[PATCH v20 12/30] 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.

Reviewed-by: Bibo Mao <maobibo@xxxxxxxxxxx>
Signed-off-by: Tianrui Zhao <zhaotianrui@xxxxxxxxxxx>
---
 arch/loongarch/kvm/interrupt.c | 113 +++++++++++++++++++++++++++++++++
 arch/loongarch/kvm/vcpu.c      |  37 +++++++++++
 2 files changed, 150 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 0000000000..14e19653b2
--- /dev/null
+++ b/arch/loongarch/kvm/interrupt.c
@@ -0,0 +1,113 @@
+// 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>
+#include <asm/kvm_csr.h>
+
+static unsigned int int_to_coreint[EXCCODE_INT_NUM] = {
+	[INT_TI]	= CPU_TIMER,
+	[INT_IPI]	= CPU_IPI,
+	[INT_SWI0]	= CPU_SIP0,
+	[INT_SWI1]	= CPU_SIP1,
+	[INT_HWI0]	= CPU_IP0,
+	[INT_HWI1]	= CPU_IP1,
+	[INT_HWI2]	= CPU_IP2,
+	[INT_HWI3]	= CPU_IP3,
+	[INT_HWI4]	= CPU_IP4,
+	[INT_HWI5]	= CPU_IP5,
+	[INT_HWI6]	= CPU_IP6,
+	[INT_HWI7]	= 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 < EXCCODE_INT_NUM)
+		irq = int_to_coreint[priority];
+
+	switch (priority) {
+	case INT_TI:
+	case INT_IPI:
+	case INT_SWI0:
+	case INT_SWI1:
+		set_gcsr_estat(irq);
+		break;
+
+	case INT_HWI0 ... INT_HWI7:
+		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 < EXCCODE_INT_NUM)
+		irq = int_to_coreint[priority];
+
+	switch (priority) {
+	case INT_TI:
+	case INT_IPI:
+	case INT_SWI0:
+	case INT_SWI1:
+		clear_gcsr_estat(irq);
+		break;
+
+	case INT_HWI0 ... INT_HWI7:
+		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 <= INT_IPI) {
+			_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 <= INT_IPI) {
+			_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(INT_TI, &vcpu->arch.irq_pending);
+}
diff --git a/arch/loongarch/kvm/vcpu.c b/arch/loongarch/kvm/vcpu.c
index 2094afcfcd..9e36482c53 100644
--- a/arch/loongarch/kvm/vcpu.c
+++ b/arch/loongarch/kvm/vcpu.c
@@ -298,6 +298,43 @@ void kvm_lose_fpu(struct kvm_vcpu *vcpu)
 	preempt_enable();
 }
 
+int kvm_vcpu_ioctl_interrupt(struct kvm_vcpu *vcpu, struct kvm_interrupt *irq)
+{
+	int intr = (int)irq->irq;
+
+	if (intr > 0)
+		_kvm_queue_irq(vcpu, intr);
+	else if (intr < 0)
+		_kvm_dequeue_irq(vcpu, -intr);
+	else {
+		kvm_err("%s: invalid interrupt ioctl %d\n", __func__, irq->irq);
+		return -EINVAL;
+	}
+
+	kvm_vcpu_kick(vcpu);
+	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_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;
-- 
2.27.0