Re: [PATCH v5 17/17] powerpc/32s: Enable CONFIG_VMAP_STACK

From: Christophe Leroy
Date: Fri Feb 07 2020 - 08:29:52 EST




On 02/07/2020 01:08 PM, Guenter Roeck wrote:
On 2/7/20 12:28 AM, Christophe Leroy wrote:


On 02/07/2020 06:13 AM, Christophe Leroy wrote:


Le 06/02/2020 Ã 21:31, Guenter Roeck a ÃcritÂ:
On Sat, Dec 21, 2019 at 08:32:38AM +0000, Christophe Leroy wrote:
A few changes to retrieve DAR and DSISR from struct regs
instead of retrieving them directly, as they may have
changed due to a TLB miss.

Also modifies hash_page() and friends to work with virtual
data addresses instead of physical ones. Same on load_up_fpu()
and load_up_altivec().

Signed-off-by: Christophe Leroy <christophe.leroy@xxxxxx>

This patch results in qemu boot failures (mac99 with pmac32_defconfig).
Images fail silently; there is no console output. Reverting the patch
fixes the problem. Bisect log is attached below.

Assuming this was tested on real hardware, am I correct to assume that qemu
for ppc32 (more specifically, qemu's mac99 and g3beige machines) no longer
works with the upstream kernel ?

Before submitting the series, I successfully tested:
- Real HW with powerpc 8xx
- Real HW with powerpc 832x
- Qemu's mac99

I'll re-check the upstream kernel.


This is still working for me with the upstream kernel:


Interesting. What is your kernel configuration, your qemu version, and
your qemu command line ?

Config is pmac32_defconfig + CONFIG_DEVTMPFS (But kernel also boots without CONFIG_DEVTMPFS)

QEMU emulator version 2.11.2

qemu-system-ppc -kernel vmlinux -M mac99 -initrd rootfs.cpio.gz -s -m 1024

Works with both GCC 5.5 and GCC 8.1

Christophe