From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([208.118.235.92]:41411) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TE4GY-0004CD-FR for qemu-devel@nongnu.org; Tue, 18 Sep 2012 16:19:31 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1TE4GX-0002Hc-4F for qemu-devel@nongnu.org; Tue, 18 Sep 2012 16:19:30 -0400 Received: from hub021-nj-8.exch021.serverdata.net ([206.225.164.233]:25348) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1TE4GX-0002HO-0P for qemu-devel@nongnu.org; Tue, 18 Sep 2012 16:19:29 -0400 Message-ID: <5058D74F.7050204@CloudSwitch.Com> Date: Tue, 18 Sep 2012 16:19:27 -0400 From: Don Slutz MIME-Version: 1.0 References: <1347979793-27045-1-git-send-email-Don@CloudSwitch.com> <1347979793-27045-2-git-send-email-Don@CloudSwitch.com> <20120918150539.GY3983@otherpad.lan.raisama.net> In-Reply-To: <20120918150539.GY3983@otherpad.lan.raisama.net> Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Subject: Re: [Qemu-devel] [PATCH 1/2] target-i386: Fix default Hypervisor level for accel=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 09/18/12 11:05, Eduardo Habkost wrote: > On Tue, Sep 18, 2012 at 10:49:52AM -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. >> --- >> target-i386/kvm.c | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/target-i386/kvm.c b/target-i386/kvm.c >> index 761a9b1..0c9f5dd 100644 >> --- a/target-i386/kvm.c >> +++ b/target-i386/kvm.c >> @@ -392,7 +392,7 @@ int kvm_arch_init_vcpu(CPUX86State *env) >> c->function = KVM_CPUID_SIGNATURE; >> if (env->cpuid_hv_level == 0) { >> memcpy(signature, "KVMKVMKVM\0\0\0", 12); >> - c->eax = 0; >> + c->eax = KVM_CPUID_FEATURES; > This makes the CPUID bits to suddenly change, when live-migrating to a > newer QEMU version. > > Strictly speaking, this is never supposed to happen, but... on both > cases the meaning of the bits are the same (0 is documented as > equivalent to KVM_CPUID_FEATURES) and probably the guest will look at > them only once on boot. Do we really want to add migration-compatibility > code for this? > My vote would be no; because this should be ok and the tests that I know of are all at boot time. I will look into adding migration-compatibility. I also do not have any direct need for this change, it just looked like the right thing to do. >> c->ebx = signature[0]; >> c->ecx = signature[1]; >> c->edx = signature[2]; >> -- >> 1.7.1 >>