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authorMarc Zyngier <marc.zyngier@arm.com>2015-10-19 16:32:20 +0100
committerMarc Zyngier <marc.zyngier@arm.com>2015-12-14 11:30:39 +0000
commit1431af367e52b08038e78d346822966d968f1694 (patch)
treeef38c2c78c5c883be30788d17abe2853b534050e /arch/arm64
parentf68d2b1b73cc3d8f6eb189c11ce79a472ed27c42 (diff)
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arm64: KVM: Implement timer save/restore
Implement the timer save restore as a direct translation of the assembly code version. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Diffstat (limited to 'arch/arm64')
-rw-r--r--arch/arm64/kvm/hyp/Makefile1
-rw-r--r--arch/arm64/kvm/hyp/hyp.h3
-rw-r--r--arch/arm64/kvm/hyp/timer-sr.c71
3 files changed, 75 insertions, 0 deletions
diff --git a/arch/arm64/kvm/hyp/Makefile b/arch/arm64/kvm/hyp/Makefile
index d1e38ce16bb5..455dc0a3acb5 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 5759f9f5ef14..f213e4652bbf 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 000000000000..1051e5d7320f
--- /dev/null
+++ b/arch/arm64/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_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);
+ }
+}