This is a note to let you know that I've just added the patch titled
powerpc/kexec: Fix kexec/kdump in P9 guest kernels
to the 4.14-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git%3Ba=su...
The filename of the patch is: powerpc-kexec-fix-kexec-kdump-in-p9-guest-kernels.patch and it can be found in the queue-4.14 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree, please let stable@vger.kernel.org know about it.
From 2621e945fbf1d6df5f3f0ba7be5bae3d2cf9b6a5 Mon Sep 17 00:00:00 2001
From: Michael Ellerman mpe@ellerman.id.au Date: Fri, 24 Nov 2017 14:51:02 +1100 Subject: powerpc/kexec: Fix kexec/kdump in P9 guest kernels
From: Michael Ellerman mpe@ellerman.id.au
commit 2621e945fbf1d6df5f3f0ba7be5bae3d2cf9b6a5 upstream.
The code that cleans up the IAMR/AMOR before kexec'ing failed to remember that when we're running as a guest AMOR is not writable, it's hypervisor privileged.
They symptom is that the kexec stops before entering purgatory and nothing else is seen on the console. If you examine the state of the system all threads will be in the 0x700 program check handler.
Fix it by making the write to AMOR dependent on HV mode.
Fixes: 1e2a516e89fc ("powerpc/kexec: Fix radix to hash kexec due to IAMR/AMOR") Reported-by: Yilin Zhang yilzhang@redhat.com Debugged-by: David Gibson david@gibson.dropbear.id.au Signed-off-by: Michael Ellerman mpe@ellerman.id.au Acked-by: Balbir Singh bsingharora@gmail.com Reviewed-by: David Gibson david@gibson.dropbear.id.au Tested-by: David Gibson david@gibson.dropbear.id.au Signed-off-by: Michael Ellerman mpe@ellerman.id.au Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- arch/powerpc/kernel/misc_64.S | 2 ++ 1 file changed, 2 insertions(+)
--- a/arch/powerpc/kernel/misc_64.S +++ b/arch/powerpc/kernel/misc_64.S @@ -623,7 +623,9 @@ BEGIN_FTR_SECTION * NOTE, we rely on r0 being 0 from above. */ mtspr SPRN_IAMR,r0 +BEGIN_FTR_SECTION_NESTED(42) mtspr SPRN_AMOR,r0 +END_FTR_SECTION_NESTED_IFSET(CPU_FTR_HVMODE, 42) END_FTR_SECTION_IFSET(CPU_FTR_ARCH_300)
/* save regs for local vars on new stack.
Patches currently in stable-queue which might be from mpe@ellerman.id.au are
queue-4.14/powerpc-powernv-fix-kexec-crashes-caused-by-tlbie-tracing.patch queue-4.14/powerpc-kexec-fix-kexec-kdump-in-p9-guest-kernels.patch queue-4.14/cxl-check-if-vphb-exists-before-iterating-over-afu-devices.patch