On Thu, Jul 04, 2013 at 08:54:32AM +0200, Paolo Bonzini wrote: > Il 03/07/2013 18:33, Cornelia Huck ha scritto: > > On Wed, 03 Jul 2013 17:30:40 +0200 > > Paolo Bonzini <pbonzini@xxxxxxxxxx> wrote: > > > >> Il 03/07/2013 16:30, Cornelia Huck ha scritto: > >>> + /* > >>> + * Return cookie in gpr 2, but don't overwrite the register if the > >>> + * diagnose will be handled by userspace. > >>> + */ > >>> + if (ret != -EOPNOTSUPP) > >>> + vcpu->run->s.regs.gprs[2] = ret; > >> > >> I think this should now be "if (ret >= 0)". > > > > Hm, we don't want to kill gpr 2's old contents if userspace will do > > something, which means -EOPNOTSUPP. > > In the end kvm_io_bus_write_cookie only returns -EOPNOTSUPP if there is > an error, so it works. But if this were to change, the code would > break. That's why I suggested testing "ret >= 0" rather than "ret != > -EOPNOTSUPP". But in the end it is the same. > > >> > >>> /* kvm_io_bus_write returns -EOPNOTSUPP if it found no match. */ > >> > >> The comment is now obsolete. > > > > s/kvm_io_bus_write/kvm_io_bus_write_cookie/ ? Otherwise, this is still > > true. > > True but somewhat misplaced, it is basically saying the same thing as > the "Return cookie in gpr 2" comment just above. > > Anyhow, these are very small details. I changed kvm_io_bus_write to > kvm_io_bus_write_cookie in the comment and applied the patches to kvm-queue. > 1/2 broke x86. QEMU prints "Invalid read from memory region kvm-pic" and guest hangs. Looks like IO is forwarded to userspace instead of in kernel device for some reason. Un-applying for now. -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
