LoongArch: KVM: Add DMSINTC inject msi to vCPU

Implement irqfd that deliver msi to vCPU and vCPU dmsintc irq injection.
Add pch_msi_set_irq() choice dmsintc to set msi irq by the msg_addr and
implement dmsintc set msi irq.

Signed-off-by: Song Gao <gaosong@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

arch/loongarch/include/asm/kvm_dmsintc.h

@@ -20,5 +20,8 @@ struct dmsintc_state {
 };
 
 int kvm_loongarch_register_dmsintc_device(void);
+void dmsintc_inject_irq(struct kvm_vcpu *vcpu);
+int dmsintc_set_irq(struct kvm *kvm, u64 addr, int data, int level);
+int dmsintc_deliver_msi_to_vcpu(struct kvm *kvm, struct kvm_vcpu *vcpu, u32 vector, int level);
 
 #endif

arch/loongarch/include/asm/kvm_pch_pic.h

@@ -68,8 +68,9 @@ struct loongarch_pch_pic {
 	uint64_t pch_pic_base;
 };
 
+struct kvm_kernel_irq_routing_entry;
 int kvm_loongarch_register_pch_pic_device(void);
 void pch_pic_set_irq(struct loongarch_pch_pic *s, int irq, int level);
-void pch_msi_set_irq(struct kvm *kvm, int irq, int level);
+int pch_msi_set_irq(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e, int level);
 
 #endif /* __ASM_KVM_PCH_PIC_H */

arch/loongarch/kvm/intc/dmsintc.c

@@ -4,9 +4,83 @@
  */
 
 #include <linux/kvm_host.h>
+#include <asm/kvm_csr.h>
 #include <asm/kvm_dmsintc.h>
 #include <asm/kvm_vcpu.h>
 
+void dmsintc_inject_irq(struct kvm_vcpu *vcpu)
+{
+	unsigned int i;
+	unsigned long vector[4], old;
+	struct dmsintc_state *ds = &vcpu->arch.dmsintc_state;
+
+	if (!ds)
+		return;
+
+	for (i = 0; i < 4; i++) {
+		old = atomic64_read(&(ds->vector_map[i]));
+		if (old)
+			vector[i] = atomic64_xchg(&(ds->vector_map[i]), 0);
+	}
+
+	if (vector[0]) {
+		old = kvm_read_hw_gcsr(LOONGARCH_CSR_ISR0);
+		kvm_write_hw_gcsr(LOONGARCH_CSR_ISR0, vector[0] | old);
+	}
+
+	if (vector[1]) {
+		old = kvm_read_hw_gcsr(LOONGARCH_CSR_ISR1);
+		kvm_write_hw_gcsr(LOONGARCH_CSR_ISR1, vector[1] | old);
+	}
+
+	if (vector[2]) {
+		old = kvm_read_hw_gcsr(LOONGARCH_CSR_ISR2);
+		kvm_write_hw_gcsr(LOONGARCH_CSR_ISR2, vector[2] | old);
+	}
+
+	if (vector[3]) {
+		old = kvm_read_hw_gcsr(LOONGARCH_CSR_ISR3);
+		kvm_write_hw_gcsr(LOONGARCH_CSR_ISR3, vector[3] | old);
+	}
+}
+
+int dmsintc_deliver_msi_to_vcpu(struct kvm *kvm,
+				struct kvm_vcpu *vcpu, u32 vector, int level)
+{
+	struct kvm_interrupt vcpu_irq;
+	struct dmsintc_state *ds = &vcpu->arch.dmsintc_state;
+
+	if (!level)
+		return 0;
+	if (!vcpu || vector >= 256)
+		return -EINVAL;
+	if (!ds)
+		return -ENODEV;
+
+	vcpu_irq.irq = INT_AVEC;
+	set_bit(vector, (unsigned long *)&ds->vector_map);
+	kvm_vcpu_ioctl_interrupt(vcpu, &vcpu_irq);
+	kvm_vcpu_kick(vcpu);
+
+	return 0;
+}
+
+int dmsintc_set_irq(struct kvm *kvm, u64 addr, int data, int level)
+{
+	unsigned int irq, cpu;
+	struct kvm_vcpu *vcpu;
+
+	irq = (addr >> AVEC_IRQ_SHIFT) & AVEC_IRQ_MASK;
+	cpu = (addr >> AVEC_CPU_SHIFT) & kvm->arch.dmsintc->cpu_mask;
+	if (cpu >= KVM_MAX_VCPUS)
+		return -EINVAL;
+	vcpu = kvm_get_vcpu_by_cpuid(kvm, cpu);
+	if (!vcpu)
+		return -EINVAL;
+
+	return dmsintc_deliver_msi_to_vcpu(kvm, vcpu, irq, level);
+}
+
 static int kvm_dmsintc_ctrl_access(struct kvm_device *dev,
 				   struct kvm_device_attr *attr, bool is_write)
 {

