From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54311) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZsF7E-0003Tq-22 for qemu-devel@nongnu.org; Fri, 30 Oct 2015 15:13:35 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZsF79-0005cZ-Tn for qemu-devel@nongnu.org; Fri, 30 Oct 2015 15:13:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:44255) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZsF79-0005au-OS for qemu-devel@nongnu.org; Fri, 30 Oct 2015 15:13:27 -0400 Date: Fri, 30 Oct 2015 17:13:23 -0200 From: Eduardo Habkost Message-ID: <20151030191323.GA20436@thinpad.lan.raisama.net> References: <1446231660-24394-1-git-send-email-ehabkost@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1446231660-24394-1-git-send-email-ehabkost@redhat.com> Subject: Re: [Qemu-devel] [PATCH 0/3] target-i386: Don't trigger "check" warnings by default in KVM mode List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Richard Henderson , "Michael S. Tsirkin" , Igor Mammedov On Fri, Oct 30, 2015 at 05:00:57PM -0200, Eduardo Habkost wrote: > The x86 change to make "check" mode be enabled by default made QEMU print a > warning in the default case if running in an Intel host: > > $ qemu-system-x86_64 -machine pc,accel=kvm > warning: host doesn't support requested feature: CPUID.80000001H:ECX.sse4a [bit 6] > > Fix this by not enabling sse4a in qemu64 when in KVM mode. > > The long term solution will probably involve creating separate "tcg64" and > "kvm64" CPU models as defaults, so we can finally choose completely diffferent > defaults in the KVM- and TCG-specific models without making the > kvm_default_props list grow too mcuh. Note that we can have a much simpler solution to this: disabling SSE4A on qemu64 completely, even on TCG. This way we can use PC_COMPAT_2_4 instead of the kvm_default_props compat hack. We can reenable SSE4A for TCG later (more exactly, we could enable everything from TCG_*_FEATURES) when we implement the kvm64/tcg64 solution. What do you think? -- Eduardo