1 files changed, 188 insertions, 62 deletions

diff --git a/virt/kvm/iommu.c b/virt/kvm/iommu.c
index 15147583abd..0df7d4b34df 100644
--- a/virt/kvm/iommu.c
+++ b/virt/kvm/iommu.c
@@ -16,6 +16,8 @@
  *
  * Copyright (C) 2006-2008 Intel Corporation
  * Copyright IBM Corporation, 2008
+ * Copyright 2010 Red Hat, Inc. and/or its affiliates.
+ *
  * Author: Allen M. Kay <allen.m.kay@intel.com>
  * Author: Weidong Han <weidong.han@intel.com>
  * Author: Ben-Ami Yassour <benami@il.ibm.com>
@@ -23,21 +25,47 @@
 
 #include <linux/list.h>
 #include <linux/kvm_host.h>
+#include <linux/module.h>
 #include <linux/pci.h>
+#include <linux/stat.h>
 #include <linux/dmar.h>
 #include <linux/iommu.h>
 #include <linux/intel-iommu.h>
 
+static bool allow_unsafe_assigned_interrupts;
+module_param_named(allow_unsafe_assigned_interrupts,
+		   allow_unsafe_assigned_interrupts, bool, S_IRUGO | S_IWUSR);
+MODULE_PARM_DESC(allow_unsafe_assigned_interrupts,
+ "Enable device assignment on platforms without interrupt remapping support.");
+
 static int kvm_iommu_unmap_memslots(struct kvm *kvm);
 static void kvm_iommu_put_pages(struct kvm *kvm,
 				gfn_t base_gfn, unsigned long npages);
 
-int kvm_iommu_map_pages(struct kvm *kvm,
-			gfn_t base_gfn, unsigned long npages)
+static pfn_t kvm_pin_pages(struct kvm_memory_slot *slot, gfn_t gfn,
+			   unsigned long size)
+{
+	gfn_t end_gfn;
+	pfn_t pfn;
+
+	pfn     = gfn_to_pfn_memslot(slot, gfn);
+	end_gfn = gfn + (size >> PAGE_SHIFT);
+	gfn    += 1;
+
+	if (is_error_noslot_pfn(pfn))
+		return pfn;
+
+	while (gfn < end_gfn)
+		gfn_to_pfn_memslot(slot, gfn++);
+
+	return pfn;
+}
+
+int kvm_iommu_map_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
 {
-	gfn_t gfn = base_gfn;
+	gfn_t gfn, end_gfn;
 	pfn_t pfn;
-	int i, r = 0;
+	int r = 0;
 	struct iommu_domain *domain = kvm->arch.iommu_domain;
 	int flags;
 
@@ -45,44 +73,89 @@ int kvm_iommu_map_pages(struct kvm *kvm,
 	if (!domain)
 		return 0;
 
-	flags = IOMMU_READ | IOMMU_WRITE;
-	if (kvm->arch.iommu_flags & KVM_IOMMU_CACHE_COHERENCY)
+	gfn     = slot->base_gfn;
+	end_gfn = gfn + slot->npages;
+
+	flags = IOMMU_READ;
+	if (!(slot->flags & KVM_MEM_READONLY))
+		flags |= IOMMU_WRITE;
+	if (!kvm->arch.iommu_noncoherent)
 		flags |= IOMMU_CACHE;
 
-	for (i = 0; i < npages; i++) {
-		/* check if already mapped */
-		if (iommu_iova_to_phys(domain, gfn_to_gpa(gfn)))
+
+	while (gfn < end_gfn) {
+		unsigned long page_size;
+
+		/* Check if already mapped */
+		if (iommu_iova_to_phys(domain, gfn_to_gpa(gfn))) {
+			gfn += 1;
 			continue;
+		}
+
+		/* Get the page size we could use to map */
+		page_size = kvm_host_page_size(kvm, gfn);
+
+		/* Make sure the page_size does not exceed the memslot */
+		while ((gfn + (page_size >> PAGE_SHIFT)) > end_gfn)
+			page_size >>= 1;
 
-		pfn = gfn_to_pfn(kvm, gfn);
-		r = iommu_map_range(domain,
-				    gfn_to_gpa(gfn),
-				    pfn_to_hpa(pfn),
-				    PAGE_SIZE, flags);
+		/* Make sure gfn is aligned to the page size we want to map */
+		while ((gfn << PAGE_SHIFT) & (page_size - 1))
+			page_size >>= 1;
+
+		/* Make sure hva is aligned to the page size we want to map */
+		while (__gfn_to_hva_memslot(slot, gfn) & (page_size - 1))
+			page_size >>= 1;
+
+		/*
+		 * Pin all pages we are about to map in memory. This is
+		 * important because we unmap and unpin in 4kb steps later.
+		 */
+		pfn = kvm_pin_pages(slot, gfn, page_size);
+		if (is_error_noslot_pfn(pfn)) {
+			gfn += 1;
+			continue;
+		}
+
+		/* Map into IO address space */
+		r = iommu_map(domain, gfn_to_gpa(gfn), pfn_to_hpa(pfn),
+			      page_size, flags);
 		if (r) {
 			printk(KERN_ERR "kvm_iommu_map_address:"
-			       "iommu failed to map pfn=%lx\n", pfn);
+			       "iommu failed to map pfn=%llx\n", pfn);
 			goto unmap_pages;
 		}
-		gfn++;
+
+		gfn += page_size >> PAGE_SHIFT;
+
+
 	}
+
 	return 0;
 
