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From: "Radim Krčmář" <rkrcmar@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: bsd@redhat.com, qemu-devel@nongnu.org, ehabkost@redhat.com,
	rth@twiddle.net
Subject: Re: [Qemu-devel] [PATCH 1/2] target-i386: emulate CPUID level of real hardware
Date: Thu, 18 Jun 2015 17:40:18 +0200	[thread overview]
Message-ID: <20150618154018.GA10217@potion.brq.redhat.com> (raw)
In-Reply-To: <5582E3EA.2070407@redhat.com>

2015-06-18 17:29+0200, Paolo Bonzini:
> On 18/06/2015 17:24, Radim Krčmář wrote:
> > W10 insider has a bug where it ignores CPUID level and interprets
> > CPUID.(EAX=07H, ECX=0H) incorrectly, because CPUID in fact returned
> > CPUID.(EAX=04H, ECX=0H);  this resulted in execution of unsupported
> > instructions.
> > 
> > While it's a Windows bug, there is no reason to emulate incorrect level;
> > and amend xlevel while at it.
> > 
> > I have used http://instlatx64.atw.hu/ as a source of CPUID and checked
> > that it matches Penryn Xeon X5472, Westmere Xeon W3520, SandyBridge
> > i5-2540M, and Haswell i5-4670T.
> > 
> > kvm64 and qemu64 were bumped to 0xD to avoid similar problems.
> 
> This unfortunately has to be done only for new machine types.  Old types
> will remain buggy forever.

Ah, ok, which machine type should I target, 2.4?
And is patch 2 is only supposed to work with new machine types?

Thanks.

  reply	other threads:[~2015-06-18 15:40 UTC|newest]

Thread overview: 13+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2015-06-18 15:24 [Qemu-devel] [PATCH 0/2] target-i386: fix W10 bug and bring CPUID levels closer to reality Radim Krčmář
2015-06-18 15:24 ` [Qemu-devel] [PATCH 1/2] target-i386: emulate CPUID level of real hardware Radim Krčmář
2015-06-18 15:29   ` Paolo Bonzini
2015-06-18 15:40     ` Radim Krčmář [this message]
2015-06-18 15:42       ` Paolo Bonzini
2015-06-18 17:26     ` Bandan Das
2015-06-18 15:24 ` [Qemu-devel] [PATCH 2/2] target-i386: automatically raise cpuid level to 0xd Radim Krčmář
2015-06-18 15:50   ` Eduardo Habkost
2015-06-18 17:12     ` Bandan Das
2015-06-18 17:26       ` Eduardo Habkost
2015-06-19  9:47     ` Radim Krčmář
2015-06-19  9:54       ` Radim Krčmář
2015-06-19 11:28       ` Radim Krčmář

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