Right now, we were using individual KVM_CAP entities to communicate userspace about which cpuids we support. This is suboptimal, since it generates a delay between the feature arriving in the host, and being available at the guest. A much better mechanism is to list para features in KVM_GET_SUPPORTED_CPUID. This makes userspace automatically aware of what we provide. And if we ever add a new cpuid bit in the future, we have to do that again, which create some complexity and delay in feature adoption. Signed-off-by: Glauber Costa <glommer@xxxxxxxxxx> --- arch/x86/include/asm/kvm_para.h | 4 ++++ arch/x86/kvm/x86.c | 27 +++++++++++++++++++++++++++ 2 files changed, 31 insertions(+), 0 deletions(-) diff --git a/arch/x86/include/asm/kvm_para.h b/arch/x86/include/asm/kvm_para.h index 9734808..f019f8c 100644 --- a/arch/x86/include/asm/kvm_para.h +++ b/arch/x86/include/asm/kvm_para.h @@ -16,6 +16,10 @@ #define KVM_FEATURE_CLOCKSOURCE 0 #define KVM_FEATURE_NOP_IO_DELAY 1 #define KVM_FEATURE_MMU_OP 2 +/* This indicates that the new set of kvmclock msrs + * are available. The use of 0x11 and 0x12 is deprecated + */ +#define KVM_FEATURE_CLOCKSOURCE2 3 #define MSR_KVM_WALL_CLOCK 0x11 #define MSR_KVM_SYSTEM_TIME 0x12 diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index eb84947..8a7cdda 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -1971,6 +1971,20 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 *entry, u32 function, } break; } + case 0x40000000: { + char signature[] = "KVMKVMKVM"; + u32 *sigptr = (u32 *)signature; + entry->eax = 1; + entry->ebx = sigptr[0]; + entry->ecx = sigptr[1]; + entry->edx = sigptr[2]; + break; + } + case 0x40000001: + entry->eax = (1 << KVM_FEATURE_CLOCKSOURCE) | + (1 << KVM_FEATURE_NOP_IO_DELAY) | + (1 << KVM_FEATURE_CLOCKSOURCE2); + break; case 0x80000000: entry->eax = min(entry->eax, 0x8000001a); break; @@ -2017,6 +2031,19 @@ static int kvm_dev_ioctl_get_supported_cpuid(struct kvm_cpuid2 *cpuid, for (func = 0x80000001; func <= limit && nent < cpuid->nent; ++func) do_cpuid_ent(&cpuid_entries[nent], func, 0, &nent, cpuid->nent); + + + + r = -E2BIG; + if (nent >= cpuid->nent) + goto out_free; + + do_cpuid_ent(&cpuid_entries[nent], 0x40000000, 0, &nent, cpuid->nent); + limit = cpuid_entries[nent - 1].eax; + for (func = 0x40000001; func <= limit && nent < cpuid->nent; ++func) + do_cpuid_ent(&cpuid_entries[nent], func, 0, + &nent, cpuid->nent); + r = -E2BIG; if (nent >= cpuid->nent) goto out_free; -- 1.6.2.2 -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html