From: Eduard - Gabriel Munteanu <eduard.munteanu@linux360.ro>
To: Avi Kivity <avi@redhat.com>
Cc: Anthony Liguori <aliguori@us.ibm.com>,
joerg.roedel@amd.com, agraf@suse.de, qemu-devel@nongnu.org,
rth@twiddle.net, David Gibson <david@gibson.dropbear.id.au>
Subject: Re: [Qemu-devel] [PATCH 01/10] Add stub functions for PCI device models to do PCI DMA
Date: Sat, 3 Sep 2011 06:04:26 +0300 [thread overview]
Message-ID: <20110903030425.GA6087@localhost> (raw)
In-Reply-To: <4E6095C5.7050500@redhat.com>
On Fri, Sep 02, 2011 at 11:37:25AM +0300, Avi Kivity wrote:
> On 09/01/2011 07:05 PM, Anthony Liguori wrote:
> >
> > The challenge is what you do about something like ne2k where the core
> > chipset can either be a PCI device or an ISA device. You would have
> > to implement a wrapper around pci_dma_rw() in order to turn it into
> > cpu_physical_memory_rw when doing ISA.
>
> btw, ISA DMA is very different, no? You program a dma controller to
> copy memory from the device to RAM (or vice versa); the device never
> initiates a transaction IIRC.
It seems to me ISA devices should use memory I/O primitives exposed by
the ISA bus code. Or maybe the DMA controllers involved should be doing
that. As for either-PCI/ISA devices, they can handle dispatching DMA
through the right interface themselves.
Anyway, I'm not sure why we're worrying about this now. Do we even have
IOMMUs for such use cases?
Eduard
next prev parent reply other threads:[~2011-09-03 3:08 UTC|newest]
Thread overview: 34+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-01 5:00 [Qemu-devel] [0/10] Preliminary work for IOMMU emulation support; the easy bits David Gibson
2011-09-01 5:00 ` [Qemu-devel] [PATCH 01/10] Add stub functions for PCI device models to do PCI DMA David Gibson
2011-09-01 15:35 ` Michael S. Tsirkin
2011-09-02 0:39 ` David Gibson
2011-09-02 4:38 ` David Gibson
2011-09-05 7:55 ` Michael S. Tsirkin
2011-09-01 15:55 ` Anthony Liguori
2011-09-01 16:03 ` Avi Kivity
2011-09-01 16:05 ` Anthony Liguori
2011-09-01 16:11 ` Avi Kivity
2011-09-01 16:32 ` Anthony Liguori
2011-09-02 8:35 ` Avi Kivity
2011-09-03 12:25 ` Blue Swirl
2011-09-02 0:38 ` David Gibson
2011-09-02 8:37 ` Avi Kivity
2011-09-03 3:04 ` Eduard - Gabriel Munteanu [this message]
2011-09-02 4:40 ` David Gibson
2011-09-03 1:16 ` Richard Henderson
2011-09-23 16:37 ` Anthony Liguori
2011-09-01 5:00 ` [Qemu-devel] [PATCH 02/10] rtl8139: Use PCI DMA stub functions David Gibson
2011-09-01 5:00 ` [Qemu-devel] [PATCH 03/10] eepro100: " David Gibson
2011-09-01 5:00 ` [Qemu-devel] [PATCH 04/10] ac97: " David Gibson
2011-09-01 5:00 ` [Qemu-devel] [PATCH 05/10] es1370: " David Gibson
2011-09-01 5:00 ` [Qemu-devel] [PATCH 06/10] e1000: " David Gibson
2011-09-01 5:01 ` [Qemu-devel] [PATCH 07/10] lsi53c895a: " David Gibson
2011-09-01 5:01 ` [Qemu-devel] [PATCH 08/10] pcnet-pci: " David Gibson
2011-09-01 5:01 ` [Qemu-devel] [PATCH 09/10] usb-ohci: " David Gibson
2011-09-01 10:10 ` Gerd Hoffmann
2011-09-02 1:47 ` David Gibson
2011-09-01 5:01 ` [Qemu-devel] [PATCH 10/10] intel-hda: " David Gibson
2011-09-01 10:16 ` Gerd Hoffmann
2011-09-02 1:42 ` David Gibson
2011-09-01 11:33 ` [Qemu-devel] [0/10] Preliminary work for IOMMU emulation support; the easy bits Eduard - Gabriel Munteanu
2011-09-02 0:36 ` David Gibson
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