On 22/03/2016 09:12, Thomas Huth wrote: > On 22.03.2016 00:56, David Gibson wrote: >> On Mon, 21 Mar 2016 12:33:34 +0100 >> Laurent Vivier <lvivier@xxxxxxxxxx> wrote: >> >>> For lswx in little-endian mode, an alignment interrupt occurs. >>> >>> Signed-off-by: Laurent Vivier <lvivier@xxxxxxxxxx> >>> Reviewed-by: Thomas Huth <thuth@xxxxxxxxxx> >> >> I'm not entirely clear here; will the test fail if the alignment >> exception doesn't occur in little endian mode? > > I think so, yes. > >> The general trend in Power has been for less and less things to trigger >> alignment exceptions, so failing to cause an alignment exception >> shouldn't cause a test failure (as long as the unaligned case is >> correctly processed, of course). > > According to the PowerISA 2.07, chapter 6.5.8, lswx should always > trigger an alignment exception in little endian mode. So that's > architected behavior and the test should be OK, as far as I can see... > In case this gets changed with a future CPU, I think the test could be > adapted later, too? Exactly. Then in the kernel, the instruction is emulated. It's why I didn't understand why this test case fails with kvm in little endian mode, while is was working on a real host or in a guest. Laurent -- To unsubscribe from this list: send the line "unsubscribe kvm-ppc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
