Add support for the in-kernel timer emulation. The include file
is a complete duplicate of the 32bit one - something to fix
at one point.
Reviewed-by: Christopher Covington <cov@xxxxxxxxxxxxxx>
Signed-off-by: Marc Zyngier <marc.zyngier@xxxxxxx>
---
arch/arm/kvm/arch_timer.c | 1 +
arch/arm64/include/asm/kvm_arch_timer.h | 58 +++++++++++++++++++++++++++++++++
arch/arm64/kvm/hyp.S | 56 +++++++++++++++++++++++++++++++
3 files changed, 115 insertions(+)
create mode 100644 arch/arm64/include/asm/kvm_arch_timer.h
diff --git a/arch/arm/kvm/arch_timer.c b/arch/arm/kvm/arch_timer.c
index c55b608..49a7516 100644
--- a/arch/arm/kvm/arch_timer.c
+++ b/arch/arm/kvm/arch_timer.c
@@ -195,6 +195,7 @@ static struct notifier_block kvm_timer_cpu_nb = {
static const struct of_device_id arch_timer_of_match[] = {
{ .compatible = "arm,armv7-timer", },
+ { .compatible = "arm,armv8-timer", },
{},
};
diff --git a/arch/arm64/include/asm/kvm_arch_timer.h b/arch/arm64/include/asm/kvm_arch_timer.h
new file mode 100644
index 0000000..eb02273
--- /dev/null
+++ b/arch/arm64/include/asm/kvm_arch_timer.h
@@ -0,0 +1,58 @@
+/*
+ * Copyright (C) 2012 ARM Ltd.
+ * Author: Marc Zyngier <marc.zyngier@xxxxxxx>
+ *
+ * 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/>.
+ */
+
+#ifndef __ARM64_KVM_ARCH_TIMER_H
+#define __ARM64_KVM_ARCH_TIMER_H
+
+#include <linux/clocksource.h>
+#include <linux/hrtimer.h>
+#include <linux/workqueue.h>
+
+struct arch_timer_kvm {
+ /* Is the timer enabled */
+ bool enabled;
+
+ /* Virtual offset, restored only */
+ cycle_t cntvoff;
+};
+
+struct arch_timer_cpu {
+ /* Background timer used when the guest is not running */
+ struct hrtimer timer;
+
+ /* Work queued with the above timer expires */
+ struct work_struct expired;
+
+ /* Background timer active */
+ bool armed;
+
+ /* Timer IRQ */
+ const struct kvm_irq_level *irq;
+
+ /* Registers: control register, timer value */
+ u32 cntv_ctl; /* Saved/restored */
+ cycle_t cntv_cval; /* Saved/restored */
+};
+
+int kvm_timer_hyp_init(void);
+int kvm_timer_init(struct kvm *kvm);
+void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu);
+void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu);
+void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu);
+void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu);
+
+#endif
diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S
index cc3192e..25da0b5 100644
--- a/arch/arm64/kvm/hyp.S
+++ b/arch/arm64/kvm/hyp.S
@@ -390,6 +390,60 @@ __kvm_hyp_code_start:
2:
.endm
+.macro save_timer_state
+ // x0: vcpu pointer
+ ldr x2, [x0, #VCPU_KVM]
+ kern_hyp_va x2
+ ldr w3, [x2, #KVM_TIMER_ENABLED]
+ cbz w3, 1f
+
+ mrs x3, cntv_ctl_el0
+ and x3, x3, #3
+ str w3, [x0, #VCPU_TIMER_CNTV_CTL]
+ bic x3, x3, #1 // Clear Enable
+ msr cntv_ctl_el0, x3
+
+ isb
+
+ mrs x3, cntv_cval_el0
+ str x3, [x0, #VCPU_TIMER_CNTV_CVAL]
+
+1:
+ // Allow physical timer/counter access for the host
+ mrs x2, cnthctl_el2
+ orr x2, x2, #3
+ msr cnthctl_el2, x2
+
+ // Clear cntvoff for the host
+ msr cntvoff_el2, xzr
+.endm
+
+.macro restore_timer_state
+ // x0: vcpu pointer
+ // Disallow physical timer access for the guest
+ // Physical counter access is allowed
+ mrs x2, cnthctl_el2
+ orr x2, x2, #1
+ bic x2, x2, #2
+ msr cnthctl_el2, x2
+
+ ldr x2, [x0, #VCPU_KVM]
+ kern_hyp_va x2
+ ldr w3, [x2, #KVM_TIMER_ENABLED]
+ cbz w3, 1f
+
+ ldr x3, [x2, #KVM_TIMER_CNTVOFF]
+ msr cntvoff_el2, x3
+ ldr x2, [x0, #VCPU_TIMER_CNTV_CVAL]
+ msr cntv_cval_el0, x2
+ isb
+
+ ldr w2, [x0, #VCPU_TIMER_CNTV_CTL]
+ and x2, x2, #3
+ msr cntv_ctl_el0, x2
+1:
+.endm
+
__save_sysregs:
save_sysregs
ret
@@ -433,6 +487,7 @@ ENTRY(__kvm_vcpu_run)
activate_vm
restore_vgic_state
+ restore_timer_state
// Guest context
add x2, x0, #VCPU_CONTEXT
@@ -456,6 +511,7 @@ __kvm_vcpu_return:
bl __save_fpsimd
bl __save_sysregs
+ save_timer_state
save_vgic_state
deactivate_traps
--
1.8.1.4
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