diff options
| -rw-r--r-- | drivers/kvm/kvm.h | 6 | ||||
| -rw-r--r-- | drivers/kvm/kvm_main.c | 22 |
2 files changed, 26 insertions, 2 deletions
diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h index f3dda088e34..82c3b13e5d0 100644 --- a/drivers/kvm/kvm.h +++ b/drivers/kvm/kvm.h @@ -41,6 +41,8 @@ #define KVM_MAX_VCPUS 4 #define KVM_ALIAS_SLOTS 4 #define KVM_MEMORY_SLOTS 8 +/* memory slots that does not exposed to userspace */ +#define KVM_PRIVATE_MEM_SLOTS 4 #define KVM_PERMILLE_MMU_PAGES 20 #define KVM_MIN_ALLOC_MMU_PAGES 64 #define KVM_NUM_MMU_PAGES 1024 @@ -361,7 +363,8 @@ struct kvm { int naliases; struct kvm_mem_alias aliases[KVM_ALIAS_SLOTS]; int nmemslots; - struct kvm_memory_slot memslots[KVM_MEMORY_SLOTS]; + struct kvm_memory_slot memslots[KVM_MEMORY_SLOTS + + KVM_PRIVATE_MEM_SLOTS]; /* * Hash table of struct kvm_mmu_page. */ @@ -529,6 +532,7 @@ int kvm_write_guest(struct kvm *kvm, gpa_t gpa, const void *data, int kvm_clear_guest_page(struct kvm *kvm, gfn_t gfn, int offset, int len); int kvm_clear_guest(struct kvm *kvm, gpa_t gpa, unsigned long len); struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn); +int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn); void mark_page_dirty(struct kvm *kvm, gfn_t gfn); enum emulation_result { diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index 5113cbf7567..a044856bd02 100644 --- a/drivers/kvm/kvm_main.c +++ b/drivers/kvm/kvm_main.c @@ -660,7 +660,7 @@ int kvm_set_memory_region(struct kvm *kvm, goto out; if (mem->guest_phys_addr & (PAGE_SIZE - 1)) goto out; - if (mem->slot >= KVM_MEMORY_SLOTS) + if (mem->slot >= KVM_MEMORY_SLOTS + KVM_PRIVATE_MEM_SLOTS) goto out; if (mem->guest_phys_addr + mem->memory_size < mem->guest_phys_addr) goto out; @@ -797,6 +797,8 @@ static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm, kvm_userspace_memory_region *mem, int user_alloc) { + if (mem->slot >= KVM_MEMORY_SLOTS) + return -EINVAL; return kvm_set_memory_region(kvm, mem, user_alloc); } @@ -1010,6 +1012,22 @@ struct kvm_memory_slot *gfn_to_memslot(struct kvm *kvm, gfn_t gfn) return __gfn_to_memslot(kvm, gfn); } +int kvm_is_visible_gfn(struct kvm *kvm, gfn_t gfn) +{ + int i; + + gfn = unalias_gfn(kvm, gfn); + for (i = 0; i < KVM_MEMORY_SLOTS; ++i) { + struct kvm_memory_slot *memslot = &kvm->memslots[i]; + + if (gfn >= memslot->base_gfn + && gfn < memslot->base_gfn + memslot->npages) + return 1; + } + return 0; +} +EXPORT_SYMBOL_GPL(kvm_is_visible_gfn); + struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn) { struct kvm_memory_slot *slot; @@ -3087,6 +3105,8 @@ static struct page *kvm_vm_nopage(struct vm_area_struct *vma, struct page *page; pgoff = ((address - vma->vm_start) >> PAGE_SHIFT) + vma->vm_pgoff; + if (!kvm_is_visible_gfn(kvm, pgoff)) + return NOPAGE_SIGBUS; page = gfn_to_page(kvm, pgoff); if (is_error_page(page)) { kvm_release_page(page); |