From d29bf2ca140410705447ac26100a149b51094c00 Mon Sep 17 00:00:00 2001 From: Sean Christopherson Date: Fri, 14 Jun 2024 22:28:57 +0200 Subject: [PATCH] KVM: x86: Prevent excluding the BSP on setting max_vcpu_ids If the BSP vCPU ID was already set, ensure it doesn't get excluded when limiting vCPU IDs via KVM_CAP_MAX_VCPU_ID. [mks: provide commit message, code by Sean] Signed-off-by: Mathias Krause Link: https://lore.kernel.org/r/20240614202859.3597745-4-minipli@grsecurity.net Signed-off-by: Sean Christopherson --- arch/x86/kvm/x86.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index f371943f2c72..994aa281b07d 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -6707,7 +6707,9 @@ split_irqchip_unlock: break; mutex_lock(&kvm->lock); - if (kvm->arch.max_vcpu_ids == cap->args[0]) { + if (kvm->arch.bsp_vcpu_id > cap->args[0]) { + ; + } else if (kvm->arch.max_vcpu_ids == cap->args[0]) { r = 0; } else if (!kvm->arch.max_vcpu_ids) { kvm->arch.max_vcpu_ids = cap->args[0]; -- 2.50.1