From mboxrd@z Thu Jan 1 00:00:00 1970 From: Andre Przywara Subject: Re: [PATCH 4/4] dont trim the guest's hypervisor CPUID bit in KVM if the guest requests it Date: Wed, 24 Jun 2009 14:28:53 +0200 Message-ID: <4A421C05.3020203@amd.com> References: <1245840276-12702-1-git-send-email-andre.przywara@amd.com> <1245840276-12702-2-git-send-email-andre.przywara@amd.com> <1245840276-12702-3-git-send-email-andre.przywara@amd.com> <1245840276-12702-4-git-send-email-andre.przywara@amd.com> <4A420DD4.4020905@redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format=flowed Content-Transfer-Encoding: 7bit Cc: kvm@vger.kernel.org To: Avi Kivity Return-path: Received: from wa4ehsobe005.messaging.microsoft.com ([216.32.181.15]:30824 "EHLO WA4EHSOBE005.bigfish.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754163AbZFXM0G (ORCPT ); Wed, 24 Jun 2009 08:26:06 -0400 In-Reply-To: <4A420DD4.4020905@redhat.com> Sender: kvm-owner@vger.kernel.org List-ID: Avi Kivity wrote: > On 06/24/2009 01:44 PM, Andre Przywara wrote: >> Signed-off-by: Andre Przywara >> --- >> arch/x86/kvm/x86.c | 2 +- >> 1 files changed, 1 insertions(+), 1 deletions(-) >> >> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c >> index e6e61ee..6ad0f93 100644 >> --- a/arch/x86/kvm/x86.c >> +++ b/arch/x86/kvm/x86.c >> @@ -1415,7 +1415,7 @@ static void do_cpuid_ent(struct kvm_cpuid_entry2 >> *entry, u32 function, >> 0 /* Reserved */ | F(CX16) | 0 /* xTPR Update, PDCM */ | >> 0 /* Reserved, DCA */ | F(XMM4_1) | >> F(XMM4_2) | 0 /* x2APIC */ | F(MOVBE) | F(POPCNT) | >> - 0 /* Reserved, XSAVE, OSXSAVE */; >> + 0 /* Reserved, XSAVE, OSXSAVE */ | F(HYPERVISOR); >> > > I think this should be handled in qemu, since it isn't really a cpu bit. But this would require to make an exception for turning this bit on again after it has been trimmed. I just made (QEMU) patches for make this trimming really work (and removing all the hacked bits), so I would like to not spoil this again by introducing another excecption. After all this is more a list of what KVM does _not_ support (should we make this a negative one? gets ugly with the reserved bits), so I would like to leave it here. I will send out the patches to qemu-devel when I found the last bug. Regards, Andre. -- Andre Przywara AMD-OSRC (Dresden) Tel: x29712