 unmap_pages:
-	kvm_iommu_put_pages(kvm, base_gfn, i);
+	kvm_iommu_put_pages(kvm, slot->base_gfn, gfn);
 	return r;
 }
 
 static int kvm_iommu_map_memslots(struct kvm *kvm)
 {
-	int i, r = 0;
+	int idx, r = 0;
+	struct kvm_memslots *slots;
+	struct kvm_memory_slot *memslot;
+
+	if (kvm->arch.iommu_noncoherent)
+		kvm_arch_register_noncoherent_dma(kvm);
 
-	for (i = 0; i < kvm->nmemslots; i++) {
-		r = kvm_iommu_map_pages(kvm, kvm->memslots[i].base_gfn,
-					kvm->memslots[i].npages);
+	idx = srcu_read_lock(&kvm->srcu);
+	slots = kvm_memslots(kvm);
+
+	kvm_for_each_memslot(memslot, slots) {
+		r = kvm_iommu_map_pages(kvm, memslot);
 		if (r)
 			break;
 	}
+	srcu_read_unlock(&kvm->srcu, idx);
 
 	return r;
 }
@@ -92,7 +165,8 @@ int kvm_assign_device(struct kvm *kvm,
 {
 	struct pci_dev *pdev = NULL;
 	struct iommu_domain *domain = kvm->arch.iommu_domain;
-	int r, last_flags;
+	int r;
+	bool noncoherent;
 
 	/* check if iommu exists and in use */
 	if (!domain)
@@ -104,31 +178,25 @@ int kvm_assign_device(struct kvm *kvm,
 
 	r = iommu_attach_device(domain, &pdev->dev);
 	if (r) {
-		printk(KERN_ERR "assign device %x:%x.%x failed",
-			pdev->bus->number,
-			PCI_SLOT(pdev->devfn),
-			PCI_FUNC(pdev->devfn));
+		dev_err(&pdev->dev, "kvm assign device failed ret %d", r);
 		return r;
 	}
 
-	last_flags = kvm->arch.iommu_flags;
-	if (iommu_domain_has_cap(kvm->arch.iommu_domain,
-				 IOMMU_CAP_CACHE_COHERENCY))
-		kvm->arch.iommu_flags |= KVM_IOMMU_CACHE_COHERENCY;
+	noncoherent = !iommu_domain_has_cap(kvm->arch.iommu_domain,
+					    IOMMU_CAP_CACHE_COHERENCY);
 
 	/* Check if need to update IOMMU page table for guest memory */
-	if ((last_flags ^ kvm->arch.iommu_flags) ==
-			KVM_IOMMU_CACHE_COHERENCY) {
+	if (noncoherent != kvm->arch.iommu_noncoherent) {
 		kvm_iommu_unmap_memslots(kvm);
+		kvm->arch.iommu_noncoherent = noncoherent;
 		r = kvm_iommu_map_memslots(kvm);
 		if (r)
 			goto out_unmap;
 	}
 
-	printk(KERN_DEBUG "assign device: host bdf = %x:%x:%x\n",
-		assigned_dev->host_busnr,
-		PCI_SLOT(assigned_dev->host_devfn),
-		PCI_FUNC(assigned_dev->host_devfn));
+	pdev->dev_flags |= PCI_DEV_FLAGS_ASSIGNED;
+
+	dev_info(&pdev->dev, "kvm assign device\n");
 
 	return 0;
 out_unmap:
@@ -152,10 +220,9 @@ int kvm_deassign_device(struct kvm *kvm,
 
 	iommu_detach_device(domain, &pdev->dev);
 
-	printk(KERN_DEBUG "deassign device: host bdf = %x:%x:%x\n",
-		assigned_dev->host_busnr,
-		PCI_SLOT(assigned_dev->host_devfn),
-		PCI_FUNC(assigned_dev->host_devfn));
+	pdev->dev_flags &= ~PCI_DEV_FLAGS_ASSIGNED;
+
+	dev_info(&pdev->dev, "kvm deassign device\n");
 
 	return 0;
 }
@@ -164,57 +231,111 @@ int kvm_iommu_map_guest(struct kvm *kvm)
 {
 	int r;
 
