On Wed, 2013-02-13 at 14:25 +0000, Marc Zyngier wrote: > Using readl() to read the magic value and then memcmp() to check it > fails on BE, as bytes will be the other way around (by virtue of > the registers to follow the endianess of the guest). Hm. Interesting. I missed the fact that readl() as a "PCI operation" will always assume LE values... > Fix it by encoding the magic as an integer instead of a string. > So I'm not completely sure this is the right fix, It seems right, however... > - Using __raw_readl() instead. Is that a generic enough API? > ... this implies that either the spec is wrong (as it should say: the device registers are always LE, in the PCI spirit) or all readl()s & co. should be replaced with __raw equivalents. Having said that, does the change make everything else work with a BE guest? (I assume we're talking about the guest being BE, right? ;-) If so it means that the host is not following the current spec and it treats all the registers as LE. > - Reading the MAGIC register byte by byte. Is that allowed? The spec > only says it is 32bit wide. And the spirit of the spec was: _exactly 32bit wide_. It's just simpler to implement one access width on the host side. Paweł _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
