[PATCH] RISC-V: KVM: Reject vCPU creation after AIA initialization

[Andrew Jones]

AIA initialization sets up per-vCPU IMSIC state by iterating over all
online vCPUs. Creating another vCPU afterwards leaves it without
initialized IMSIC state, but KVM currently permits that sequence.

Reject KVM_CREATE_VCPU once AIA initialization succeeds. Both paths are
serialized by kvm->lock, so checking the initialized state from
kvm_arch_vcpu_precreate() freezes the vCPU set used by AIA.

Fixes: 89d01306e34d ("RISC-V: KVM: Implement device interface for AIA irqchip")
Signed-off-by: Andrew Jones <andrew.jones at oss.qualcomm.com>
---
 arch/riscv/kvm/vcpu.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/arch/riscv/kvm/vcpu.c b/arch/riscv/kvm/vcpu.c
index e062ca19f9d8..ccf2def834f1 100644
--- a/arch/riscv/kvm/vcpu.c
+++ b/arch/riscv/kvm/vcpu.c
@@ -138,6 +138,9 @@ static void kvm_riscv_reset_vcpu(struct kvm_vcpu *vcpu, bool kvm_sbi_reset)
 
 int kvm_arch_vcpu_precreate(struct kvm *kvm, unsigned int id)
 {
+	if (kvm_riscv_aia_initialized(kvm))
+		return -EBUSY;
+
 	return 0;
 }
 
-- 
2.43.0