Reverting a 3.16 patch, fixing two bugs in device assignment

(one has a CVE), and fixing some problems introduced during the merge window
 (the CMA bug came in via Andrew, the x86 ones via yours truly).
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Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm

Pull KVM fixes from Paolo Bonzini:
 "Reverting a 3.16 patch, fixing two bugs in device assignment (one has
  a CVE), and fixing some problems introduced during the merge window
  (the CMA bug came in via Andrew, the x86 ones via yours truly)"

* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm:
  virt/kvm/assigned-dev.c: Set 'dev->irq_source_id' to '-1' after free it
  Revert "KVM: x86: Increase the number of fixed MTRR regs to 10"
  KVM: x86: do not check CS.DPL against RPL during task switch
  KVM: x86: Avoid emulating instructions on #UD mistakenly
  PC, KVM, CMA: Fix regression caused by wrong get_order() use
  kvm: iommu: fix the third parameter of kvm_iommu_put_pages (CVE-2014-3601)

arch/powerpc/kvm/book3s_hv_builtin.c

@@ -101,7 +101,7 @@ struct kvm_rma_info *kvm_alloc_rma()
 	ri = kmalloc(sizeof(struct kvm_rma_info), GFP_KERNEL);
 	if (!ri)
 		return NULL;
-	page = cma_alloc(kvm_cma, kvm_rma_pages, get_order(kvm_rma_pages));
+	page = cma_alloc(kvm_cma, kvm_rma_pages, order_base_2(kvm_rma_pages));
 	if (!page)
 		goto err_out;
 	atomic_set(&ri->use_count, 1);
@@ -135,12 +135,12 @@ struct page *kvm_alloc_hpt(unsigned long nr_pages)
 {
 	unsigned long align_pages = HPT_ALIGN_PAGES;
 
-	VM_BUG_ON(get_order(nr_pages) < KVM_CMA_CHUNK_ORDER - PAGE_SHIFT);
+	VM_BUG_ON(order_base_2(nr_pages) < KVM_CMA_CHUNK_ORDER - PAGE_SHIFT);
 
 	/* Old CPUs require HPT aligned on a multiple of its size */
 	if (!cpu_has_feature(CPU_FTR_ARCH_206))
 		align_pages = nr_pages;
-	return cma_alloc(kvm_cma, nr_pages, get_order(align_pages));
+	return cma_alloc(kvm_cma, nr_pages, order_base_2(align_pages));
 }
 EXPORT_SYMBOL_GPL(kvm_alloc_hpt);
 

arch/x86/include/asm/kvm_host.h

@@ -95,7 +95,7 @@ static inline gfn_t gfn_to_index(gfn_t gfn, gfn_t base_gfn, int level)
 #define KVM_REFILL_PAGES 25
 #define KVM_MAX_CPUID_ENTRIES 80
 #define KVM_NR_FIXED_MTRR_REGION 88
-#define KVM_NR_VAR_MTRR 10
+#define KVM_NR_VAR_MTRR 8
 
 #define ASYNC_PF_PER_VCPU 64
 

arch/x86/kvm/emulate.c

@@ -1491,9 +1491,6 @@ static int __load_segment_descriptor(struct x86_emulate_ctxt *ctxt,
 			goto exception;
 		break;
 	case VCPU_SREG_CS:
-		if (in_task_switch && rpl != dpl)
-			goto exception;
-
 		if (!(seg_desc.type & 8))
 			goto exception;
 
@@ -4394,8 +4391,11 @@ done_prefixes:
 
 	ctxt->execute = opcode.u.execute;
 
+	if (unlikely(ctxt->ud) && likely(!(ctxt->d & EmulateOnUD)))
+		return EMULATION_FAILED;
+
 	if (unlikely(ctxt->d &
-		     (NotImpl|EmulateOnUD|Stack|Op3264|Sse|Mmx|Intercept|CheckPerm))) {
+		     (NotImpl|Stack|Op3264|Sse|Mmx|Intercept|CheckPerm))) {
 		/*
 		 * These are copied unconditionally here, and checked unconditionally
 		 * in x86_emulate_insn.
@@ -4406,9 +4406,6 @@ done_prefixes:
 		if (ctxt->d & NotImpl)
 			return EMULATION_FAILED;
 
-		if (!(ctxt->d & EmulateOnUD) && ctxt->ud)
-			return EMULATION_FAILED;
-
 		if (mode == X86EMUL_MODE_PROT64 && (ctxt->d & Stack))
 			ctxt->op_bytes = 8;
 

virt/kvm/assigned-dev.c

@@ -526,8 +526,10 @@ static int assign_guest_irq(struct kvm *kvm,
 		dev->irq_requested_type |= guest_irq_type;
 		if (dev->ack_notifier.gsi != -1)
 			kvm_register_irq_ack_notifier(kvm, &dev->ack_notifier);
-	} else
+	} else {
 		kvm_free_irq_source_id(kvm, dev->irq_source_id);
+		dev->irq_source_id = -1;
+	}
 
 	return r;
 }

virt/kvm/iommu.c

@@ -61,6 +61,14 @@ static pfn_t kvm_pin_pages(struct kvm_memory_slot *slot, gfn_t gfn,
 	return pfn;
 }
 
+static void kvm_unpin_pages(struct kvm *kvm, pfn_t pfn, unsigned long npages)
+{
+	unsigned long i;
+
+	for (i = 0; i < npages; ++i)
+		kvm_release_pfn_clean(pfn + i);
+}
+
 int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
 {
 	gfn_t gfn, end_gfn;
@@ -123,6 +131,7 @@ int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
 		if (r) {
 			printk(KERN_ERR "kvm_iommu_map_address:"
 			       "iommu failed to map pfn=%llx\n", pfn);
+			kvm_unpin_pages(kvm, pfn, page_size);
 			goto unmap_pages;
 		}
 
@@ -134,7 +143,7 @@ int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
 	return 0;
 
 unmap_pages:
-	kvm_iommu_put_pages(kvm, slot->base_gfn, gfn);
+	kvm_iommu_put_pages(kvm, slot->base_gfn, gfn - slot->base_gfn);
 	return r;
 }
 
@@ -266,14 +275,6 @@ out_unlock:
 	return r;
 }
 
-static void kvm_unpin_pages(struct kvm *kvm, pfn_t pfn, unsigned long npages)
-{
-	unsigned long i;
-
-	for (i = 0; i < npages; ++i)
-		kvm_release_pfn_clean(pfn + i);
-}
-
 static void kvm_iommu_put_pages(struct kvm *kvm,
 				gfn_t base_gfn, unsigned long npages)
 {