Re: [PULL 17/20] target/arm: Do memory type alignment check when translation disabled

[Peter Maydell]

On Sat, 25 May 2024 at 14:41, Bernhard Beschow <shentey@gmail.com> wrote:
>
>
>
> Am 5. März 2024 13:52:34 UTC schrieb Peter Maydell <peter.maydell@linaro.org>:
> >From: Richard Henderson <richard.henderson@linaro.org>
> >
> >If translation is disabled, the default memory type is Device, which
> >requires alignment checking.  This is more optimally done early via
> >the MemOp given to the TCG memory operation.
> >
> >Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
> >Reported-by: Idan Horowitz <idan.horowitz@gmail.com>
> >Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> >Message-id: 20240301204110.656742-6-richard.henderson@linaro.org
> >Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1204
> >Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
> >Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
>
> Hi,
>
> This change causes an old 4.14.40 Linux kernel to panic on boot using the 
> sabrelite machine:
>
> [snip]
> Alignment trap: init (1) PC=0x76f1e3d4 Instr=0x14913004 Address=0x76f34f3e 
> FSR 0x001
> Alignment trap: init (1) PC=0x76f1e3d8 Instr=0x148c3004 Address=0x7e8492bd 
> FSR 0x801
> Alignment trap: init (1) PC=0x76f0dab0 Instr=0x6823 Address=0x7e849fbb FSR 
> 0x001
> Alignment trap: init (1) PC=0x76f0dab2 Instr=0x6864 Address=0x7e849fbf FSR 
> 0x001
> scsi 0:0:0:0: Direct-Access     QEMU     QEMU HARDDISK    2.5+ PQ: 0 ANSI: 5
> fsl-asoc-card sound: ASoC: CODEC DAI sgtl5000 not registered
> imx-sgtl5000 sound: ASoC: CODEC DAI sgtl5000 not registered
> imx-sgtl5000 sound: snd_soc_register_card failed (-517)
> Alignment trap: init (1) PC=0x76eac95a Instr=0xf8dd5015 Address=0x7e849b05 
> FSR 0x001
> Alignment trap: not handling instruction f8dd5015 at [<76eac95a>]
> Unhandled fault: alignment exception (0x001) at 0x7e849b05
> pgd = 9c59c000
> [7e849b05] *pgd=2c552831, *pte=109eb34f, *ppte=109eb83f
> Kernel panic - not syncing: Attempted to kill init! exitcode=0x00000007
>
> ---[ end Kernel panic - not syncing: Attempted to kill init! 
> exitcode=0x00000007

I think this is the same bug as reported in
https://gitlab.com/qemu-project/qemu/-/issues/2326
and which I've just sent a patchset for:
20240809160430.1144805-1-peter.maydell@linaro.org/">https://patchew.org/QEMU/20240809160430.1144805-1-peter.maydell@linaro.org/

(The problem was that we were looking at the wrong banked
SCTLR when running at Secure EL0.)

thanks
-- PMM