arch/x86/kvm/iommu.c - kernel/bruno - Git at Google

 /*
  * Copyright (c) 2006, Intel Corporation.
  *
  * This program is free software; you can redistribute it and/or modify it
  * under the terms and conditions of the GNU General Public License,
  * version 2, as published by the Free Software Foundation.
  *
  * This program is distributed in the hope it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
  * more details.
  *
  * You should have received a copy of the GNU General Public License along with
  * this program; if not, write to the Free Software Foundation, Inc., 59 Temple
  * Place - Suite 330, Boston, MA 02111-1307 USA.
  *
  * 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>
  */

 #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>
 #include "assigned-dev.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);

 static pfn_t kvm_pin_pages(struct kvm_memory_slot *slot, gfn_t gfn,
 			   unsigned long npages)
 {
 	gfn_t end_gfn;
 	pfn_t pfn;

 	pfn     = gfn_to_pfn_memslot(slot, gfn);
 	end_gfn = gfn + npages;
 	gfn    += 1;

 	if (is_error_noslot_pfn(pfn))
 		return pfn;

 	while (gfn < end_gfn)
 		gfn_to_pfn_memslot(slot, 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;
 	pfn_t pfn;
 	int r = 0;
 	struct iommu_domain *domain = kvm->arch.iommu_domain;
 	int flags;

 	/* check if iommu exists and in use */
 	if (!domain)
 		return 0;

 	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;


 	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;

 		/* 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 >> PAGE_SHIFT);
 		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=%llx\n", pfn);
 			kvm_unpin_pages(kvm, pfn, page_size >> PAGE_SHIFT);
 			goto unmap_pages;
 		}

 		gfn += page_size >> PAGE_SHIFT;

 		cond_resched();
 	}

 	return 0;

 unmap_pages:
 	kvm_iommu_put_pages(kvm, slot->base_gfn, gfn - slot->base_gfn);
 	return r;
 }

 static int kvm_iommu_map_memslots(struct kvm *kvm)
 {
 	int idx, r = 0;
 	struct kvm_memslots *slots;
 	struct kvm_memory_slot *memslot;

 	if (kvm->arch.iommu_noncoherent)
 		kvm_arch_register_noncoherent_dma(kvm);

 	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;
 }

 int kvm_assign_device(struct kvm *kvm, struct pci_dev *pdev)
 {
 	struct iommu_domain *domain = kvm->arch.iommu_domain;
 	int r;
 	bool noncoherent;

 	/* check if iommu exists and in use */
 	if (!domain)
 		return 0;

 	if (pdev == NULL)
 		return -ENODEV;

 	r = iommu_attach_device(domain, &pdev->dev);
 	if (r) {
 		dev_err(&pdev->dev, "kvm assign device failed ret %d", r);
 		return r;
 	}

 	noncoherent = !iommu_capable(&pci_bus_type, IOMMU_CAP_CACHE_COHERENCY);

 	/* Check if need to update IOMMU page table for guest memory */
 	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;
 	}

 	kvm_arch_start_assignment(kvm);
 	pci_set_dev_assigned(pdev);

 	dev_info(&pdev->dev, "kvm assign device\n");

 	return 0;
 out_unmap:
 	kvm_iommu_unmap_memslots(kvm);
 	return r;
 }

 int kvm_deassign_device(struct kvm *kvm, struct pci_dev *pdev)
 {
 	struct iommu_domain *domain = kvm->arch.iommu_domain;

 	/* check if iommu exists and in use */
 	if (!domain)
 		return 0;

 	if (pdev == NULL)
 		return -ENODEV;

 	iommu_detach_device(domain, &pdev->dev);

 	pci_clear_dev_assigned(pdev);
 	kvm_arch_end_assignment(kvm);

 	dev_info(&pdev->dev, "kvm deassign device\n");

 	return 0;
 }

 int kvm_iommu_map_guest(struct kvm *kvm)
 {
 	int r;

 	if (!iommu_present(&pci_bus_type)) {
 		printk(KERN_ERR "%s: iommu not found\n", __func__);
 		return -ENODEV;
 	}

 	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_capable(&pci_bus_type, 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)
 		kvm_iommu_unmap_memslots(kvm);

 out_unlock:
 	mutex_unlock(&kvm->slots_lock);
 	return r;
 }

 static void kvm_iommu_put_pages(struct kvm *kvm,
 				gfn_t base_gfn, unsigned long npages)
 {
 	struct iommu_domain *domain;
 	gfn_t end_gfn, gfn;
 	pfn_t pfn;
 	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;

 	while (gfn < end_gfn) {
 		unsigned long unmap_pages;
 		size_t size;

 		/* Get physical address */
 		phys = iommu_iova_to_phys(domain, gfn_to_gpa(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;

 		cond_resched();
 	}
 }

 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 idx;
 	struct kvm_memslots *slots;
 	struct kvm_memory_slot *memslot;

