On Mon, May 14, 2012 at 9:07 AM, Marc Zyngier <marc.zyngier at arm.com> wrote: > Do the necessary save/restore dance for the timers in the world > switch code. In the process, allow the guest to read the physical > counter, which is useful for its own clock_event_device. > > Signed-off-by: Marc Zyngier <marc.zyngier at arm.com> > --- > ?arch/arm/kernel/asm-offsets.c | ? ?8 +++++++ > ?arch/arm/kvm/arm.c ? ? ? ? ? ?| ? ?2 + > ?arch/arm/kvm/interrupts.S ? ? | ? 43 +++++++++++++++++++++++++++++++++++++++++ > ?3 files changed, 53 insertions(+), 0 deletions(-) > > diff --git a/arch/arm/kernel/asm-offsets.c b/arch/arm/kernel/asm-offsets.c > index d5f4ddf..039ef64 100644 > --- a/arch/arm/kernel/asm-offsets.c > +++ b/arch/arm/kernel/asm-offsets.c > @@ -184,6 +184,14 @@ int main(void) > ? DEFINE(VCPU_VGIC_APR, ? ? ? ? ? ? ? ?offsetof(struct kvm_vcpu, arch.vgic_cpu.vgic_apr)); > ? DEFINE(VCPU_VGIC_LR, ? ? ? ? offsetof(struct kvm_vcpu, arch.vgic_cpu.vgic_lr)); > ? DEFINE(VCPU_VGIC_NR_LR, ? ? ?offsetof(struct kvm_vcpu, arch.vgic_cpu.nr_lr)); > +#ifdef CONFIG_KVM_ARM_TIMER > + ?DEFINE(VCPU_TIMER_CNTV_CTL, ?offsetof(struct kvm_vcpu, arch.timer_cpu.cntv_ctl)); > + ?DEFINE(VCPU_TIMER_CNTV_CVALH, ? ? ? ?offsetof(struct kvm_vcpu, arch.timer_cpu.cntv_cval_high)); > + ?DEFINE(VCPU_TIMER_CNTV_CVALL, ? ? ? ?offsetof(struct kvm_vcpu, arch.timer_cpu.cntv_cval_low)); > + ?DEFINE(KVM_TIMER_CNTVOFF_H, ?offsetof(struct kvm, arch.timer.cntvoff32.cntvoff_high)); > + ?DEFINE(KVM_TIMER_CNTVOFF_L, ?offsetof(struct kvm, arch.timer.cntvoff32.cntvoff_low)); > + ?DEFINE(KVM_TIMER_ENABLED, ? ?offsetof(struct kvm, arch.timer.enabled)); > +#endif > ? DEFINE(KVM_VGIC_VCTRL, ? ? ? offsetof(struct kvm, arch.vgic.vctrl_base)); > ?#endif > ? DEFINE(KVM_VTTBR, ? ? ? ? ? ?offsetof(struct kvm, arch.vttbr)); > diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c > index 86eca66..ccb2c08 100644 > --- a/arch/arm/kvm/arm.c > +++ b/arch/arm/kvm/arm.c > @@ -511,9 +511,11 @@ int kvm_arch_vcpu_ioctl_run(struct kvm_vcpu *vcpu, struct kvm_run *run) > ? ? ? ? ? ? ? ?kvm_guest_enter(); > ? ? ? ? ? ? ? ?vcpu->mode = IN_GUEST_MODE; > ? ? ? ? ? ? ? ?kvm_vgic_sync_to_cpu(vcpu); > + ? ? ? ? ? ? ? kvm_timer_sync_to_cpu(vcpu); > > ? ? ? ? ? ? ? ?ret = __kvm_vcpu_run(vcpu); > > + ? ? ? ? ? ? ? kvm_timer_sync_from_cpu(vcpu); > ? ? ? ? ? ? ? ?kvm_vgic_sync_from_cpu(vcpu); > ? ? ? ? ? ? ? ?vcpu->mode = OUTSIDE_GUEST_MODE; > ? ? ? ? ? ? ? ?vcpu->stat.exits++; > diff --git a/arch/arm/kvm/interrupts.S b/arch/arm/kvm/interrupts.S > index 56a65c4..1481d44 100644 > --- a/arch/arm/kvm/interrupts.S > +++ b/arch/arm/kvm/interrupts.S > @@ -312,10 +312,33 @@ ENTRY(__kvm_flush_vm_context) > ?