From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932794Ab3GWNtH (ORCPT ); Tue, 23 Jul 2013 09:49:07 -0400 Received: from mx1.redhat.com ([209.132.183.28]:36192 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757510Ab3GWNtF (ORCPT ); Tue, 23 Jul 2013 09:49:05 -0400 Date: Tue, 23 Jul 2013 16:48:55 +0300 From: Gleb Natapov To: Jason Wang Cc: tglx@linutronix.de, mingo@redhat.com, hpa@zytor.com, x86@kernel.org, pbonzini@redhat.com, kvm@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 1/4] x86: introduce hypervisor_cpuid_base() Message-ID: <20130723134855.GA6029@redhat.com> References: <1374572465-15278-1-git-send-email-jasowang@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1374572465-15278-1-git-send-email-jasowang@redhat.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 23, 2013 at 05:41:02PM +0800, Jason Wang wrote: > This patch introduce hypervisor_cpuid_base() which loop test the hypervisor > existence function until the signature match and check the number of leaves if > required. This could be used by Xen/KVM guest to detect the existence of > hypervisor. > Looks good to me. Since this touches common code, kvm and xen I expect this to be taken via the tip tree, correct? > Cc: Thomas Gleixner > Cc: Ingo Molnar > Cc: "H. Peter Anvin" > Cc: "Paolo Bonzini" > Cc: Gleb Natapov > Cc: x86@kernel.org > Signed-off-by: Jason Wang > --- > arch/x86/include/asm/processor.h | 20 ++++++++++++++++++++ > 1 files changed, 20 insertions(+), 0 deletions(-) > > diff --git a/arch/x86/include/asm/processor.h b/arch/x86/include/asm/processor.h > index 24cf5ae..a8136d0 100644 > --- a/arch/x86/include/asm/processor.h > +++ b/arch/x86/include/asm/processor.h > @@ -971,6 +971,26 @@ unsigned long calc_aperfmperf_ratio(struct aperfmperf *old, > return ratio; > } > > +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; > +} > + > extern unsigned long arch_align_stack(unsigned long sp); > extern void free_init_pages(char *what, unsigned long begin, unsigned long end); > > -- > 1.7.1 -- Gleb.