 	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;
 }

 int kvm_iommu_unmap_guest(struct kvm *kvm)
 {
 	struct iommu_domain *domain = kvm->arch.iommu_domain;

 	/* check if iommu exists and in use */
 	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;
 }
	/*
	* Copyright (c) 2006, Intel Corporation.
	*
	* This program is free software; you can redistribute it and/or modify it
	* under the terms and conditions of the GNU General Public License,
	* version 2, as published by the Free Software Foundation.
	*
	* This program is distributed in the hope it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
	* more details.
	*
	* You should have received a copy of the GNU General Public License along with
	* this program; if not, write to the Free Software Foundation, Inc., 59 Temple
	* Place - Suite 330, Boston, MA 02111-1307 USA.
	*
	* 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>
	*/

	#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>
	#include "assigned-dev.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);

	static pfn_t kvm_pin_pages(struct kvm_memory_slot *slot, gfn_t gfn,
	unsigned long npages)
	{
	gfn_t end_gfn;
	pfn_t pfn;

	pfn = gfn_to_pfn_memslot(slot, gfn);
	end_gfn = gfn + npages;
	gfn += 1;

	if (is_error_noslot_pfn(pfn))
	return pfn;

	while (gfn < end_gfn)
	gfn_to_pfn_memslot(slot, 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;
	pfn_t pfn;
	int r = 0;
	struct iommu_domain *domain = kvm->arch.iommu_domain;
	int flags;

	/* check if iommu exists and in use */
	if (!domain)
	return 0;

	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;


	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;

	/* 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 >> PAGE_SHIFT);
	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=%llx\n", pfn);
	kvm_unpin_pages(kvm, pfn, page_size >> PAGE_SHIFT);
	goto unmap_pages;
	}

	gfn += page_size >> PAGE_SHIFT;

	cond_resched();
	}

	return 0;

	unmap_pages:
	kvm_iommu_put_pages(kvm, slot->base_gfn, gfn - slot->base_gfn);
	return r;
	}

	static int kvm_iommu_map_memslots(struct kvm *kvm)
	{
	int idx, r = 0;
	struct kvm_memslots *slots;
	struct kvm_memory_slot *memslot;

	if (kvm->arch.iommu_noncoherent)
	kvm_arch_register_noncoherent_dma(kvm);

	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;
	}

	int kvm_assign_device(struct kvm kvm, struct pci_dev pdev)
	{
	struct iommu_domain *domain = kvm->arch.iommu_domain;
	int r;
	bool noncoherent;

	/* check if iommu exists and in use */
	if (!domain)
	return 0;

	if (pdev == NULL)
	return -ENODEV;

	r = iommu_attach_device(domain, &pdev->dev);
	if (r) {
	dev_err(&pdev->dev, "kvm assign device failed ret %d", r);
	return r;
	}

	noncoherent = !iommu_capable(&pci_bus_type, IOMMU_CAP_CACHE_COHERENCY);

	/* Check if need to update IOMMU page table for guest memory */
	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;
	}

	kvm_arch_start_assignment(kvm);
	pci_set_dev_assigned(pdev);

	dev_info(&pdev->dev, "kvm assign device\n");

	return 0;
	out_unmap:
	kvm_iommu_unmap_memslots(kvm);
	return r;
	}

	int kvm_deassign_device(struct kvm kvm, struct pci_dev pdev)
	{
	struct iommu_domain *domain = kvm->arch.iommu_domain;

	/* check if iommu exists and in use */
	if (!domain)
	return 0;

	if (pdev == NULL)
	return -ENODEV;

	iommu_detach_device(domain, &pdev->dev);

	pci_clear_dev_assigned(pdev);
	kvm_arch_end_assignment(kvm);

	dev_info(&pdev->dev, "kvm deassign device\n");

	return 0;
	}

	int kvm_iommu_map_guest(struct kvm *kvm)
	{
	int r;

	if (!iommu_present(&pci_bus_type)) {
	printk(KERN_ERR "%s: iommu not found\n", __func__);
	return -ENODEV;
	}

	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_capable(&pci_bus_type, 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)
	kvm_iommu_unmap_memslots(kvm);

	out_unlock:
	mutex_unlock(&kvm->slots_lock);
	return r;
	}

	static void kvm_iommu_put_pages(struct kvm *kvm,
	gfn_t base_gfn, unsigned long npages)
	{
	struct iommu_domain *domain;
	gfn_t end_gfn, gfn;
	pfn_t pfn;
	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;

	while (gfn < end_gfn) {
	unsigned long unmap_pages;
	size_t size;

	/* Get physical address */
	phys = iommu_iova_to_phys(domain, gfn_to_gpa(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;

	cond_resched();
	}
	}

	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 idx;
	struct kvm_memslots *slots;
	struct kvm_memory_slot *memslot;

	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;
	}

	int kvm_iommu_unmap_guest(struct kvm *kvm)
	{
	struct iommu_domain *domain = kvm->arch.iommu_domain;

	/* check if iommu exists and in use */
	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;
	}