All of lore.kernel.org
 help / color / mirror / Atom feed
From: "Jan H. Schönherr" <jschoenh@amazon.de>
To: Xiao Guangrong <guangrong.xiao@gmail.com>
Cc: "Paolo Bonzini" <pbonzini@redhat.com>,
	"Radim Krčmář" <rkrcmar@redhat.com>,
	"Thomas Gleixner" <tglx@linutronix.de>,
	"Ingo Molnar" <mingo@redhat.com>,
	"H. Peter Anvin" <hpa@zytor.com>,
	x86@kernel.org, kvm@vger.kernel.org
Subject: Re: [PATCH] KVM: x86: Fix virtual wire mode
Date: Mon, 22 May 2017 10:54:07 +0200	[thread overview]
Message-ID: <b7fef2c0-cc88-8aa1-d02a-5d7483bfd6e7@amazon.de> (raw)
In-Reply-To: <6c3f2b42-df47-46c3-afb9-5fbb0869f1cd@gmail.com>

On 05/22/2017 09:19 AM, Xiao Guangrong wrote:
>
>
> On 05/20/2017 07:24 PM, Jan H. Schönherr wrote:
>> Intel SDM says, that at most one LAPIC should be configured with ExtINT
>> delivery. KVM configures all LAPICs this way. This causes pic_unlock()
>> to kick the first available vCPU from the internal KVM data structures.
>> If this vCPU is not the BSP, but some not-yet-booted AP, the BSP may
>> never realize that there is an interrupt.
>>
>> Fix that by enabling ExtINT delivery only for the BSP.
>>
>> This allows booting a Linux guest without a TSC in the above situation.
>> Otherwise the BSP gets stuck in calibrate_delay_converge().
>
> Patch looks good to me.
>
> BTW, what benefit do you want to get from notsc?
>

None. I just want my guest to boot in case it does that. :)

Regards
Jan
Amazon Development Center Germany GmbH
Berlin - Dresden - Aachen
main office: Krausenstr. 38, 10117 Berlin
Geschaeftsfuehrer: Dr. Ralf Herbrich, Christian Schlaeger
Ust-ID: DE289237879
Eingetragen am Amtsgericht Charlottenburg HRB 149173 B

      parent reply	other threads:[~2017-05-22  8:54 UTC|newest]

Thread overview: 3+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-05-20 11:24 [PATCH] KVM: x86: Fix virtual wire mode Jan H. Schönherr
2017-05-21 22:50 ` Wanpeng Li
     [not found] ` <6c3f2b42-df47-46c3-afb9-5fbb0869f1cd@gmail.com>
2017-05-22  8:54   ` Jan H. Schönherr [this message]

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=b7fef2c0-cc88-8aa1-d02a-5d7483bfd6e7@amazon.de \
    --to=jschoenh@amazon.de \
    --cc=guangrong.xiao@gmail.com \
    --cc=hpa@zytor.com \
    --cc=kvm@vger.kernel.org \
    --cc=mingo@redhat.com \
    --cc=pbonzini@redhat.com \
    --cc=rkrcmar@redhat.com \
    --cc=tglx@linutronix.de \
    --cc=x86@kernel.org \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.