ifdeffery, just delete it, as it's unlikely to test a kernel
based on anything older than v5.2 with the get-reg-list test,
which is a test meant to check for regressions in new kernels.
(And, an older version of the test can still be used for older
kernels if necessary.)

Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
---
.../selftests/kvm/aarch64/get-reg-list.c | 83 +++----------------
1 file changed, 10 insertions(+), 73 deletions(-)

diff --git a/tools/testing/selftests/kvm/aarch64/get-reg-list.c b/tools/testing/selftests/kvm/aarch64/get-reg-list.c
index aae2056379f7..c8b44389d2ee 100644
--- a/tools/testing/selftests/kvm/aarch64/get-reg-list.c
+++ b/tools/testing/selftests/kvm/aarch64/get-reg-list.c
@@ -17,12 +17,10 @@
* by running the test with the --list command line argument.
*
* Note, the blessed list should be created from the oldest possible
- * kernel. We can't go older than v4.15, though, because that's the first
- * release to expose the ID system registers in KVM_GET_REG_LIST, see
- * commit 93390c0a1b20 ("arm64: KVM: Hide unsupported AArch64 CPU features
- * from guests"). Also, one must use the --core-reg-fixup command line
- * option when running on an older kernel that doesn't include df205b5c6328
- * ("KVM: arm64: Filter out invalid core register IDs in KVM_GET_REG_LIST")
+ * kernel. We can't go older than v5.2, though, because that's the first
+ * release which includes df205b5c6328 ("KVM: arm64: Filter out invalid
+ * core register IDs in KVM_GET_REG_LIST"). Without that commit the core
+ * registers won't match expectations.
*/
#include <stdio.h>
#include <stdlib.h>
@@ -269,63 +267,6 @@ static void print_reg(const char *prefix, __u64 id)
}
}

-/*
- * Older kernels listed each 32-bit word of CORE registers separately.
- * For 64 and 128-bit registers we need to ignore the extra words. We
- * also need to fixup the sizes, because the older kernels stated all
- * registers were 64-bit, even when they weren't.
- */
-static void core_reg_fixup(void)
-{
- struct kvm_reg_list *tmp;
- __u64 id, core_off;
- int i;
-
- tmp = calloc(1, sizeof(*tmp) + reg_list->n * sizeof(__u64));
-
- for (i = 0; i < reg_list->n; ++i) {
- id = reg_list->reg[i];
-
- if ((id & KVM_REG_ARM_COPROC_MASK) != KVM_REG_ARM_CORE) {
- tmp->reg[tmp->n++] = id;
- continue;
- }
-
- core_off = id & ~REG_MASK;
-
- switch (core_off) {
- case 0x52: case 0xd2: case 0xd6:
- /*
- * These offsets are pointing at padding.
- * We need to ignore them too.
- */
- continue;
- case KVM_REG_ARM_CORE_REG(fp_regs.vregs[0]) ...
- KVM_REG_ARM_CORE_REG(fp_regs.vregs[31]):
- if (core_off & 3)
- continue;
- id &= ~KVM_REG_SIZE_MASK;
- id |= KVM_REG_SIZE_U128;
- tmp->reg[tmp->n++] = id;
- continue;
- case KVM_REG_ARM_CORE_REG(fp_regs.fpsr):
- case KVM_REG_ARM_CORE_REG(fp_regs.fpcr):
- id &= ~KVM_REG_SIZE_MASK;
- id |= KVM_REG_SIZE_U32;
- tmp->reg[tmp->n++] = id;
- continue;
- default:
- if (core_off & 1)
- continue;
- tmp->reg[tmp->n++] = id;
- break;
- }
- }
-
- free(reg_list);
- reg_list = tmp;
-}
-
static void prepare_vcpu_init(struct vcpu_reg_list *c, struct kvm_vcpu_init *init)
{
struct vcpu_reg_sublist *s;
@@ -364,7 +305,6 @@ static void check_supported(struct vcpu_reg_list *c)

static bool print_list;
static bool print_filtered;
-static bool fixup_core_regs;

static void run_test(struct vcpu_reg_list *c)
{
@@ -385,9 +325,6 @@ static void run_test(struct vcpu_reg_list *c)

reg_list = vcpu_get_reg_list(vcpu);

- if (fixup_core_regs)
- core_reg_fixup();
-
if (print_list || print_filtered) {
putchar('\n');
for_each_reg(i) {
@@ -515,7 +452,7 @@ static void help(void)

printf(
"\n"
- "usage: get-reg-list [--config=<selection>] [--list] [--list-filtered] [--core-reg-fixup]\n\n"
+ "usage: get-reg-list [--config=<selection>] [--list] [--list-filtered]\n\n"
" --config=<selection> Used to select a specific vcpu configuration for the test/listing\n"
" '<selection>' may be\n");

@@ -529,7 +466,6 @@ static void help(void)
"\n"
" --list Print the register list rather than test it (requires --config)\n"
" --list-filtered Print registers that would normally be filtered out (requires --config)\n"
- " --core-reg-fixup Needed when running on old kernels with broken core reg listings\n"
"\n"
);
}
@@ -561,9 +497,7 @@ int main(int ac, char **av)
pid_t pid;

for (i = 1; i < ac; ++i) {
- if (strcmp(av[i], "--core-reg-fixup") == 0)
- fixup_core_regs = true;
- else if (strncmp(av[i], "--config", 8) == 0)
+ if (strncmp(av[i], "--config", 8) == 0)
sel = parse_config(av[i]);
else if (strcmp(av[i], "--list") == 0)
print_list = true;
@@ -606,8 +540,11 @@ int main(int ac, char **av)
}

/*
- * The current blessed list was primed with the output of kernel version
+ * The original blessed list was primed with the output of kernel version
* v4.15 with --core-reg-fixup and then later updated with new registers.
+ * (The --core-reg-fixup option and it's fixup function have been removed
+ * from the test, as it's unlikely to use this type of test on a kernel
+ * older than v5.2.)
*
* The blessed list is up to date with kernel version v6.4 (or so we hope)
*/
--
2.34.1