-	if (!iommu_found()) {
+	if (!iommu_present(&pci_bus_type)) {
 		printk(KERN_ERR "%s: iommu not found\n", __func__);
 		return -ENODEV;
 	}
 
-	kvm->arch.iommu_domain = iommu_domain_alloc();
-	if (!kvm->arch.iommu_domain)
-		return -ENOMEM;
+	mutex_lock(&kvm->slots_lock);
+
+	kvm->arch.iommu_domain = iommu_domain_alloc(&pci_bus_type);
+	if (!kvm->arch.iommu_domain) {
+		r = -ENOMEM;
+		goto out_unlock;
+	}
+
+	if (!allow_unsafe_assigned_interrupts &&
+	    !iommu_domain_has_cap(kvm->arch.iommu_domain,
+				  IOMMU_CAP_INTR_REMAP)) {
+		printk(KERN_WARNING "%s: No interrupt remapping support,"
+		       " disallowing device assignment."
+		       " Re-enble with \"allow_unsafe_assigned_interrupts=1\""
+		       " module option.\n", __func__);
+		iommu_domain_free(kvm->arch.iommu_domain);
+		kvm->arch.iommu_domain = NULL;
+		r = -EPERM;
+		goto out_unlock;
+	}
 
 	r = kvm_iommu_map_memslots(kvm);
 	if (r)
-		goto out_unmap;
-
-	return 0;
+		kvm_iommu_unmap_memslots(kvm);
 
-out_unmap:
-	kvm_iommu_unmap_memslots(kvm);
+out_unlock:
+	mutex_unlock(&kvm->slots_lock);
 	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)
 {
-	gfn_t gfn = base_gfn;
+	struct iommu_domain *domain;
+	gfn_t end_gfn, gfn;
 	pfn_t pfn;
-	struct iommu_domain *domain = kvm->arch.iommu_domain;
-	unsigned long i;
 	u64 phys;
 
+	domain  = kvm->arch.iommu_domain;
+	end_gfn = base_gfn + npages;
+	gfn     = base_gfn;
+
 	/* check if iommu exists and in use */
 	if (!domain)
 		return;
 
-	for (i = 0; i < npages; i++) {
+	while (gfn < end_gfn) {
+		unsigned long unmap_pages;
+		size_t size;
+
+		/* Get physical address */
 		phys = iommu_iova_to_phys(domain, gfn_to_gpa(gfn));
-		pfn = phys >> PAGE_SHIFT;
-		kvm_release_pfn_clean(pfn);
-		gfn++;
+
+		if (!phys) {
+			gfn++;
+			continue;
+		}
+
+		pfn  = phys >> PAGE_SHIFT;
+
+		/* Unmap address from IO address space */
+		size       = iommu_unmap(domain, gfn_to_gpa(gfn), PAGE_SIZE);
+		unmap_pages = 1ULL << get_order(size);
+
+		/* Unpin all pages we just unmapped to not leak any memory */
+		kvm_unpin_pages(kvm, pfn, unmap_pages);
+
+		gfn += unmap_pages;
 	}
+}
 
-	iommu_unmap_range(domain, gfn_to_gpa(base_gfn), PAGE_SIZE * npages);
+void kvm_iommu_unmap_pages(struct kvm *kvm, struct kvm_memory_slot *slot)
+{
+	kvm_iommu_put_pages(kvm, slot->base_gfn, slot->npages);
 }
 
 static int kvm_iommu_unmap_memslots(struct kvm *kvm)
 {
-	int i;
+	int idx;
+	struct kvm_memslots *slots;
+	struct kvm_memory_slot *memslot;
 
-	for (i = 0; i < kvm->nmemslots; i++) {
-		kvm_iommu_put_pages(kvm, kvm->memslots[i].base_gfn,
-				    kvm->memslots[i].npages);
-	}
+	idx = srcu_read_lock(&kvm->srcu);
+	slots = kvm_memslots(kvm);
+
+	kvm_for_each_memslot(memslot, slots)
+		kvm_iommu_unmap_pages(kvm, memslot);
+
+	srcu_read_unlock(&kvm->srcu, idx);
+
+	if (kvm->arch.iommu_noncoherent)
+		kvm_arch_unregister_noncoherent_dma(kvm);
 
 	return 0;
 }
@@ -227,7 +348,12 @@ int kvm_iommu_unmap_guest(struct kvm *kvm)
 	if (!domain)
 		return 0;
 
+	mutex_lock(&kvm->slots_lock);
 	kvm_iommu_unmap_memslots(kvm);
+	kvm->arch.iommu_domain = NULL;
+	kvm->arch.iommu_noncoherent = false;
+	mutex_unlock(&kvm->slots_lock);
+
 	iommu_domain_free(domain);
 	return 0;
 }