From: Avi Kivity <avi@redhat.com>
To: Anthony Liguori <anthony@codemonkey.ws>
Cc: qemu-devel@nongnu.org, kvm@vger.kernel.org
Subject: Re: [Qemu-devel] [PATCH 16/23] ioport: register ranges by byte aligned addresses always
Date: Tue, 26 Jul 2011 13:59:58 +0300 [thread overview]
Message-ID: <4E2E9E2E.7050404@redhat.com> (raw)
In-Reply-To: <4E2DC209.9070103@codemonkey.ws>
On 07/25/2011 10:20 PM, Anthony Liguori wrote:
> On 07/25/2011 09:02 AM, Avi Kivity wrote:
>> The I/O port space is byte addressable, even for word and long accesses.
>>
>> An example is the VMware svga card, which has long ports on offsets 0,
>> 1, and 2.
>>
>> Signed-off-by: Avi Kivity<avi@redhat.com>
>
> I've always thought this was odd but didn't know of a specific
> circumstance where it broke a device.
>
> This was a big problem with the old API. Devices don't register their
> interest in specific sizes. They may ignore certain size accesses but
> that's a device specific behavior.
In fact there's on counterexample - 440FX consumes dword accesses on
port cf8 but forwards byte and word accesses to the PCI bus. This
cannot be implemented with the current API (it requires the opaque to be
equal for all word sizes). The new API doesn't support it either; if we
need to, we can re-issue the access but using the PCI address space
instead of the root I/O address space.
(of course this is purely theoretical)
--
error compiling committee.c: too many arguments to function
next prev parent reply other threads:[~2011-07-26 11:00 UTC|newest]
Thread overview: 66+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-07-25 14:02 [PATCH 00/23] Memory API, batch 1 Avi Kivity
2011-07-25 14:02 ` [PATCH 01/23] Hierarchical memory region API Avi Kivity
2011-07-25 18:41 ` [Qemu-devel] " Anthony Liguori
2011-07-26 9:35 ` Avi Kivity
2011-07-25 14:02 ` [PATCH 02/23] memory: implement dirty tracking Avi Kivity
2011-07-25 18:43 ` Anthony Liguori
2011-07-25 14:02 ` [PATCH 03/23] memory: merge adjacent segments of a single memory region Avi Kivity
2011-07-25 18:48 ` [Qemu-devel] " Anthony Liguori
2011-07-26 9:55 ` Avi Kivity
2011-07-25 14:02 ` [PATCH 04/23] Internal interfaces for memory API Avi Kivity
2011-07-25 18:49 ` [Qemu-devel] " Anthony Liguori
2011-07-25 14:02 ` [PATCH 05/23] memory: abstract address space operations Avi Kivity
2011-07-25 18:51 ` [Qemu-devel] " Anthony Liguori
2011-07-25 14:02 ` [PATCH 06/23] memory: rename MemoryRegion::has_ram_addr to ::terminates Avi Kivity
2011-07-25 18:56 ` [Qemu-devel] " Anthony Liguori
2011-07-26 9:59 ` Avi Kivity
2011-07-25 14:02 ` [PATCH 07/23] memory: late initialization of ram_addr Avi Kivity
2011-07-25 14:02 ` [PATCH 08/23] memory: I/O address space support Avi Kivity
2011-07-25 19:00 ` [Qemu-devel] " Anthony Liguori
2011-07-25 14:02 ` [PATCH 09/23] memory: add backward compatibility for old portio registration Avi Kivity
2011-07-25 19:01 ` [Qemu-devel] " Anthony Liguori
2011-07-25 14:02 ` [PATCH 10/23] memory: add backward compatibility for old mmio registration Avi Kivity
2011-07-25 19:02 ` [Qemu-devel] " Anthony Liguori
2011-07-25 14:02 ` [PATCH 11/23] memory: add ioeventfd support Avi Kivity
2011-07-25 15:16 ` [Qemu-devel] " malc
2011-07-25 15:17 ` Avi Kivity
2011-07-25 15:22 ` malc
2011-07-25 15:28 ` [Qemu-devel] " Avi Kivity
2011-07-25 15:38 ` malc
2011-07-25 15:43 ` Avi Kivity
2011-07-25 19:08 ` Anthony Liguori
2011-07-26 10:08 ` Avi Kivity
2011-07-25 14:02 ` [PATCH 12/23] memory: separate building the final memory map into two steps Avi Kivity
2011-07-25 19:12 ` [Qemu-devel] " Anthony Liguori
2011-07-26 10:43 ` Avi Kivity
2011-07-25 14:02 ` [PATCH 13/23] memory: document the memory API Avi Kivity
2011-07-25 19:15 ` [Qemu-devel] " Anthony Liguori
2011-07-26 10:44 ` Avi Kivity
2011-07-25 14:02 ` [PATCH 14/23] memory: transaction API Avi Kivity
2011-07-25 19:16 ` [Qemu-devel] " Anthony Liguori
2011-07-26 10:48 ` Avi Kivity
2011-07-26 11:39 ` Avi Kivity
2011-07-25 14:02 ` [PATCH 15/23] exec.c: initialize memory map Avi Kivity
2011-07-25 19:17 ` [Qemu-devel] " Anthony Liguori
2011-07-26 10:55 ` Avi Kivity
2011-07-25 14:02 ` [PATCH 16/23] ioport: register ranges by byte aligned addresses always Avi Kivity
2011-07-25 19:20 ` [Qemu-devel] " Anthony Liguori
2011-07-26 10:59 ` Avi Kivity [this message]
2011-07-25 14:02 ` [PATCH 17/23] pc: grab system_memory Avi Kivity
2011-07-25 19:22 ` [Qemu-devel] " Anthony Liguori
2011-07-25 14:02 ` [PATCH 18/23] pc: convert pc_memory_init() to memory API Avi Kivity
2011-07-25 19:23 ` [Qemu-devel] " Anthony Liguori
2011-07-25 14:03 ` [PATCH 19/23] pc: move global memory map out of pc_init1() and into its callers Avi Kivity
2011-07-25 20:02 ` [Qemu-devel] " Anthony Liguori
2011-07-26 11:02 ` Avi Kivity
2011-07-25 14:03 ` [PATCH 20/23] pci: pass address space to pci bus when created Avi Kivity
2011-07-25 20:03 ` Anthony Liguori
2011-07-25 14:03 ` [PATCH 21/23] pci: add MemoryRegion based BAR management API Avi Kivity
2011-07-25 20:20 ` Anthony Liguori
2011-07-26 11:06 ` Avi Kivity
2011-07-25 14:03 ` [PATCH 22/23] sysbus: add MemoryRegion based memory " Avi Kivity
2011-07-25 20:21 ` Anthony Liguori
2011-07-25 14:03 ` [PATCH 23/23] usb-ohci: convert to MemoryRegion Avi Kivity
2011-07-25 20:22 ` [Qemu-devel] " Anthony Liguori
2011-07-25 20:23 ` [PATCH 00/23] Memory API, batch 1 Anthony Liguori
2011-07-26 11:32 ` [Qemu-devel] " Avi Kivity
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