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[Qemu-devel] Re: [PATCH 1/6] Make config space accessor host bus trapabl
From: |
Alexander Graf |
Subject: |
[Qemu-devel] Re: [PATCH 1/6] Make config space accessor host bus trapable |
Date: |
Sun, 3 Jan 2010 18:40:52 +0100 |
On 03.01.2010, at 18:29, Michael S. Tsirkin wrote:
> On Sun, Jan 03, 2010 at 05:09:32PM +0100, Alexander Graf wrote:
>>
>> On 03.01.2010, at 16:45, Michael S. Tsirkin wrote:
>>
>>> On Sun, Jan 03, 2010 at 02:50:45AM +0100, Alexander Graf wrote:
>>>> Different host buses may have different layouts for config space accessors.
>>>>
>>>> The Mac U3 for example uses the following define to access Type 0 (directly
>>>> attached) devices:
>>>>
>>>> #define MACRISC_CFA0(devfn, off) \
>>>> ((1 << (unsigned int)PCI_SLOT(dev_fn)) \
>>>> | (((unsigned int)PCI_FUNC(dev_fn)) << 8) \
>>>> | (((unsigned int)(off)) & 0xFCUL))
>>>>
>>>> Obviously, this is different from the encoding we interpret in qemu. In
>>>> order to let host controllers take some influence there, we can just
>>>> introduce a converter function that takes whatever accessor we have and
>>>> makes a qemu understandable one out of it.
>>>>
>>>> This patch is the groundwork for Uninorth PCI config space fixes.
>>>>
>>>> Signed-off-by: Alexander Graf <address@hidden>
>>>> CC: Michael S. Tsirkin <address@hidden>
>>>
>>> Thanks!
>>>
>>> It always bothered me that the code in pci_host uses x86 encoding and
>>> other architectures are converted to x86. As long as we are adding
>>> redirection, maybe we should get rid of this, and make get_config_reg
>>> return register and devfn separately, so we don't need to encode/decode
>>> back and forth?
>>
>> Hmm, when touching code I'm not 100% sure what I'm doing I usually try to
>> build on stuff that is there already. That's exactly what happened here.
>>
>> I'm personally not against defining the x86 format as qemu default. That way
>> everyone knows what to deal with. I'm not sure if PCI defines anything that
>> couldn't be represented by the x86 encoding in 32 bits. I actually doubt it.
>> So it seems like a pretty good fit, especially given that all the other code
>> is already in place.
>>
>>> OTOH if we are after a quick fix, won't it be simpler to have
>>> unin_pci simply use its own routines instead of pci_host_conf_register_mmio
>>> etc?
>>
>> Hm, I figured this is less work :-).
>
> Let me explain the idea: we have:
>
> static void pci_host_config_writel_ioport(void *opaque,
> uint32_t addr, uint32_t val)
> {
> PCIHostState *s = opaque;
>
> PCI_DPRINTF("%s addr %"PRIx32 " val %"PRIx32"\n", __func__, addr,
> val);
> s->config_reg = val;
> }
>
> static uint32_t pci_host_config_readl_ioport(void *opaque, uint32_t
> addr)
> {
> PCIHostState *s = opaque;
> uint32_t val = s->config_reg;
>
> PCI_DPRINTF("%s addr %"PRIx32" val %"PRIx32"\n", __func__, addr,
> val);
> return val;
> }
>
> void pci_host_conf_register_ioport(pio_addr_t ioport, PCIHostState *s)
> {
> register_ioport_write(ioport, 4, 4, pci_host_config_writel_ioport,
> s);
> register_ioport_read(ioport, 4, 4, pci_host_config_readl_ioport, s);
> }
>
> If instead of a simple config_reg = val we translate to pc format
> here, the rest will work. No?
Well, that'd mean I'd have to implement a config_reg read function and do the
conversion backwards again there. Or I could just save it off in the unin state
... hmm ...
Either way, let's better get this done right. I'd rather want to have a proper
framework in place in case someone else stumbles across something similar.
Alex
[Qemu-devel] [PATCH 4/6] Include dump of lspci -nn on real G5, Alexander Graf, 2010/01/02
[Qemu-devel] [PATCH 6/6] Enable secondary cmd64x, Alexander Graf, 2010/01/02
[Qemu-devel] [PATCH 1/6] Make config space accessor host bus trapable, Alexander Graf, 2010/01/02
- [Qemu-devel] Re: [PATCH 1/6] Make config space accessor host bus trapable, Michael S. Tsirkin, 2010/01/03
- [Qemu-devel] Re: [PATCH 1/6] Make config space accessor host bus trapable, Alexander Graf, 2010/01/03
- [Qemu-devel] Re: [PATCH 1/6] Make config space accessor host bus trapable, Michael S. Tsirkin, 2010/01/03
- [Qemu-devel] Re: [PATCH 1/6] Make config space accessor host bus trapable,
Alexander Graf <=
- [Qemu-devel] Re: [PATCH 1/6] Make config space accessor host bus trapable, Michael S. Tsirkin, 2010/01/03
- [Qemu-devel] Re: [PATCH 1/6] Make config space accessor host bus trapable, Alexander Graf, 2010/01/03
- [Qemu-devel] Re: [PATCH 1/6] Make config space accessor host bus trapable, Michael S. Tsirkin, 2010/01/03
- [Qemu-devel] Re: [PATCH 1/6] Make config space accessor host bus trapable, Blue Swirl, 2010/01/03
- [Qemu-devel] Re: [PATCH 1/6] Make config space accessor host bus trapable, Blue Swirl, 2010/01/10
- [Qemu-devel] Re: [PATCH 1/6] Make config space accessor host bus trapable, Blue Swirl, 2010/01/11
- [Qemu-devel] Re: [PATCH 1/6] Make config space accessor host bus trapable, Igor Kovalenko, 2010/01/11
- [Qemu-devel] Re: [PATCH 1/6] Make config space accessor host bus trapable, Blue Swirl, 2010/01/12
- [Qemu-devel] Re: [PATCH 1/6] Make config space accessor host bus trapable, Blue Swirl, 2010/01/18
[Qemu-devel] Re: [PATCH 1/6] Make config space accessor host bus trapable, Alexander Graf, 2010/01/03