[PATCH v4 9/9] virt: geniezone: Add virtual timer support

[Yi-De Wu]

From: "Willix Yeh" <chi-shen.yeh@xxxxxxxxxxxx>

Implement vtimer migration handler.
- Using hrtimer for guest vtimer migration
- Identify migrate flag to do register hrtimer

Signed-off-by: Willix Yeh <chi-shen.yeh@xxxxxxxxxxxx>
Signed-off-by: Liju Chen <liju-clr.chen@xxxxxxxxxxxx>
Signed-off-by: Yi-De Wu <yi-de.wu@xxxxxxxxxxxx>
---
 arch/arm64/geniezone/gzvm_arch_common.h |  2 ++
 arch/arm64/geniezone/vcpu.c             | 40 +++++++++++++++++++++++++
 drivers/virt/geniezone/gzvm_vcpu.c      | 34 +++++++++++++++++++++
 drivers/virt/geniezone/gzvm_vm.c        | 10 +++++++
 include/linux/gzvm_drv.h                |  9 ++++++
 include/uapi/linux/gzvm.h               |  2 ++
 6 files changed, 97 insertions(+)

diff --git a/arch/arm64/geniezone/gzvm_arch_common.h b/arch/arm64/geniezone/gzvm_arch_common.h
index ccd2a7516eeb..a7ee6b959c18 100644
--- a/arch/arm64/geniezone/gzvm_arch_common.h
+++ b/arch/arm64/geniezone/gzvm_arch_common.h
@@ -80,6 +80,8 @@ static inline gzvm_vcpu_id_t get_vcpuid_from_tuple(unsigned int tuple)
 struct gzvm_vcpu_hwstate {
 	__u32 nr_lrs;
 	__u64 lr[GIC_V3_NR_LRS];
+	__u64 vtimer_delay;
+	__u32 vtimer_migrate;
 };
 
 static inline unsigned int
diff --git a/arch/arm64/geniezone/vcpu.c b/arch/arm64/geniezone/vcpu.c
index 8d2572bdf053..b26393a355bd 100644
--- a/arch/arm64/geniezone/vcpu.c
+++ b/arch/arm64/geniezone/vcpu.c
@@ -4,6 +4,7 @@
  */
 
 #include <linux/arm-smccc.h>
+#include <linux/clocksource.h>
 #include <linux/err.h>
 #include <linux/uaccess.h>
 
@@ -40,15 +41,54 @@ int gzvm_arch_vcpu_update_one_reg(struct gzvm_vcpu *vcpu, __u64 reg_id,
 	return ret;
 }
 
+static void clear_migrate_state(struct gzvm_vcpu *vcpu)
+{
+	vcpu->hwstate->vtimer_migrate = 0;
+	vcpu->hwstate->vtimer_delay = 0;
+}
+
+static u64 gzvm_mtimer_delay_time(u64 delay)
+{
+	u64 ns;
+
+	ns = clocksource_cyc2ns(delay, timecycle.mult, timecycle.shift);
+
+	return ns;
+}
+
+static void gzvm_mtimer_release(struct gzvm_vcpu *vcpu)
+{
+	hrtimer_cancel(&vcpu->gzvm_mtimer);
+
+	clear_migrate_state(vcpu);
+}
+
+static void gzvm_mtimer_catch(struct hrtimer *hrt, u64 delay)
+{
+	u64 ns;
+
+	ns = gzvm_mtimer_delay_time(delay);
+	hrtimer_start(hrt, ktime_add_ns(ktime_get(), ns), HRTIMER_MODE_ABS_HARD);
+}
+
 int gzvm_arch_vcpu_run(struct gzvm_vcpu *vcpu, __u64 *exit_reason)
 {
 	struct arm_smccc_res res;
 	unsigned long a1;
 	int ret;
 
