Re: [PATCH 1/3] xen, pvh: fix unbootable VMs (PVH + KASAN)

[Jürgen Groß <jgross@xxxxxxxx>]

On 01.08.24 21:16, Alexey Dobriyan wrote:
> Uninstrument arch/x86/platform/pvh/enlighten.c: KASAN is not setup
> _this_ early in the boot process.
>
> Steps to reproduce:
>
>         make allnoconfig
>         make sure CONFIG_AMD_MEM_ENCRYPT is disabled
>                 AMD_MEM_ENCRYPT independently uninstruments lib/string.o
>                 so PVH boot code calls into uninstrumented memset() and
>                 memcmp() which can make the bug disappear depending on
>                 the compiler.
>         enable CONFIG_PVH
>         enable CONFIG_KASAN
>         enable serial console
>                 this is fun exercise if you never done it from nothing :^)
>
>         make
>
>         qemu-system-x86_64      \
>                 -enable-kvm     \
>                 -cpu host       \
>                 -smp cpus=1     \
>                 -m 4096         \
>                 -serial stdio   \
>                 -kernel vmlinux \
>                 -append 'console=ttyS0 ignore_loglevel'
>
> Messages on serial console will easily tell OK kernel from unbootable
> kernel. In bad case qemu hangs in an infinite loop stroboscoping
> "SeaBIOS" message.
>
> Signed-off-by: Alexey Dobriyan <adobriyan@xxxxxxxxx>
Acked-by: Juergen Gross <jgross@xxxxxxxx>


Juergen