From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43498) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ezMH1-0002df-2t for qemu-devel@nongnu.org; Fri, 23 Mar 2018 08:58:24 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ezMGy-00016n-0U for qemu-devel@nongnu.org; Fri, 23 Mar 2018 08:58:23 -0400 From: Roman Kagan Date: Fri, 23 Mar 2018 15:58:06 +0300 Message-Id: <20180323125808.4479-1-rkagan@virtuozzo.com> MIME-Version: 1.0 Content-Type: text/plain Subject: [Qemu-devel] [PATCH for-2.12 0/2] i386/hyperv: fully control Hyper-V features in CPUID List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org, Paolo Bonzini , Eduardo Habkost , Vitaly Kuznetsov Cc: qemu-stable@nongnu.org In order to guarantee compatibility on migration, QEMU should have complete control over the features it announces to the guest via CPUID. However, a number of Hyper-V-related features happen to depend on the support in the underlying KVM, with no regard to QEMU configuration. Make QEMU regain control over what Hyper-V features it announces to the guest. Note: the patches are also being proposed for stable-2.11, even though one of them introduces a new cpu property. This is done to minimize the number of published QEMU releases where the behavior of the features is unpredictable, with potentially fatal consequences for the guest. Note #2: there are other problems in the surrounding code, like ugly error reporting or inconsistent population of MSRs. I think this can be put off to post-2.12. Roman Kagan (2): i386/hyperv: add hv-frequencies cpu property i386/hyperv: error out if features requested but unsupported Cc: qemu-stable@nongnu.org target/i386/cpu.h | 1 + target/i386/cpu.c | 1 + target/i386/kvm.c | 37 +++++++++++++++++++++++++++++-------- 3 files changed, 31 insertions(+), 8 deletions(-) -- 2.14.3