From: Marc Zyngier maz@kernel.org
stable inclusion from stable-v6.6.9 commit 71c631a9fb211df4ea5a59ac68a310c5854f07f1 category: bugfix bugzilla: https://gitee.com/openeuler/kernel/issues/I8SU2D
Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=...
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commit 01ad29d224ff73bc4e16e0ef9ece17f28598c4a4 upstream.
When destroying a vgic, we have rather cumbersome rules about when slots_lock and config_lock are held, resulting in fun buglets.
The first port of call is to simplify kvm_vgic_map_resources() so that there is only one call to kvm_vgic_destroy() instead of two, with the second only holding half of the locks.
For that, we kill the non-locking primitive and move the call outside of the locking altogether. This doesn't change anything (we re-acquire the locks and teardown the whole vgic), and simplifies the code significantly.
Cc: stable@vger.kernel.org Signed-off-by: Marc Zyngier maz@kernel.org Link: https://lore.kernel.org/r/20231207151201.3028710-2-maz@kernel.org Signed-off-by: Oliver Upton oliver.upton@linux.dev Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org Signed-off-by: Zheng Zengkai zhengzengkai@huawei.com --- arch/arm64/kvm/vgic/vgic-init.c | 29 ++++++++++++++--------------- 1 file changed, 14 insertions(+), 15 deletions(-)
diff --git a/arch/arm64/kvm/vgic/vgic-init.c b/arch/arm64/kvm/vgic/vgic-init.c index c8c3cb812783..ad7e86879eb9 100644 --- a/arch/arm64/kvm/vgic/vgic-init.c +++ b/arch/arm64/kvm/vgic/vgic-init.c @@ -382,26 +382,24 @@ void kvm_vgic_vcpu_destroy(struct kvm_vcpu *vcpu) vgic_cpu->rd_iodev.base_addr = VGIC_ADDR_UNDEF; }
-static void __kvm_vgic_destroy(struct kvm *kvm) +void kvm_vgic_destroy(struct kvm *kvm) { struct kvm_vcpu *vcpu; unsigned long i;
- lockdep_assert_held(&kvm->arch.config_lock); + mutex_lock(&kvm->slots_lock);
vgic_debug_destroy(kvm);
kvm_for_each_vcpu(i, vcpu, kvm) kvm_vgic_vcpu_destroy(vcpu);
+ mutex_lock(&kvm->arch.config_lock); + kvm_vgic_dist_destroy(kvm); -}
-void kvm_vgic_destroy(struct kvm *kvm) -{ - mutex_lock(&kvm->arch.config_lock); - __kvm_vgic_destroy(kvm); mutex_unlock(&kvm->arch.config_lock); + mutex_unlock(&kvm->slots_lock); }
/** @@ -469,25 +467,26 @@ int kvm_vgic_map_resources(struct kvm *kvm) type = VGIC_V3; }
- if (ret) { - __kvm_vgic_destroy(kvm); + if (ret) goto out; - } + dist->ready = true; dist_base = dist->vgic_dist_base; mutex_unlock(&kvm->arch.config_lock);
ret = vgic_register_dist_iodev(kvm, dist_base, type); - if (ret) { + if (ret) kvm_err("Unable to register VGIC dist MMIO regions\n"); - kvm_vgic_destroy(kvm); - } - mutex_unlock(&kvm->slots_lock); - return ret;
+ goto out_slots; out: mutex_unlock(&kvm->arch.config_lock); +out_slots: mutex_unlock(&kvm->slots_lock); + + if (ret) + kvm_vgic_destroy(kvm); + return ret; }