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From: Arnd Bergmann <arnd@arndb.de>
To: Chris Wright <chrisw@sous-sol.org>
Cc: Gregory Haskins <gregory.haskins@gmail.com>,
	Gregory Haskins <ghaskins@novell.com>,
	Avi Kivity <avi@redhat.com>,
	linux-kernel@vger.kernel.org, kvm@vger.kernel.org,
	Anthony Liguori <anthony@codemonkey.ws>,
	Benjamin Herrenschmidt <benh@kernel.crashing.org>
Subject: Re: [RFC PATCH 0/3] generic hypercall support
Date: Fri, 8 May 2009 00:11:52 +0200	[thread overview]
Message-ID: <200905080011.52958.arnd@arndb.de> (raw)
In-Reply-To: <20090507215712.GI3036@sequoia.sous-sol.org>

On Thursday 07 May 2009, Chris Wright wrote:
> 
> > Chris, is that issue with the non ioread/iowrite access of a mangled
> > pointer still an issue here?  I would think so, but I am a bit fuzzy on
> > whether there is still an issue of non-wrapped MMIO ever occuring.
> 
> Arnd was saying it's a bug for other reasons, so perhaps it would work
> out fine.

Well, maybe. I only said that __raw_writel and pointer dereference is
bad, but not writel.

IIRC when we had that discussion about io-workarounds on powerpc,
the outcome was that passing an IORESOURCE_MEM resource into pci_iomap
must still result in something that can be passed into writel in addition
to iowrite32, while an IORESOURCE_IO resource may or may not be valid for
writel and/or outl.

Unfortunately, this means that either readl/writel needs to be adapted
in some way (e.g. the address also ioremapped to the mangled pointer)
or the mechanism will be limited to I/O space accesses.

Maybe BenH remembers the details better than me.

	Arnd <><

  reply	other threads:[~2009-05-07 22:13 UTC|newest]

