ARM: KVM: arch_timers: Add guest timer core support

Add some the architected timer related infrastructure, and support timer
interrupt injection, which can happen as a resultof three possible
events:

- The virtual timer interrupt has fired while we were still
  executing the guest
- The timer interrupt hasn't fired, but it expired while we
  were doing the world switch
- A hrtimer we programmed earlier has fired

Reviewed-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Christoffer Dall <c.dall@virtualopensystems.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>

2 files changed, 90 insertions, 0 deletions

diff --git a/arch/arm/include/asm/kvm_arch_timer.h b/arch/arm/include/asm/kvm_arch_timer.h
new file mode 100644
index 000000000000..68cb9e1dfb81
--- /dev/null
+++ b/arch/arm/include/asm/kvm_arch_timer.h
@@ -0,0 +1,85 @@
+/*
+ * Copyright (C) 2012 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, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#ifndef __ASM_ARM_KVM_ARCH_TIMER_H
+#define __ASM_ARM_KVM_ARCH_TIMER_H
+
+#include <linux/clocksource.h>
+#include <linux/hrtimer.h>
+#include <linux/workqueue.h>
+
+struct arch_timer_kvm {
+#ifdef CONFIG_KVM_ARM_TIMER
+        /* Is the timer enabled */
+        bool                    enabled;
+
+        /* Virtual offset */
+        cycle_t                 cntvoff;
+#endif
+};
+
+struct arch_timer_cpu {
+#ifdef CONFIG_KVM_ARM_TIMER
+        /* Registers: control register, timer value */
+        u32                             cntv_ctl;       /* Saved/restored */
+        cycle_t                         cntv_cval;      /* Saved/restored */
+
+        /*
+         * Anything that is not used directly from assembly code goes
+         * here.
+         */
+
+        /* 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;
+#endif
+};
+
+#ifdef CONFIG_KVM_ARM_TIMER
+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);
+#else
+static inline int kvm_timer_hyp_init(void)
+{
+        return 0;
+};
+
+static inline int kvm_timer_init(struct kvm *kvm)
+{
+        return 0;
+}
+
+static inline void kvm_timer_vcpu_init(struct kvm_vcpu *vcpu) {}
+static inline void kvm_timer_flush_hwstate(struct kvm_vcpu *vcpu) {}
+static inline void kvm_timer_sync_hwstate(struct kvm_vcpu *vcpu) {}
+static inline void kvm_timer_vcpu_terminate(struct kvm_vcpu *vcpu) {}
+#endif
+
+#endif
diff --git a/arch/arm/include/asm/kvm_host.h b/arch/arm/include/asm/kvm_host.h
index 6791c888b9f4..dfe98866a992 100644
--- a/arch/arm/include/asm/kvm_host.h
+++ b/arch/arm/include/asm/kvm_host.h
@@ -23,6 +23,7 @@
 #include <asm/kvm_asm.h>
 #include <asm/kvm_mmio.h>
 #include <asm/fpstate.h>
+#include <asm/kvm_arch_timer.h>
 
 #define KVM_MAX_VCPUS CONFIG_KVM_ARM_MAX_VCPUS
 #define KVM_MEMORY_SLOTS 32
@@ -49,6 +50,9 @@ struct kvm_arch {
         /* VTTBR value associated with below pgd and vmid */
         u64    vttbr;
 
+        /* Timer */
+        struct arch_timer_kvm   timer;
+
         /*
          * Anything that is not used directly from assembly code goes
          * here.
@@ -99,6 +103,7 @@ struct kvm_vcpu_arch {
 
         /* VGIC state */
         struct vgic_cpu vgic_cpu;
+        struct arch_timer_cpu timer_cpu;
 
         /*
          * Anything that is not used directly from assembly code goes