From 3d1ad640f8c94a9ae9c7c8bbb311614bc0332a7e Mon Sep 17 00:00:00 2001 From: Christoffer Dall Date: Fri, 10 Nov 2017 09:16:23 +0100 Subject: KVM: arm/arm64: Fix GICv4 ITS initialization issues We should only try to initialize GICv4 data structures on a GICv4 capable system. Move the vgic_supports_direct_msis() check inito vgic_v4_init() so that any KVM VGIC initialization path does not fail on non-GICv4 systems. Also be slightly more strict in the checking of the return value in vgic_its_create, and only error out on negative return values from the vgic_v4_init() function. This is important because the kvm device code only treats negative values as errors and only cleans up in this case. Errornously treating a positive return value as an error from the vgic_v4_init() function can lead to NULL pointer dereferences, as has recently been observed. Acked-by: Marc Zyngier Signed-off-by: Christoffer Dall --- virt/kvm/arm/vgic/vgic-init.c | 8 +++----- virt/kvm/arm/vgic/vgic-its.c | 2 +- virt/kvm/arm/vgic/vgic-v4.c | 3 +++ 3 files changed, 7 insertions(+), 6 deletions(-) (limited to 'virt') diff --git a/virt/kvm/arm/vgic/vgic-init.c b/virt/kvm/arm/vgic/vgic-init.c index 40be908da238..62310122ee78 100644 --- a/virt/kvm/arm/vgic/vgic-init.c +++ b/virt/kvm/arm/vgic/vgic-init.c @@ -285,11 +285,9 @@ int vgic_init(struct kvm *kvm) if (ret) goto out; - if (vgic_supports_direct_msis(kvm)) { - ret = vgic_v4_init(kvm); - if (ret) - goto out; - } + ret = vgic_v4_init(kvm); + if (ret) + goto out; kvm_for_each_vcpu(i, vcpu, kvm) kvm_vgic_vcpu_enable(vcpu); diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c index b8c1b724ba3e..c93ecd4a903b 100644 --- a/virt/kvm/arm/vgic/vgic-its.c +++ b/virt/kvm/arm/vgic/vgic-its.c @@ -1673,7 +1673,7 @@ static int vgic_its_create(struct kvm_device *dev, u32 type) if (vgic_initialized(dev->kvm)) { int ret = vgic_v4_init(dev->kvm); - if (ret) { + if (ret < 0) { kfree(its); return ret; } diff --git a/virt/kvm/arm/vgic/vgic-v4.c b/virt/kvm/arm/vgic/vgic-v4.c index 915d09dc2638..53c324aa44ef 100644 --- a/virt/kvm/arm/vgic/vgic-v4.c +++ b/virt/kvm/arm/vgic/vgic-v4.c @@ -118,6 +118,9 @@ int vgic_v4_init(struct kvm *kvm) struct kvm_vcpu *vcpu; int i, nr_vcpus, ret; + if (!vgic_supports_direct_msis(kvm)) + return 0; /* Nothing to see here... move along. */ + if (dist->its_vm.vpes) return 0; -- cgit