From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:55938) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zthiu-0003Of-Td for qemu-devel@nongnu.org; Tue, 03 Nov 2015 14:58:29 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1Zthiq-0001ur-SW for qemu-devel@nongnu.org; Tue, 03 Nov 2015 14:58:28 -0500 Received: from mx1.redhat.com ([209.132.183.28]:50840) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1Zthiq-0001uZ-Ms for qemu-devel@nongnu.org; Tue, 03 Nov 2015 14:58:24 -0500 From: Eduardo Habkost Date: Tue, 3 Nov 2015 17:58:12 -0200 Message-Id: <1446580695-28525-1-git-send-email-ehabkost@redhat.com> Subject: [Qemu-devel] [PATCH v2 0/3] target-i386: Don't trigger CPUID warnings by default in KVM mode (in most hosts) List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org Cc: Paolo Bonzini , Igor Mammedov , Richard Henderson , "Dr. David Alan Gilbert" , "Michael S. Tsirkin" The x86 change to make "check" mode be enabled by default made QEMU print warnings 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] There's also a warning when about missing the ABM feature if running on a Sandy Bridge or older host. ABM is not available on Sandy Bridge and older, SSE4a is not available in any Intel host. We want to make the default CPU runnable in most hosts, so those features won't be enabled by default in KVM mode. We should eventually have all features supported by TCG enabled by default in TCG mode, but as we don't have a good mechanism today to ensure we have different defaults in KVM and TCG mode, disable ABM and SSE4a in the qemu64 CPU model entirely. Also, as we can't change the guest ABI in pc-*-2.4, disable "check" mode by default in pc-*-2.4 and older so we don't print spurious warnings. Note that with this change, the qemu64 CPU model still requires a host supporting POPCNT (Nehalem or newer, and Opteron_G3 or newer). Eduardo Habkost (3): target-i386: Set "check=off" by default on pc-*-2.4 and older target-i386: Remove SSE4a from qemu64 CPU model target-i386: Remove ABM from qemu64 CPU model include/hw/i386/pc.h | 15 +++++++++++++++ target-i386/cpu.c | 3 +-- 2 files changed, 16 insertions(+), 2 deletions(-) -- 2.1.0