From a1a39128faabc9883a7f9e3f8777b3fbd560fa5f Mon Sep 17 00:00:00 2001 From: Paolo Bonzini Date: Fri, 25 Mar 2022 12:42:52 -0400 Subject: [PATCH] KVM: MMU: propagate alloc_workqueue failure If kvm->arch.tdp_mmu_zap_wq cannot be created, the failure has to be propagated up to kvm_mmu_init_vm and kvm_arch_init_vm. kvm_arch_init_vm also has to undo all the initialization, so group all the MMU initialization code at the beginning and handle cleaning up of kvm_page_track_init. Signed-off-by: Paolo Bonzini --- arch/x86/include/asm/kvm_host.h | 2 +- arch/x86/kvm/mmu/mmu.c | 11 +++++++++-- arch/x86/kvm/mmu/tdp_mmu.c | 17 ++++++++++------- arch/x86/kvm/mmu/tdp_mmu.h | 4 ++-- arch/x86/kvm/x86.c | 15 ++++++++++----- 5 files changed, 32 insertions(+), 17 deletions(-) diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 0ddc2e67a731..469c7702fad9 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1584,7 +1584,7 @@ void kvm_mmu_module_exit(void); void kvm_mmu_destroy(struct kvm_vcpu *vcpu); int kvm_mmu_create(struct kvm_vcpu *vcpu); -void kvm_mmu_init_vm(struct kvm *kvm); +int kvm_mmu_init_vm(struct kvm *kvm); void kvm_mmu_uninit_vm(struct kvm *kvm); void kvm_mmu_after_set_cpuid(struct kvm_vcpu *vcpu); diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 51671cb34fb6..857ba93b5c92 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -5768,17 +5768,24 @@ static void kvm_mmu_invalidate_zap_pages_in_memslot(struct kvm *kvm, kvm_mmu_zap_all_fast(kvm); } -void kvm_mmu_init_vm(struct kvm *kvm) +int kvm_mmu_init_vm(struct kvm *kvm) { struct kvm_page_track_notifier_node *node = &kvm->arch.mmu_sp_tracker; + int r; + INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); + INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages); + INIT_LIST_HEAD(&kvm->arch.lpage_disallowed_mmu_pages); spin_lock_init(&kvm->arch.mmu_unsync_pages_lock); - kvm_mmu_init_tdp_mmu(kvm); + r = kvm_mmu_init_tdp_mmu(kvm); + if (r < 0) + return r; node->track_write = kvm_mmu_pte_write; node->track_flush_slot = kvm_mmu_invalidate_zap_pages_in_memslot; kvm_page_track_register_notifier(kvm, node); + return 0; } void kvm_mmu_uninit_vm(struct kvm *kvm) diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index e7e7876251b3..4be517a9f22f 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -14,21 +14,24 @@ static bool __read_mostly tdp_mmu_enabled = true; module_param_named(tdp_mmu, tdp_mmu_enabled, bool, 0644); /* Initializes the TDP MMU for the VM, if enabled. */ -bool kvm_mmu_init_tdp_mmu(struct kvm *kvm) +int kvm_mmu_init_tdp_mmu(struct kvm *kvm) { + struct workqueue_struct *wq; + if (!tdp_enabled || !READ_ONCE(tdp_mmu_enabled)) - return false; + return 0; + + wq = alloc_workqueue("kvm", WQ_UNBOUND|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE, 0); + if (!wq) + return -ENOMEM; /* This should not be changed for the lifetime of the VM. */ kvm->arch.tdp_mmu_enabled = true; - INIT_LIST_HEAD(&kvm->arch.tdp_mmu_roots); spin_lock_init(&kvm->arch.tdp_mmu_pages_lock); INIT_LIST_HEAD(&kvm->arch.tdp_mmu_pages); - kvm->arch.tdp_mmu_zap_wq = - alloc_workqueue("kvm", WQ_UNBOUND|WQ_MEM_RECLAIM|WQ_CPU_INTENSIVE, 0); - - return true; + kvm->arch.tdp_mmu_zap_wq = wq; + return 1; } /* Arbitrarily returns true so that this may be used in if statements. */ diff --git a/arch/x86/kvm/mmu/tdp_mmu.h b/arch/x86/kvm/mmu/tdp_mmu.h index 5e5ef2576c81..647926541e38 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.h +++ b/arch/x86/kvm/mmu/tdp_mmu.h @@ -72,7 +72,7 @@ u64 *kvm_tdp_mmu_fast_pf_get_last_sptep(struct kvm_vcpu *vcpu, u64 addr, u64 *spte); #ifdef CONFIG_X86_64 -bool kvm_mmu_init_tdp_mmu(struct kvm *kvm); +int kvm_mmu_init_tdp_mmu(struct kvm *kvm); void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm); static inline bool is_tdp_mmu_page(struct kvm_mmu_page *sp) { return sp->tdp_mmu_page; } @@ -93,7 +93,7 @@ static inline bool is_tdp_mmu(struct kvm_mmu *mmu) return sp && is_tdp_mmu_page(sp) && sp->root_count; } #else -static inline bool kvm_mmu_init_tdp_mmu(struct kvm *kvm) { return false; } +static inline int kvm_mmu_init_tdp_mmu(struct kvm *kvm) { return 0; } static inline void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm) {} static inline bool is_tdp_mmu_page(struct kvm_mmu_page *sp) { return false; } static inline bool is_tdp_mmu(struct kvm_mmu *mmu) { return false; } diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index fe2171b11441..89b6efb7f504 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -11629,12 +11629,13 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) ret = kvm_page_track_init(kvm); if (ret) - return ret; + goto out; + + ret = kvm_mmu_init_vm(kvm); + if (ret) + goto out_page_track; INIT_HLIST_HEAD(&kvm->arch.mask_notifier_list); - INIT_LIST_HEAD(&kvm->arch.active_mmu_pages); - INIT_LIST_HEAD(&kvm->arch.zapped_obsolete_pages); - INIT_LIST_HEAD(&kvm->arch.lpage_disallowed_mmu_pages); INIT_LIST_HEAD(&kvm->arch.assigned_dev_head); atomic_set(&kvm->arch.noncoherent_dma_count, 0); @@ -11666,10 +11667,14 @@ int kvm_arch_init_vm(struct kvm *kvm, unsigned long type) kvm_apicv_init(kvm); kvm_hv_init_vm(kvm); - kvm_mmu_init_vm(kvm); kvm_xen_init_vm(kvm); return static_call(kvm_x86_vm_init)(kvm); + +out_page_track: + kvm_page_track_cleanup(kvm); +out: + return ret; } int kvm_arch_post_init_vm(struct kvm *kvm)