[PATCH v3 24/70] i386/kvm: Move architectural CPUID leaf generation to separate helper

Xiaoyao Li
2023-11-15T07:18:13Z

From: Sean Christopherson <sean.j.christopherson@intel.com>

Move the architectural (for lack of a better term) CPUID leaf generation
to a separate helper so that the generation code can be reused by TDX,
which needs to generate a canonical VM-scoped configuration.

Signed-off-by: Sean Christopherson <sean.j.christopherson@intel.com>
Signed-off-by: Xiaoyao Li <xiaoyao.li@intel.com>
---
target/i386/kvm/kvm.c | 454 +++++++++++++++++++------------------
target/i386/kvm/kvm_i386.h | 3 +
2 files changed, 235 insertions(+), 222 deletions(-)

diff --git a/target/i386/kvm/kvm.c b/target/i386/kvm/kvm.c
index f2627dd61d2b..dafe4d262977 100644
--- a/target/i386/kvm/kvm.c
+++ b/target/i386/kvm/kvm.c
@@ -1733,6 +1733,236 @@ static void kvm_init_nested_state(CPUX86State *env)
}
}

+uint32_t kvm_x86_arch_cpuid(CPUX86State *env, struct kvm_cpuid_entry2 *entries,
+ uint32_t cpuid_i)
+{
+ uint32_t limit, i, j;
+ uint32_t unused;
+ struct kvm_cpuid_entry2 *c;
+
+ cpu_x86_cpuid(env, 0, 0, &limit, &unused, &unused, &unused);
+
+ for (i = 0; i <= limit; i++) {
+ if (cpuid_i == KVM_MAX_CPUID_ENTRIES) {
+ fprintf(stderr, "unsupported level value: 0x%x\n", limit);
+ abort();
+ }
+ c = &entries[cpuid_i++];
+
+ switch (i) {
+ case 2: {
+ /* Keep reading function 2 till all the input is received */
+ int times;
+
+ c->function = i;
+ c->flags = KVM_CPUID_FLAG_STATEFUL_FUNC |
+ KVM_CPUID_FLAG_STATE_READ_NEXT;
+ cpu_x86_cpuid(env, i, 0, &c->eax, &c->ebx, &c->ecx, &c->edx);
+ times = c->eax & 0xff;
+
+ for (j = 1; j < times; ++j) {
+ if (cpuid_i == KVM_MAX_CPUID_ENTRIES) {
+ fprintf(stderr, "cpuid_data is full, no space for "
+ "cpuid(eax:2):eax & 0xf = 0x%x\n", times);
+ abort();
+ }
+ c = &entries[cpuid_i++];
+ c->function = i;
+ c->flags = KVM_CPUID_FLAG_STATEFUL_FUNC;
+ cpu_x86_cpuid(env, i, 0, &c->eax, &c->ebx, &c->ecx, &c->edx);
+ }
+ break;
+ }
+ case 0x1f:
+ if (env->nr_dies < 2) {
+ cpuid_i--;
+ break;
+ }
+ /* fallthrough */
+ case 4:
+ case 0xb:
+ case 0xd:
+ for (j = 0; ; j++) {
+ if (i == 0xd && j == 64) {
+ break;
+ }
+
+ c->function = i;
