[PATCH v2 12/29] LoongArch: KVM: Implement vcpu interrupt operations

[Tianrui Zhao]

Implement vcpu interrupt operations such as vcpu set irq and
vcpu clear irq, using set_gcsr_estat to set irq which is
parsed by the irq bitmap.

Signed-off-by: Tianrui Zhao <zhaotianrui@xxxxxxxxxxx>
---
 arch/loongarch/kvm/interrupt.c | 126 +++++++++++++++++++++++++++++++++
 arch/loongarch/kvm/vcpu.c      |  45 ++++++++++++
 2 files changed, 171 insertions(+)
 create mode 100644 arch/loongarch/kvm/interrupt.c

diff --git a/arch/loongarch/kvm/interrupt.c b/arch/loongarch/kvm/interrupt.c
new file mode 100644
index 000000000..02267a71d
--- /dev/null
+++ b/arch/loongarch/kvm/interrupt.c
@@ -0,0 +1,126 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Copyright (C) 2020-2023 Loongson Technology Corporation Limited
+ */
+
+#include <linux/errno.h>
+#include <linux/err.h>
+#include <asm/kvm_vcpu.h>
+
+static unsigned int int_to_coreint[LOONGARCH_EXC_MAX] = {
+	[LARCH_INT_TIMER]	= CPU_TIMER,
+	[LARCH_INT_IPI]		= CPU_IPI,
+	[LARCH_INT_SIP0]	= CPU_SIP0,
+	[LARCH_INT_SIP1]	= CPU_SIP1,
+	[LARCH_INT_IP0]		= CPU_IP0,
+	[LARCH_INT_IP1]		= CPU_IP1,
+	[LARCH_INT_IP2]		= CPU_IP2,
+	[LARCH_INT_IP3]		= CPU_IP3,
+	[LARCH_INT_IP4]		= CPU_IP4,
+	[LARCH_INT_IP5]		= CPU_IP5,
+	[LARCH_INT_IP6]		= CPU_IP6,
+	[LARCH_INT_IP7]		= CPU_IP7,
+};
+
+static int _kvm_irq_deliver(struct kvm_vcpu *vcpu, unsigned int priority)
+{
+	unsigned int irq = 0;
+
+	clear_bit(priority, &vcpu->arch.irq_pending);
+	if (priority < LOONGARCH_EXC_MAX)
+		irq = int_to_coreint[priority];
+
+	switch (priority) {
+	case LARCH_INT_TIMER:
+	case LARCH_INT_IPI:
+	case LARCH_INT_SIP0:
+	case LARCH_INT_SIP1:
+		set_gcsr_estat(irq);
+		break;
+
+	case LARCH_INT_IP0:
+	case LARCH_INT_IP1:
+	case LARCH_INT_IP2:
+	case LARCH_INT_IP3:
+	case LARCH_INT_IP4:
+	case LARCH_INT_IP5:
+	case LARCH_INT_IP6:
+	case LARCH_INT_IP7:
+		set_csr_gintc(irq);
+		break;
+
+	default:
+		break;
+	}
+
+	return 1;
+}
+
+static int _kvm_irq_clear(struct kvm_vcpu *vcpu, unsigned int priority)
+{
+	unsigned int irq = 0;
+
+	clear_bit(priority, &vcpu->arch.irq_clear);
+	if (priority < LOONGARCH_EXC_MAX)
+		irq = int_to_coreint[priority];
+
+	switch (priority) {
+	case LARCH_INT_TIMER:
+	case LARCH_INT_IPI:
+	case LARCH_INT_SIP0:
+	case LARCH_INT_SIP1:
+		clear_gcsr_estat(irq);
+		break;
+
+	case LARCH_INT_IP0:
+	case LARCH_INT_IP1:
+	case LARCH_INT_IP2:
+	case LARCH_INT_IP3:
+	case LARCH_INT_IP4:
+	case LARCH_INT_IP5:
+	case LARCH_INT_IP6:
+	case LARCH_INT_IP7:
+		clear_csr_gintc(irq);
+		break;
+
+	default:
+		break;
+	}
+
+	return 1;
+}
+
+void _kvm_deliver_intr(struct kvm_vcpu *vcpu)
+{
+	unsigned long *pending = &vcpu->arch.irq_pending;
+	unsigned long *pending_clr = &vcpu->arch.irq_clear;
+	unsigned int priority;
+
+	if (!(*pending) && !(*pending_clr))
+		return;
+
+	if (*pending_clr) {
+		priority = __ffs(*pending_clr);
+		while (priority <= LOONGARCH_EXC_IPNUM) {
+			_kvm_irq_clear(vcpu, priority);
+			priority = find_next_bit(pending_clr,
+					BITS_PER_BYTE * sizeof(*pending_clr),
+					priority + 1);
+		}
+	}
+
+	if (*pending) {
+		priority = __ffs(*pending);
+		while (priority <= LOONGARCH_EXC_IPNUM) {
+			_kvm_irq_deliver(vcpu, priority);
+			priority = find_next_bit(pending,
+					BITS_PER_BYTE * sizeof(*pending),
+					priority + 1);
+		}
+	}
+}
+
+int _kvm_pending_timer(struct kvm_vcpu *vcpu)
+{
+	return test_bit(LARCH_INT_TIMER, &vcpu->arch.irq_pending);
+}
diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c
index 5c7216607..a60ac6576 100644
--- a/arch/loongarch/kvm/vcpu.c
+++ b/arch/loongarch/kvm/vcpu.c
@@ -504,6 +504,51 @@ void kvm_lose_fpu(struct kvm_vcpu *vcpu)
 	preempt_enable();
 }
 
+int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu,
+			     struct kvm_loongarch_interrupt *irq)
+{
+	int intr = (int)irq->irq;
+	struct kvm_vcpu *dvcpu = NULL;
+
+	if (irq->cpu == -1)
+		dvcpu = vcpu;
+	else
+		dvcpu = kvm_get_vcpu(vcpu->kvm, irq->cpu);
+
+	if (intr > 0)
+		_kvm_queue_irq(dvcpu, intr);
+	else if (intr < 0)
+		_kvm_dequeue_irq(dvcpu, -intr);
+	else {
+		kvm_err("%s: invalid interrupt ioctl (%d:%d)\n", __func__,
+				irq->cpu, irq->irq);
+		return -EINVAL;
+	}
+
+	kvm_vcpu_kick(dvcpu);
+	return 0;
+}
+
+long kvm_arch_vcpu_async_ioctl(struct file *filp,
+			       unsigned int ioctl, unsigned long arg)
+{
+	struct kvm_vcpu *vcpu = filp->private_data;
+	void __user *argp = (void __user *)arg;
+
+	if (ioctl == KVM_INTERRUPT) {
+		struct kvm_loongarch_interrupt irq;
+
+		if (copy_from_user(&irq, argp, sizeof(irq)))
+			return -EFAULT;
+		kvm_debug("[%d] %s: irq: %d\n", vcpu->vcpu_id, __func__,
+			  irq.irq);
+
+		return kvm_vcpu_ioctl_interrupt(vcpu, &irq);
+	}
+
+	return -ENOIOCTLCMD;
+}
+
 int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
 {
 	return 0;
-- 
2.31.1