4.14-stable review patch. If anyone has any objections, please let me know.
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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.