+ c->flags = KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
+ c->index = j;
+ cpu_x86_cpuid(env, i, j, &c->eax, &c->ebx, &c->ecx, &c->edx);
+
+ if (i == 4 && c->eax == 0) {
+ break;
+ }
+ if (i == 0xb && !(c->ecx & 0xff00)) {
+ break;
+ }
+ if (i == 0x1f && !(c->ecx & 0xff00)) {
+ break;
+ }
+ if (i == 0xd && c->eax == 0) {
+ continue;
+ }
+ if (cpuid_i == KVM_MAX_CPUID_ENTRIES) {
+ fprintf(stderr, "cpuid_data is full, no space for "
+ "cpuid(eax:0x%x,ecx:0x%x)\n", i, j);
+ abort();
+ }
+ c = &entries[cpuid_i++];
+ }
+ break;
+ case 0x7:
+ case 0x12:
+ for (j = 0; ; j++) {
+ c->function = i;
+ c->flags = KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
+ c->index = j;
+ cpu_x86_cpuid(env, i, j, &c->eax, &c->ebx, &c->ecx, &c->edx);
+
+ if (j > 1 && (c->eax & 0xf) != 1) {
+ break;
+ }
+
+ if (cpuid_i == KVM_MAX_CPUID_ENTRIES) {
+ fprintf(stderr, "cpuid_data is full, no space for "
+ "cpuid(eax:0x12,ecx:0x%x)\n", j);
+ abort();
+ }
+ c = &entries[cpuid_i++];
+ }
+ break;
+ case 0x14:
+ case 0x1d:
+ case 0x1e: {
+ uint32_t times;
+
+ c->function = i;
+ c->index = 0;
+ c->flags = KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
+ cpu_x86_cpuid(env, i, 0, &c->eax, &c->ebx, &c->ecx, &c->edx);
+ times = c->eax;
+
+ for (j = 1; j <= times; ++j) {
+ if (cpuid_i == KVM_MAX_CPUID_ENTRIES) {
+ fprintf(stderr, "cpuid_data is full, no space for "
+ "cpuid(eax:0x%x,ecx:0x%x)\n", i, j);
+ abort();
+ }
+ c = &entries[cpuid_i++];
+ c->function = i;
+ c->index = j;
+ c->flags = KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
+ cpu_x86_cpuid(env, i, j, &c->eax, &c->ebx, &c->ecx, &c->edx);
+ }
+ break;
+ }
+ default:
+ c->function = i;
+ c->flags = 0;
+ cpu_x86_cpuid(env, i, 0, &c->eax, &c->ebx, &c->ecx, &c->edx);
+ if (!c->eax && !c->ebx && !c->ecx && !c->edx) {
+ /*
+ * KVM already returns all zeroes if a CPUID entry is missing,
+ * so we can omit it and avoid hitting KVM's 80-entry limit.
+ */
+ cpuid_i--;
+ }
+ break;
+ }
+ }
+
+ if (limit >= 0x0a) {
+ uint32_t eax, edx;
+
+ cpu_x86_cpuid(env, 0x0a, 0, &eax, &unused, &unused, &edx);
+
+ has_architectural_pmu_version = eax & 0xff;
+ if (has_architectural_pmu_version > 0) {
+ num_architectural_pmu_gp_counters = (eax & 0xff00) >> 8;
+
