Kernel/linux-stable
1
0
Fork 0
mirror of https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git synced 2025-01-08 14:13:53 +00:00
Code Issues Actions Packages Projects Releases Wiki Activity

arm64: KVM: Implement timer save/restore

Browse Source 
Implement the timer save restore as a direct translation of
the assembly code version.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
This commit is contained in:
Marc Zyngier 2015-10-19 16:32:20 +01:00
parent f68d2b1b73
commit 1431af367e
4 changed files with 81 additions and 0 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

1
arch/arm64/kvm/hyp/Makefile
View File

@ -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

3
arch/arm64/kvm/hyp/hyp.h
View File

@ -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__ */

71
arch/arm64/kvm/hyp/timer-sr.c Normal file
View File

@ -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_el0);
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);
}
}

6
include/clocksource/arm_arch_timer.h
View File

@ -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,