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From: Peter Maydell <peter.maydell@linaro.org>
Date: Sat, 23 Feb 2019 16:18:15 +0000
Message-ID: <CAFEAcA8kOEJe-Ax_SFOCa49og-N7gpO-ptsANdvXPhKthrpb8A@mail.gmail.com>
Content-Type: text/plain; charset="UTF-8"
Subject: Re: [Qemu-devel] [Qemu-block] Guest unresponsive after Virtqueue
 size exceeded error
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To: Natanael Copa <ncopa@alpinelinux.org>
Cc: Stefan Hajnoczi <stefanha@gmail.com>, Paolo Bonzini <pbonzini@redhat.com>, =?UTF-8?Q?Fernando_Casas_Sch=C3=B6ssow?= <casasfernando@outlook.com>, qemu-devel <qemu-devel@nongnu.org>, Richard Henderson <rth@twiddle.net>

On Sat, 23 Feb 2019 at 16:05, Natanael Copa <ncopa@alpinelinux.org> wrote:
> I was thinking of something in the lines of:
>
> typedef volatile uint16_t __attribute__((__may_alias__)) volatile_uint16_t;
> static inline int lduw_he_p(const void *ptr)
> {
>      volatile_uint16_t r = *(volatile_uint16_t*)ptr;
>      return r;
> }

This won't correctly handle accesses with unaligned pointers,
I'm afraid. We rely on these functions correctly working
with pointers that are potentially unaligned.

thanks
-- PMM