diff options
| -rw-r--r-- | src/fw/paravirt.c | 30 |
1 files changed, 21 insertions, 9 deletions
diff --git a/src/fw/paravirt.c b/src/fw/paravirt.c index fba4e52d..42abac84 100644 --- a/src/fw/paravirt.c +++ b/src/fw/paravirt.c @@ -53,23 +53,35 @@ inline int qemu_cfg_dma_enabled(void) * should be used to determine that a VM is running under KVM. */ #define KVM_CPUID_SIGNATURE 0x40000000 +static unsigned int kvm_cpuid_base = 0; static void kvm_detect(void) { + unsigned int i, max = 0; unsigned int eax, ebx, ecx, edx; char signature[13]; - cpuid(KVM_CPUID_SIGNATURE, &eax, &ebx, &ecx, &edx); - memcpy(signature + 0, &ebx, 4); - memcpy(signature + 4, &ecx, 4); - memcpy(signature + 8, &edx, 4); - signature[12] = 0; + for (i = KVM_CPUID_SIGNATURE;; i += 0x100) { + eax = 0; + cpuid(i, &eax, &ebx, &ecx, &edx); + if (eax < i) + break; + memcpy(signature + 0, &ebx, 4); + memcpy(signature + 4, &ecx, 4); + memcpy(signature + 8, &edx, 4); + signature[12] = 0; + dprintf(1, "cpuid 0x%x: eax %x, signature '%s'\n", i, eax, signature); + if (strcmp(signature, "KVMKVMKVM") == 0) { + kvm_cpuid_base = i; + max = eax; + } + } - if (strcmp(signature, "KVMKVMKVM") == 0) { + if (kvm_cpuid_base) { dprintf(1, "Running on KVM\n"); PlatformRunningOn |= PF_KVM; - if (eax >= KVM_CPUID_SIGNATURE + 0x10) { - cpuid(KVM_CPUID_SIGNATURE + 0x10, &eax, &ebx, &ecx, &edx); + if (max >= kvm_cpuid_base + 0x10) { + cpuid(kvm_cpuid_base + 0x10, &eax, &ebx, &ecx, &edx); dprintf(1, "kvm: have invtsc, freq %u kHz\n", eax); tsctimer_setfreq(eax, "invtsc"); } @@ -93,7 +105,7 @@ static void kvmclock_init(void) if (!runningOnKVM()) return; - cpuid(KVM_CPUID_SIGNATURE + 0x01, &eax, &ebx, &ecx, &edx); + cpuid(kvm_cpuid_base + 0x01, &eax, &ebx, &ecx, &edx); if (eax & (1 << KVM_FEATURE_CLOCKSOURCE2)) msr = MSR_KVM_SYSTEM_TIME_NEW; else if (eax & (1 << KVM_FEATURE_CLOCKSOURCE)) |