From: Paul Mackerras <paulus@samba.org>
To: Alexander Graf <agraf@suse.de>
Cc: "Alexey Kardashevskiy" <aik@ozlabs.ru>,
"QEMU Developers" <qemu-devel@nongnu.org>,
"list@suse.de:PReP" <qemu-ppc@nongnu.org>,
"Anthony Liguori" <anthony@codemonkey.ws>,
open@suse.de, "Andreas Färber" <afaerber@suse.de>
Subject: Re: [Qemu-devel] [PATCH] RFC: powerpc: add PVR compatibility check
Date: Tue, 5 Nov 2013 15:00:10 +1100 [thread overview]
Message-ID: <20131105040010.GB2832@drongo> (raw)
In-Reply-To: <FFBE76C2-8856-466A-8660-30167D2BEF0D@suse.de>
On Mon, Nov 04, 2013 at 10:05:58AM +0100, Alexander Graf wrote:
>
> Yeah, we really need to check that guest vpcu == host vcpu for HV KVM.
In general I agree, but the one difficulty I see is that a check for
exact equality will interact badly with qemu's habit of picking a
specific processor version when the user specifies something general
like "POWER7". So if the user does -cpu POWER7 on a machine with
(for example) a POWER7 v2.1 processor, but qemu arbitrarily picks the
PVR for POWER7 v2.3, then it will fail, which will be completely
puzzling to the user -- "I asked for POWER7, and it is a POWER7,
what's the problem??".
Maybe if the user asks for a non-specific processor type, and the
host's PVR matches the request, then qemu should take the host's PVR
rather than just picking some arbitrary processor version.
Paul.
next prev parent reply other threads:[~2013-11-05 4:00 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-11-04 3:36 [Qemu-devel] [PATCH] RFC: powerpc: add PVR compatibility check Alexey Kardashevskiy
2013-11-04 7:47 ` Alexander Graf
2013-11-04 8:58 ` Alexey Kardashevskiy
2013-11-04 9:05 ` Alexander Graf
2013-11-04 9:24 ` Alexey Kardashevskiy
2013-11-04 9:29 ` Alexander Graf
2013-11-05 4:00 ` Paul Mackerras [this message]
2013-11-05 6:05 ` Alexander Graf
2013-11-05 16:16 ` Andreas Färber
2013-11-05 16:18 ` Alexander Graf
2013-11-06 3:02 ` Paul Mackerras
2013-11-06 12:19 ` Alexander Graf
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