From: Paolo Bonzini pbonzini@redhat.com
[ Upstream commit 897218ff7cf19290ec2d69652ce673d8ed6fedeb ]
The TDP MMU assumes that it can do atomic accesses to 64-bit PTEs. Rather than just disabling it, compile it out completely so that it is possible to use for example 64-bit xchg.
To limit the number of stubs, wrap all accesses to tdp_mmu_enabled or tdp_mmu_page with a function. Calls to all other functions in tdp_mmu.c are eliminated and do not even reach the linker.
Reviewed-by: Sean Christopherson seanjc@google.com Tested-by: Sean Christopherson seanjc@google.com Signed-off-by: Paolo Bonzini pbonzini@redhat.com Signed-off-by: Sasha Levin sashal@kernel.org --- arch/x86/include/asm/kvm_host.h | 2 ++ arch/x86/kvm/Makefile | 3 ++- arch/x86/kvm/mmu/mmu.c | 36 ++++++++++++++++----------------- arch/x86/kvm/mmu/mmu_internal.h | 2 ++ arch/x86/kvm/mmu/tdp_mmu.c | 29 +------------------------- arch/x86/kvm/mmu/tdp_mmu.h | 32 +++++++++++++++++++++++++---- 6 files changed, 53 insertions(+), 51 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 47cd8f9b3fe7..af858f495e75 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -1001,6 +1001,7 @@ struct kvm_arch { struct kvm_pmu_event_filter *pmu_event_filter; struct task_struct *nx_lpage_recovery_thread;
+#ifdef CONFIG_X86_64 /* * Whether the TDP MMU is enabled for this VM. This contains a * snapshot of the TDP MMU module parameter from when the VM was @@ -1027,6 +1028,7 @@ struct kvm_arch { * the thread holds the MMU lock in write mode. */ spinlock_t tdp_mmu_pages_lock; +#endif /* CONFIG_X86_64 */ };
struct kvm_vm_stat { diff --git a/arch/x86/kvm/Makefile b/arch/x86/kvm/Makefile index b804444e16d4..1d1e31917a88 100644 --- a/arch/x86/kvm/Makefile +++ b/arch/x86/kvm/Makefile @@ -16,7 +16,8 @@ kvm-$(CONFIG_KVM_ASYNC_PF) += $(KVM)/async_pf.o kvm-y += x86.o emulate.o i8259.o irq.o lapic.o \ i8254.o ioapic.o irq_comm.o cpuid.o pmu.o mtrr.o \ hyperv.o debugfs.o mmu/mmu.o mmu/page_track.o \ - mmu/spte.o mmu/tdp_iter.o mmu/tdp_mmu.o + mmu/spte.o +kvm-$(CONFIG_X86_64) += mmu/tdp_iter.o mmu/tdp_mmu.o
kvm-intel-y += vmx/vmx.o vmx/vmenter.o vmx/pmu_intel.o vmx/vmcs12.o \ vmx/evmcs.o vmx/nested.o vmx/posted_intr.o diff --git a/arch/x86/kvm/mmu/mmu.c b/arch/x86/kvm/mmu/mmu.c index 0f45ad05f895..94e6bf004576 100644 --- a/arch/x86/kvm/mmu/mmu.c +++ b/arch/x86/kvm/mmu/mmu.c @@ -1225,7 +1225,7 @@ static void kvm_mmu_write_protect_pt_masked(struct kvm *kvm, { struct kvm_rmap_head *rmap_head;
- if (kvm->arch.tdp_mmu_enabled) + if (is_tdp_mmu_enabled(kvm)) kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, slot->base_gfn + gfn_offset, mask, true); while (mask) { @@ -1254,7 +1254,7 @@ void kvm_mmu_clear_dirty_pt_masked(struct kvm *kvm, { struct kvm_rmap_head *rmap_head;
