tjh.dev
Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
kernel
os
linux
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>
+80
+1
arch/arm/kvm/hyp/Makefile
+1
arch/arm/kvm/hyp/Makefile
+8
arch/arm/kvm/hyp/hyp.h
+8
arch/arm/kvm/hyp/hyp.h
···
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#define TTBR1 __ACCESS_CP15_64(1, c2)
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#define VTTBR __ACCESS_CP15_64(6, c2)
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#define PAR __ACCESS_CP15_64(0, c7)
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#define CNTV_CVAL __ACCESS_CP15_64(3, c14)
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#define CNTVOFF __ACCESS_CP15_64(4, c14)
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#define CSSELR __ACCESS_CP15(c0, 2, c0, 0)
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#define VMPIDR __ACCESS_CP15(c0, 4, c0, 5)
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#define SCTLR __ACCESS_CP15(c1, 0, c0, 0)
···
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#define TID_URO __ACCESS_CP15(c13, 0, c0, 3)
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#define TID_PRIV __ACCESS_CP15(c13, 0, c0, 4)
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#define CNTKCTL __ACCESS_CP15(c14, 0, c1, 0)
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#define CNTV_CTL __ACCESS_CP15(c14, 0, c3, 1)
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#define CNTHCTL __ACCESS_CP15(c14, 4, c1, 0)
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void __timer_save_state(struct kvm_vcpu *vcpu);
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void __timer_restore_state(struct kvm_vcpu *vcpu);
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void __sysreg_save_state(struct kvm_cpu_context *ctxt);
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void __sysreg_restore_state(struct kvm_cpu_context *ctxt);
+71
arch/arm/kvm/hyp/timer-sr.c
+71
arch/arm/kvm/hyp/timer-sr.c
···
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/*
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* Copyright (C) 2012-2015 - ARM Ltd
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* Author: Marc Zyngier <marc.zyngier@arm.com>
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License version 2 as
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* published by the Free Software Foundation.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <clocksource/arm_arch_timer.h>
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#include <linux/compiler.h>
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#include <linux/kvm_host.h>
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#include <asm/kvm_mmu.h>
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#include "hyp.h"
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/* vcpu is already in the HYP VA space */
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void __hyp_text __timer_save_state(struct kvm_vcpu *vcpu)
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{
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struct kvm *kvm = kern_hyp_va(vcpu->kvm);
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struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
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u64 val;
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if (kvm->arch.timer.enabled) {
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timer->cntv_ctl = read_sysreg(CNTV_CTL);
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timer->cntv_cval = read_sysreg(CNTV_CVAL);
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}
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/* Disable the virtual timer */
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write_sysreg(0, CNTV_CTL);
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/* Allow physical timer/counter access for the host */
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val = read_sysreg(CNTHCTL);
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val |= CNTHCTL_EL1PCTEN | CNTHCTL_EL1PCEN;
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write_sysreg(val, CNTHCTL);
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/* Clear cntvoff for the host */
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write_sysreg(0, CNTVOFF);
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}
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void __hyp_text __timer_restore_state(struct kvm_vcpu *vcpu)
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{
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struct kvm *kvm = kern_hyp_va(vcpu->kvm);
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struct arch_timer_cpu *timer = &vcpu->arch.timer_cpu;
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u64 val;
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/*
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* Disallow physical timer access for the guest
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* Physical counter access is allowed
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*/
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val = read_sysreg(CNTHCTL);
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val &= ~CNTHCTL_EL1PCEN;
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val |= CNTHCTL_EL1PCTEN;
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write_sysreg(val, CNTHCTL);
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if (kvm->arch.timer.enabled) {
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write_sysreg(kvm->arch.timer.cntvoff, CNTVOFF);
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write_sysreg(timer->cntv_cval, CNTV_CVAL);
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isb();
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write_sysreg(timer->cntv_ctl, CNTV_CTL);
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}
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}