| Message ID | 1449485618-9443-7-git-send-email-marc.zyngier@arm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 12/7/2015 2:53 AM, Marc Zyngier wrote: > Implement the timer save restore as a direct translation of > the assembly code version. > > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> > --- > arch/arm64/kvm/hyp/Makefile | 1 + > arch/arm64/kvm/hyp/hyp.h | 3 ++ > arch/arm64/kvm/hyp/timer-sr.c | 72 ++++++++++++++++++++++++++++++++++++ > include/clocksource/arm_arch_timer.h | 6 +++ > 4 files changed, 82 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 5759f9f..f213e46 100644 > --- a/arch/arm64/kvm/hyp/hyp.h > +++ b/arch/arm64/kvm/hyp/hyp.h > @@ -35,5 +35,8 @@ 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..67292c0 > --- /dev/null > +++ b/arch/arm64/kvm/hyp/timer-sr.c > @@ -0,0 +1,72 @@ > +/* > + * Copyright (C) 2012-2015 - ARM Ltd > + * Author: Marc Zyngier <marc.zyngier@arm.com> > + * > + * 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 <clocksource/arm_arch_timer.h> > +#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; > + u64 val; > + > + if (kvm->arch.timer.enabled) { > + timer->cntv_ctl = read_sysreg(cntv_ctl_el0); > + isb(); Can you share the subtle insight why is the isb() needed here? B2.7.3 mentions changes to system registers only. > + 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 */ > + val = read_sysreg(cnthctl_el2); > + val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN; > + write_sysreg(val, cnthctl_el2); > + > + /* 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 &= ~CNTHCTL_EL1PCEN; > + val |= CNTHCTL_EL1PCTEN; > + 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); > + } > +} > diff --git a/include/clocksource/arm_arch_timer.h b/include/clocksource/arm_arch_timer.h > index 9916d0e..25d0914 100644 > --- a/include/clocksource/arm_arch_timer.h > +++ b/include/clocksource/arm_arch_timer.h > @@ -23,6 +23,12 @@ > #define ARCH_TIMER_CTRL_IT_MASK (1 << 1) > #define ARCH_TIMER_CTRL_IT_STAT (1 << 2) > > +#define CNTHCTL_EL1PCTEN (1 << 0) > +#define CNTHCTL_EL1PCEN (1 << 1) > +#define CNTHCTL_EVNTEN (1 << 2) > +#define CNTHCTL_EVNTDIR (1 << 3) > +#define CNTHCTL_EVNTI (0xF << 4) > + > enum arch_timer_reg { > ARCH_TIMER_REG_CTRL, > ARCH_TIMER_REG_TVAL, > -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On 08/12/15 02:18, Mario Smarduch wrote: > > > On 12/7/2015 2:53 AM, Marc Zyngier wrote: >> Implement the timer save restore as a direct translation of >> the assembly code version. >> >> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> >> --- >> arch/arm64/kvm/hyp/Makefile | 1 + >> arch/arm64/kvm/hyp/hyp.h | 3 ++ >> arch/arm64/kvm/hyp/timer-sr.c | 72 ++++++++++++++++++++++++++++++++++++ >> include/clocksource/arm_arch_timer.h | 6 +++ >> 4 files changed, 82 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 5759f9f..f213e46 100644 >> --- a/arch/arm64/kvm/hyp/hyp.h >> +++ b/arch/arm64/kvm/hyp/hyp.h >> @@ -35,5 +35,8 @@ 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..67292c0 >> --- /dev/null >> +++ b/arch/arm64/kvm/hyp/timer-sr.c >> @@ -0,0 +1,72 @@ >> +/* >> + * Copyright (C) 2012-2015 - ARM Ltd >> + * Author: Marc Zyngier <marc.zyngier@arm.com> >> + * >> + * 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 <clocksource/arm_arch_timer.h> >> +#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; >> + u64 val; >> + >> + if (kvm->arch.timer.enabled) { >> + timer->cntv_ctl = read_sysreg(cntv_ctl_el0); >> + isb(); > > Can you share the subtle insight why is the isb() needed here? > B2.7.3 mentions changes to system registers only. This is actually a leftover of some previous code rework in the assembly version of this code, which has found its way into the new implementation. Duh. Thanks for pointing this out. M.
On Mon, Dec 07, 2015 at 10:53:22AM +0000, Marc Zyngier wrote: > Implement the timer save restore as a direct translation of > the assembly code version. > > Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
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 5759f9f..f213e46 100644 --- a/arch/arm64/kvm/hyp/hyp.h +++ b/arch/arm64/kvm/hyp/hyp.h @@ -35,5 +35,8 @@ 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..67292c0 --- /dev/null +++ b/arch/arm64/kvm/hyp/timer-sr.c @@ -0,0 +1,72 @@ +/* + * Copyright (C) 2012-2015 - ARM Ltd + * Author: Marc Zyngier <marc.zyngier@arm.com> + * + * 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 <clocksource/arm_arch_timer.h> +#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; + u64 val; + + if (kvm->arch.timer.enabled) { + timer->cntv_ctl = read_sysreg(cntv_ctl_el0); + 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 */ + val = read_sysreg(cnthctl_el2); + val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN; + write_sysreg(val, cnthctl_el2); + + /* 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 &= ~CNTHCTL_EL1PCEN; + val |= CNTHCTL_EL1PCTEN; + 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); + } +} diff --git a/include/clocksource/arm_arch_timer.h b/include/clocksource/arm_arch_timer.h index 9916d0e..25d0914 100644 --- a/include/clocksource/arm_arch_timer.h +++ b/include/clocksource/arm_arch_timer.h @@ -23,6 +23,12 @@ #define ARCH_TIMER_CTRL_IT_MASK (1 << 1) #define ARCH_TIMER_CTRL_IT_STAT (1 << 2) +#define CNTHCTL_EL1PCTEN (1 << 0) +#define CNTHCTL_EL1PCEN (1 << 1) +#define CNTHCTL_EVNTEN (1 << 2) +#define CNTHCTL_EVNTDIR (1 << 3) +#define CNTHCTL_EVNTI (0xF << 4) + enum arch_timer_reg { ARCH_TIMER_REG_CTRL, ARCH_TIMER_REG_TVAL,
Implement the timer save restore as a direct translation of the assembly code version. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> --- arch/arm64/kvm/hyp/Makefile | 1 + arch/arm64/kvm/hyp/hyp.h | 3 ++ arch/arm64/kvm/hyp/timer-sr.c | 72 ++++++++++++++++++++++++++++++++++++ include/clocksource/arm_arch_timer.h | 6 +++ 4 files changed, 82 insertions(+) create mode 100644 arch/arm64/kvm/hyp/timer-sr.c