#endif > ?.endm > > +#ifdef CONFIG_KVM_ARM_TIMER > +#define PL1P_ENABLE ? ?3 > +#define PL1P_DISABLE ? 2 > +#else > ?#define PL1P_ENABLE ? ?3 > ?#define PL1P_DISABLE ? 3 > +#endif > > ?.macro save_timer_state ? ? ? ?vcpup > +#ifdef CONFIG_KVM_ARM_TIMER > + ? ? ? ldr ? ? r4, [\vcpup, #VCPU_KVM] > + ? ? ? ldr ? ? r2, [r4, #KVM_TIMER_ENABLED] > + ? ? ? cmp ? ? r2, #0 > + ? ? ? beq ? ? 1f > + > + ? ? ? mrc ? ? p15, 0, r2, c14, c3, 1 ?@ CNTV_CTL > + ? ? ? and ? ? r2, #3 > + ? ? ? str ? ? r2, [\vcpup, #VCPU_TIMER_CNTV_CTL] > + ? ? ? bic ? ? r2, #1 ? ? ? ? ? ? ? ? ?@ Clear ENABLE > + ? ? ? mcr ? ? p15, 0, r2, c14, c3, 1 ?@ CNTV_CTL > + > + ? ? ? mrrc ? ?p15, 3, r2, r3, c14 ? ? @ CNTV_CVAL > + ? ? ? str ? ? r3, [\vcpup, #VCPU_TIMER_CNTV_CVALH] > + ? ? ? str ? ? r2, [\vcpup, #VCPU_TIMER_CNTV_CVALL] > + > +1: > +#endif > ? ? ? ?@ Allow physical timer access for the host > ? ? ? ?mrc ? ? p15, 4, r2, c14, c1, 0 ?@ CNTHCTL > ? ? ? ?orr ? ? r2, r2, #PL1P_ENABLE > @@ -328,6 +351,26 @@ ENTRY(__kvm_flush_vm_context) > ? ? ? ?bic ? ? r2, r2, #PL1P_DISABLE > ? ? ? ?mcr ? ? p15, 4, r2, c14, c1, 0 ?@ CNTHCTL > > +#ifdef CONFIG_KVM_ARM_TIMER > + ? ? ? ldr ? ? r4, [\vcpup, #VCPU_KVM] > + ? ? ? ldr ? ? r2, [r4, #KVM_TIMER_ENABLED] > + ? ? ? cmp ? ? r2, #0 > + ? ? ? beq ? ? 1f > + > + ? ? ? ldr ? ? r3, [\vcpup, #VCPU_TIMER_CNTV_CVALH] > + ? ? ? ldr ? ? r2, [\vcpup, #VCPU_TIMER_CNTV_CVALL] > + ? ? ? mcrr ? ?p15, 3, r2, r3, c14 ? ? @ CNTV_CVAL > + > + ? ? ? ldr ? ? r3, [r4, #KVM_TIMER_CNTVOFF_H] > + ? ? ? ldr ? ? r2, [r4, #KVM_TIMER_CNTVOFF_L] > + ? ? ? mcrr ? ?p15, 4, r2, r3, c14 ? ? @ CNTVOFF still not quite understanding where we adjust this or why we don't. If this is effectively zero do we have to bother with it on every world-switch and could this be documented somewhere? > + ? ? ? isb > + > + ? ? ? ldr ? ? r2, [\vcpup, #VCPU_TIMER_CNTV_CTL] > + ? ? ? and ? ? r2, #3 Are we clearing the enable and mask bits here, because in any case we offloaded a remaining timer from last time around to a host timer? > + ? ? ? mcr ? ? p15, 0, r2, c14, c3, 1 ?@ CNTV_CTL > +1: > +#endif > ? ? ? ?isb > ?.endm > > -- > 1.7.7.1 > Thanks, -Christoffer
