On Wed, Aug 16, 2017 at 12:10:53PM +0100, Marc Zyngier wrote: > On 16/08/17 11:54, Dave Martin wrote: > > On Tue, Aug 15, 2017 at 05:37:55PM +0100, Marc Zyngier wrote: > >> On 09/08/17 13:05, Dave Martin wrote: [...] > >>> + if (id == SYS_ID_AA64PFR0_EL1) { > >>> + static bool printed; > >>> + > >>> + if ((val & (0xfUL << ID_AA64PFR0_SVE_SHIFT)) && !printed) { > >>> + kvm_info("SVE unsupported for guests, suppressing\n"); > >>> + printed = true; > >>> + } > >> > >> Ideally, this should be a vcpu_unimpl_once(). But: > >> - it doesn't exist > >> - vcpu_unimpl looks hopelessly x86 specific > > > > Yeah, I looked for an appropriate function and didn't find one ... and > > writing one just for this seemed overkill. > > > >> How about turning it into a pr_err_once() instead? > > > > Can do, though should it be an err? > > > > No error has occurred here, rather I want people who discover that their > > guest mysteriously doesn't see SVE gets a clue about why. > An "err" is a good way to make it appear on the console. If you want to > make it noticed, that's the way. OK, I was concerned that overuse of err might be frowned upon. If this is the preferred way to signal such things, I'm happy to that. Cheers ---Dave