From mboxrd@z Thu Jan 1 00:00:00 1970 From: bugzilla-daemon@bugzilla.kernel.org Subject: [Bug 77271] CPUID Leaf 0x40000000 return 0 in eax Date: Tue, 03 Jun 2014 20:44:52 +0000 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit To: kvm@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.19.201]:32929 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933394AbaFCUoz (ORCPT ); Tue, 3 Jun 2014 16:44:55 -0400 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id CAA6A20320 for ; Tue, 3 Jun 2014 20:44:54 +0000 (UTC) Received: from bugzilla2.web.kernel.org (bugzilla2.web.kernel.org [172.20.200.52]) by mail.kernel.org (Postfix) with ESMTP id BC636202A1 for ; Tue, 3 Jun 2014 20:44:52 +0000 (UTC) In-Reply-To: Sender: kvm-owner@vger.kernel.org List-ID: https://bugzilla.kernel.org/show_bug.cgi?id=77271 Alex Williamson changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |alex.williamson@redhat.com --- Comment #1 from Alex Williamson --- Further up in cpuid.txt is the statement: "This is not always guaranteed to work, since userspace can mask-out some, or even all KVM-related cpuid features before launching a guest." Which is exactly what is happening here. QEMU sets eax = 0 for this leaf: target-i386/kvm.c memcpy(signature, "KVMKVMKVM\0\0\0", 12); c = &cpuid_data.entries[cpuid_i++]; c->function = KVM_CPUID_SIGNATURE | kvm_base; c->eax = 0; c->ebx = signature[0]; c->ecx = signature[1]; c->edx = signature[2]; So I don't think there's a bug here. -- You are receiving this mail because: You are watching the assignee of the bug.