diff mbox series

[v3,3/5] KVM: x86: Prevent excluding the BSP on setting max_vcpu_ids

Message ID 20240614202859.3597745-4-minipli@grsecurity.net (mailing list archive)
State New, archived
Headers show
Series KVM: Reject vCPU IDs above 2^32 | expand

Commit Message

Mathias Krause June 14, 2024, 8:28 p.m. UTC 
From: Sean Christopherson <seanjc@google.com>

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 <minipli@grsecurity.net>
---
 arch/x86/kvm/x86.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)
diff mbox series

Patch

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 686606f61dee..eeb35fb1573a 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6701,7 +6701,9 @@  int kvm_vm_ioctl_enable_cap(struct kvm *kvm,
 			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];