On Tue, 12 Nov 2019, 04:01 Stefano Stabellini, <sstabell...@kernel.org> wrote:
> On Sat, 9 Nov 2019, Julien Grall wrote: > > On Sat, 9 Nov 2019, 04:27 Stefano Stabellini, <sstabell...@kernel.org> > wrote: > > On Thu, 7 Nov 2019, Peng Fan wrote: > > > The end should be GICD_ISACTIVERN not GICD_ISACTIVER. > > > > > > Signed-off-by: Peng Fan <peng....@nxp.com> > > > > Reviewed-by: Stefano Stabellini <sstabell...@kernel.org> > > > > > > To be honest, I am not sure the code is correct. A read to those > registers should tell you the list of interrupts active. As we always > > return 0, this will not return the correct state of the GIC. > > > > I know that returning the list of actives interrupts is complicated with > the old vGIC, but I don't think silently ignoring it is a good > > idea. > > The question here is why the guest accessed those registers? What is it > trying to figure out? > > We are not going to solve the general problem at this stage. At the > moment the code: > > - ignore the first register only > - print an error and return an IO_ABORT error for the other regs > > For the inconsistency alone the second option is undesirable. Also it > doesn't match the write implementation, which does the same thing for > all the GICD_ISACTIVER* regs instead of having a special treatment for > the first one only. It looks like a typo in the original patch to me. > > The proposed patch switches the behavior to: > > - silently ignore all the GICD_ISACTIVER* regs (as proposed) > is an improvement. > Peng mentioned that Linux is accessing it, so the worst thing we can do is lying to the guest (as you suggest here). I would definitely not call that an improvement. In the current state, it is a Nack. If there were a warning, then I would be more inclined to see this patch going through. Cheers,
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