On Mon, Jan 14, 2013 at 10:08:39PM +0000, Christoffer Dall wrote: > can't we also get rid of the isb on the return path then? > > do you agree with this patch: > > diff --git a/arch/arm/kvm/interrupts_head.S b/arch/arm/kvm/interrupts_head.S > index 57cfa84..7e6eedf 100644 > --- a/arch/arm/kvm/interrupts_head.S > +++ b/arch/arm/kvm/interrupts_head.S > @@ -492,7 +492,6 @@ vcpu .req r0 @ vcpu pointer always > in r0 > str r2, [vcpu, #VCPU_TIMER_CNTV_CTL] > bic r2, #1 @ Clear ENABLE > mcr p15, 0, r2, c14, c3, 1 @ CNTV_CTL > - isb
I'd keep this one as it stops speculation of CVAL until the timer is disabled. > mrrc p15, 3, r2, r3, c14 @ CNTV_CVAL > ldr r4, =VCPU_TIMER_CNTV_CVAL > @@ -532,18 +531,17 @@ vcpu .req r0 @ vcpu pointer always > in r0 > ldr r2, [r4, #KVM_TIMER_CNTVOFF] > ldr r3, [r4, #(KVM_TIMER_CNTVOFF + 4)] > mcrr p15, 4, r2, r3, c14 @ CNTVOFF > - isb > > ldr r4, =VCPU_TIMER_CNTV_CVAL > add vcpu, vcpu, r4 > ldrd r2, r3, [vcpu] > sub vcpu, vcpu, r4 > mcrr p15, 3, r2, r3, c14 @ CNTV_CVAL > + isb > > ldr r2, [vcpu, #VCPU_TIMER_CNTV_CTL] > and r2, r2, #3 > mcr p15, 0, r2, c14, c3, 1 @ CNTV_CTL > - isb Looks ok to me, but I'll let Marc decide as it's his code. Will -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
