From 2621e945fbf1d6df5f3f0ba7be5bae3d2cf9b6a5 Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Fri, 24 Nov 2017 14:51:02 +1100 Subject: powerpc/kexec: Fix kexec/kdump in P9 guest kernels 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") Cc: stable@vger.kernel.org # v4.10+ Reported-by: Yilin Zhang Debugged-by: David Gibson Signed-off-by: Michael Ellerman Acked-by: Balbir Singh Reviewed-by: David Gibson Tested-by: David Gibson Signed-off-by: Michael Ellerman --- arch/powerpc/kernel/misc_64.S | 2 ++ 1 file changed, 2 insertions(+) diff --git a/arch/powerpc/kernel/misc_64.S b/arch/powerpc/kernel/misc_64.S index 8ac0bd2..3280953 100644 --- 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. -- cgit v1.1