Thread overview: 115+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2009-05-05 13:24 [RFC PATCH 0/3] generic hypercall support Gregory Haskins
2009-05-05 13:24 ` [RFC PATCH 1/3] add " Gregory Haskins
2009-05-05 17:03   ` Hollis Blanchard
2009-05-06 13:52   ` Anthony Liguori
2009-05-06 15:16     ` Gregory Haskins
2009-05-06 16:52       ` Arnd Bergmann
2009-05-05 13:24 ` [RFC PATCH 2/3] x86: " Gregory Haskins
2009-05-05 13:24 ` [RFC PATCH 3/3] kvm: add pv_cpu_ops.hypercall support to the guest Gregory Haskins
2009-05-05 13:36 ` [RFC PATCH 0/3] generic hypercall support Avi Kivity
2009-05-05 13:40   ` Gregory Haskins
2009-05-05 14:00     ` Avi Kivity
2009-05-05 14:14       ` Gregory Haskins
2009-05-05 14:21         ` Gregory Haskins
2009-05-05 15:02         ` Avi Kivity
2009-05-05 23:17         ` Chris Wright
2009-05-06  3:51           ` Gregory Haskins
2009-05-06  7:22             ` Chris Wright
2009-05-06 13:17               ` Gregory Haskins
2009-05-06 16:07                 ` Chris Wright
2009-05-07 17:03                   ` Gregory Haskins
2009-05-07 18:05                     ` Avi Kivity
2009-05-07 18:08                       ` Gregory Haskins
2009-05-07 18:12                         ` Avi Kivity
2009-05-07 18:16                           ` Gregory Haskins
2009-05-07 18:24                             ` Avi Kivity
2009-05-07 18:37                               ` Gregory Haskins
2009-05-07 19:00                                 ` Avi Kivity
2009-05-07 19:05                                   ` Gregory Haskins
2009-05-07 19:43                                     ` Avi Kivity
2009-05-07 20:07                                       ` Gregory Haskins
2009-05-07 20:15                                         ` Avi Kivity
2009-05-07 20:26                                           ` Gregory Haskins
2009-05-08  8:35                                             ` Avi Kivity
2009-05-08 11:29                                               ` Gregory Haskins
2009-05-07 19:07                                   ` Chris Wright
2009-05-07 19:12                                     ` Gregory Haskins
2009-05-07 19:21                                       ` Chris Wright
2009-05-07 19:26                                         ` Avi Kivity
2009-05-07 19:44                                           ` Avi Kivity
2009-05-07 19:29                                         ` Gregory Haskins
2009-05-07 20:25                                           ` Chris Wright
2009-05-07 20:34                                             ` Gregory Haskins
2009-05-07 20:54                                           ` Arnd Bergmann
2009-05-07 21:13                                             ` Gregory Haskins
2009-05-07 21:57                                               ` Chris Wright
2009-05-07 22:11                                                 ` Arnd Bergmann [this message]
2009-05-08 22:33                                                   ` Benjamin Herrenschmidt
2009-05-11 13:01                                                     ` Arnd Bergmann
2009-05-11 13:04                                                       ` Gregory Haskins
2009-05-07 20:00                             ` Arnd Bergmann
2009-05-07 20:31                               ` Gregory Haskins
2009-05-07 20:42                                 ` Arnd Bergmann
2009-05-07 20:47                                   ` Arnd Bergmann
2009-05-07 20:50                                 ` Chris Wright
2009-05-07 23:35                     ` Marcelo Tosatti
2009-05-07 23:43                       ` Marcelo Tosatti
2009-05-08  3:17                         ` Gregory Haskins
2009-05-08  7:55                         ` Avi Kivity
     [not found]                           ` <20090508103253.GC3011@amt.cnet>
2009-05-08 11:37                             ` Avi Kivity
2009-05-08 14:35                           ` Marcelo Tosatti
2009-05-08 14:45                             ` Gregory Haskins
2009-05-08 15:51                               ` Marcelo Tosatti
2009-05-08 19:56                                 ` David S. Ahern
2009-05-08 20:01                                   ` Gregory Haskins
2009-05-08 23:23                                     ` David S. Ahern
2009-05-09  8:45                                       ` Avi Kivity
2009-05-09 11:27                                         ` Gregory Haskins
2009-05-10  4:27                                           ` David S. Ahern
2009-05-10  5:24                                             ` Avi Kivity
2009-05-10  4:24                                         ` David S. Ahern
2009-05-08  3:13                       ` Gregory Haskins
2009-05-08  7:59                       ` Avi Kivity
2009-05-08 11:09                         ` Gregory Haskins
     [not found]                         ` <20090508104228.GD3011@amt.cnet>
2009-05-08 12:43                           ` Gregory Haskins
2009-05-08 15:33                             ` Marcelo Tosatti
2009-05-08 19:02                               ` Avi Kivity
2009-05-08 16:48                             ` Paul E. McKenney
2009-05-08 19:55                               ` Gregory Haskins
2009-05-08 14:15                       ` Gregory Haskins
2009-05-08 14:53                         ` Anthony Liguori
2009-05-08 18:50                           ` Avi Kivity
2009-05-08 19:02                             ` Anthony Liguori
2009-05-08 19:06                               ` Avi Kivity
2009-05-11 16:37                               ` Jeremy Fitzhardinge
2009-05-07 12:29                 ` Avi Kivity
2009-05-08 14:59                   ` Anthony Liguori
2009-05-09 12:01                     ` Gregory Haskins
2009-05-10 18:38                       ` Anthony Liguori
2009-05-11 13:14                         ` Gregory Haskins
2009-05-11 16:35                           ` Hollis Blanchard
2009-05-11 17:06                             ` Avi Kivity
2009-05-11 17:29                               ` Gregory Haskins
2009-05-11 17:53                                 ` Avi Kivity
2009-05-11 17:51                               ` Anthony Liguori
2009-05-11 18:02                                 ` Avi Kivity
2009-05-11 18:18                                   ` Anthony Liguori
2009-05-11 17:31                           ` Anthony Liguori
2009-05-13 10:53                             ` Gregory Haskins
2009-05-13 14:45                             ` Gregory Haskins
2009-05-11 16:44                         ` Hollis Blanchard
2009-05-11 17:54                           ` Anthony Liguori
2009-05-11 19:24                             ` PowerPC page faults Hollis Blanchard
2009-05-11 22:17                               ` Anthony Liguori
2009-05-12  5:46                                 ` Liu Yu-B13201
2009-05-12 14:50                                 ` Hollis Blanchard
2009-05-06 13:56             ` [RFC PATCH 0/3] generic hypercall support Anthony Liguori
2009-05-06 16:03               ` Gregory Haskins
2009-05-08  8:17                 ` Avi Kivity
2009-05-08 15:20                   ` Gregory Haskins
2009-05-08 17:00                     ` Avi Kivity
2009-05-08 18:55                       ` Gregory Haskins
2009-05-08 19:05                         ` Anthony Liguori
2009-05-08 19:12                         ` Avi Kivity
2009-05-08 19:59                           ` Gregory Haskins
2009-05-10  9:59                             ` Avi Kivity

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