From: David Gibson <david@gibson.dropbear.id.au>
To: Blue Swirl <blauwirbel@gmail.com>
Cc: qemu-devel@nongnu.org, anthony@codemonkey.ws
Subject: Re: [Qemu-devel] [PATCH 8/8] Make dma_addr_t 64 bit always
Date: Mon, 27 Feb 2012 23:58:24 +1100 [thread overview]
Message-ID: <20120227125824.GJ3433@truffala.fritz.box> (raw)
In-Reply-To: <CAAu8pHvRGh8j3PKXdhw5DLDU6N3cFinYRf11ZahopOetKModZA@mail.gmail.com>
On Sun, Feb 26, 2012 at 09:46:52PM +0000, Blue Swirl wrote:
> On Fri, Feb 24, 2012 at 04:57, David Gibson <david@gibson.dropbear.id.au> wrote:
> > On Fri, Feb 24, 2012 at 02:27:43PM +1100, David Gibson wrote:
> >
> > Oops, ignore this one folks. As is probably obvious, this was a
> > testing patch not meant to go into the main series.
>
> Actually I'm not sure what would be the correct way to calculate the
> size. For example, on Sparc32 the virtual address space and CPU
> registers are 32 bits, physical address space 36 bits, but device
> virtual memory address space (DVMA, used by devices to talk to IOMMU)
> is only 32 bits.
Well, yes, in fact I think we probably do need to use 64-bit addresses
always (or at least whenever we have any kind of IOMMU support
available), because it's almost impossible to be certain that a
platform could never have a 64-bit bus of some kind plugged in.
But that's a matter for another day.
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
prev parent reply other threads:[~2012-02-27 13:31 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-02-24 3:27 [Qemu-devel] [0/8] RFC: A second batch of preliminaries towards guest visible IOMMUS David Gibson
2012-02-24 3:27 ` [Qemu-devel] [PATCH 1/8] Use DMADirection type for dma_bdrv_io David Gibson
2012-02-24 3:27 ` [Qemu-devel] [PATCH 2/8] Better support for dma_addr_t variables David Gibson
2012-02-24 3:27 ` [Qemu-devel] [PATCH 3/8] usb-xhci: Use PCI DMA helper functions David Gibson
2012-02-24 3:27 ` [Qemu-devel] [PATCH 4/8] Add universal " David Gibson
2012-02-26 10:04 ` Michael S. Tsirkin
2012-02-26 21:09 ` Eduard - Gabriel Munteanu
2012-02-27 0:22 ` David Gibson
2012-02-27 10:33 ` Michael S. Tsirkin
2012-02-27 11:55 ` Eduard - Gabriel Munteanu
2012-02-26 21:24 ` Eduard - Gabriel Munteanu
2012-02-24 3:27 ` [Qemu-devel] [PATCH 5/8] usb-ohci: Use " David Gibson
2012-02-24 3:27 ` [Qemu-devel] [PATCH 6/8] Make sglists and dma_bdrv helpers use new universal DMA herlpers David Gibson
2012-02-24 3:27 ` [Qemu-devel] [PATCH 7/8] ide/ahci: Use universal DMA helper functions David Gibson
2012-02-24 3:27 ` [Qemu-devel] [PATCH 8/8] Make dma_addr_t 64 bit always David Gibson
2012-02-24 4:57 ` David Gibson
2012-02-26 21:46 ` Blue Swirl
2012-02-27 12:58 ` David Gibson [this message]
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