Re: [PULL v2 05/13] accel/tcg: Relax va restrictions on 64-bit guests

[Laurent Vivier]

On 15/05/2020 16:43, Alex Bennée wrote:
> From: Richard Henderson <richard.henderson@linaro.org>
> 
> We cannot at present limit a 64-bit guest to a virtual address
> space smaller than the host.  It will mostly work to ignore this
> limitation, except if the guest uses high bits of the address
> space for tags.  But it will certainly work better, as presently
> we can wind up failing to allocate the guest stack.
> 
> Widen our user-only page tree to the host or abi pointer width.
> Remove the workaround for this problem from target/alpha.
> Always validate guest addresses vs reserved_va, as there we
> control allocation ourselves.
> 
> Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
> 
> Message-Id: <20200513175134.19619-7-alex.bennee@linaro.org>
> 

This patch breaks a test case in LTP with 64bit targets on x86_64 host:

sudo linux-user/mips64el-linux-user/qemu-mips64el \
-L chroot/mips64el/stretch/ \
chroot/mips64el/stretch/opt/ltp/testcases/bin/mmap15

qemu-mips64el: accel/tcg/translate-all.c:2533: page_set_flags: Assertion
`start < end' failed.
qemu:handle_cpu_signal received signal outside vCPU context @
pc=0x7f0015f6e7cb

Could you have a look?

Thanks,
Laurent