All of lore.kernel.org
 help / color / mirror / Atom feed
From: Greg Kurz <groug@kaod.org>
To: "Cédric Le Goater" <clg@kaod.org>
Cc: aik@ozlabs.ru, andmike@linux.ibm.com,
	Ram Pai <linuxram@us.ibm.com>,
	kvm-ppc@vger.kernel.org, sukadev@linux.vnet.ibm.com,
	linuxppc-dev@lists.ozlabs.org, bauerman@linux.ibm.com,
	David Gibson <david@gibson.dropbear.id.au>
Subject: Re: [EXTERNAL] Re: [RFC PATCH v1] powerpc/prom_init: disable XIVE in Secure VM.
Date: Wed, 4 Mar 2020 09:34:44 +0100	[thread overview]
Message-ID: <20200304093444.5e524ef6@bahia.home> (raw)
In-Reply-To: <a1570b0d-c443-3140-31f0-bddd9f31f54b@kaod.org>

On Tue, 3 Mar 2020 20:18:18 +0100
Cédric Le Goater <clg@kaod.org> wrote:

> >> **** BTW: I figured, I dont need this intermin patch to disable xive for
> >> secure VM.  Just doing "svm=on xive=off" on the kernel command line is
> >> sufficient for now. *****
> >>
> > 
> > No it is not. If the hypervisor doesn't propose XIVE (ie. ic-mode=xive
> > on the QEMU command line), the kernel simply ignores "xive=off".
> 

Ah... sorry for the typo... "doesn't propose XICS" of course :)

> If I am correct, with the option ic-mode=xive, the hypervisor will 
> propose only 'xive' in OV5 and not both 'xive' and 'xics'. But the
> result is the same because xive can not be turned off and "xive=off" 
> is ignored.
> 
> Anyway, it's not the most common case of usage of the QEMU command
> like. I think it's OK to use "xive=off" on the kernel command line 
> for now.
> 

Sure, I just wanted to make things clear. Like you said it's a chicken
switch introduced for distro testing. I think it should not be used
to do anything else. If "svm=1" needs to enforce supported.xive == false
as a temporary workaround, it should do it explicitly.

> C.


WARNING: multiple messages have this Message-ID (diff)
From: Greg Kurz <groug@kaod.org>
To: "Cédric Le Goater" <clg@kaod.org>
Cc: aik@ozlabs.ru, andmike@linux.ibm.com,
	Ram Pai <linuxram@us.ibm.com>,
	kvm-ppc@vger.kernel.org, sukadev@linux.vnet.ibm.com,
	linuxppc-dev@lists.ozlabs.org, bauerman@linux.ibm.com,
	David Gibson <david@gibson.dropbear.id.au>
Subject: Re: [EXTERNAL] Re: [RFC PATCH v1] powerpc/prom_init: disable XIVE in Secure VM.
Date: Wed, 04 Mar 2020 08:34:44 +0000	[thread overview]
Message-ID: <20200304093444.5e524ef6@bahia.home> (raw)
In-Reply-To: <a1570b0d-c443-3140-31f0-bddd9f31f54b@kaod.org>

On Tue, 3 Mar 2020 20:18:18 +0100
Cédric Le Goater <clg@kaod.org> wrote:

> >> **** BTW: I figured, I dont need this intermin patch to disable xive for
> >> secure VM.  Just doing "svm=on xive=off" on the kernel command line is
> >> sufficient for now. *****
> >>
> > 
> > No it is not. If the hypervisor doesn't propose XIVE (ie. ic-mode=xive
> > on the QEMU command line), the kernel simply ignores "xive=off".
> 

Ah... sorry for the typo... "doesn't propose XICS" of course :)

> If I am correct, with the option ic-mode=xive, the hypervisor will 
> propose only 'xive' in OV5 and not both 'xive' and 'xics'. But the
> result is the same because xive can not be turned off and "xive=off" 
> is ignored.
> 
> Anyway, it's not the most common case of usage of the QEMU command
> like. I think it's OK to use "xive=off" on the kernel command line 
> for now.
> 

Sure, I just wanted to make things clear. Like you said it's a chicken
switch introduced for distro testing. I think it should not be used
to do anything else. If "svm=1" needs to enforce supported.xive = false
as a temporary workaround, it should do it explicitly.

> C.

  reply	other threads:[~2020-03-04  8:57 UTC|newest]

Thread overview: 47+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2020-02-29  7:54 [RFC PATCH v1] powerpc/prom_init: disable XIVE in Secure VM Ram Pai
2020-02-29  7:54 ` Ram Pai
2020-02-29  8:27 ` Cédric Le Goater
2020-02-29  8:27   ` Cédric Le Goater
2020-02-29 22:51   ` Ram Pai
2020-02-29 22:51     ` Ram Pai
2020-03-02  7:34     ` Cédric Le Goater
2020-03-02  7:34       ` Cédric Le Goater
2020-03-02 20:54 ` Greg Kurz
2020-03-02 20:54   ` Greg Kurz
2020-03-02 23:32 ` David Gibson
2020-03-02 23:32   ` David Gibson
2020-03-03  6:50   ` Cédric Le Goater
2020-03-03  6:50     ` Cédric Le Goater
2020-03-03 17:02     ` Ram Pai
2020-03-03 17:02       ` Ram Pai
2020-03-03 17:45       ` Greg Kurz
2020-03-03 17:45         ` Greg Kurz
2020-03-03 18:56         ` Ram Pai
2020-03-03 18:56           ` Ram Pai
2020-03-04 10:59           ` Greg Kurz
2020-03-04 10:59             ` Greg Kurz
2020-03-04 15:13             ` Ram Pai
2020-03-04 15:13               ` Ram Pai
2020-03-04 15:37             ` Ram Pai
2020-03-04 15:37               ` Ram Pai
2020-03-04 15:56               ` Cédric Le Goater
2020-03-04 15:56                 ` Cédric Le Goater
2020-03-04 23:55                 ` David Gibson
2020-03-04 23:55                   ` David Gibson
2020-03-05  7:15                   ` Cédric Le Goater
2020-03-05  7:15                     ` Cédric Le Goater
2020-03-05 15:15                   ` Ram Pai
2020-03-05 15:15                     ` Ram Pai
2020-03-05 15:36                     ` Cédric Le Goater
2020-03-05 15:36                       ` Cédric Le Goater
2020-03-03 19:18         ` [EXTERNAL] " Cédric Le Goater
2020-03-03 19:18           ` Cédric Le Goater
2020-03-04  8:34           ` Greg Kurz [this message]
2020-03-04  8:34             ` Greg Kurz
2020-03-03 19:08       ` Cédric Le Goater
2020-03-03 19:08         ` Cédric Le Goater
2020-03-03 20:29         ` Ram Pai
2020-03-03 20:29           ` Ram Pai
2020-03-05 11:41           ` Cédric Le Goater
2020-03-05 11:41             ` Cédric Le Goater
  -- strict thread matches above, loose matches on Subject: below --
2020-02-29  7:27 Ram Pai

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=20200304093444.5e524ef6@bahia.home \
    --to=groug@kaod.org \
    --cc=aik@ozlabs.ru \
    --cc=andmike@linux.ibm.com \
    --cc=bauerman@linux.ibm.com \
    --cc=clg@kaod.org \
    --cc=david@gibson.dropbear.id.au \
    --cc=kvm-ppc@vger.kernel.org \
    --cc=linuxppc-dev@lists.ozlabs.org \
    --cc=linuxram@us.ibm.com \
    --cc=sukadev@linux.vnet.ibm.com \
    /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.