Query cpuid once per guest selftest and store the cpu vendor type so that subsequent queries can reuse the cached cpu vendor type.
Signed-off-by: Vishal Annapurve vannapurve@google.com --- .../selftests/kvm/lib/x86_64/processor.c | 33 ++++++++++++++++--- 1 file changed, 28 insertions(+), 5 deletions(-)
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index 097cef430774..1e93bb3cb058 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -20,6 +20,9 @@
vm_vaddr_t exception_handlers;
+static bool is_cpu_vendor_intel; +static bool is_cpu_vendor_amd; + static void regs_dump(FILE *stream, struct kvm_regs *regs, uint8_t indent) { fprintf(stream, "%*srax: 0x%.16llx rbx: 0x%.16llx " @@ -1017,18 +1020,36 @@ void kvm_x86_state_cleanup(struct kvm_x86_state *state) free(state); }
-static bool cpu_vendor_string_is(const char *vendor) +static void check_cpu_vendor(void) { - const uint32_t *chunk = (const uint32_t *)vendor; + const char *intel_id = "GenuineIntel"; + const uint32_t *intel_id_chunks = (const uint32_t *)intel_id; + const char *amd_id = "AuthenticAMD"; + const uint32_t *amd_id_chunks = (const uint32_t *)amd_id; + static bool cpu_vendor_checked; uint32_t eax, ebx, ecx, edx;
+ if (cpu_vendor_checked) + return; + cpuid(0, &eax, &ebx, &ecx, &edx); - return (ebx == chunk[0] && edx == chunk[1] && ecx == chunk[2]); + + if (ebx == intel_id_chunks[0] && edx == intel_id_chunks[1] && + ecx == intel_id_chunks[2]) + is_cpu_vendor_intel = true; + else { + if (ebx == amd_id_chunks[0] && edx == amd_id_chunks[1] && + ecx == amd_id_chunks[2]) + is_cpu_vendor_amd = true; + } + cpu_vendor_checked = true; }
bool is_intel_cpu(void) { - return cpu_vendor_string_is("GenuineIntel"); + check_cpu_vendor(); + + return is_cpu_vendor_intel; }
/* @@ -1036,7 +1057,9 @@ bool is_intel_cpu(void) */ bool is_amd_cpu(void) { - return cpu_vendor_string_is("AuthenticAMD"); + check_cpu_vendor(); + + return is_cpu_vendor_amd; }
void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits)