From: Paul Mackerras <paulus@ozlabs.org>
To: David Gibson <david@gibson.dropbear.id.au>
Cc: benh@au1.ibm.com, Alexander Graf <agraf@suse.de>,
qemu-devel@nongnu.org, qemu-ppc@nongnu.org,
Aravinda Prasad <aravinda@linux.vnet.ibm.com>,
Sam Bobroff <sam.bobroff@au1.ibm.com>
Subject: Re: [Qemu-devel] [Qemu-ppc] [PATCH v3 0/4] target-ppc: Add FWNMI support in qemu for powerKVM guests
Date: Thu, 3 Sep 2015 15:18:23 +1000 [thread overview]
Message-ID: <20150903051823.GE3380@iris.ozlabs.ibm.com> (raw)
In-Reply-To: <20150903050521.GK6537@voom.redhat.com>
On Thu, Sep 03, 2015 at 03:05:21PM +1000, David Gibson wrote:
> On Thu, Sep 03, 2015 at 01:24:21PM +1000, Sam Bobroff wrote:
> > PAPR only says SPRGs 0 to 3 are for software use, but the kernel (see
> > arch/powerpc/include/asm/reg.h) defines SPRG2 as an exception scratch register
> > so it should be the right one to use here.
>
> Uh.. no. If 0..3 are for software (i.e. OS) use, then this needs to
> use a different one, since it's being used as a firmware resource
> here. Linux might treat SPRG2 as scratch, but another OS would be
> within its rights to use it for something persistent.
PAPR says in requirement R1-14.1.2-3 "To avoid conflict with the
platform’s hypervisor, the OS must be prepared to share use of SPRG2
as the interrupt scratch register whenever an hcall() is made, or a
machine check or reset interrupt is taken." So, SPRG2 is the one to
use here.
Paul.
next prev parent reply other threads:[~2015-09-03 5:21 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-11-05 7:12 [Qemu-devel] [PATCH v3 0/4] target-ppc: Add FWNMI support in qemu for powerKVM guests Aravinda Prasad
2014-11-05 7:12 ` [Qemu-devel] [PATCH v3 1/4] target-ppc: Extend rtas-blob Aravinda Prasad
2014-11-05 8:11 ` [Qemu-devel] [Qemu-ppc] " Alexander Graf
2014-11-05 8:46 ` Aravinda Prasad
2014-11-05 9:00 ` Alexander Graf
2014-11-05 9:07 ` Alexander Graf
2014-11-05 10:41 ` Aravinda Prasad
2014-11-05 7:12 ` [Qemu-devel] [PATCH v3 2/4] target-ppc: Register and handle HCALL to receive updated RTAS region Aravinda Prasad
2014-11-05 7:12 ` [Qemu-devel] [PATCH v3 3/4] target-ppc: Build error log Aravinda Prasad
2014-11-05 7:13 ` [Qemu-devel] [PATCH v3 4/4] target-ppc: Handle ibm, nmi-register RTAS call Aravinda Prasad
2014-11-05 8:32 ` [Qemu-devel] [Qemu-ppc] " Alexander Graf
2014-11-05 10:37 ` Aravinda Prasad
2014-11-05 11:07 ` Alexander Graf
2014-11-05 11:24 ` Aravinda Prasad
2014-11-05 11:27 ` Alexander Graf
2014-11-05 15:46 ` Tom Musta
2014-11-06 10:00 ` Aravinda Prasad
2014-11-06 10:29 ` Alexander Graf
2014-11-06 10:36 ` Aravinda Prasad
2014-11-11 3:19 ` David Gibson
2014-11-11 5:48 ` Aravinda Prasad
2014-11-11 6:11 ` David Gibson
2014-11-11 6:51 ` Aravinda Prasad
2014-11-11 11:30 ` David Gibson
2014-11-11 3:16 ` [Qemu-devel] " David Gibson
2014-11-11 6:44 ` Aravinda Prasad
2014-11-13 3:52 ` David Gibson
2014-11-13 5:58 ` Aravinda Prasad
2014-11-13 10:32 ` David Gibson
2014-11-13 11:48 ` Aravinda Prasad
2014-11-13 12:44 ` David Gibson
2014-11-13 14:36 ` Aravinda Prasad
2014-11-14 0:42 ` David Gibson
2014-11-14 8:24 ` Aravinda Prasad
2014-11-11 3:24 ` [Qemu-devel] [PATCH v3 0/4] target-ppc: Add FWNMI support in qemu for powerKVM guests David Gibson
2014-11-11 7:15 ` Aravinda Prasad
2014-11-13 3:57 ` David Gibson
2014-11-13 6:10 ` Aravinda Prasad
2014-11-19 5:48 ` Aravinda Prasad
2014-11-19 10:32 ` Alexander Graf
2014-11-19 11:44 ` David Gibson
2014-11-19 12:22 ` Alexander Graf
2014-11-19 12:42 ` [Qemu-devel] [Qemu-ppc] " Alexander Graf
2014-11-19 12:57 ` [Qemu-devel] " David Gibson
2015-04-02 4:28 ` [Qemu-devel] [Qemu-ppc] " Alexey Kardashevskiy
2015-04-02 4:46 ` David Gibson
2015-07-02 9:11 ` Alexey Kardashevskiy
2015-07-03 6:01 ` David Gibson
2015-07-08 8:28 ` Aravinda Prasad
2015-08-07 3:37 ` Sam Bobroff
2015-08-09 13:53 ` Alexander Graf
2015-08-10 4:05 ` Sam Bobroff
2015-09-01 11:07 ` Aravinda Prasad
2015-09-02 6:34 ` Sam Bobroff
2015-09-02 10:37 ` Aravinda Prasad
2015-09-02 23:53 ` David Gibson
2015-09-03 3:24 ` Sam Bobroff
2015-09-03 5:05 ` David Gibson
2015-09-03 5:18 ` Paul Mackerras [this message]
2015-09-03 6:22 ` Sam Bobroff
2015-09-03 18:30 ` Aravinda Prasad
2015-09-04 5:02 ` David Gibson
2015-09-04 5:01 ` David Gibson
2015-09-03 2:02 ` Paul Mackerras
2015-09-03 17:49 ` Aravinda Prasad
2015-09-01 6:21 ` Aravinda Prasad
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