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author | Marc Zyngier <marc.zyngier@arm.com> | 2016-01-04 08:54:50 +0000 |
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committer | Marc Zyngier <marc.zyngier@arm.com> | 2016-02-29 18:34:13 +0000 |
commit | e59bff9bf302bf1332c6421b39ba2e82b84e63a6 (patch) | |
tree | 77555ba3c94f53e9d19e1d8a3ffb824dac708492 /arch/arm/kvm | |
parent | c7ce6c63a05f83998996fdebc4867b007a571f82 (diff) | |
download | linux-e59bff9bf302bf1332c6421b39ba2e82b84e63a6.tar.gz linux-e59bff9bf302bf1332c6421b39ba2e82b84e63a6.tar.bz2 linux-e59bff9bf302bf1332c6421b39ba2e82b84e63a6.zip |
ARM: KVM: Add timer save/restore
This patch shouldn't exist, as we should be able to reuse the
arm64 version for free. I'll get there eventually, but in the
meantime I need a timer ticking.
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm/kvm')
-rw-r--r-- | arch/arm/kvm/hyp/Makefile | 1 | ||||
-rw-r--r-- | arch/arm/kvm/hyp/hyp.h | 8 | ||||
-rw-r--r-- | arch/arm/kvm/hyp/timer-sr.c | 71 |
3 files changed, 80 insertions, 0 deletions
diff --git a/arch/arm/kvm/hyp/Makefile b/arch/arm/kvm/hyp/Makefile index 9f96fcbbcd8d..9241ae845252 100644 --- a/arch/arm/kvm/hyp/Makefile +++ b/arch/arm/kvm/hyp/Makefile @@ -4,3 +4,4 @@ obj-$(CONFIG_KVM_ARM_HOST) += tlb.o obj-$(CONFIG_KVM_ARM_HOST) += cp15-sr.o +obj-$(CONFIG_KVM_ARM_HOST) += timer-sr.o diff --git a/arch/arm/kvm/hyp/hyp.h b/arch/arm/kvm/hyp/hyp.h index ab2cb828d60a..4924418aee4f 100644 --- a/arch/arm/kvm/hyp/hyp.h +++ b/arch/arm/kvm/hyp/hyp.h @@ -46,6 +46,9 @@ #define TTBR1 __ACCESS_CP15_64(1, c2) #define VTTBR __ACCESS_CP15_64(6, c2) #define PAR __ACCESS_CP15_64(0, c7) +#define CNTV_CVAL __ACCESS_CP15_64(3, c14) +#define CNTVOFF __ACCESS_CP15_64(4, c14) + #define CSSELR __ACCESS_CP15(c0, 2, c0, 0) #define VMPIDR __ACCESS_CP15(c0, 4, c0, 5) #define SCTLR __ACCESS_CP15(c1, 0, c0, 0) @@ -71,6 +74,11 @@ #define TID_URO __ACCESS_CP15(c13, 0, c0, 3) #define TID_PRIV __ACCESS_CP15(c13, 0, c0, 4) #define CNTKCTL __ACCESS_CP15(c14, 0, c1, 0) +#define CNTV_CTL __ACCESS_CP15(c14, 0, c3, 1) +#define CNTHCTL __ACCESS_CP15(c14, 4, c1, 0) + +void __timer_save_state(struct kvm_vcpu *vcpu); +void __timer_restore_state(struct kvm_vcpu *vcpu); void __sysreg_save_state(struct kvm_cpu_context *ctxt); void __sysreg_restore_state(struct kvm_cpu_context *ctxt); diff --git a/arch/arm/kvm/hyp/timer-sr.c b/arch/arm/kvm/hyp/timer-sr.c new file mode 100644 index 000000000000..d7535fd0784e --- /dev/null +++ b/arch/arm/kvm/hyp/timer-sr.c @@ -0,0 +1,71 @@ +/* + * 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); + timer->cntv_cval = read_sysreg(CNTV_CVAL); + } + + /* Disable the virtual timer */ + write_sysreg(0, CNTV_CTL); + + /* Allow physical timer/counter access for the host */ + val = read_sysreg(CNTHCTL); + val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN; + write_sysreg(val, CNTHCTL); + + /* Clear cntvoff for the host */ + write_sysreg(0, CNTVOFF); +} + +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); + val &= ~CNTHCTL_EL1PCEN; + val |= CNTHCTL_EL1PCTEN; + write_sysreg(val, CNTHCTL); + + if (kvm->arch.timer.enabled) { + write_sysreg(kvm->arch.timer.cntvoff, CNTVOFF); + write_sysreg(timer->cntv_cval, CNTV_CVAL); + isb(); + write_sysreg(timer->cntv_ctl, CNTV_CTL); + } +} |