On Mon, Nov 16, 2015 at 01:11:43PM +0000, Marc Zyngier wrote: > Implement the timer save restore as a direct translation of > the assembly code version. Hi Marc, some comments below. Cheers, -- Steve > > Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx> > --- > arch/arm64/kvm/hyp/Makefile | 1 + > arch/arm64/kvm/hyp/hyp.h | 3 ++ > arch/arm64/kvm/hyp/timer-sr.c | 68 +++++++++++++++++++++++++++++++++++++++++++ > 3 files changed, 72 insertions(+) > create mode 100644 arch/arm64/kvm/hyp/timer-sr.c > > diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile > index d1e38ce..455dc0a 100644 > --- a/arch/arm64/kvm/hyp/Makefile > +++ b/arch/arm64/kvm/hyp/Makefile > @@ -4,3 +4,4 @@ > > obj-$(CONFIG_KVM_ARM_HOST) += vgic-v2-sr.o > obj-$(CONFIG_KVM_ARM_HOST) += vgic-v3-sr.o > +obj-$(CONFIG_KVM_ARM_HOST) += timer-sr.o > diff --git a/arch/arm64/kvm/hyp/hyp.h b/arch/arm64/kvm/hyp/hyp.h > index a31cb6e..86aa5a2 100644 > --- a/arch/arm64/kvm/hyp/hyp.h > +++ b/arch/arm64/kvm/hyp/hyp.h > @@ -33,5 +33,8 @@ void __vgic_v2_restore_state(struct kvm_vcpu *vcpu); > void __vgic_v3_save_state(struct kvm_vcpu *vcpu); > void __vgic_v3_restore_state(struct kvm_vcpu *vcpu); > > +void __timer_save_state(struct kvm_vcpu *vcpu); > +void __timer_restore_state(struct kvm_vcpu *vcpu); > + > #endif /* __ARM64_KVM_HYP_H__ */ > > diff --git a/arch/arm64/kvm/hyp/timer-sr.c b/arch/arm64/kvm/hyp/timer-sr.c > new file mode 100644 > index 0000000..1a1d2ac > --- /dev/null > +++ b/arch/arm64/kvm/hyp/timer-sr.c > @@ -0,0 +1,68 @@ > +/* > + * Copyright (C) 2012-2015 - ARM Ltd > + * Author: Marc Zyngier <marc.zyngier@xxxxxxx> > + * > + * This program is free software; you can redistribute it and/or modify > + * it under the terms of the GNU General Public License version 2 as > + * published by the Free Software Foundation. > + * > + * This program is distributed in the hope that it will be useful, > + * but WITHOUT ANY WARRANTY; without even the implied warranty of > + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the > + * GNU General Public License for more details. > + * > + * You should have received a copy of the GNU General Public License > + * along with this program. If not, see <http://www.gnu.org/licenses/>. > + */ > + > +#include <linux/compiler.h> > +#include <linux/kvm_host.h> > + > +#include <asm/kvm_mmu.h> > + > +#include "hyp.h" > + > +/* vcpu is already in the HYP VA space */ > +void __hyp_text __timer_save_state(struct kvm_vcpu *vcpu) > +{ > + struct kvm *kvm = kern_hyp_va(vcpu->kvm); > + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; > + > + if (kvm->arch.timer.enabled) { > + timer->cntv_ctl = read_sysreg(cntv_ctl_el0); The old assembler version ands this value with 3 before storing it. Are we not worried about the ISTATUS bit? > + isb(); > + timer->cntv_cval = read_sysreg(cntv_cval_el0); > + } > + > + /* Disable the virtual timer */ > + write_sysreg(0, cntv_ctl_el0); > + > + /* Allow physical timer/counter access for the host */ > + write_sysreg(read_sysreg(cnthctl_el2) | 3, cnthctl_el2); nit: EL1PCTEN | EL1PCEN or something similar? > + > + /* Clear cntvoff for the host */ > + write_sysreg(0, cntvoff_el2); > +} > + > +void __hyp_text __timer_restore_state(struct kvm_vcpu *vcpu) > +{ > + struct kvm *kvm = kern_hyp_va(vcpu->kvm); > + struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu; > + u64 val; > + > + /* > + * Disallow physical timer access for the guest > + * Physical counter access is allowed > + */ > + val = read_sysreg(cnthctl_el2); > + val &= ~(1 << 1); > + val |= 1; Similar nit here about constants. > + write_sysreg(val, cnthctl_el2); > + > + if (kvm->arch.timer.enabled) { > + write_sysreg(kvm->arch.timer.cntvoff, cntvoff_el2); > + write_sysreg(timer->cntv_cval, cntv_cval_el0); > + isb(); > + write_sysreg(timer->cntv_ctl, cntv_ctl_el0); In the assembler version we and cntv_ctl with 3 before writing to cntv_ctl_el0. > + } > +} > -- > 2.1.4 > > _______________________________________________ > kvmarm mailing list > kvmarm@xxxxxxxxxxxxxxxxxxxxx > https://lists.cs.columbia.edu/mailman/listinfo/kvmarm -- 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
