From: "H. Peter Anvin" <hpa@zytor.com>
To: Jason Wang <jasowang@redhat.com>
Cc: tglx@linutronix.de, mingo@redhat.com, x86@kernel.org,
gleb@redhat.com, pbonzini@redhat.com, kvm@vger.kernel.org,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH 1/4] x86: introduce hypervisor_cpuid_base()
Date: Tue, 23 Jul 2013 03:04:44 -0700 [thread overview]
Message-ID: <51EE553C.40305@zytor.com> (raw)
In-Reply-To: <1374572465-15278-1-git-send-email-jasowang@redhat.com>
On 07/23/2013 02:41 AM, Jason Wang wrote:
>
> +static inline uint32_t hypervisor_cpuid_base(const char *sig, uint32_t leaves)
> +{
> + uint32_t base, eax, ebx, ecx, edx;
> + char signature[13];
> +
> + for (base = 0x40000000; base < 0x40010000; base += 0x100) {
> + cpuid(base, &eax, &ebx, &ecx, &edx);
> + *(uint32_t *)(signature + 0) = ebx;
> + *(uint32_t *)(signature + 4) = ecx;
> + *(uint32_t *)(signature + 8) = edx;
> + signature[12] = 0;
> +
> + if (!strcmp(sig, signature) &&
> + (leaves == 0 || ((eax - base) >= leaves)))
> + return base;
> + }
> +
> + return 0;
> +}
> +
Hmm... how about:
uint32_t sign[3];
cpuid(base, &eax, &sign[0], &sign[1], &sign[2]);
if (!memcmp(sig, sign, 12) && ...);
-hpa
next prev parent reply other threads:[~2013-07-23 10:04 UTC|newest]
Thread overview: 30+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-07-23 9:41 [PATCH 1/4] x86: introduce hypervisor_cpuid_base() Jason Wang
2013-07-23 9:41 ` [PATCH 2/4] xen: switch to use hypervisor_cpuid_base() Jason Wang
2013-07-23 11:16 ` Paolo Bonzini
2013-07-23 15:55 ` Konrad Rzeszutek Wilk
2013-07-23 9:41 ` [PATCH 3/4] kvm: " Jason Wang
2013-07-23 11:16 ` Paolo Bonzini
2013-07-23 9:41 ` [PATCH 4/4] x86: properly handle kvm emulation of hyperv Jason Wang
2013-07-23 11:17 ` Paolo Bonzini
2013-07-23 13:55 ` KY Srinivasan
2013-07-23 14:48 ` H. Peter Anvin
2013-07-23 17:45 ` KY Srinivasan
2013-07-23 18:45 ` H. Peter Anvin
2013-07-23 22:42 ` KY Srinivasan
2013-07-24 4:37 ` Jason Wang
2013-07-24 4:48 ` H. Peter Anvin
2013-07-24 6:54 ` Jason Wang
2013-07-24 7:06 ` Paolo Bonzini
2013-07-24 14:01 ` KY Srinivasan
2013-07-24 15:14 ` H. Peter Anvin
2013-07-24 19:05 ` KY Srinivasan
2013-07-24 21:37 ` H. Peter Anvin
2013-07-25 7:59 ` Paolo Bonzini
2013-07-25 8:12 ` Jason Wang
2013-07-23 10:04 ` H. Peter Anvin [this message]
2013-07-23 11:16 ` [PATCH 1/4] x86: introduce hypervisor_cpuid_base() Paolo Bonzini
2013-07-23 16:03 ` H. Peter Anvin
2013-07-24 4:44 ` Jason Wang
2013-07-24 4:47 ` H. Peter Anvin
2013-07-23 13:48 ` Gleb Natapov
2013-07-24 4:34 ` Jason Wang
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