- if (kvm->arch.tdp_mmu_enabled) + if (is_tdp_mmu_enabled(kvm)) kvm_tdp_mmu_clear_dirty_pt_masked(kvm, slot, slot->base_gfn + gfn_offset, mask, false); while (mask) { @@ -1301,7 +1301,7 @@ bool kvm_mmu_slot_gfn_write_protect(struct kvm *kvm, write_protected |= __rmap_write_protect(kvm, rmap_head, true); }
- if (kvm->arch.tdp_mmu_enabled) + if (is_tdp_mmu_enabled(kvm)) write_protected |= kvm_tdp_mmu_write_protect_gfn(kvm, slot, gfn);
@@ -1513,7 +1513,7 @@ int kvm_unmap_hva_range(struct kvm *kvm, unsigned long start, unsigned long end,
r = kvm_handle_hva_range(kvm, start, end, 0, kvm_unmap_rmapp);
- if (kvm->arch.tdp_mmu_enabled) + if (is_tdp_mmu_enabled(kvm)) r |= kvm_tdp_mmu_zap_hva_range(kvm, start, end);
return r; @@ -1525,7 +1525,7 @@ int kvm_set_spte_hva(struct kvm *kvm, unsigned long hva, pte_t pte)
r = kvm_handle_hva(kvm, hva, (unsigned long)&pte, kvm_set_pte_rmapp);
- if (kvm->arch.tdp_mmu_enabled) + if (is_tdp_mmu_enabled(kvm)) r |= kvm_tdp_mmu_set_spte_hva(kvm, hva, &pte);
return r; @@ -1580,7 +1580,7 @@ int kvm_age_hva(struct kvm *kvm, unsigned long start, unsigned long end) int young = false;
young = kvm_handle_hva_range(kvm, start, end, 0, kvm_age_rmapp); - if (kvm->arch.tdp_mmu_enabled) + if (is_tdp_mmu_enabled(kvm)) young |= kvm_tdp_mmu_age_hva_range(kvm, start, end);
return young; @@ -1591,7 +1591,7 @@ int kvm_test_age_hva(struct kvm *kvm, unsigned long hva) int young = false;
young = kvm_handle_hva(kvm, hva, 0, kvm_test_age_rmapp); - if (kvm->arch.tdp_mmu_enabled) + if (is_tdp_mmu_enabled(kvm)) young |= kvm_tdp_mmu_test_age_hva(kvm, hva);
return young; @@ -3153,7 +3153,7 @@ static void mmu_free_root_page(struct kvm *kvm, hpa_t *root_hpa, sp = to_shadow_page(*root_hpa & PT64_BASE_ADDR_MASK);
if (kvm_mmu_put_root(kvm, sp)) { - if (sp->tdp_mmu_page) + if (is_tdp_mmu_page(sp)) kvm_tdp_mmu_free_root(kvm, sp); else if (sp->role.invalid) kvm_mmu_prepare_zap_page(kvm, sp, invalid_list); @@ -3247,7 +3247,7 @@ static int mmu_alloc_direct_roots(struct kvm_vcpu *vcpu) hpa_t root; unsigned i;
- if (vcpu->kvm->arch.tdp_mmu_enabled) { + if (is_tdp_mmu_enabled(vcpu->kvm)) { root = kvm_tdp_mmu_get_vcpu_root_hpa(vcpu);
if (!VALID_PAGE(root)) @@ -5434,7 +5434,7 @@ static void kvm_mmu_zap_all_fast(struct kvm *kvm)
kvm_zap_obsolete_pages(kvm);
- if (kvm->arch.tdp_mmu_enabled) + if (is_tdp_mmu_enabled(kvm)) kvm_tdp_mmu_zap_all(kvm);
spin_unlock(&kvm->mmu_lock); @@ -5497,7 +5497,7 @@ void kvm_zap_gfn_range(struct kvm *kvm, gfn_t gfn_start, gfn_t gfn_end) } }
- if (kvm->arch.tdp_mmu_enabled) { + if (is_tdp_mmu_enabled(kvm)) { flush = kvm_tdp_mmu_zap_gfn_range(kvm, gfn_start, gfn_end); if (flush) kvm_flush_remote_tlbs(kvm); @@ -5521,7 +5521,7 @@ void kvm_mmu_slot_remove_write_access(struct kvm *kvm, spin_lock(&kvm->mmu_lock); flush = slot_handle_level(kvm, memslot, slot_rmap_write_protect, start_level, KVM_MAX_HUGEPAGE_LEVEL, false); - if (kvm->arch.tdp_mmu_enabled) + if (is_tdp_mmu_enabled(kvm)) flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, PG_LEVEL_4K); spin_unlock(&kvm->mmu_lock);
