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From: Haozhong Zhang <haozhong.zhang@intel.com>
To: Ashok Raj <ashok.raj@intel.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>,
	Laszlo Ersek <lersek@redhat.com>,
	seabios@seabios.org, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [SeaBIOS] [PATCH v3] fw/msr_feature_control: add support to set MSR_IA32_FEATURE_CONTROL
Date: Wed, 6 Jul 2016 14:28:32 +0800	[thread overview]
Message-ID: <20160706062832.py2denwwvhw24f52@hz-desktop> (raw)
In-Reply-To: <234271213.4215596.1467785884526.JavaMail.zimbra@redhat.com>

Hi Ashok,

On 07/06/16 02:18, Paolo Bonzini wrote:
> > I forgot to restore MSR_IA32_FEATURE_CONTROL in the resume path, and
> > MSR_IA32_FEATURE_CONTROL is zero after S3 resume.
> 
> This is a bug.  Sorry Laszlo. :)
> 
> > Not restore MSR_IA32_FEATURE_CONTROL during S3 resume does not affect
> > at least Linux guest (tested 4.5). Current QEMU may advise the guest
> > firmware to set bit 20 (for LMCE), bit 2 (for VMX) and bit 0 (lock
> > bit).
> > - For LMCE, Linux only checks bit 20 and bit 0 at boot time and then
> >   keeps using the result even after resume.
> 
> On real hardware, LMCE would not be enabled after resume.  I'm not
> sure what would happen, but it wouldn't be good.

Could you help to check if the LMCE bit in MSR_IA32_FEATURE_CONTROL is
set after S3 resume on the real hardware?

Thanks,
Haozhong

  reply	other threads:[~2016-07-06  6:28 UTC|newest]

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2016-06-22  6:53 [Qemu-devel] [PATCH v3] fw/msr_feature_control: add support to set MSR_IA32_FEATURE_CONTROL Haozhong Zhang
2016-07-01 12:02 ` [Qemu-devel] [SeaBIOS] " Gerd Hoffmann
2016-07-05 22:19 ` Laszlo Ersek
2016-07-06  1:26   ` Haozhong Zhang
2016-07-06  6:18     ` Paolo Bonzini
2016-07-06  6:28       ` Haozhong Zhang [this message]
2016-07-06  6:42         ` Laszlo Ersek
2016-07-06  6:49           ` Haozhong Zhang
2016-07-06  7:44             ` Laszlo Ersek
2016-07-06  8:48               ` Haozhong Zhang
2016-07-06  9:00                 ` Laszlo Ersek
2016-07-06  9:05                   ` Laszlo Ersek
2016-07-06  9:07                   ` Haozhong Zhang
2016-07-06  9:13                     ` Laszlo Ersek
2016-07-06 11:04           ` Laszlo Ersek
2016-07-06 12:18             ` Paolo Bonzini
2016-07-06 15:43               ` Laszlo Ersek
2016-07-07 12:12                 ` Paolo Bonzini
2016-07-07 12:44                   ` Laszlo Ersek
2016-07-07 13:19                     ` [Qemu-devel] " Paolo Bonzini
2016-07-06 13:03             ` [Qemu-devel] [SeaBIOS] " Haozhong Zhang
2016-07-06 15:32               ` Laszlo Ersek

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