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author | Benjamin Herrenschmidt <benh@kernel.crashing.org> | 2019-02-15 17:16:45 +0100 |
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committer | David Gibson <david@gibson.dropbear.id.au> | 2019-02-26 09:21:24 +1100 |
commit | f8154fd22bf80b1555bac46119747e899c09d0c9 (patch) | |
tree | 0a0a86b075f140dd74b90857942f31221e647ccf /target | |
parent | a790e82b13854f443850cbf11b25cdb98f6885c5 (diff) | |
download | qemu-f8154fd22bf80b1555bac46119747e899c09d0c9.zip qemu-f8154fd22bf80b1555bac46119747e899c09d0c9.tar.gz qemu-f8154fd22bf80b1555bac46119747e899c09d0c9.tar.bz2 |
target/ppc: Detect erroneous condition in interrupt delivery
It's very easy for the CPU specific has_work() implementation
and the logic in ppc_hw_interrupt() to be subtly out of sync.
This can occasionally allow a CPU to wakeup from a PM state
and resume executing past the PM instruction when it should
resume at the 0x100 vector.
This detects if it happens and aborts, making it a lot easier
to catch such bugs when testing rather than chasing obscure
guest misbehaviour.
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Reviewed-by: David Gibson <david@gibson.dropbear.id.au>
Message-Id: <20190215161648.9600-8-clg@kaod.org>
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Diffstat (limited to 'target')
-rw-r--r-- | target/ppc/excp_helper.c | 16 |
1 files changed, 16 insertions, 0 deletions
diff --git a/target/ppc/excp_helper.c b/target/ppc/excp_helper.c index 37546bb..1a2f469 100644 --- a/target/ppc/excp_helper.c +++ b/target/ppc/excp_helper.c @@ -878,6 +878,22 @@ static void ppc_hw_interrupt(CPUPPCState *env) return; } } + + if (env->resume_as_sreset) { + /* + * This is a bug ! It means that has_work took us out of halt without + * anything to deliver while in a PM state that requires getting + * out via a 0x100 + * + * This means we will incorrectly execute past the power management + * instruction instead of triggering a reset. + * + * It generally means a discrepancy between the wakup conditions in the + * processor has_work implementation and the logic in this function. + */ + cpu_abort(CPU(ppc_env_get_cpu(env)), + "Wakeup from PM state but interrupt Undelivered"); + } } void ppc_cpu_do_system_reset(CPUState *cs) |