Cache the vendor CPU type in a global variable so that multiple calls to is_amd/intel_cpu() do not need to re-execute CPUID.
Sync the global variable is_cpu_amd into the guest so the guest can also avoid executing CPUID instruction.
Suggested-by: Sean Christopherson seanjc@google.com Signed-off-by: Vishal Annapurve vannapurve@google.com --- tools/testing/selftests/kvm/lib/x86_64/processor.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/kvm/lib/x86_64/processor.c b/tools/testing/selftests/kvm/lib/x86_64/processor.c index fa65e8142c16..f508e58346e9 100644 --- a/tools/testing/selftests/kvm/lib/x86_64/processor.c +++ b/tools/testing/selftests/kvm/lib/x86_64/processor.c @@ -19,6 +19,7 @@ #define MAX_NR_CPUID_ENTRIES 100
vm_vaddr_t exception_handlers; +static bool is_cpu_amd;
static void regs_dump(FILE *stream, struct kvm_regs *regs, uint8_t indent) { @@ -1046,7 +1047,7 @@ static bool cpu_vendor_string_is(const char *vendor)
bool is_intel_cpu(void) { - return cpu_vendor_string_is("GenuineIntel"); + return !is_cpu_amd; }
/* @@ -1054,7 +1055,7 @@ bool is_intel_cpu(void) */ bool is_amd_cpu(void) { - return cpu_vendor_string_is("AuthenticAMD"); + return is_cpu_amd; }
void kvm_get_cpu_address_width(unsigned int *pa_bits, unsigned int *va_bits) @@ -1328,8 +1329,13 @@ bool vm_is_unrestricted_guest(struct kvm_vm *vm) return get_kvm_intel_param_bool("unrestricted_guest"); }
+void kvm_selftest_arch_init(void) +{ + is_cpu_amd = cpu_vendor_string_is("AuthenticAMD"); +}
void kvm_arch_vm_post_create(struct kvm_vm *vm) { vm_create_irqchip(vm); + sync_global_to_guest(vm, is_cpu_amd); }