From: Bibo Mao <maobibo@loongson.cn>
Date: Sun, 9 Nov 2025 08:02:09 +0000 (+0800)
Subject: LoongArch: KVM: Fix max supported vCPUs set with EIOINTC
X-Git-Tag: v6.18-rc6~36^2
X-Git-Url: http://git.ipfire.org/?a=commitdiff_plain;h=237e74bfa261fb0cf75bd08c9be0c5094018ee20;p=thirdparty%2Fkernel%2Flinux.git

LoongArch: KVM: Fix max supported vCPUs set with EIOINTC

VM fails to boot with 256 vCPUs, the detailed command is

  qemu-system-loongarch64 -smp 256

and there is an error reported as follows:

  KVM_LOONGARCH_EXTIOI_INIT_NUM_CPU failed: Invalid argument

There is typo issue in function kvm_eiointc_ctrl_access() when set
max supported vCPUs.

Cc: stable@vger.kernel.org
Fixes: 47256c4c8b1b ("LoongArch: KVM: Avoid copy_*_user() with lock hold in kvm_eiointc_ctrl_access()")
Signed-off-by: Bibo Mao <maobibo@loongson.cn>
Signed-off-by: Huacai Chen <chenhuacai@loongson.cn>
---

diff --git a/arch/loongarch/kvm/intc/eiointc.c b/arch/loongarch/kvm/intc/eiointc.c
index c32333695381..a1cc116b4dac 100644
--- a/arch/loongarch/kvm/intc/eiointc.c
+++ b/arch/loongarch/kvm/intc/eiointc.c
@@ -439,7 +439,7 @@ 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 (val >= EIOINTC_ROUTE_MAX_VCPUS)
+		if (val > EIOINTC_ROUTE_MAX_VCPUS)
 			ret = -EINVAL;
 		else
 			s->num_cpu = val;