On Tue, 9 Sep 2014 21:34:46 +1000
Alexey Kardashevskiy <a...@ozlabs.ru> wrote:
> This reverts commit c40708176a6b52b73bec14796b7c71b882ceb102.
>
> The idea not to swap bytes at all did not work out as MMIO interface
> is defined as target host endian and it is always big-endian for PPC64
s/target host endian/target endian/
> so the original part broke PPC64 guests on LE hosts (x86/ppc64le).
>
What about a simpler description ?
The resulting code wrongly assumed target and host endianness are the same.
> Signed-off-by: Alexey Kardashevskiy <a...@ozlabs.ru>
> ---
> hw/misc/vfio.c | 41 ++++++++++-------------------------------
> 1 file changed, 10 insertions(+), 31 deletions(-)
>
> diff --git a/hw/misc/vfio.c b/hw/misc/vfio.c
> index 40dcaa6..22ebcbd 100644
> --- a/hw/misc/vfio.c
> +++ b/hw/misc/vfio.c
> @@ -1098,10 +1098,10 @@ static void vfio_bar_write(void *opaque, hwaddr addr,
> buf.byte = data;
> break;
> case 2:
> - buf.word = data;
> + buf.word = cpu_to_le16(data);
> break;
> case 4:
> - buf.dword = data;
> + buf.dword = cpu_to_le32(data);
> break;
> default:
> hw_error("vfio: unsupported write size, %d bytes", size);
> @@ -1158,10 +1158,10 @@ static uint64_t vfio_bar_read(void *opaque,
> data = buf.byte;
> break;
> case 2:
> - data = buf.word;
> + data = le16_to_cpu(buf.word);
> break;
> case 4:
> - data = buf.dword;
> + data = le32_to_cpu(buf.dword);
> break;
> default:
> hw_error("vfio: unsupported read size, %d bytes", size);
> @@ -1188,7 +1188,7 @@ static uint64_t vfio_bar_read(void *opaque,
> static const MemoryRegionOps vfio_bar_ops = {
> .read = vfio_bar_read,
> .write = vfio_bar_write,
> - .endianness = DEVICE_NATIVE_ENDIAN,
> + .endianness = DEVICE_LITTLE_ENDIAN,
> };
>
> static void vfio_pci_load_rom(VFIODevice *vdev)
> @@ -1250,42 +1250,21 @@ static void vfio_pci_load_rom(VFIODevice *vdev)
> static uint64_t vfio_rom_read(void *opaque, hwaddr addr, unsigned size)
> {
> VFIODevice *vdev = opaque;
> - union {
> - uint8_t byte;
> - uint16_t word;
> - uint32_t dword;
> - uint64_t qword;
> - } buf;
> - uint64_t data = 0;
> + uint64_t val = ((uint64_t)1 << (size * 8)) - 1;
>
> /* Load the ROM lazily when the guest tries to read it */
> if (unlikely(!vdev->rom && !vdev->rom_read_failed)) {
> vfio_pci_load_rom(vdev);
> }
>
> - memcpy(&buf, vdev->rom + addr,
> + memcpy(&val, vdev->rom + addr,
> (addr < vdev->rom_size) ? MIN(size, vdev->rom_size - addr) : 0);
>
> - switch (size) {
> - case 1:
> - data = buf.byte;
> - break;
> - case 2:
> - data = buf.word;
> - break;
> - case 4:
> - data = buf.dword;
> - break;
> - default:
> - hw_error("vfio: unsupported read size, %d bytes", size);
> - break;
> - }
> -
> DPRINTF("%s(%04x:%02x:%02x.%x, 0x%"HWADDR_PRIx", 0x%x) = 0x%"PRIx64"\n",
> __func__, vdev->host.domain, vdev->host.bus, vdev->host.slot,
> - vdev->host.function, addr, size, data);
> + vdev->host.function, addr, size, val);
>
> - return data;
> + return val;
> }
>
> static void vfio_rom_write(void *opaque, hwaddr addr,
> @@ -1296,7 +1275,7 @@ static void vfio_rom_write(void *opaque, hwaddr addr,
> static const MemoryRegionOps vfio_rom_ops = {
> .read = vfio_rom_read,
> .write = vfio_rom_write,
> - .endianness = DEVICE_NATIVE_ENDIAN,
> + .endianness = DEVICE_LITTLE_ENDIAN,
> };
>
> static bool vfio_blacklist_opt_rom(VFIODevice *vdev)
--
Gregory Kurz kurzg...@fr.ibm.com
gk...@linux.vnet.ibm.com
Software Engineer @ IBM/Meiosys http://www.ibm.com
Tel +33 (0)562 165 496
"Anarchy is about taking complete responsibility for yourself."
Alan Moore.
