From e0d62c7f48605119a7f9fa632e77561c89928963 Mon Sep 17 00:00:00 2001 From: Izik Eidus Date: Wed, 24 Oct 2007 23:57:46 +0200 Subject: KVM: Add kernel-internal memory slots Reserve a few memory slots for kernel internal use. This is good for case you have to register memory region and you want to be sure it was not registered from userspace, and for case you want to register a memory region that won't be seen from userspace. Signed-off-by: Izik Eidus Signed-off-by: Avi Kivity --- drivers/kvm/kvm_main.c | 22 +++++++++++++++++++++- 1 file changed, 21 insertions(+), 1 deletion(-) (limited to 'drivers/kvm/kvm_main.c') diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c index 5113cbf75674..a044856bd02b 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); -- cgit v1.2.3