+ /* Shouldn't be more than 32, since that's the number of bits
+ * available in EBX to tell us _which_ counters are available.
+ * Play it safe.
+ */
+ if (num_architectural_pmu_gp_counters > MAX_GP_COUNTERS) {
+ num_architectural_pmu_gp_counters = MAX_GP_COUNTERS;
+ }
+
+ if (has_architectural_pmu_version > 1) {
+ num_architectural_pmu_fixed_counters = edx & 0x1f;
+
+ if (num_architectural_pmu_fixed_counters > MAX_FIXED_COUNTERS) {
+ num_architectural_pmu_fixed_counters = MAX_FIXED_COUNTERS;
+ }
+ }
+ }
+ }
+
+ cpu_x86_cpuid(env, 0x80000000, 0, &limit, &unused, &unused, &unused);
+
+ for (i = 0x80000000; i <= limit; i++) {
+ if (cpuid_i == KVM_MAX_CPUID_ENTRIES) {
+ fprintf(stderr, "unsupported xlevel value: 0x%x\n", limit);
+ abort();
+ }
+ c = &entries[cpuid_i++];
+
+ switch (i) {
+ case 0x8000001d:
+ /* Query for all AMD cache information leaves */
+ for (j = 0; ; j++) {
+ c->function = i;
+ c->flags = KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
+ c->index = j;
+ cpu_x86_cpuid(env, i, j, &c->eax, &c->ebx, &c->ecx, &c->edx);
+
+ if (c->eax == 0) {
+ break;
+ }
+ if (cpuid_i == KVM_MAX_CPUID_ENTRIES) {
+ fprintf(stderr, "cpuid_data is full, no space for "
+ "cpuid(eax:0x%x,ecx:0x%x)\n", i, j);
+ abort();
+ }
+ c = &entries[cpuid_i++];
+ }
+ break;
+ default:
+ c->function = i;
+ c->flags = 0;
+ cpu_x86_cpuid(env, i, 0, &c->eax, &c->ebx, &c->ecx, &c->edx);
+ if (!c->eax && !c->ebx && !c->ecx && !c->edx) {
+ /*
+ * KVM already returns all zeroes if a CPUID entry is missing,
+ * so we can omit it and avoid hitting KVM's 80-entry limit.
+ */
+ cpuid_i--;
+ }
+ break;
+ }
+ }
+
+ /* Call Centaur's CPUID instructions they are supported. */
+ if (env->cpuid_xlevel2 > 0) {
+ cpu_x86_cpuid(env, 0xC0000000, 0, &limit, &unused, &unused, &unused);
+
+ for (i = 0xC0000000; i <= limit; i++) {
+ if (cpuid_i == KVM_MAX_CPUID_ENTRIES) {
+ fprintf(stderr, "unsupported xlevel2 value: 0x%x\n", limit);
+ abort();
+ }
+ c = &entries[cpuid_i++];
+
+ c->function = i;
+ c->flags = 0;
+ cpu_x86_cpuid(env, i, 0, &c->eax, &c->ebx, &c->ecx, &c->edx);
+ }
+ }
+
+ return cpuid_i;
+}
+
int kvm_arch_init_vcpu(CPUState *cs)
{
struct {
@@ -1749,8 +1979,7 @@ int kvm_arch_init_vcpu(CPUState *cs)

