LoongArch: KVM: Disable updating of "num_cpu" and "feature"

Property "num_cpu" and "feature" are read-only once eiointc is created,
which are set with KVM_DEV_LOONGARCH_EXTIOI_GRP_CTRL attr group before
device creation.

Attr group KVM_DEV_LOONGARCH_EXTIOI_GRP_SW_STATUS is to update register
and software state for migration and reset usage, property "num_cpu" and
"feature" can not be update again if it is created already.

Here discard write operation with property "num_cpu" and "feature" in
attr group KVM_DEV_LOONGARCH_EXTIOI_GRP_CTRL.

Cc: stable@vger.kernel.org
Fixes: 1ad7efa552 ("LoongArch: KVM: Add EIOINTC user mode read and write functions")
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>

arch/loongarch/kvm/intc/eiointc.c

@@ -9,7 +9,8 @@
 
 static void eiointc_set_sw_coreisr(struct loongarch_eiointc *s)
 {
-	int ipnum, cpu, irq_index, irq_mask, irq;
+	int ipnum, cpu, cpuid, irq_index, irq_mask, irq;
+	struct kvm_vcpu *vcpu;
 
 	for (irq = 0; irq < EIOINTC_IRQS; irq++) {
 		ipnum = s->ipmap.reg_u8[irq / 32];
@@ -20,7 +21,12 @@ static void eiointc_set_sw_coreisr(struct loongarch_eiointc *s)
 		irq_index = irq / 32;
 		irq_mask = BIT(irq & 0x1f);
 
-		cpu = s->coremap.reg_u8[irq];
+		cpuid = s->coremap.reg_u8[irq];
+		vcpu = kvm_get_vcpu_by_cpuid(s->kvm, cpuid);
+		if (!vcpu)
+			continue;
+
+		cpu = vcpu->vcpu_id;
 		if (!!(s->coreisr.reg_u32[cpu][irq_index] & irq_mask))
 			set_bit(irq, s->sw_coreisr[cpu][ipnum]);
 		else
@@ -66,20 +72,25 @@ static void eiointc_update_irq(struct loongarch_eiointc *s, int irq, int level)
 }
 
 static inline void eiointc_update_sw_coremap(struct loongarch_eiointc *s,
-					int irq, void *pvalue, u32 len, bool notify)
+					int irq, u64 val, u32 len, bool notify)
 {
-	int i, cpu;
-	u64 val = *(u64 *)pvalue;
+	int i, cpu, cpuid;
+	struct kvm_vcpu *vcpu;
 
 	for (i = 0; i < len; i++) {
-		cpu = val & 0xff;
+		cpuid = val & 0xff;
 		val = val >> 8;
 
 		if (!(s->status & BIT(EIOINTC_ENABLE_CPU_ENCODE))) {
-			cpu = ffs(cpu) - 1;
-			cpu = (cpu >= 4) ? 0 : cpu;
+			cpuid = ffs(cpuid) - 1;
+			cpuid = (cpuid >= 4) ? 0 : cpuid;
 		}
 
+		vcpu = kvm_get_vcpu_by_cpuid(s->kvm, cpuid);
+		if (!vcpu)
+			continue;
+
+		cpu = vcpu->vcpu_id;
 		if (s->sw_coremap[irq + i] == cpu)
 			continue;
 
@@ -305,6 +316,12 @@ static int kvm_eiointc_read(struct kvm_vcpu *vcpu,
 		return -EINVAL;
 	}
 
+	/* len must be 1/2/4/8 from function kvm_emu_iocsr() */
+	if (addr & (len - 1)) {
+		kvm_err("%s: eiointc not aligned addr %llx len %d\n", __func__, addr, len);
+		return -EINVAL;
+	}
+
 	vcpu->kvm->stat.eiointc_read_exits++;
 	spin_lock_irqsave(&eiointc->lock, flags);
 	switch (len) {
@@ -398,7 +415,7 @@ static int loongarch_eiointc_writeb(struct kvm_vcpu *vcpu,
 		irq = offset - EIOINTC_COREMAP_START;
 		index = irq;
 		s->coremap.reg_u8[index] = data;
-		eiointc_update_sw_coremap(s, irq, (void *)&data, sizeof(data), true);
+		eiointc_update_sw_coremap(s, irq, data, sizeof(data), true);
 		break;
 	default:
 		ret = -EINVAL;
@@ -483,7 +500,7 @@ static int loongarch_eiointc_writew(struct kvm_vcpu *vcpu,
 		irq = offset - EIOINTC_COREMAP_START;
 		index = irq >> 1;
 		s->coremap.reg_u16[index] = data;
-		eiointc_update_sw_coremap(s, irq, (void *)&data, sizeof(data), true);
+		eiointc_update_sw_coremap(s, irq, data, sizeof(data), true);
 		break;
 	default:
 		ret = -EINVAL;
@@ -568,7 +585,7 @@ static int loongarch_eiointc_writel(struct kvm_vcpu *vcpu,
 		irq = offset - EIOINTC_COREMAP_START;
 		index = irq >> 2;
 		s->coremap.reg_u32[index] = data;
-		eiointc_update_sw_coremap(s, irq, (void *)&data, sizeof(data), true);
+		eiointc_update_sw_coremap(s, irq, data, sizeof(data), true);
 		break;
 	default:
 		ret = -EINVAL;
@@ -653,7 +670,7 @@ static int loongarch_eiointc_writeq(struct kvm_vcpu *vcpu,
 		irq = offset - EIOINTC_COREMAP_START;
 		index = irq >> 3;
 		s->coremap.reg_u64[index] = data;
-		eiointc_update_sw_coremap(s, irq, (void *)&data, sizeof(data), true);
+		eiointc_update_sw_coremap(s, irq, data, sizeof(data), true);
 		break;
 	default:
 		ret = -EINVAL;
@@ -676,6 +693,12 @@ static int kvm_eiointc_write(struct kvm_vcpu *vcpu,
 		return -EINVAL;
 	}
 
