On 29 May 2016 at 16:22, Dmitry Fleytman <dmi...@daynix.com> wrote:
> It turned out that the issue is not in the new code but in
> pci.h helper functions used by the new code to fill DSN capability.
Thanks for tracking this down.
> Following patch fixes the problem:
>
> diff --git a/include/hw/pci/pci.h b/include/hw/pci/pci.h
> index ef6ba51..ee238ad
> --- a/include/hw/pci/pci.h
> +++ b/include/hw/pci/pci.h
> @@ -468,13 +468,13 @@ pci_get_long(const uint8_t *config)
> static inline void
> pci_set_quad(uint8_t *config, uint64_t val)
> {
> - cpu_to_le64w((uint64_t *)config, val);
> + stq_le_p(config, val);
> }
>
> static inline uint64_t
> pci_get_quad(const uint8_t *config)
> {
> - return le64_to_cpup((const uint64_t *)config);
> + return ldq_le_p(config);
> }
>
> I see from git blame that some time ago you did similar change in all other
> pci_set_* pci_get_* functions except these two.
>
> Is there any specific reason you did not change these two functions then?
The patches where I changed the other functions were cleanups
to convert away from some legacy *_to_cpupu() functions, which
were specifically intended to work with unaligned pointers
(which is what the "u" indicated). I was doing the cleanups
per-conversion-function, not per-callsite, and since these
two functions aren't using a _to_cpupu() function but just
_to_cpup() they wouldn't have shown up in my searches.
In any case this is the correct fix, and we should probably
audit the other uses of *_to_cpup and cpu_to_* -- I suspect
many of them are working with possibly-unaligned
pointers in to guest memory and we should replace them with
ld*_*_p functions and get rid of the _to_cpup functions entirely.
thanks
-- PMM