arch/loongarch/kvm/intc/pch_pic.c

@@ -3,6 +3,7 @@
  * Copyright (C) 2024 Loongson Technology Corporation Limited
  */
 
+#include <asm/kvm_dmsintc.h>
 #include <asm/kvm_eiointc.h>
 #include <asm/kvm_pch_pic.h>
 #include <asm/kvm_vcpu.h>
@@ -67,9 +68,19 @@ void pch_pic_set_irq(struct loongarch_pch_pic *s, int irq, int level)
 }
 
 /* msi irq handler */
-void pch_msi_set_irq(struct kvm *kvm, int irq, int level)
+int pch_msi_set_irq(struct kvm *kvm, struct kvm_kernel_irq_routing_entry *e, int level)
 {
-	eiointc_set_irq(kvm->arch.eiointc, irq, level);
+	u64 msg_addr = (((u64)e->msi.address_hi) << 32) | e->msi.address_lo;
+
+	if (cpu_has_msgint && kvm->arch.dmsintc &&
+		msg_addr >= kvm->arch.dmsintc->msg_addr_base &&
+		msg_addr < (kvm->arch.dmsintc->msg_addr_base + kvm->arch.dmsintc->msg_addr_size)) {
+		return dmsintc_set_irq(kvm, msg_addr, e->msi.data, level);
+	}
+
+	eiointc_set_irq(kvm->arch.eiointc, e->msi.data, level);
+
+	return 0;
 }
 
 static int loongarch_pch_pic_read(struct loongarch_pch_pic *s, gpa_t addr, int len, void *val)

arch/loongarch/kvm/interrupt.c

@@ -7,6 +7,7 @@
 #include <linux/errno.h>
 #include <asm/kvm_csr.h>
 #include <asm/kvm_vcpu.h>
+#include <asm/kvm_dmsintc.h>
 
 static unsigned int priority_to_irq[EXCCODE_INT_NUM] = {
 	[INT_TI]	= CPU_TIMER,
@@ -33,6 +34,7 @@ static int kvm_irq_deliver(struct kvm_vcpu *vcpu, unsigned int priority)
 		irq = priority_to_irq[priority];
 
 	if (kvm_guest_has_msgint(&vcpu->arch) && (priority == INT_AVEC)) {
+		dmsintc_inject_irq(vcpu);
 		set_gcsr_estat(irq);
 		return 1;
 	}

arch/loongarch/kvm/irqfd.c

@@ -29,9 +29,7 @@ int kvm_set_msi(struct kvm_kernel_irq_routing_entry *e,
 	if (!level)
 		return -1;
 
-	pch_msi_set_irq(kvm, e->msi.data, level);
-
-	return 0;
+	return pch_msi_set_irq(kvm, e, level);
 }
 
 /*
@@ -71,13 +69,15 @@ int kvm_set_routing_entry(struct kvm *kvm,
 int kvm_arch_set_irq_inatomic(struct kvm_kernel_irq_routing_entry *e,
 		struct kvm *kvm, int irq_source_id, int level, bool line_status)
 {
+	if (!level)
+		return -EWOULDBLOCK;
+
 	switch (e->type) {
 	case KVM_IRQ_ROUTING_IRQCHIP:
 		pch_pic_set_irq(kvm->arch.pch_pic, e->irqchip.pin, level);
 		return 0;
 	case KVM_IRQ_ROUTING_MSI:
-		pch_msi_set_irq(kvm, e->msi.data, level);
-		return 0;
+		return pch_msi_set_irq(kvm, e, level);
 	default:
 		return -EWOULDBLOCK;
 	}