X86CPU *cpu = X86_CPU(cs);
CPUX86State *env = &cpu->env;
- uint32_t limit, i, j, cpuid_i;
- uint32_t unused;
+ uint32_t cpuid_i;
struct kvm_cpuid_entry2 *c;
uint32_t signature[3];
int kvm_base = KVM_CPUID_SIGNATURE;
@@ -1903,8 +2132,6 @@ int kvm_arch_init_vcpu(CPUState *cs)
c->edx = env->features[FEAT_KVM_HINTS];
}

- cpu_x86_cpuid(env, 0, 0, &limit, &unused, &unused, &unused);
-
if (cpu->kvm_pv_enforce_cpuid) {
r = kvm_vcpu_enable_cap(cs, KVM_CAP_ENFORCE_PV_FEATURE_CPUID, 0, 1);
if (r < 0) {
@@ -1915,224 +2142,7 @@ int kvm_arch_init_vcpu(CPUState *cs)
}
}

- for (i = 0; i <= limit; i++) {
- if (cpuid_i == KVM_MAX_CPUID_ENTRIES) {
- fprintf(stderr, "unsupported level value: 0x%x\n", limit);
- abort();
- }
- c = &cpuid_data.entries[cpuid_i++];
-
- switch (i) {
- case 2: {
- /* Keep reading function 2 till all the input is received */
- int times;
-
- c->function = i;
- c->flags = KVM_CPUID_FLAG_STATEFUL_FUNC |
- KVM_CPUID_FLAG_STATE_READ_NEXT;
- cpu_x86_cpuid(env, i, 0, &c->eax, &c->ebx, &c->ecx, &c->edx);
- times = c->eax & 0xff;
-
- for (j = 1; j < times; ++j) {
- if (cpuid_i == KVM_MAX_CPUID_ENTRIES) {
- fprintf(stderr, "cpuid_data is full, no space for "
- "cpuid(eax:2):eax & 0xf = 0x%x\n", times);
- abort();
- }
- c = &cpuid_data.entries[cpuid_i++];
- c->function = i;
- c->flags = KVM_CPUID_FLAG_STATEFUL_FUNC;
- cpu_x86_cpuid(env, i, 0, &c->eax, &c->ebx, &c->ecx, &c->edx);
- }
- break;
- }
- case 0x1f:
- if (env->nr_dies < 2) {
- cpuid_i--;
- break;
- }
- /* fallthrough */
- case 4:
- case 0xb:
- case 0xd:
- for (j = 0; ; j++) {
- if (i == 0xd && j == 64) {
- break;
- }
-
- c->function = i;
- c->flags = KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
- c->index = j;
- cpu_x86_cpuid(env, i, j, &c->eax, &c->ebx, &c->ecx, &c->edx);
-
- if (i == 4 && c->eax == 0) {
- break;
- }
- if (i == 0xb && !(c->ecx & 0xff00)) {
- break;
- }
- if (i == 0x1f && !(c->ecx & 0xff00)) {
- break;
- }
- if (i == 0xd && c->eax == 0) {
- continue;
- }
- if (cpuid_i == KVM_MAX_CPUID_ENTRIES) {
- fprintf(stderr, "cpuid_data is full, no space for "
- "cpuid(eax:0x%x,ecx:0x%x)\n", i, j);
- abort();
- }
- c = &cpuid_data.entries[cpuid_i++];
- }
- break;
- case 0x7:
- case 0x12:
- for (j = 0; ; j++) {
- c->function = i;
- c->flags = KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
- c->index = j;
- cpu_x86_cpuid(env, i, j, &c->eax, &c->ebx, &c->ecx, &c->edx);
-
- if (j > 1 && (c->eax & 0xf) != 1) {
- break;
- }
-
- if (cpuid_i == KVM_MAX_CPUID_ENTRIES) {
- fprintf(stderr, "cpuid_data is full, no space for "
- "cpuid(eax:0x12,ecx:0x%x)\n", j);
- abort();
- }
- c = &cpuid_data.entries[cpuid_i++];
- }
- break;
- case 0x14:
- case 0x1d:
- case 0x1e: {
- uint32_t times;
-
- c->function = i;
- c->index = 0;
- c->flags = KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
- cpu_x86_cpuid(env, i, 0, &c->eax, &c->ebx, &c->ecx, &c->edx);
- times = c->eax;
-
- for (j = 1; j <= times; ++j) {
- if (cpuid_i == KVM_MAX_CPUID_ENTRIES) {
- fprintf(stderr, "cpuid_data is full, no space for "
- "cpuid(eax:0x%x,ecx:0x%x)\n", i, j);
- abort();
- }
- c = &cpuid_data.entries[cpuid_i++];
- c->function = i;
- c->index = j;
- c->flags = KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
- cpu_x86_cpuid(env, i, j, &c->eax, &c->ebx, &c->ecx, &c->edx);