+	/* hrtimer cancel and clear migrate state */
+	if (vcpu->hwstate->vtimer_migrate)
+		gzvm_mtimer_release(vcpu);
+
 	a1 = assemble_vm_vcpu_tuple(vcpu->gzvm->vm_id, vcpu->vcpuid);
 	ret = gzvm_hypcall_wrapper(MT_HVC_GZVM_RUN, a1, 0, 0, 0, 0, 0,
 				   0, &res);
+
+	/* hrtimer register if migration needed */
+	if (vcpu->hwstate->vtimer_migrate)
+		gzvm_mtimer_catch(&vcpu->gzvm_mtimer, vcpu->hwstate->vtimer_delay);
+
 	*exit_reason = res.a1;
 	return ret;
 }
diff --git a/drivers/virt/geniezone/gzvm_vcpu.c b/drivers/virt/geniezone/gzvm_vcpu.c
index 40b57d85eaa2..74001589571e 100644
--- a/drivers/virt/geniezone/gzvm_vcpu.c
+++ b/drivers/virt/geniezone/gzvm_vcpu.c
@@ -5,12 +5,14 @@
 
 #include <asm/sysreg.h>
 #include <linux/anon_inodes.h>
+#include <linux/clocksource.h>
 #include <linux/device.h>
 #include <linux/file.h>
 #include <linux/mm.h>
 #include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/gzvm_drv.h>
+#include "gzvm_common.h"
 
 /* maximum size needed for holding an integer */
 #define ITOA_MAX_LEN 12
@@ -73,6 +75,33 @@ static bool gzvm_vcpu_handle_mmio(struct gzvm_vcpu *vcpu)
 	return gzvm_ioevent_write(vcpu, addr, len, val_ptr);
 }
 
+static void mtimer_irq_forward(struct gzvm_vcpu *vcpu)
+{
+	struct gzvm *gzvm;
+	unsigned int irq_num, irq_type, vcpu_idx;
+
+	gzvm = vcpu->gzvm;
+
+	irq_num = (GZVM_VTIMER_IRQ >> GZVM_IRQ_NUM_SHIFT) & GZVM_IRQ_NUM_MASK;
+	irq_type = (GZVM_VTIMER_IRQ >> GZVM_IRQ_TYPE_SHIFT) & GZVM_IRQ_TYPE_MASK;
+	vcpu_idx = (GZVM_VTIMER_IRQ >> GZVM_IRQ_VCPU_SHIFT) & GZVM_IRQ_VCPU_MASK;
+	vcpu_idx += ((GZVM_VTIMER_IRQ >> GZVM_IRQ_VCPU2_SHIFT) & GZVM_IRQ_VCPU2_MASK) *
+		     (GZVM_IRQ_VCPU_MASK + 1);
+
+	gzvm_irqchip_inject_irq(gzvm, vcpu_idx, irq_type, irq_num, 1);
+}
+
+static enum hrtimer_restart gzvm_mtimer_expire(struct hrtimer *hrt)
+{
+	struct gzvm_vcpu *vcpu;
+
+	vcpu = container_of(hrt, struct gzvm_vcpu, gzvm_mtimer);
+
+	mtimer_irq_forward(vcpu);
+
+	return HRTIMER_NORESTART;
+}
+
 /**
  * gzvm_vcpu_run() - Handle vcpu run ioctl, entry point to guest and exit
  *		     point from guest
@@ -172,6 +201,7 @@ static void gzvm_destroy_vcpu(struct gzvm_vcpu *vcpu)
 	if (!vcpu)
 		return;
 
+	hrtimer_cancel(&vcpu->gzvm_mtimer);
 	gzvm_arch_destroy_vcpu(vcpu->gzvm->vm_id, vcpu->vcpuid);
 	/* clean guest's data */
 	memset(vcpu->run, 0, GZVM_VCPU_RUN_MAP_SIZE);
@@ -241,6 +271,10 @@ int gzvm_vm_ioctl_create_vcpu(struct gzvm *gzvm, u32 cpuid)
 	vcpu->gzvm = gzvm;
 	mutex_init(&vcpu->lock);
 
