From: Tao Xu <tao3.xu@intel.com>
To: Eduardo Habkost <ehabkost@redhat.com>
Cc: "pbonzini@redhat.com" <pbonzini@redhat.com>,
"qemu-devel@nongnu.org" <qemu-devel@nongnu.org>,
"rth@twiddle.net" <rth@twiddle.net>
Subject: Re: [PATCH v3 2/4] target/i386: Remove monitor from some CPU models
Date: Mon, 2 Mar 2020 19:47:28 +0800 [thread overview]
Message-ID: <06a6cd99-7d11-7eee-c337-c71e756fc53f@intel.com> (raw)
In-Reply-To: <20200228213909.GA481504@habkost.net>
On 2/29/2020 5:39 AM, Eduardo Habkost wrote:
> On Wed, Feb 12, 2020 at 04:13:26PM +0800, Tao Xu wrote:
>> Add new version of Snowridge, Denverton, Opteron_G3, EPYC, and Dhyana
>> CPU model to uremove MONITOR/MWAIT featre.
>>
>> After QEMU/KVM use "-overcommit cpu-pm=on" to expose MONITOR/MWAIT
>> (commit id 6f131f13e68d648a8e4f083c667ab1acd88ce4cd), the MONITOR/MWAIT
>> feature in these CPU model is unused.
>>
>> Signed-off-by: Tao Xu <tao3.xu@intel.com>
>
> What exactly is the problem you are trying to fix?
>
> No CPU model will ever have monitor=on set by default with KVM,
> because kvm_default_props has a monitor=off element.
>
Maybe it is not a fix. For example, when we boot a guest with Denverton
cpu model, guest cannot detect MONITOR/MWAIT and boot with no warning,
because of "monitor=off" by default. The MONITOR/MWAIT feature in these
CPU model is unused,but no harm. I am wondering if we should remove it
from existing CPU models.
next prev parent reply other threads:[~2020-03-02 11:48 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-12 8:13 [PATCH v3 0/4] Add extra information to versioned CPU models Tao Xu
2020-02-12 8:13 ` [PATCH v3 1/4] target/i386: Add Denverton-v2 (no MPX) CPU model Tao Xu
2020-02-28 21:46 ` Eduardo Habkost
2020-02-12 8:13 ` [PATCH v3 2/4] target/i386: Remove monitor from some CPU models Tao Xu
2020-02-28 21:39 ` Eduardo Habkost
2020-03-02 11:47 ` Tao Xu [this message]
2020-03-02 17:19 ` Eduardo Habkost
2020-03-03 0:18 ` Tao Xu
2020-02-12 8:13 ` [PATCH v3 3/4] target/i386: Add new property note to versioned " Tao Xu
2020-02-28 21:53 ` Eduardo Habkost
2020-02-12 8:13 ` [PATCH v3 4/4] target/i386: Add notes for " Tao Xu
2020-02-12 9:00 ` Igor Mammedov
2020-02-13 6:55 ` Tao Xu
2020-02-28 21:52 ` Eduardo Habkost
2020-03-02 12:01 ` Tao Xu
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