From: "Jan Beulich" <JBeulich@suse.com>
To: "Chao Gao" <chao.gao@intel.com>
Cc: Sergey Dyasli <sergey.dyasli@citrix.com>,
Ashok Raj <ashok.raj@intel.com>, WeiLiu <wl@xen.org>,
Andrew Cooper <andrew.cooper3@citrix.com>,
xen-devel <xen-devel@lists.xenproject.org>,
Roger Pau Monne <roger.pau@citrix.com>
Subject: Re: [Xen-devel] [PATCH v7 09/10] microcode: remove microcode_update_lock
Date: Tue, 11 Jun 2019 07:23:27 -0600 [thread overview]
Message-ID: <5CFFAB4F02000078002370E2@prv1-mh.provo.novell.com> (raw)
In-Reply-To: <20190611124604.GB22930@gao-cwp>
>>> On 11.06.19 at 14:46, <chao.gao@intel.com> wrote:
> On Wed, Jun 05, 2019 at 08:53:46AM -0600, Jan Beulich wrote:
>>>>> On 27.05.19 at 10:31, <chao.gao@intel.com> wrote:
>>> @@ -307,8 +303,7 @@ static int apply_microcode(const struct microcode_patch *patch)
>>>
>>> mc_intel = patch->mc_intel;
>>>
>>> - /* serialize access to the physical write to MSR 0x79 */
>>> - spin_lock_irqsave(µcode_update_lock, flags);
>>> + BUG_ON(local_irq_is_enabled());
>>>
>>> /*
>>> * Writeback and invalidate caches before updating microcode to avoid
>>
>>Thinking about it - what happens if we hit an NMI or #MC here?
>>watchdog_disable(), a call to which you add in an earlier patch,
>>doesn't really suppress the generation of NMIs, it only tells the
>>handler not to look at the accumulated statistics.
>
> I think they should be suppressed. Ashok, could you confirm it?
>
> I will figure out how to suppress them in Xen.
Well, afaik suppressing #MC is impossible. CR4.MCE clear leads
to immediate shutdown in case of a machine check, unless I'm
mistaken. The watchdog NMI, otoh, could of course be "properly"
disabled.
Jan
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next prev parent reply other threads:[~2019-06-11 13:24 UTC|newest]
Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-05-27 8:31 [PATCH v7 00/10] improve late microcode loading Chao Gao
2019-05-27 8:31 ` [Xen-devel] " Chao Gao
2019-05-27 8:31 ` [PATCH v7 01/10] misc/xen-ucode: Upload a microcode blob to the hypervisor Chao Gao
2019-05-27 8:31 ` [Xen-devel] " Chao Gao
2019-06-04 16:14 ` Andrew Cooper
2019-06-04 16:23 ` Jan Beulich
2019-06-06 2:29 ` Chao Gao
2019-05-27 8:31 ` [PATCH v7 02/10] microcode/intel: extend microcode_update_match() Chao Gao
2019-05-27 8:31 ` [Xen-devel] " Chao Gao
2019-06-04 14:39 ` Jan Beulich
2019-06-05 13:22 ` Roger Pau Monné
2019-06-05 14:16 ` Jan Beulich
2019-06-06 8:26 ` Chao Gao
2019-06-06 9:01 ` Jan Beulich
2019-05-27 8:31 ` [PATCH v7 03/10] microcode: introduce a global cache of ucode patch Chao Gao
2019-05-27 8:31 ` [Xen-devel] " Chao Gao
2019-06-04 15:03 ` Jan Beulich
2019-06-10 5:33 ` Chao Gao
2019-06-11 6:50 ` Jan Beulich
2019-05-27 8:31 ` [PATCH v7 04/10] microcode: remove struct ucode_cpu_info Chao Gao
2019-05-27 8:31 ` [Xen-devel] " Chao Gao
2019-06-04 15:13 ` Jan Beulich
2019-06-10 7:19 ` Chao Gao
2019-05-27 8:31 ` [PATCH v7 05/10] microcode: remove pointless 'cpu' parameter Chao Gao
2019-05-27 8:31 ` [Xen-devel] " Chao Gao
2019-06-04 15:29 ` Jan Beulich
2019-06-10 7:31 ` Chao Gao
2019-05-27 8:31 ` [PATCH v7 06/10] microcode: split out apply_microcode() from cpu_request_microcode() Chao Gao
2019-05-27 8:31 ` [Xen-devel] " Chao Gao
2019-06-05 12:37 ` Jan Beulich
2019-06-11 3:32 ` Chao Gao
2019-06-11 7:08 ` Jan Beulich
2019-06-11 8:53 ` Chao Gao
2019-06-11 9:15 ` Jan Beulich
2019-05-27 8:31 ` [PATCH v7 07/10] microcode/intel: Writeback and invalidate caches before updating microcode Chao Gao
2019-05-27 8:31 ` [Xen-devel] " Chao Gao
2019-06-05 13:20 ` Jan Beulich
2019-05-27 8:31 ` [PATCH v7 08/10] x86/microcode: Synchronize late microcode loading Chao Gao
2019-05-27 8:31 ` [Xen-devel] " Chao Gao
2019-06-05 14:09 ` Jan Beulich
2019-06-11 12:36 ` Chao Gao
2019-06-11 12:58 ` Jan Beulich
2019-06-11 15:47 ` Raj, Ashok
2019-06-05 14:42 ` Roger Pau Monné
2019-05-27 8:31 ` [PATCH v7 09/10] microcode: remove microcode_update_lock Chao Gao
2019-05-27 8:31 ` [Xen-devel] " Chao Gao
2019-06-05 14:52 ` Roger Pau Monné
2019-06-05 15:15 ` Jan Beulich
2019-06-05 14:53 ` Jan Beulich
2019-06-11 12:46 ` Chao Gao
2019-06-11 13:23 ` Jan Beulich [this message]
2019-06-11 16:04 ` Raj, Ashok
2019-06-12 7:38 ` Jan Beulich
2019-06-13 14:05 ` Chao Gao
2019-06-13 14:08 ` Jan Beulich
2019-06-13 14:58 ` Chao Gao
2019-06-13 17:47 ` Raj, Ashok
2019-06-14 8:58 ` Jan Beulich
2019-05-27 8:31 ` [PATCH v7 10/10] x86/microcode: always collect_cpu_info() during boot Chao Gao
2019-05-27 8:31 ` [Xen-devel] " Chao Gao
2019-06-05 14:56 ` Roger Pau Monné
2019-06-11 13:02 ` Chao Gao
2019-06-05 15:05 ` Jan Beulich
2019-06-11 12:58 ` Chao Gao
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