+	/* gzvm_mtimer init based on hrtimer */
+	hrtimer_init(&vcpu->gzvm_mtimer, CLOCK_MONOTONIC, HRTIMER_MODE_ABS_HARD);
+	vcpu->gzvm_mtimer.function = gzvm_mtimer_expire;
+
 	ret = gzvm_arch_create_vcpu(gzvm->vm_id, vcpu->vcpuid, vcpu->run);
 	if (ret < 0)
 		goto free_vcpu_run;
diff --git a/drivers/virt/geniezone/gzvm_vm.c b/drivers/virt/geniezone/gzvm_vm.c
index d379793deace..74268d294800 100644
--- a/drivers/virt/geniezone/gzvm_vm.c
+++ b/drivers/virt/geniezone/gzvm_vm.c
@@ -4,6 +4,7 @@
  */
 
 #include <linux/anon_inodes.h>
+#include <linux/clocksource.h>
 #include <linux/file.h>
 #include <linux/kdev_t.h>
 #include <linux/miscdevice.h>
@@ -17,6 +18,8 @@
 static DEFINE_MUTEX(gzvm_list_lock);
 static LIST_HEAD(gzvm_list);
 
+struct timecycle timecycle;
+
 /**
  * hva_to_pa_fast() - converts hva to pa in generic fast way
  *
@@ -474,6 +477,13 @@ static struct gzvm *gzvm_create_vm(unsigned long vm_type)
 		return ERR_PTR(ret);
 	}
 
+	/* timecycle init mult shift */
+	clocks_calc_mult_shift(&timecycle.mult,
+			       &timecycle.shift,
+			       arch_timer_get_cntfrq(),
+			       NSEC_PER_SEC,
+			       10);
+
 	mutex_lock(&gzvm_list_lock);
 	list_add(&gzvm->vm_list, &gzvm_list);
 	mutex_unlock(&gzvm_list_lock);
diff --git a/include/linux/gzvm_drv.h b/include/linux/gzvm_drv.h
index e920397e83d3..5953cc1ff8fc 100644
--- a/include/linux/gzvm_drv.h
+++ b/include/linux/gzvm_drv.h
@@ -6,6 +6,7 @@
 #ifndef __GZVM_DRV_H__
 #define __GZVM_DRV_H__
 
+#include <asm/arch_timer.h>
 #include <linux/eventfd.h>
 #include <linux/list.h>
 #include <linux/miscdevice.h>
@@ -40,6 +41,13 @@
 
 #define GZVM_VCPU_RUN_MAP_SIZE		(PAGE_SIZE * 2)
 
+struct timecycle {
+	u32 mult;
+	u32 shift;
+};
+
+extern struct timecycle timecycle;
+
 /* struct mem_region_addr_range - Identical to ffa memory constituent */
 struct mem_region_addr_range {
 	/* the base IPA of the constituent memory region, aligned to 4 kiB */
@@ -74,6 +82,7 @@ struct gzvm_vcpu {
 	struct mutex lock;
 	struct gzvm_vcpu_run *run;
 	struct gzvm_vcpu_hwstate *hwstate;
+	struct hrtimer gzvm_mtimer;
 };
 
 struct gzvm {
diff --git a/include/uapi/linux/gzvm.h b/include/uapi/linux/gzvm.h
index 28354c17ed9c..b1c42145823a 100644
--- a/include/uapi/linux/gzvm.h
+++ b/include/uapi/linux/gzvm.h
@@ -61,6 +61,8 @@ struct gzvm_userspace_memory_region {
 #define GZVM_SET_USER_MEMORY_REGION _IOW(GZVM_IOC_MAGIC, 0x46, \
 					 struct gzvm_userspace_memory_region)
 
+#define GZVM_VTIMER_IRQ			27
+
 /* for GZVM_IRQ_LINE, irq field index values */
 #define GZVM_IRQ_VCPU2_SHIFT		28
 #define GZVM_IRQ_VCPU2_MASK		0xf
-- 
2.18.0