From: Eduardo Habkost <ehabkost@redhat.com>
To: Peter Maydell <peter.maydell@linaro.org>
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
"Richard Henderson" <rth@twiddle.net>,
"Andreas Färber" <afaerber@suse.de>,
qemu-devel@nongnu.org
Subject: [Qemu-devel] [PULL 1/5] target-i386: Set "check=off" by default on pc-*-2.4 and older
Date: Thu, 5 Nov 2015 17:37:07 -0200 [thread overview]
Message-ID: <1446752231-3715-2-git-send-email-ehabkost@redhat.com> (raw)
In-Reply-To: <1446752231-3715-1-git-send-email-ehabkost@redhat.com>
The default CPU model (qemu64) have some issues today: it enables some
features (ABM and SSE4a) that are not present in many host CPUs. That
means many hosts (but not all of them) had those features silently
disabled in the default configuration in QEMU 2.4 and older.
With the new "check=on" default, this causes warnings to be printed in
the default configuration, because of the lack of SSE4A on all Intel
hosts, and the lack of ABM on Sandy Bridge and older hosts:
$ qemu-system-x86_64 -machine pc,accel=kvm
warning: host doesn't support requested feature: CPUID.80000001H:ECX.abm [bit 5]
warning: host doesn't support requested feature: CPUID.80000001H:ECX.sse4a [bit 6]
Those issues will be fixed in pc-*-2.5 and newer. But 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.
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
---
include/hw/i386/pc.h | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/include/hw/i386/pc.h b/include/hw/i386/pc.h
index 606dbc2..8be4520 100644
--- a/include/hw/i386/pc.h
+++ b/include/hw/i386/pc.h
@@ -322,6 +322,11 @@ bool e820_get_entry(int, uint32_t, uint64_t *, uint64_t *);
.driver = "host" "-" TYPE_X86_CPU,\
.property = "host-cache-info",\
.value = "on",\
+ },\
+ {\
+ .driver = TYPE_X86_CPU,\
+ .property = "check",\
+ .value = "off",\
},
#define PC_COMPAT_2_3 \
--
2.1.0
next prev parent reply other threads:[~2015-11-05 19:37 UTC|newest]
Thread overview: 7+ messages / expand[flat|nested] mbox.gz Atom feed top
2015-11-05 19:37 [Qemu-devel] [PULL 0/5] X86 queue, 2015-11-05 Eduardo Habkost
2015-11-05 19:37 ` Eduardo Habkost [this message]
2015-11-05 19:37 ` [Qemu-devel] [PULL 2/5] target-i386: Remove SSE4a from qemu64 CPU model Eduardo Habkost
2015-11-05 19:37 ` [Qemu-devel] [PULL 3/5] target-i386: Remove ABM " Eduardo Habkost
2015-11-05 19:37 ` [Qemu-devel] [PULL 4/5] target-i386: Remove POPCNT from qemu64 and qemu32 CPU models Eduardo Habkost
2015-11-05 19:37 ` [Qemu-devel] [PULL 5/5] target-i386: Enable clflushopt/clwb/pcommit instructions Eduardo Habkost
2015-11-06 11:03 ` [Qemu-devel] [PULL 0/5] X86 queue, 2015-11-05 Peter Maydell
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