From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Pavel Fedin , Marc Zyngier Subject: [PATCH 4.2 035/134] arm/arm64: KVM: vgic: Check for !irqchip_in_kernel() when mapping resources Date: Sat, 26 Sep 2015 13:54:47 -0700 Message-Id: <20150926205313.877041701@linuxfoundation.org> In-Reply-To: <20150926205311.819185658@linuxfoundation.org> References: <20150926205311.819185658@linuxfoundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-15 Sender: linux-kernel-owner@vger.kernel.org List-ID: 4.2-stable review patch. If anyone has any objections, please let me know. ------------------ From: Pavel Fedin 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 [maz: reworked commit message] Signed-off-by: Marc Zyngier Signed-off-by: Greg Kroah-Hartman --- arch/arm/kvm/arm.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -449,7 +449,7 @@ static int kvm_vcpu_first_run_init(struc * 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;