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From: "Hervé Poussineau" <hpoussin@reactos.org>
To: Richard Henderson <rth@twiddle.net>
Cc: "Andreas Färber" <andreas.faerber@web.de>, qemu-devel@nongnu.org
Subject: Re: [Qemu-devel] [PATCH 3/3] prep: improve Raven PCI host emulation
Date: Mon, 02 Sep 2013 22:26:27 +0200	[thread overview]
Message-ID: <5224F473.2060208@reactos.org> (raw)
In-Reply-To: <5217BE5F.5000708@twiddle.net>

Richard Henderson a écrit :
> On 08/23/2013 11:52 AM, Hervé Poussineau wrote:
>> +    uint8_t buf[4];
>> +    uint64_t val;
>> +
>> +    if (s->contiguous_map == 0) {
>> +        /* 64 KB contiguous space for IOs */
>> +        addr &= 0xFFFF;
>> +    } else {
>> +        /* 8 MB non-contiguous space for IOs */
>> +        addr = (addr & 0x1F) | ((addr & 0x007FFF000) >> 7);
>> +    }
>> +
>> +    address_space_read(&s->pci_io_as, addr + 0x80000000, buf, size);
>> +    memcpy(&val, buf, size);
>> +    return val;
> 
> This memcpy can't be right, especially for big-endian host.

pci_io_as is supposed to contain words/longs in little-endian mode (PCI 
is always little-endian).
prep_io_ops endianness is DEVICE_LITTLE_ENDIAN, so, AFAIK, this means 
that returned val should be LE.
Why should it break on big-endian hosts?

Regards,

Hervé

  reply	other threads:[~2013-09-02 20:27 UTC|newest]

Thread overview: 10+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2013-08-23 18:52 [Qemu-devel] [PATCH 0/3] prep: improve Raven PCI host emulation Hervé Poussineau
2013-08-23 18:52 ` [Qemu-devel] [PATCH 1/3] pci: remove explicit check to 64K ioport size Hervé Poussineau
2013-08-23 18:52 ` [Qemu-devel] [PATCH 2/3] prep: kill get_system_io() usage Hervé Poussineau
2013-08-23 18:52 ` [Qemu-devel] [PATCH 3/3] prep: improve Raven PCI host emulation Hervé Poussineau
2013-08-23 19:56   ` Richard Henderson
2013-09-02 20:26     ` Hervé Poussineau [this message]
2013-09-02 20:48       ` Peter Maydell
2013-09-02 20:59   ` Peter Maydell
2013-09-02 21:18     ` Hervé Poussineau
2013-09-02 21:34       ` Peter Maydell

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