powerpc/64s: Machine check handle ifetch from foreign real address for POWER9
The i-side 0111b machine check, which is "Instruction Fetch to foreign address space", was missed by 7b9f71f9 ("powerpc/64s: POWER9 machine check handler"). The POWER9 processor core considers host real addresses with a nonzero value in RA(8:12) as foreign address space, accessible only by the copy and paste instructions. The copy and paste instruction pair can be used to invoke the Nest accelerators via the Virtual Accelerator Switchboard (VAS). It is an error for any regular load/store or ifetch to go to a foreign addresses. When relocation is on, this causes an MMU exception. When relocation is off, a machine check exception. It is possible to trigger this machine check by branching to a foreign address with MSR[IR]=0. Fixes: 7b9f71f9 ("powerpc/64s: POWER9 machine check handler") Reported-by: Mahesh Salgaonkar <mahesh@linux.vnet.ibm.com> Signed-off-by: Nicholas Piggin <npiggin@gmail.com> Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
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