@@ -5587,7 +5587,7 @@ void kvm_mmu_zap_collapsible_sptes(struct kvm *kvm, slot_handle_leaf(kvm, (struct kvm_memory_slot *)memslot, kvm_mmu_zap_collapsible_spte, true);
- if (kvm->arch.tdp_mmu_enabled) + if (is_tdp_mmu_enabled(kvm)) kvm_tdp_mmu_zap_collapsible_sptes(kvm, memslot); spin_unlock(&kvm->mmu_lock); } @@ -5614,7 +5614,7 @@ void kvm_mmu_slot_leaf_clear_dirty(struct kvm *kvm,
spin_lock(&kvm->mmu_lock); flush = slot_handle_leaf(kvm, memslot, __rmap_clear_dirty, false); - if (kvm->arch.tdp_mmu_enabled) + if (is_tdp_mmu_enabled(kvm)) flush |= kvm_tdp_mmu_clear_dirty_slot(kvm, memslot); spin_unlock(&kvm->mmu_lock);
@@ -5637,7 +5637,7 @@ void kvm_mmu_slot_largepage_remove_write_access(struct kvm *kvm, spin_lock(&kvm->mmu_lock); flush = slot_handle_large_level(kvm, memslot, slot_rmap_write_protect, false); - if (kvm->arch.tdp_mmu_enabled) + if (is_tdp_mmu_enabled(kvm)) flush |= kvm_tdp_mmu_wrprot_slot(kvm, memslot, PG_LEVEL_2M); spin_unlock(&kvm->mmu_lock);
@@ -5653,7 +5653,7 @@ void kvm_mmu_slot_set_dirty(struct kvm *kvm,
spin_lock(&kvm->mmu_lock); flush = slot_handle_all_level(kvm, memslot, __rmap_set_dirty, false); - if (kvm->arch.tdp_mmu_enabled) + if (is_tdp_mmu_enabled(kvm)) flush |= kvm_tdp_mmu_slot_set_dirty(kvm, memslot); spin_unlock(&kvm->mmu_lock);
@@ -5681,7 +5681,7 @@ void kvm_mmu_zap_all(struct kvm *kvm)
kvm_mmu_commit_zap_page(kvm, &invalid_list);
- if (kvm->arch.tdp_mmu_enabled) + if (is_tdp_mmu_enabled(kvm)) kvm_tdp_mmu_zap_all(kvm);
spin_unlock(&kvm->mmu_lock); @@ -5992,7 +5992,7 @@ static void kvm_recover_nx_lpages(struct kvm *kvm) struct kvm_mmu_page, lpage_disallowed_link); WARN_ON_ONCE(!sp->lpage_disallowed); - if (sp->tdp_mmu_page) { + if (is_tdp_mmu_page(sp)) { kvm_tdp_mmu_zap_gfn_range(kvm, sp->gfn, sp->gfn + KVM_PAGES_PER_HPAGE(sp->role.level)); } else { diff --git a/arch/x86/kvm/mmu/mmu_internal.h b/arch/x86/kvm/mmu/mmu_internal.h index 7f599cc64178..cf67fa6fb8fe 100644 --- a/arch/x86/kvm/mmu/mmu_internal.h +++ b/arch/x86/kvm/mmu/mmu_internal.h @@ -56,10 +56,12 @@ struct kvm_mmu_page { /* Number of writes since the last time traversal visited this page. */ atomic_t write_flooding_count;
+#ifdef CONFIG_X86_64 bool tdp_mmu_page;
/* Used for freeing the page asyncronously if it is a TDP MMU page. */ struct rcu_head rcu_head; +#endif };
extern struct kmem_cache *mmu_page_header_cache; diff --git a/arch/x86/kvm/mmu/tdp_mmu.c b/arch/x86/kvm/mmu/tdp_mmu.c index eb38f74af3f2..075b9d63bd57 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.c +++ b/arch/x86/kvm/mmu/tdp_mmu.c @@ -10,24 +10,13 @@ #include <asm/cmpxchg.h> #include <trace/events/kvm.h>
-#ifdef CONFIG_X86_64 static bool __read_mostly tdp_mmu_enabled = false; module_param_named(tdp_mmu, tdp_mmu_enabled, bool, 0644); -#endif - -static bool is_tdp_mmu_enabled(void) -{ -#ifdef CONFIG_X86_64 - return tdp_enabled && READ_ONCE(tdp_mmu_enabled); -#else - return false; -#endif /* CONFIG_X86_64 */ -}
/* Initializes the TDP MMU for the VM, if enabled. */ void kvm_mmu_init_tdp_mmu(struct kvm *kvm) { - if (!is_tdp_mmu_enabled()) + if (!tdp_enabled || !READ_ONCE(tdp_mmu_enabled)) return;
/* This should not be changed for the lifetime of the VM. */ @@ -96,22 +85,6 @@ static inline struct kvm_mmu_page *tdp_mmu_next_root(struct kvm *kvm, #define for_each_tdp_mmu_root(_kvm, _root) \ list_for_each_entry(_root, &_kvm->arch.tdp_mmu_roots, link)
-bool is_tdp_mmu_root(struct kvm *kvm, hpa_t hpa) -{ - struct kvm_mmu_page *sp; - - if (!kvm->arch.tdp_mmu_enabled) - return false; - if (WARN_ON(!VALID_PAGE(hpa))) - return false; - - sp = to_shadow_page(hpa); - if (WARN_ON(!sp)) - return false; - - return sp->tdp_mmu_page && sp->root_count; -} - static bool zap_gfn_range(struct kvm *kvm, struct kvm_mmu_page *root, gfn_t start, gfn_t end, bool can_yield, bool flush);
diff --git a/arch/x86/kvm/mmu/tdp_mmu.h b/arch/x86/kvm/mmu/tdp_mmu.h index cbbdbadd1526..b4b65e3699b3 100644 --- a/arch/x86/kvm/mmu/tdp_mmu.h +++ b/arch/x86/kvm/mmu/tdp_mmu.h @@ -5,10 +5,6 @@
#include <linux/kvm_host.h>
-void kvm_mmu_init_tdp_mmu(struct kvm *kvm); -void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm); - -bool is_tdp_mmu_root(struct kvm *kvm, hpa_t root); hpa_t kvm_tdp_mmu_get_vcpu_root_hpa(struct kvm_vcpu *vcpu); void kvm_tdp_mmu_free_root(struct kvm *kvm, struct kvm_mmu_page *root);
@@ -47,4 +43,32 @@ bool kvm_tdp_mmu_write_protect_gfn(struct kvm *kvm, int kvm_tdp_mmu_get_walk(struct kvm_vcpu *vcpu, u64 addr, u64 *sptes, int *root_level);
+#ifdef CONFIG_X86_64 +void kvm_mmu_init_tdp_mmu(struct kvm *kvm); +void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm); +static inline bool is_tdp_mmu_enabled(struct kvm *kvm) { return kvm->arch.tdp_mmu_enabled; } +static inline bool is_tdp_mmu_page(struct kvm_mmu_page *sp) { return sp->tdp_mmu_page; } +#else +static inline void kvm_mmu_init_tdp_mmu(struct kvm *kvm) {} +static inline void kvm_mmu_uninit_tdp_mmu(struct kvm *kvm) {} +static inline bool is_tdp_mmu_enabled(struct kvm *kvm) { return false; } +static inline bool is_tdp_mmu_page(struct kvm_mmu_page *sp) { return false; } +#endif + +static inline bool is_tdp_mmu_root(struct kvm *kvm, hpa_t hpa) +{ + struct kvm_mmu_page *sp; + + if (!is_tdp_mmu_enabled(kvm)) + return false; + if (WARN_ON(!VALID_PAGE(hpa))) + return false; + + sp = to_shadow_page(hpa); + if (WARN_ON(!sp)) + return false; + + return is_tdp_mmu_page(sp) && sp->root_count; +} + #endif /* __KVM_X86_MMU_TDP_MMU_H */