From: Tengfei Yu <moehanabichan@gmail.com>
Date: Thu, 25 Jan 2024 05:08:23 +0000 (+0800)
Subject: KVM: x86: Check irqchip mode before create PIT
X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=9e05d9b06757732477cca428e87f3d72163d01cf;p=linux.git

KVM: x86: Check irqchip mode before create PIT

As the kvm api(https://docs.kernel.org/virt/kvm/api.html) reads,
KVM_CREATE_PIT2 call is only valid after enabling in-kernel irqchip
support via KVM_CREATE_IRQCHIP.

Without this check, I can create PIT first and enable irqchip-split
then, which may cause the PIT invalid because of lacking of in-kernel
PIC to inject the interrupt.

Signed-off-by: Tengfei Yu <moehanabichan@gmail.com>
Message-Id: <20240125050823.4893-1-moehanabichan@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---

diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 363b1c0802057..9a89471a613cd 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -7016,6 +7016,9 @@ set_identity_unlock:
 		r = -EEXIST;
 		if (kvm->arch.vpit)
 			goto create_pit_unlock;
+		r = -ENOENT;
+		if (!pic_in_kernel(kvm))
+			goto create_pit_unlock;
 		r = -ENOMEM;
 		kvm->arch.vpit = kvm_create_pit(kvm, u.pit_config.flags);
 		if (kvm->arch.vpit)