From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gleb Natapov Subject: Re: [PATCHv2] x86info: dump kvm cpuid's Date: Mon, 30 Apr 2012 18:03:20 +0300 Message-ID: <20120430150320.GA16592@redhat.com> References: <20120430143835.GA10190@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Content-Disposition: inline In-Reply-To: <20120430143835.GA10190@redhat.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: virtualization-bounces@lists.linux-foundation.org Errors-To: virtualization-bounces@lists.linux-foundation.org To: "Michael S. Tsirkin" Cc: xen-devel@lists.xensource.com, kvm@vger.kernel.org, pv-drivers@vmware.com, virtualization@lists.linux-foundation.org, devel@linuxdriverproject.org, davej@redhat.com List-Id: xen-devel@lists.xenproject.org On Mon, Apr 30, 2012 at 05:38:35PM +0300, Michael S. Tsirkin wrote: > The following makes 'x86info -r' dump hypervisor leaf cpu ids > (for kvm this is signature+features) when running in a vm. > > On the guest we see the signature and the features: > eax in: 0x40000000, eax = 00000000 ebx = 4b4d564b ecx = 564b4d56 edx = 0000004d > eax in: 0x40000001, eax = 0100007b ebx = 00000000 ecx = 00000000 edx = 00000000 > > Hypervisor flag is checked to avoid output changes when not > running on a VM. > > Signed-off-by: Michael S. Tsirkin > Looks good to me. > Changes from v1: > Make work on non KVM hypervisors (only KVM was tested). > Avi Kivity said kvm will in the future report > max HV leaf in eax. For now it reports eax = 0 > so add a work around for that. > > --- > > diff --git a/identify.c b/identify.c > index 33f35de..a4a3763 100644 > --- a/identify.c > +++ b/identify.c > @@ -9,8 +9,8 @@ > > void get_cpu_info_basics(struct cpudata *cpu) > { > - unsigned int maxi, maxei, vendor, address_bits; > - unsigned int eax; > + unsigned int maxi, maxei, maxhv, vendor, address_bits; > + unsigned int eax, ebx, ecx; > > cpuid(cpu->number, 0, &maxi, &vendor, NULL, NULL); > maxi &= 0xffff; /* The high-order word is non-zero on some Cyrix CPUs */ > @@ -19,7 +19,7 @@ void get_cpu_info_basics(struct cpudata *cpu) > return; > > /* Everything that supports cpuid supports these. */ > - cpuid(cpu->number, 1, &eax, NULL, NULL, NULL); > + cpuid(cpu->number, 1, &eax, &ebx, &ecx, NULL); > cpu->stepping = eax & 0xf; > cpu->model = (eax >> 4) & 0xf; > cpu->family = (eax >> 8) & 0xf; > @@ -29,6 +29,19 @@ void get_cpu_info_basics(struct cpudata *cpu) > > cpuid(cpu->number, 0xC0000000, &maxei, NULL, NULL, NULL); > cpu->maxei2 = maxei; > + if (ecx & 0x80000000) { > + cpuid(cpu->number, 0x40000000, &maxhv, NULL, NULL, NULL); > + /* > + * KVM up to linux 3.4 reports 0 as the max hypervisor leaf, > + * where it really means 0x40000001. > + * Most (all?) hypervisors have at least one CPUID besides > + * the vendor ID so assume that. > + */ > + cpu->maxhv = maxhv ? maxhv : 0x40000001; > + } else { > + /* Suppress hypervisor cpuid unless running on a hypervisor */ > + cpu->maxhv = 0; > + } > > cpuid(cpu->number, 0x80000008,&address_bits, NULL, NULL, NULL); > cpu->phyaddr_bits = address_bits & 0xFF; > diff --git a/x86info.c b/x86info.c > index 22c4734..80cae36 100644 > --- a/x86info.c > +++ b/x86info.c > @@ -44,6 +44,10 @@ static void display_detailed_info(struct cpudata *cpu) > > if (cpu->maxei2 >=0xC0000000) > dump_raw_cpuid(cpu->number, 0xC0000000, cpu->maxei2); > + > + if (cpu->maxhv >= 0x40000000) > + dump_raw_cpuid(cpu->number, 0x40000000, cpu->maxhv); > + > } > > if (show_cacheinfo) { > diff --git a/x86info.h b/x86info.h > index 7d2a455..c4f5d81 100644 > --- a/x86info.h > +++ b/x86info.h > @@ -84,7 +84,7 @@ struct cpudata { > unsigned int cachesize_trace; > unsigned int phyaddr_bits; > unsigned int viraddr_bits; > - unsigned int cpuid_level, maxei, maxei2; > + unsigned int cpuid_level, maxei, maxei2, maxhv; > char name[CPU_NAME_LEN]; > enum connector connector; > unsigned int flags_ecx; -- Gleb.