- }
- break;
- }
- default:
- c->function = i;
- c->flags = 0;
- cpu_x86_cpuid(env, i, 0, &c->eax, &c->ebx, &c->ecx, &c->edx);
- if (!c->eax && !c->ebx && !c->ecx && !c->edx) {
- /*
- * KVM already returns all zeroes if a CPUID entry is missing,
- * so we can omit it and avoid hitting KVM's 80-entry limit.
- */
- cpuid_i--;
- }
- break;
- }
- }
-
- if (limit >= 0x0a) {
- uint32_t eax, edx;
-
- cpu_x86_cpuid(env, 0x0a, 0, &eax, &unused, &unused, &edx);
-
- has_architectural_pmu_version = eax & 0xff;
- if (has_architectural_pmu_version > 0) {
- num_architectural_pmu_gp_counters = (eax & 0xff00) >> 8;
-
- /* Shouldn't be more than 32, since that's the number of bits
- * available in EBX to tell us _which_ counters are available.
- * Play it safe.
- */
- if (num_architectural_pmu_gp_counters > MAX_GP_COUNTERS) {
- num_architectural_pmu_gp_counters = MAX_GP_COUNTERS;
- }
-
- if (has_architectural_pmu_version > 1) {
- num_architectural_pmu_fixed_counters = edx & 0x1f;
-
- if (num_architectural_pmu_fixed_counters > MAX_FIXED_COUNTERS) {
- num_architectural_pmu_fixed_counters = MAX_FIXED_COUNTERS;
- }
- }
- }
- }
-
- cpu_x86_cpuid(env, 0x80000000, 0, &limit, &unused, &unused, &unused);
-
- for (i = 0x80000000; i <= limit; i++) {
- if (cpuid_i == KVM_MAX_CPUID_ENTRIES) {
- fprintf(stderr, "unsupported xlevel value: 0x%x\n", limit);
- abort();
- }
- c = &cpuid_data.entries[cpuid_i++];
-
- switch (i) {
- case 0x8000001d:
- /* Query for all AMD cache information leaves */
- for (j = 0; ; j++) {
- c->function = i;
- c->flags = KVM_CPUID_FLAG_SIGNIFCANT_INDEX;
- c->index = j;
- cpu_x86_cpuid(env, i, j, &c->eax, &c->ebx, &c->ecx, &c->edx);
-
- if (c->eax == 0) {
- break;
- }
- if (cpuid_i == KVM_MAX_CPUID_ENTRIES) {
- fprintf(stderr, "cpuid_data is full, no space for "
- "cpuid(eax:0x%x,ecx:0x%x)\n", i, j);
- abort();
- }
- c = &cpuid_data.entries[cpuid_i++];
- }
- break;
- default:
- c->function = i;
- c->flags = 0;
- cpu_x86_cpuid(env, i, 0, &c->eax, &c->ebx, &c->ecx, &c->edx);
- if (!c->eax && !c->ebx && !c->ecx && !c->edx) {
- /*
- * KVM already returns all zeroes if a CPUID entry is missing,
- * so we can omit it and avoid hitting KVM's 80-entry limit.
- */
- cpuid_i--;
- }
- break;
- }
- }
-
- /* Call Centaur's CPUID instructions they are supported. */
- if (env->cpuid_xlevel2 > 0) {
- cpu_x86_cpuid(env, 0xC0000000, 0, &limit, &unused, &unused, &unused);
-
- for (i = 0xC0000000; i <= limit; i++) {
- if (cpuid_i == KVM_MAX_CPUID_ENTRIES) {
- fprintf(stderr, "unsupported xlevel2 value: 0x%x\n", limit);
- abort();
- }
- c = &cpuid_data.entries[cpuid_i++];
-
- c->function = i;
- c->flags = 0;
- cpu_x86_cpuid(env, i, 0, &c->eax, &c->ebx, &c->ecx, &c->edx);
- }
- }
-
+ cpuid_i = kvm_x86_arch_cpuid(env, cpuid_data.entries, cpuid_i);
cpuid_data.cpuid.nent = cpuid_i;

if (((env->cpuid_version >> 8)&0xF) >= 6
diff --git a/target/i386/kvm/kvm_i386.h b/target/i386/kvm/kvm_i386.h
index c3ef46a97a7b..cbf52c1c6d17 100644
--- a/target/i386/kvm/kvm_i386.h
+++ b/target/i386/kvm/kvm_i386.h
@@ -24,6 +24,9 @@
#define kvm_ioapic_in_kernel() \
(kvm_irqchip_in_kernel() && !kvm_irqchip_is_split())

+uint32_t kvm_x86_arch_cpuid(CPUX86State *env, struct kvm_cpuid_entry2 *entries,
+ uint32_t cpuid_i);
+
#else

#define kvm_pit_in_kernel() 0
--
2.34.1