diff options
Diffstat (limited to 'arch/powerpc/kvm/book3s_xive.c')
| -rw-r--r-- | arch/powerpc/kvm/book3s_xive.c | 51 |
1 files changed, 41 insertions, 10 deletions
diff --git a/arch/powerpc/kvm/book3s_xive.c b/arch/powerpc/kvm/book3s_xive.c index 922689b768e6..4280cd8bb70c 100644 --- a/arch/powerpc/kvm/book3s_xive.c +++ b/arch/powerpc/kvm/book3s_xive.c @@ -846,7 +846,8 @@ int kvmppc_xive_set_icp(struct kvm_vcpu *vcpu, u64 icpval) /* * We can't update the state of a "pushed" VCPU, but that - * shouldn't happen. + * shouldn't happen because the vcpu->mutex makes running a + * vcpu mutually exclusive with doing one_reg get/set on it. */ if (WARN_ON(vcpu->arch.xive_pushed)) return -EIO; @@ -1835,7 +1836,7 @@ void kvmppc_xive_free_sources(struct kvmppc_xive_src_block *sb) } /* - * Called when device fd is closed + * Called when device fd is closed. kvm->lock is held. */ static void kvmppc_xive_release(struct kvm_device *dev) { @@ -1843,21 +1844,46 @@ static void kvmppc_xive_release(struct kvm_device *dev) struct kvm *kvm = xive->kvm; struct kvm_vcpu *vcpu; int i; + int was_ready; pr_devel("Releasing xive device\n"); + debugfs_remove(xive->dentry); + /* - * When releasing the KVM device fd, the vCPUs can still be - * running and we should clean up the vCPU interrupt - * presenters first. + * Clearing mmu_ready temporarily while holding kvm->lock + * is a way of ensuring that no vcpus can enter the guest + * until we drop kvm->lock. Doing kick_all_cpus_sync() + * ensures that any vcpu executing inside the guest has + * exited the guest. Once kick_all_cpus_sync() has finished, + * we know that no vcpu can be executing the XIVE push or + * pull code, or executing a XICS hcall. + * + * Since this is the device release function, we know that + * userspace does not have any open fd referring to the + * device. Therefore there can not be any of the device + * attribute set/get functions being executed concurrently, + * and similarly, the connect_vcpu and set/clr_mapped + * functions also cannot be being executed. */ - kvm_for_each_vcpu(i, vcpu, kvm) - kvmppc_xive_cleanup_vcpu(vcpu); + was_ready = kvm->arch.mmu_ready; + kvm->arch.mmu_ready = 0; + kick_all_cpus_sync(); - debugfs_remove(xive->dentry); + /* + * We should clean up the vCPU interrupt presenters first. + */ + kvm_for_each_vcpu(i, vcpu, kvm) { + /* + * Take vcpu->mutex to ensure that no one_reg get/set ioctl + * (i.e. kvmppc_xive_[gs]et_icp) can be done concurrently. + */ + mutex_lock(&vcpu->mutex); + kvmppc_xive_cleanup_vcpu(vcpu); + mutex_unlock(&vcpu->mutex); + } - if (kvm) - kvm->arch.xive = NULL; + kvm->arch.xive = NULL; /* Mask and free interrupts */ for (i = 0; i <= xive->max_sbid; i++) { @@ -1870,6 +1896,8 @@ static void kvmppc_xive_release(struct kvm_device *dev) if (xive->vp_base != XIVE_INVALID_VP) xive_native_free_vp_block(xive->vp_base); + kvm->arch.mmu_ready = was_ready; + /* * A reference of the kvmppc_xive pointer is now kept under * the xive_devices struct of the machine for reuse. It is @@ -1906,6 +1934,9 @@ struct kvmppc_xive *kvmppc_xive_get_device(struct kvm *kvm, u32 type) return xive; } +/* + * Create a XICS device with XIVE backend. kvm->lock is held. + */ static int kvmppc_xive_create(struct kvm_device *dev, u32 type) { struct kvmppc_xive *xive; |