From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:44945) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TENC8-00020l-2K for qemu-devel@nongnu.org; Wed, 19 Sep 2012 12:32:17 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TENC6-0008OS-8N for qemu-devel@nongnu.org; Wed, 19 Sep 2012 12:32:11 -0400 Received: from hub021-nj-2.exch021.serverdata.net ([206.225.164.217]:33101) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TENC6-0008NV-4r for qemu-devel@nongnu.org; Wed, 19 Sep 2012 12:32:10 -0400 Message-ID: <5059F388.6010007@CloudSwitch.Com> Date: Wed, 19 Sep 2012 12:32:08 -0400 From: Don Slutz MIME-Version: 1.0 References: <1347979793-27045-1-git-send-email-Don@CloudSwitch.com> <1347979793-27045-3-git-send-email-Don@CloudSwitch.com> <20120918170049.GB3983@otherpad.lan.raisama.net> <5058CC34.3030405@CloudSwitch.Com> <20120919132030.GE3983@otherpad.lan.raisama.net> In-Reply-To: <20120919132030.GE3983@otherpad.lan.raisama.net> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 2/2] target-i386: Fix default Hypervisor level for hypervisor-vendor=kvm. List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eduardo Habkost Cc: imammedo@redhat.com, qemu-devel@nongnu.org, kvm@vger.kernel.org On 09/19/12 09:20, Eduardo Habkost wrote: > On Tue, Sep 18, 2012 at 03:32:04PM -0400, Don Slutz wrote: >> On 09/18/12 13:00, Eduardo Habkost wrote: >>> On Tue, Sep 18, 2012 at 10:49:53AM -0400, Don Slutz wrote: >>>> From http://lkml.indiana.edu/hypermail/linux/kernel/1205.0/00100.html >>>> EAX should be KVM_CPUID_FEATURES (0x40000001) not 0. >>>> >>>> If kvm is not configured, the additional option of hypervisor-level=1 >>>> (or hypervisor-level=0x40000001) needs to be specified to get this. >>>> --- >>>> target-i386/cpu.c | 12 +++++++++++- >>>> 1 files changed, 11 insertions(+), 1 deletions(-) >>>> >>>> diff --git a/target-i386/cpu.c b/target-i386/cpu.c >>>> index 6e43eff..d73b0a8 100644 >>>> --- a/target-i386/cpu.c >>>> +++ b/target-i386/cpu.c >>>> @@ -1248,7 +1248,12 @@ static char *x86_cpuid_get_hv_vendor(Object *obj, Error **errp) >>>> env->cpuid_hv_level == CPUID_HV_LEVEL_XEN) { >>>> pstrcpy(value, sizeof(value), "xen"); >>>> } else if (!strcmp(value, CPUID_HV_VENDOR_KVM) && >>>> - env->cpuid_hv_level == 0) { >>>> +#if defined(CONFIG_KVM) >>>> + env->cpuid_hv_level == KVM_CPUID_FEATURES >>>> +#else >>>> + env->cpuid_hv_level == 0 >>>> +#endif >>>> + ) { >>>> pstrcpy(value, sizeof(value), "kvm"); >>>> } >>>> return value; >>>> @@ -1281,6 +1286,11 @@ static void x86_cpuid_set_hv_vendor(Object *obj, const char *value, >>>> } >>>> pstrcpy(adj_value, sizeof(adj_value), CPUID_HV_VENDOR_XEN); >>>> } else if (!strcmp(value, "kvm")) { >>>> +#if defined(CONFIG_KVM) >>>> + if (env->cpuid_hv_level == 0) { >>>> + env->cpuid_hv_level = KVM_CPUID_FEATURES; >>>> + } >>>> +#endif >>> If CPUID[0x40000000].EAX set to 0 is documented as equivalent to having >>> it set to 0x40000001 (KVM_CPUID_FEATURES), why the confusing checks for >>> CONFIG_KVM? Why not always set it to KVM_CPUID_FEATURES? >>> >> At line 36 of the file: >> >> #if defined(CONFIG_KVM) >> #include >> #endif >> >> So without the check you get compile failures (i386-linux-user). >> > Right. We can't include linux/kvm_para.h on a non-Linux build host, but > on the other hand I don't see any reason to not have > cpuid_hv_level=0x40000001 on builds without CONFIG_KVM too. > > If we want to allow fake KVM CPUID leaves on non-CONFIG_KVM builds like > the code above does, QEMU needs its own constant for > KVM_CPUID_FEATURES/0x40000001, so it doesn't depend on the Linux header. > Will do a V2 with a local define. >> I have no issue with removing the check(s) for 0. Currently >> hypervisor-level=0 will not force the old values; I can make a change >> so that works. >> -Don Slutz -Don Slutz