On 05/18/2016 09:01 PM, Thomas Huth wrote:
If kvmppc_handle_exit_pr() calls kvmppc_emulate_instruction() to emulate
one instruction (in the BOOK3S_INTERRUPT_H_EMUL_ASSIST case), it calls
kvmppc_core_queue_program() afterwards if kvmppc_emulate_instruction()
returned EMULATE_FAIL, so the guest gets an program interrupt for the
illegal opcode.
However, the kvmppc_emulate_instruction() also tried to inject a
program exception for this already, so the program interrupt gets
injected twice and the return address in srr0 gets destroyed.
All other callers of kvmppc_emulate_instruction() are also injecting
a program interrupt, and since the callers have the right knowledge
about the srr1 flags that should be used, it is the function
kvmppc_emulate_instruction() that should _not_ inject program
interrupts, so remove the kvmppc_core_queue_program() here.
This fixes the issue discovered by Laurent Vivier with kvm-unit-tests
where the logs are filled with these messages when the test tries
to execute an illegal instruction:
Couldn't emulate instruction 0x00000000 (op 0 xop 0)
kvmppc_handle_exit_pr: emulation at 700 failed (00000000)
Signed-off-by: Thomas Huth <thuth@xxxxxxxxxx>
I'm surprised you're the first one to encounter this :).
Reviewed-by: Alexander Graf <agraf@xxxxxxx>
Alex
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