[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: Howto read MSR thermal under XEN-4.15.0
- To: Jan Beulich <jbeulich@xxxxxxxx>, Julien Grall <julien@xxxxxxx>, "Bobbi Sanchez" <bobbisanchez@xxxxxx>
- From: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
- Date: Thu, 17 Jun 2021 12:43:40 +0100
- Arc-authentication-results: i=1; mx.microsoft.com 1; spf=pass smtp.mailfrom=citrix.com; dmarc=pass action=none header.from=citrix.com; dkim=pass header.d=citrix.com; arc=none
- Arc-message-signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=microsoft.com; s=arcselector9901; h=From:Date:Subject:Message-ID:Content-Type:MIME-Version:X-MS-Exchange-SenderADCheck; bh=V1oB+KouzyAYbH5dZayQSj+aZa8vZ644FUTTy1X0pJs=; b=Luew0nlqJq7sXMlpDE261kXGUCAkBZKdAKbjNl3gICmjsjrOniaNKGU5bnbI/vdSUr6lP91GlZO8HTcl/ewbOMxoMefW4AZgtmsUmXA7PIslTCpN8Xgnxw70oELDEDa5DDhFFvNmTtW4NOcgLTRU9OF5CC7h+Qa8wJnAEo5kU+nC3A61fPMvN7o/sIitOVpmhJTQ6qAyI54Ij6TCMuqjPeDcHkM9GXnpcxkRxxitF0B22D2APPaJBSX+cT8+fXQnkevYjpOEIUkohYLxmGnL4b/gDQrtpiYH5XYYa7E7Xcv1msdaMNLGBNAVb+EWAWRJCx3T9I0xFIOUuLSM/F688w==
- Arc-seal: i=1; a=rsa-sha256; s=arcselector9901; d=microsoft.com; cv=none; b=NUOIvhU0IDD/peZOMLgpALactD9dsOna9huQpJzKKDgRT16U7Tn8U+pHN3LaeZyZ3RUy86Du85JAWxliEJ2b5u9R3WKUko45olfnlybZYOJ/w2wFt+fb31FG0sIId2bSsRndLsUW3LgLjFb8NrUm0FnDp9aGEAETqClSW6tDW0EZP1n4KNKGoECcFSn7Ixw0WaZgHPHbNkoFmasImHBPoXI9ylnPbagZqx8EUgJzqwRCMg49EInRSZSezj/p5IUBedY5yFQunconLJippHBccFii4i+Cag71aUIsx50a8hBOh19x29DaV4RcG+Q3B5Pl5YALQfC4VCY3rQaxhCCl1g==
- Authentication-results: esa5.hc3370-68.iphmx.com; dkim=pass (signature verified) header.i=@citrix.onmicrosoft.com
- Cc: <Xen-users@xxxxxxxxxxxxxxxxxxxx>
- Delivery-date: Thu, 17 Jun 2021 11:44:08 +0000
- Ironport-hdrordr: A9a23:QuPNk6HRdJwpGKmopLqFA5HXdLJyesId70hD6qkvc3Nom52j+/ xGws536faVslcssHFJo6HkBEDyewKiyXcT2/hsAV7CZniahILMFu9fBOTZskXd8kHFh4lgPO JbAtJD4b7LfCtHZKTBkXCF+r8bqbHtmsDY5paq854ud3APV0gJ1XYINu/xKDwReOApP+taKH PR3Ls9m9L2Ek5nH/hTS0N1E9TrlpnurtbLcBQGDxko5E2nii6p0qfzF1y90g0FWz1C7L8++S yd+jaJqJmLgrWe8FvxxmXT55NZlJ/IzcZCPtWFjowwJi/3ggilSYx9U/mpvSwzosuo9FE2+e O87CsIDoBW0Tf8b2u1qRzi103LyzA18ULvzleenD/KvdH5bChSMbsDuatpNj/ir2YwttB116 xGm0iDsYBMMB/GlCPho/DVShBRkFauq3ZKq59Ss5Vma/paVFZtl/1awKsMe61wWx4SqbpXUd WGNfuspsq/KjihHjbkVgAF+q3fYpwxdi32CXTq9PbligS+p0oJuHfw8vZv1kvoxKhNP6Ws2N 60RJiAtIs+BPP+PpgNSdvof6OMeyXwqEX3QRyvyBLcZfk6B04=
- Ironport-sdr: 2DnrLphgyRk6srXIzwRmcBqkbRr11RpX1PtrW8NDT7/aWn3PSTygwT0TSeWMO7K5IBTlCTlZeX hG41tTbUy3/NDtl8TAKmtFq7KCU+Nxe3fs1fd1Gs2n1oy9/EvCSL+ImopHeZm48GmHycEU3MJZ 0JXBTKvLkHQbbC+CFqmpRkUElsV3ZVcWKdEjj1RMPxVfgnjUg7j6/BfothtyUroQFCAM+4HwEI GUlLKrIKWiH907E/TWk9gjniRjmwiyddAMql6bTrqvzz9DnuNn2PwfHTE3z7b8YgZaFV200PAK r/k=
- List-id: Xen user discussion <xen-users.lists.xenproject.org>
On 17/06/2021 12:26, Jan Beulich wrote:
> On 17.06.2021 13:09, Julien Grall wrote:
>> On 16/06/2021 23:39, Bobbi Sanchez wrote:
>>> how can i read the MSR Thermal Values under XEN-4.15.0 ?
>>>
>>> Usually without having XEN-4.15.0 installed i can read the MSR Thermal
>>> Values like this:
>>>
>>> rdmsr -p 0 -d -f22:16 0x19c
>>>
>>> this works for my Core2Quod Q6600.
>>>
>>> But after having xen-4.15.0 installed and booted, same command shows now: 0
>> I believe the access was restricted as part of XSA-351 [1]. I am not
>> sure if there are a safe generic way to access them. I will let Andrew
>> and Jan commenting.
> just as additional context (i.e. on top of Andrew's reply): It wasn't
> that XSA, but our general switch of policy from blacklisting to
> whitelisting MSRs. The XSA was about *_POWER_* and *_PERF_* MSRs.
Well - that XSA was the trigger for finally removing default read access
from all VMs, but yes - this specific issue described here only on Xen
4.15 and later.
You can use boot with dom0=msr-relaxed to regain read access, but will
still be subject to all the reasons I explained before about this not
actually working properly.
~Andrew
|
