public inbox for kvm@vger.kernel.org
 help / color / mirror / Atom feed
From: "Cédric Le Goater" <clg@kaod.org>
To: David Gibson <david@gibson.dropbear.id.au>
Cc: kvm-ppc@vger.kernel.org, Paul Mackerras <paulus@samba.org>,
	kvm@vger.kernel.org
Subject: Re: [PATCH 0/3] KVM: PPC: Book3S HV: XIVE: assorted fixes on vCPU and RAM limits
Date: Thu, 23 May 2019 08:06:45 +0200	[thread overview]
Message-ID: <10ae32dc-a103-e523-1da2-a5ebedf9432f@kaod.org> (raw)
In-Reply-To: <20190522233043.GO30423@umbus.fritz.box>

On 5/23/19 1:30 AM, David Gibson wrote:
> On Mon, May 20, 2019 at 09:15:11AM +0200, Cédric Le Goater wrote:
>> Hello,
>>
>> Here are a couple of fixes for issues in the XIVE KVM device when
>> testing the limits : RAM size and number of vCPUS.

This summary is wrong. RAM size was fixed in QEMU.

> How serious are the problems these patches fix?  I'm wondering if I
> need to make a backport for RHEL8.1.

Patch 1 is a cleanup patch. It does not fix any critical issues.

Patch 2 fixes CPU hotplug. The test on the EQ flag is at the wrong 
place :/ This is important I think.

Patch 3 fixes the maximum number of vCPUS supported. This one is 
less important maybe, unless we want to run a guest with 1024 vCPUs.
Which is quite slow to run on most P9 systems. 

QEMU emits a warning :

  warning: Number of SMP cpus requested (1024) exceeds the recommended cpus supported by KVM (120)

May be we should refuse to run QEMU when that number is above a 
certain threshold ? 

C. 



>>
>> Based on 5.2-rc1.
>>
>> Available on GitHub:
>>
>>     https://github.com/legoater/linux/commits/xive-5.2
>>
>> Thanks,
>>
>> C. 
>>
>> Cédric Le Goater (3):
>>   KVM: PPC: Book3S HV: XIVE: clear file mapping when device is released
>>   KVM: PPC: Book3S HV: XIVE: do not test the EQ flag validity when
>>     reseting
>>   KVM: PPC: Book3S HV: XIVE: fix the enforced limit on the vCPU
>>     identifier
>>
>>  arch/powerpc/kvm/book3s_xive_native.c | 46 ++++++++++++++++-----------
>>  1 file changed, 27 insertions(+), 19 deletions(-)
>>
> 


  parent reply	other threads:[~2019-05-23  6:06 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-05-20  7:15 [PATCH 0/3] KVM: PPC: Book3S HV: XIVE: assorted fixes on vCPU and RAM limits Cédric Le Goater
2019-05-20  7:15 ` [PATCH 1/3] KVM: PPC: Book3S HV: XIVE: clear file mapping when device is released Cédric Le Goater
2019-05-20  7:15 ` [PATCH 2/3] KVM: PPC: Book3S HV: XIVE: do not test the EQ flag validity when resetting Cédric Le Goater
2019-05-20  8:06   ` Greg Kurz
2019-05-20  7:15 ` [PATCH 3/3] KVM: PPC: Book3S HV: XIVE: fix the enforced limit on the vCPU identifier Cédric Le Goater
2019-05-20  9:23   ` Greg Kurz
2019-05-22 23:30 ` [PATCH 0/3] KVM: PPC: Book3S HV: XIVE: assorted fixes on vCPU and RAM limits David Gibson
2019-05-23  6:01   ` Greg Kurz
2019-05-23  6:27     ` David Gibson
2019-05-23 12:44       ` Greg Kurz
2019-05-23  6:06   ` Cédric Le Goater [this message]
2019-05-31  6:33 ` Paul Mackerras

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=10ae32dc-a103-e523-1da2-a5ebedf9432f@kaod.org \
    --to=clg@kaod.org \
    --cc=david@gibson.dropbear.id.au \
    --cc=kvm-ppc@vger.kernel.org \
    --cc=kvm@vger.kernel.org \
    --cc=paulus@samba.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 a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox