diff options
| -rw-r--r-- | arch/x86/include/asm/kvm_host.h | 4 | ||||
| -rw-r--r-- | arch/x86/kvm/x86.c | 60 | ||||
| -rw-r--r-- | include/linux/kvm_host.h | 6 | ||||
| -rw-r--r-- | virt/kvm/kvm_main.c | 4 |
4 files changed, 63 insertions, 11 deletions
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h index 7cdcb3d0f770..6c8c7c578c46 100644 --- a/arch/x86/include/asm/kvm_host.h +++ b/arch/x86/include/asm/kvm_host.h @@ -368,8 +368,12 @@ struct kvm_mem_alias { gfn_t base_gfn; unsigned long npages; gfn_t target_gfn; +#define KVM_ALIAS_INVALID 1UL + unsigned long flags; }; +#define KVM_ARCH_HAS_UNALIAS_INSTANTIATION + struct kvm_mem_aliases { struct kvm_mem_alias aliases[KVM_ALIAS_SLOTS]; int naliases; diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c index e7488350ca16..28127c936c3b 100644 --- a/arch/x86/kvm/x86.c +++ b/arch/x86/kvm/x86.c @@ -38,6 +38,7 @@ #include <linux/intel-iommu.h> #include <linux/cpufreq.h> #include <linux/user-return-notifier.h> +#include <linux/srcu.h> #include <trace/events/kvm.h> #undef TRACE_INCLUDE_FILE #define CREATE_TRACE_POINTS @@ -2223,11 +2224,32 @@ static int kvm_vm_ioctl_get_nr_mmu_pages(struct kvm *kvm) return kvm->arch.n_alloc_mmu_pages; } +gfn_t unalias_gfn_instantiation(struct kvm *kvm, gfn_t gfn) +{ + int i; + struct kvm_mem_alias *alias; + struct kvm_mem_aliases *aliases; + + aliases = rcu_dereference(kvm->arch.aliases); + + for (i = 0; i < aliases->naliases; ++i) { + alias = &aliases->aliases[i]; + if (alias->flags & KVM_ALIAS_INVALID) + continue; + if (gfn >= alias->base_gfn + && gfn < alias->base_gfn + alias->npages) + return alias->target_gfn + gfn - alias->base_gfn; + } + return gfn; +} + gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn) { int i; struct kvm_mem_alias *alias; - struct kvm_mem_aliases *aliases = kvm->arch.aliases; + struct kvm_mem_aliases *aliases; + + aliases = rcu_dereference(kvm->arch.aliases); for (i = 0; i < aliases->naliases; ++i) { alias = &aliases->aliases[i]; @@ -2248,7 +2270,7 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm, { int r, n; struct kvm_mem_alias *p; - struct kvm_mem_aliases *aliases; + struct kvm_mem_aliases *aliases, *old_aliases; r = -EINVAL; /* General sanity checks */ @@ -2265,28 +2287,48 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm, < alias->target_phys_addr) goto out; + r = -ENOMEM; + aliases = kzalloc(sizeof(struct kvm_mem_aliases), GFP_KERNEL); + if (!aliases) + goto out; + down_write(&kvm->slots_lock); - spin_lock(&kvm->mmu_lock); - aliases = kvm->arch.aliases; + /* invalidate any gfn reference in case of deletion/shrinking */ + memcpy(aliases, kvm->arch.aliases, sizeof(struct kvm_mem_aliases)); + aliases->aliases[alias->slot].flags |= KVM_ALIAS_INVALID; + old_aliases = kvm->arch.aliases; + rcu_assign_pointer(kvm->arch.aliases, aliases); + synchronize_srcu_expedited(&kvm->srcu); + kvm_mmu_zap_all(kvm); + kfree(old_aliases); + + r = -ENOMEM; + aliases = kzalloc(sizeof(struct kvm_mem_aliases), GFP_KERNEL); + if (!aliases) + goto out_unlock; + + memcpy(aliases, kvm->arch.aliases, sizeof(struct kvm_mem_aliases)); p = &aliases->aliases[alias->slot]; p->base_gfn = alias->guest_phys_addr >> PAGE_SHIFT; p->npages = alias->memory_size >> PAGE_SHIFT; p->target_gfn = alias->target_phys_addr >> PAGE_SHIFT; + p->flags &= ~(KVM_ALIAS_INVALID); for (n = KVM_ALIAS_SLOTS; n > 0; --n) if (aliases->aliases[n - 1].npages) break; aliases->naliases = n; - spin_unlock(&kvm->mmu_lock); - kvm_mmu_zap_all(kvm); + old_aliases = kvm->arch.aliases; + rcu_assign_pointer(kvm->arch.aliases, aliases); + synchronize_srcu_expedited(&kvm->srcu); + kfree(old_aliases); + r = 0; +out_unlock: up_write(&kvm->slots_lock); - - return 0; - out: return r; } diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h index 93bd30701ca7..20941c0f4045 100644 --- a/include/linux/kvm_host.h +++ b/include/linux/kvm_host.h @@ -266,6 +266,8 @@ void kvm_arch_commit_memory_region(struct kvm *kvm, void kvm_disable_largepages(void); void kvm_arch_flush_shadow(struct kvm *kvm); gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn); +gfn_t unalias_gfn_instantiation(struct kvm *kvm, gfn_t gfn); + struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn); unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn); void kvm_release_page_clean(struct page *page); @@ -539,6 +541,10 @@ static inline int mmu_notifier_retry(struct kvm_vcpu *vcpu, unsigned long mmu_se } #endif +#ifndef KVM_ARCH_HAS_UNALIAS_INSTANTIATION +#define unalias_gfn_instantiation unalias_gfn +#endif + #ifdef CONFIG_HAVE_KVM_IRQCHIP #define KVM_MAX_IRQ_ROUTES 1024 diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c index 2bb24a814fdf..c680f7b64c6f 100644 --- a/virt/kvm/kvm_main.c +++ b/virt/kvm/kvm_main.c @@ -859,7 +859,7 @@ int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn) int i; struct kvm_memslots *slots = rcu_dereference(kvm->memslots); - gfn = unalias_gfn(kvm, gfn); + gfn = unalias_gfn_instantiation(kvm, gfn); for (i = 0; i < KVM_MEMORY_SLOTS; ++i) { struct kvm_memory_slot *memslot = &slots->memslots[i]; @@ -896,7 +896,7 @@ unsigned long gfn_to_hva(struct kvm *kvm, gfn_t gfn) { struct kvm_memory_slot *slot; - gfn = unalias_gfn(kvm, gfn); + gfn = unalias_gfn_instantiation(kvm, gfn); slot = gfn_to_memslot_unaliased(kvm, gfn); if (!slot || slot->flags & KVM_MEMSLOT_INVALID) return bad_hva(); |