Re: [PATCH] powerpc/pseries: Fix scv instruction crash with kexec

2024-07-09 Thread Michal Suchánek
On Tue, Jul 09, 2024 at 11:03:10PM +1000, Michael Ellerman wrote: > Michal Suchánek writes: > > Hello, > > > > On Tue, Jun 25, 2024 at 11:40:47PM +1000, Nicholas Piggin wrote: > >> kexec on pseries disables AIL (reloc_on_exc), required for scv > >> instruction support, before other CPUs have been

Re: [PATCH] powerpc/pseries: Fix scv instruction crash with kexec

2024-07-09 Thread Michael Ellerman
Michal Suchánek writes: > Hello, > > On Tue, Jun 25, 2024 at 11:40:47PM +1000, Nicholas Piggin wrote: >> kexec on pseries disables AIL (reloc_on_exc), required for scv >> instruction support, before other CPUs have been shut down. This means >> they can execute scv instructions after AIL is disabl

Re: [PATCH] powerpc/pseries: Fix scv instruction crash with kexec

2024-07-09 Thread Michal Suchánek
Hello, On Tue, Jun 25, 2024 at 11:40:47PM +1000, Nicholas Piggin wrote: > kexec on pseries disables AIL (reloc_on_exc), required for scv > instruction support, before other CPUs have been shut down. This means > they can execute scv instructions after AIL is disabled, which causes an > interrupt a

Re: [PATCH] powerpc/pseries: Fix scv instruction crash with kexec

2024-07-06 Thread Michael Ellerman
On Tue, 25 Jun 2024 23:40:47 +1000, Nicholas Piggin wrote: > kexec on pseries disables AIL (reloc_on_exc), required for scv > instruction support, before other CPUs have been shut down. This means > they can execute scv instructions after AIL is disabled, which causes an > interrupt at an unexpecte

Re: [PATCH] powerpc/pseries: Fix scv instruction crash with kexec

2024-06-30 Thread Sourabh Jain
On 26/06/24 15:10, Gautam Menghani wrote: Without this patch, we had an issue where if we have some cpus disabled in the system and we try to do a 2 stage kexec as follows: kexec -l vmlinux kexec -e we would hit the following Oops [ 2598.923098] kernel BUG at arch/powerpc/kernel/except

Re: [PATCH] powerpc/pseries: Fix scv instruction crash with kexec

2024-06-28 Thread Michael Ellerman
Sourabh Jain writes: > On 26/06/24 14:57, Michael Ellerman wrote: >> Nicholas Piggin writes: >>> kexec on pseries disables AIL (reloc_on_exc), required for scv >>> instruction support, before other CPUs have been shut down. This means >>> they can execute scv instructions after AIL is disabled, w

Re: [PATCH] powerpc/pseries: Fix scv instruction crash with kexec

2024-06-26 Thread Sourabh Jain
Hello Michael, On 26/06/24 14:57, Michael Ellerman wrote: Nicholas Piggin writes: kexec on pseries disables AIL (reloc_on_exc), required for scv instruction support, before other CPUs have been shut down. This means they can execute scv instructions after AIL is disabled, which causes an inter

Re: [PATCH] powerpc/pseries: Fix scv instruction crash with kexec

2024-06-26 Thread Gautam Menghani
Without this patch, we had an issue where if we have some cpus disabled in the system and we try to do a 2 stage kexec as follows: kexec -l vmlinux kexec -e we would hit the following Oops [ 2598.923098] kernel BUG at arch/powerpc/kernel/exceptions-64s.S:501! [ 2598.923103] Oops: Exception

Re: [PATCH] powerpc/pseries: Fix scv instruction crash with kexec

2024-06-26 Thread Michael Ellerman
Nicholas Piggin writes: > kexec on pseries disables AIL (reloc_on_exc), required for scv > instruction support, before other CPUs have been shut down. This means > they can execute scv instructions after AIL is disabled, which causes an > interrupt at an unexpected entry location that crashes the