+	/* len must be 1/2/4/8 from function kvm_emu_iocsr() */
+	if (addr & (len - 1)) {
+		kvm_err("%s: eiointc not aligned addr %llx len %d\n", __func__, addr, len);
+		return -EINVAL;
+	}
+
 	vcpu->kvm->stat.eiointc_write_exits++;
 	spin_lock_irqsave(&eiointc->lock, flags);
 	switch (len) {
@@ -784,7 +807,7 @@ static int kvm_eiointc_ctrl_access(struct kvm_device *dev,
 	int ret = 0;
 	unsigned long flags;
 	unsigned long type = (unsigned long)attr->attr;
-	u32 i, start_irq;
+	u32 i, start_irq, val;
 	void __user *data;
 	struct loongarch_eiointc *s = dev->kvm->arch.eiointc;
 
@@ -792,8 +815,14 @@ static int kvm_eiointc_ctrl_access(struct kvm_device *dev,
 	spin_lock_irqsave(&s->lock, flags);
 	switch (type) {
 	case KVM_DEV_LOONGARCH_EXTIOI_CTRL_INIT_NUM_CPU:
-		if (copy_from_user(&s->num_cpu, data, 4))
+		if (copy_from_user(&val, data, 4) < 0)
 			ret = -EFAULT;
+		else {
+			if (val >= EIOINTC_ROUTE_MAX_VCPUS)
+				ret = -EINVAL;
+			else
+				s->num_cpu = val;
+		}
 		break;
 	case KVM_DEV_LOONGARCH_EXTIOI_CTRL_INIT_FEATURE:
 		if (copy_from_user(&s->features, data, 4))
@@ -806,7 +835,7 @@ static int kvm_eiointc_ctrl_access(struct kvm_device *dev,
 		for (i = 0; i < (EIOINTC_IRQS / 4); i++) {
 			start_irq = i * 4;
 			eiointc_update_sw_coremap(s, start_irq,
-					(void *)&s->coremap.reg_u32[i], sizeof(u32), false);
+					s->coremap.reg_u32[i], sizeof(u32), false);
 		}
 		break;
 	default:
@@ -821,7 +850,7 @@ static int kvm_eiointc_regs_access(struct kvm_device *dev,
 					struct kvm_device_attr *attr,
 					bool is_write)
 {
-	int addr, cpuid, offset, ret = 0;
+	int addr, cpu, offset, ret = 0;
 	unsigned long flags;
 	void *p = NULL;
 	void __user *data;
@@ -829,7 +858,7 @@ static int kvm_eiointc_regs_access(struct kvm_device *dev,
 
 	s = dev->kvm->arch.eiointc;
 	addr = attr->attr;
-	cpuid = addr >> 16;
+	cpu = addr >> 16;
 	addr &= 0xffff;
 	data = (void __user *)attr->addr;
 	switch (addr) {
@@ -854,8 +883,11 @@ static int kvm_eiointc_regs_access(struct kvm_device *dev,
 		p = &s->isr.reg_u32[offset];
 		break;
 	case EIOINTC_COREISR_START ... EIOINTC_COREISR_END:
+		if (cpu >= s->num_cpu)
+			return -EINVAL;
+
 		offset = (addr - EIOINTC_COREISR_START) / 4;
-		p = &s->coreisr.reg_u32[cpuid][offset];
+		p = &s->coreisr.reg_u32[cpu][offset];
 		break;
 	case EIOINTC_COREMAP_START ... EIOINTC_COREMAP_END:
 		offset = (addr - EIOINTC_COREMAP_START) / 4;
@@ -896,9 +928,15 @@ static int kvm_eiointc_sw_status_access(struct kvm_device *dev,
 	data = (void __user *)attr->addr;
 	switch (addr) {
 	case KVM_DEV_LOONGARCH_EXTIOI_SW_STATUS_NUM_CPU:
+		if (is_write)
+			return ret;
+
 		p = &s->num_cpu;
 		break;
 	case KVM_DEV_LOONGARCH_EXTIOI_SW_STATUS_FEATURE:
+		if (is_write)
+			return ret;
+
 		p = &s->features;
 		break;
 	case KVM_DEV_LOONGARCH_EXTIOI_SW_STATUS_STATE: