Re: [Qemu-devel] [Qemu-block] Guest unresponsive after Virtqueue size exceeded error

[Peter Maydell]

On Mon, 25 Feb 2019 at 12:22, Natanael Copa <address@hidden> wrote:
>
> On Mon, 25 Feb 2019 10:34:23 +0000
> Peter Maydell <address@hidden> wrote:
> > The short term fix is to fix your toolchain/compilation
> > environment options so that it isn't trying to override
> > the definition of memcpy().
>
> The easiest workaround is to simply disable FORTIY_SOURCE, but that
> will weaken the security for all implemented string functions, strcpy,
> memmove etc, so I don't want to do that.
>
> Is it only lduw_he_p that needs to be atomic or are the other functions
> in include/qemu/bswap.h using memcpy also required to be atomic?

Hard to say, since we haven't done the "audit all the callers"
step that Stefan mentioned. If you're going to replace memcpy
with __builtin_memcpy then the safest thing is to do it for
all those uses (this will also give you much better generated
code for performance purposes).

thanks
-- PMM