Re: [PATCH] target/i386: do not access beyond the low 128 bits of SSE registers

["Alex Bennée" <alex.bennee@linaro.org>]

Paolo Bonzini <pbonzini@redhat.com> writes:

> The i386 target consolidates all vector registers so that instead of
> XMMReg, YMMReg and ZMMReg structs there is a single ZMMReg that can
> fit all of SSE, AVX and AVX512.
>
> When TCG copies data from and to the SSE registers, it uses the
> full 64-byte width.  This is not a correctness issue because TCG
> never lets guest code see beyond the first 128 bits of the ZMM
> registers, however it causes uninitialized stack memory to
> make it to the CPU's migration stream.
>
> Fix it by only copying the low 16 bytes of the ZMMReg union into
> the destination register.
>
> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

And:

Fixes: b7711471f5 ("target-i386: make xmm_regs 512-bit wide")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/420

?
-- 
Alex Bennée