On Wed, Oct 18, 2017 at 5:01 PM, Dave Martin <Dave.Martin@xxxxxxx> wrote: > On Wed, Oct 18, 2017 at 03:21:45PM +0200, Christoffer Dall wrote: >> On Tue, Oct 17, 2017 at 04:47:08PM +0100, Dave Martin wrote: >> > On Tue, Oct 17, 2017 at 03:29:36PM +0100, Marc Zyngier wrote: >> > > On 17/10/17 15:07, Dave Martin wrote: >> > > > On Tue, Oct 17, 2017 at 06:58:16AM -0700, Christoffer Dall wrote: >> > > >> On Tue, Oct 10, 2017 at 07:38:41PM +0100, Dave Martin wrote: > > [...] > >> > > >>> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c > > [...] > >> > > >>> @@ -897,8 +898,17 @@ static u64 read_id_reg(struct sys_reg_desc const *r, bool raz) >> > > >>> { >> > > >>> u32 id = sys_reg((u32)r->Op0, (u32)r->Op1, >> > > >>> (u32)r->CRn, (u32)r->CRm, (u32)r->Op2); >> > > >>> + u64 val = raz ? 0 : read_sanitised_ftr_reg(id); >> > > >>> >> > > >>> - return raz ? 0 : read_sanitised_ftr_reg(id); >> > > >>> + if (id == SYS_ID_AA64PFR0_EL1) { >> > > >>> + if (val & (0xfUL << ID_AA64PFR0_SVE_SHIFT)) >> > > >>> + pr_err_once("kvm [%i]: SVE unsupported for guests, suppressing\n", >> > > >>> + task_pid_nr(current)); >> > > >> >> > > >> nit: does this really qualify as an error print? >> > > > >> > > > I have no strong opinion on this: maz suggested I should add this -- >> > > > his concern was to make it difficult to ignore. >> > > > >> > > > This is transitional: the main purpose is to circumvent bug reports from >> > > > people who find that SVE doesn't work in their guests, in the interim >> > > > before proper KVM support lands upstream. >> > > > >> > > > Marc, do you still agree with this position? >> > > >> > > As long as this is transitional, I'm OK with this. >> > >> > No argument from me, since it was your request in the first place ;) >> > >> > Christoffer? >> > >> No (further) argument from me. > > OK, thanks. Can I take that as an Ack? > Yes: Acked-by: Christoffer Dall <christoffer.dall@xxxxxxxxxx>