target/i386/mshv: fix various cpuid traversal bugs
- Hardcoded max_leaf was not accurate. We query leaf 0x0 and 0x80000000 to get the actual max leaves - On all 0 zeroes on leaf 0x0d, we register 0-63 subleaves with zeros indicating XSAVE is disabled - Subleaf 0 was hardcoded, so the Hypervisor returned defaults for other subleaves - Subleaf 0 was hardcoded, so we were passing 0 instead of actual subleaf when adding entries. We now pass the correct subleaf value to add_cpuid_entry() - Leaves 0x04,0x07,0d,0f,10 weren't marked as subleaf-specific Signed-off-by: Magnus Kulke <magnuskulke@linux.microsoft.com> Acked-by: Wei Liu <wei.liu@kernel.org> Reviewed-by: Doru Blânzeanu <dblanzeanu@linux.microsoft.com> Link: https://lore.kernel.org/r/20260416121116.527927-4-magnuskulke@linux.microsoft.com Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Magnus Kulke committed
Apr 16, 2026 at 14:11 UTC
c851e0da56d2d892c906fffc4a9780403855caec
1 file changed
+61
-27
target/i386/mshv/mshv-cpu.c
+61
-27
@@ -465,14 +465,17 @@ static void collect_cpuid_entries(const CPUState *cpu, GList **cpuid_entries)
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CPUX86State *env = &x86_cpu->env;
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uint32_t eax, ebx, ecx, edx;
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uint32_t leaf, subleaf;
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- size_t max_leaf = 0x1F;
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- size_t max_subleaf = 0x20;
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-
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- uint32_t leaves_with_subleaves[] = {0x4, 0x7, 0xD, 0xF, 0x10};
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+ uint32_t max_basic_leaf, max_extended_leaf;
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+ uint32_t max_subleaf = 0x20;
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+ uint32_t leaves_with_subleaves[] = {0x04, 0x07, 0x0d, 0x0f, 0x10};
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int n_subleaf_leaves = ARRAY_SIZE(leaves_with_subleaves);
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- /* Regular leaves without subleaves */
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- for (leaf = 0; leaf <= max_leaf; leaf++) {
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+ /* Get maximum basic and and extended CPUID leaves */
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+ cpu_x86_cpuid(env, 0, 0, &max_basic_leaf, &ebx, &ecx, &edx);
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+ cpu_x86_cpuid(env, 0x80000000, 0, &max_extended_leaf, &ebx, &ecx, &edx);
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+
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+ /* Collect basic leaves (0x0 to max_basic_leaf) */
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+ for (leaf = 0; leaf <= max_basic_leaf; leaf++) {
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bool has_subleaves = false;
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for (int i = 0; i < n_subleaf_leaves; i++) {
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if (leaf == leaves_with_subleaves[i]) {
@@ -483,27 +486,40 @@ static void collect_cpuid_entries(const CPUState *cpu, GList **cpuid_entries)
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if (!has_subleaves) {
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cpu_x86_cpuid(env, leaf, 0, &eax, &ebx, &ecx, &edx);
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- if (eax == 0 && ebx == 0 && ecx == 0 && edx == 0) {
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- /* all zeroes indicates no more leaves */
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- continue;
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- }
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-
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add_cpuid_entry(cpuid_entries, leaf, 0, eax, ebx, ecx, edx);
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continue;
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}
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+ /*
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+ * Valid XSAVE components can exist at a higher index se we need to set
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+ * all subleaves for leaf 0x0d, even if we encounter an empty one.
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+ */
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+ if (leaf == 0x0d) {
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+ for (subleaf = 0; subleaf <= 63; subleaf++) {
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+ cpu_x86_cpuid(env, leaf, subleaf, &eax, &ebx, &ecx, &edx);
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+ add_cpuid_entry(cpuid_entries, leaf, subleaf,
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+ eax, ebx, ecx, edx);
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+ }
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+ continue;
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+ }
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+
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subleaf = 0;
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while (subleaf < max_subleaf) {
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cpu_x86_cpuid(env, leaf, subleaf, &eax, &ebx, &ecx, &edx);
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if (eax == 0 && ebx == 0 && ecx == 0 && edx == 0) {
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- /* all zeroes indicates no more leaves */
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break;
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}
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- add_cpuid_entry(cpuid_entries, leaf, 0, eax, ebx, ecx, edx);
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+ add_cpuid_entry(cpuid_entries, leaf, subleaf, eax, ebx, ecx, edx);
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subleaf++;
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}
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}
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+
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+ /* Collect extended leaves (0x80000000 to max_extended_leaf) */
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+ for (leaf = 0x80000000; leaf <= max_extended_leaf; leaf++) {
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+ cpu_x86_cpuid(env, leaf, 0, &eax, &ebx, &ecx, &edx);
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+ add_cpuid_entry(cpuid_entries, leaf, 0, eax, ebx, ecx, edx);
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+ }
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}
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static int register_intercept_result_cpuid_entry(const CPUState *cpu,
@@ -576,22 +592,40 @@ static int register_intercept_result_cpuid(const CPUState *cpu,
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subleaf_specific = 0;
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always_override = 1;
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- /* Intel */
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- /* 0xb - Extended Topology Enumeration Leaf */
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- /* 0x1f - V2 Extended Topology Enumeration Leaf */
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- /* AMD */
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- /* 0x8000_001e - Processor Topology Information */
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- /* 0x8000_0026 - Extended CPU Topology */
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- if (entry->function == 0xb
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- || entry->function == 0x1f
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- || entry->function == 0x8000001e
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- || entry->function == 0x80000026) {
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+ /*
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+ * Intel
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+ * 0xb - Extended Topology Enumeration Leaf
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+ * 0x1f - V2 Extended Topology Enumeration Leaf
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+ * AMD
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+ * 0x8000_001e - Processor Topology Information
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+ * 0x8000_0026 - Extended CPU Topology
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+ */
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+ if (entry->function == 0xb ||
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+ entry->function == 0x1f ||
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+ entry->function == 0x8000001e ||
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+ entry->function == 0x80000026) {
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+ subleaf_specific = 1;
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+ always_override = 1;
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+ /*
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+ * Feature enumeration leaves (subleaf-specific)
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+ * 0x04: Deterministic Cache Parameters
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+ * 0x07: Structured Extended Feature Flags
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+ * 0x0D: Processor Extended State Enumeration
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+ * 0x0F: Platform QoS Monitoring
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+ * 0x10: Platform QoS Enforcement
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+ */
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+ } else if (entry->function == 0x04 ||
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+ entry->function == 0x07 ||
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+ entry->function == 0x0d ||
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+ entry->function == 0x0f ||
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+ entry->function == 0x10) {
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subleaf_specific = 1;
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always_override = 1;
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- } else if (entry->function == 0x00000001
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- || entry->function == 0x80000000
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- || entry->function == 0x80000001
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- || entry->function == 0x80000008) {
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+ /* Basic feature leaves (no subleaves) */
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+ } else if (entry->function == 0x00000001 ||
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+ entry->function == 0x80000000 ||
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+ entry->function == 0x80000001 ||
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+ entry->function == 0x80000008) {
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subleaf_specific = 0;
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always_override = 1;
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}