From: Jean-Philippe Brucker jean-philippe@linaro.org
[ Upstream commit 9cf2f840c439b6b23bd99f584f2917ca425ae406 ]
vgic_its_create() changes the vgic state without holding the config_lock, which triggers a lockdep warning in vgic_v4_init():
[ 358.667941] WARNING: CPU: 3 PID: 178 at arch/arm64/kvm/vgic/vgic-v4.c:245 vgic_v4_init+0x15c/0x7a8 ... [ 358.707410] vgic_v4_init+0x15c/0x7a8 [ 358.708550] vgic_its_create+0x37c/0x4a4 [ 358.709640] kvm_vm_ioctl+0x1518/0x2d80 [ 358.710688] __arm64_sys_ioctl+0x7ac/0x1ba8 [ 358.711960] invoke_syscall.constprop.0+0x70/0x1e0 [ 358.713245] do_el0_svc+0xe4/0x2d4 [ 358.714289] el0_svc+0x44/0x8c [ 358.715329] el0t_64_sync_handler+0xf4/0x120 [ 358.716615] el0t_64_sync+0x190/0x194
Wrap the whole of vgic_its_create() with config_lock since, in addition to calling vgic_v4_init(), it also modifies the global kvm->arch.vgic state.
Fixes: f00327731131 ("KVM: arm64: Use config_lock to protect vgic state") Signed-off-by: Jean-Philippe Brucker jean-philippe@linaro.org Reviewed-by: Oliver Upton oliver.upton@linux.dev Signed-off-by: Marc Zyngier maz@kernel.org Link: https://lore.kernel.org/r/20230518100914.2837292-3-jean-philippe@linaro.org Signed-off-by: Sasha Levin sashal@kernel.org --- arch/arm64/kvm/vgic/vgic-its.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-)
diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c index c9a03033d5077..00ad6587bee9a 100644 --- a/arch/arm64/kvm/vgic/vgic-its.c +++ b/arch/arm64/kvm/vgic/vgic-its.c @@ -1936,6 +1936,7 @@ void vgic_lpi_translation_cache_destroy(struct kvm *kvm)
static int vgic_its_create(struct kvm_device *dev, u32 type) { + int ret; struct vgic_its *its;
if (type != KVM_DEV_TYPE_ARM_VGIC_ITS) @@ -1945,9 +1946,12 @@ static int vgic_its_create(struct kvm_device *dev, u32 type) if (!its) return -ENOMEM;
+ mutex_lock(&dev->kvm->arch.config_lock); + if (vgic_initialized(dev->kvm)) { - int ret = vgic_v4_init(dev->kvm); + ret = vgic_v4_init(dev->kvm); if (ret < 0) { + mutex_unlock(&dev->kvm->arch.config_lock); kfree(its); return ret; } @@ -1960,12 +1964,10 @@ static int vgic_its_create(struct kvm_device *dev, u32 type)
/* Yep, even more trickery for lock ordering... */ #ifdef CONFIG_LOCKDEP - mutex_lock(&dev->kvm->arch.config_lock); mutex_lock(&its->cmd_lock); mutex_lock(&its->its_lock); mutex_unlock(&its->its_lock); mutex_unlock(&its->cmd_lock); - mutex_unlock(&dev->kvm->arch.config_lock); #endif
its->vgic_its_base = VGIC_ADDR_UNDEF; @@ -1986,7 +1988,11 @@ static int vgic_its_create(struct kvm_device *dev, u32 type)
dev->private = its;
- return vgic_its_set_abi(its, NR_ITS_ABIS - 1); + ret = vgic_its_set_abi(its, NR_ITS_ABIS - 1); + + mutex_unlock(&dev->kvm->arch.config_lock); + + return ret; }
static void vgic_its_destroy(struct kvm_device *kvm_dev)