arm/arm64: KVM: vgic: Check for !irqchip_in_kernel() when mapping resources

commit c2f58514cfb374d5368c9da945f1765cd48eb0da upstream.

Until b26e5fdac43c ("arm/arm64: KVM: introduce per-VM ops"),
kvm_vgic_map_resources() used to include a check on irqchip_in_kernel(),
and vgic_v2_map_resources() still has it.

But now vm_ops are not initialized until we call kvm_vgic_create().
Therefore kvm_vgic_map_resources() can being called without a VGIC,
and we die because vm_ops.map_resources is NULL.

Fixing this restores QEMU's kernel-irqchip=off option to a working state,
allowing to use GIC emulation in userspace.

Fixes: b26e5fdac43c ("arm/arm64: KVM: introduce per-VM ops")
Signed-off-by: Pavel Fedin <p.fedin@samsung.com>
[maz: reworked commit message]
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index d9631ecddd56ea09a9b9f922520e2e05576c974a..d6223cbcb6618a5bf11e82307cbf40e9bae6c40c 100644 (file)
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -450,7 +450,7 @@ static int kvm_vcpu_first_run_init(struct kvm_vcpu *vcpu)
         * Map the VGIC hardware resources before running a vcpu the first
         * time on this VM.
         */
-       if (unlikely(!vgic_ready(kvm))) {
+       if (unlikely(irqchip_in_kernel(kvm) && !vgic_ready(kvm))) {
                ret = kvm_vgic_map_resources(kvm);
                if (ret)
                        return ret;