/*
* Kernel-based Virtual Machine - device assignment support
*
* Copyright (C) 2010 Red Hat, Inc. and/or its affiliates.
*
* This work is licensed under the terms of the GNU GPL, version 2. See
* the COPYING file in the top-level directory.
*
*/
#include <linux/kvm_host.h>
#include <linux/kvm.h>
#include <linux/uaccess.h>
#include <linux/vmalloc.h>
#include <linux/errno.h>
#include <linux/spinlock.h>
#include <linux/pci.h>
#include <linux/interrupt.h>
#include <linux/slab.h>
#include "irq.h"
static struct kvm_assigned_dev_kernel *kvm_find_assigned_dev(struct list_head *head,
int assigned_dev_id)
{
struct list_head *ptr;
struct kvm_assigned_dev_kernel *match;
list_for_each(ptr, head) {
match = list_entry(ptr, struct kvm_assigned_dev_kernel, list);
if (match->assigned_dev_id == assigned_dev_id)
return match;
}
return NULL;
}
static int find_index_from_host_irq(struct kvm_assigned_dev_kernel
*assigned_dev, int irq)
{
int i, index;
struct msix_entry *host_msix_entries;
host_msix_entries = assigned_dev->host_msix_entries;
index = -1;
for (i = 0; i < assigned_dev->entries_nr; i++)
if (irq == host_msix_entries[i].vector) {
index = i;
break;
}
if (index < 0) {
printk(KERN_WARNING "Fail to find correlated MSI-X entry!\n");
return 0;
}
return index;
}
static irqreturn_t kvm_assigned_dev_thread(int irq, void *dev_id)
{
struct kvm_assigned_dev_kernel *assigned_dev = dev_id;
u32 vector;
int index;
if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_INTX) {
spin_lock(&assigned_dev->intx_lock);
disable_irq_nosync(irq);
assigned_dev->host_irq_disabled = true;
spin_unlock(&assigned_dev->intx_lock);
}
if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX) {
index = find_index_from_host_irq(assigned_dev, irq);
if (index >= 0) {
vector = assigned_dev->
guest_msix_entries[index].vector;
kvm_set_irq(assigned_dev->kvm,
assigned_dev->irq_source_id, vector, 1);
}
} else
kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id,
assigned_dev->guest_irq, 1);
return IRQ_HANDLED;
}
/* Ack the irq line for an assigned device */
static void kvm_assigned_dev_ack_irq(struct kvm_irq_ack_notifier *kian)
{
struct kvm_assigned_dev_kernel *dev;
if (kian->gsi == -1)
return;
dev = container_of(kian, struct kvm_assigned_dev_kernel,
ack_notifier);
kvm_set_irq(dev->kvm, dev->irq_source_id, dev->guest_irq, 0);
/* The guest irq may be shared so this ack may be
* from another device.
*/
spin_lock(&dev->intx_lock);
if (dev->host_irq_disabled) {
enable_irq(dev->host_irq);
dev->host_irq_disabled = false;
}
spin_unlock(&dev->intx_lock);
}
static void deassign_guest_irq(struct kvm *kvm,
struct kvm_assigned_dev_kernel *assigned_dev)
{
kvm_unregister_irq_ack_notifier(kvm, &assigned_dev->ack_notifier);
assigned_dev->ack_notifier.gsi = -1;
kvm_set_irq(assigned_dev->kvm, assigned_dev->irq_source_id,
assigned_dev->guest_irq, 0);
if (assigned_dev->irq_source_id != -1)
kvm_free_irq_source_id(kvm, assigned_dev->irq_source_id);
assigned_dev->irq_source_id = -1;
assigned_dev->irq_requested_type &= ~(KVM_DEV_IRQ_GUEST_MASK);
}
/* The function implicit hold kvm->lock mutex due to cancel_work_sync() */
static void deassign_host_irq(struct kvm *kvm,
struct kvm_assigned_dev_kernel *assigned_dev)
{
/*
* We disable irq here to prevent further events.
*
* Notice this maybe result in nested disable if the interrupt type is
* INTx, but it's OK for we are going to free it.
*
* If this function is a part of VM destroy, please ensure that till
* now, the kvm state is still legal for probably we also have to wait
* on a currently running IRQ handler.
*/
if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSIX) {
int i;
for (i = 0; i < assigned_dev->entries_nr; i++)
disable_irq(assigned_dev->host_msix_entries[i].vector);
for (i = 0; i < assigned_dev->entries_nr; i++)
free_irq(assigned_dev->host_msix_entries[i].vector,
(void *)assigned_dev);
assigned_dev->entries_nr = 0;
kfree(assigned_dev->host_msix_entries);
kfree(assigned_dev->guest_msix_entries);
pci_disable_msix(assigned_dev->dev);
} else {
/* Deal with MSI and INTx */
disable_irq(assigned_dev->host_irq);
free_irq(assigned_dev->host_irq, (void *)assigned_dev);
if (assigned_dev->irq_requested_type & KVM_DEV_IRQ_HOST_MSI)
pci_disable_msi(assigned_dev->dev);
}
assigned_dev->irq_requested_type &= ~(KVM_DEV_IRQ_HOST_MASK);
}
static int kvm_deassign_irq(struct kvm *kvm,
struct kvm_assigned_dev_kernel *assigned_dev,
unsigned long irq_requested_type)
{
unsigned long guest_irq_type, host_irq_type;
if (!irqchip_in_kernel(kvm))
return -EINVAL;
/* no irq assignment to deassign */
if (!assigned_dev->irq_requested_type)
return -ENXIO;
host_irq_type = irq_requested_type & KVM_DEV_IRQ_HOST_MASK;
guest_irq_type = irq_requested_type & KVM_DEV_IRQ_GUEST_MASK;
if (host_irq_type)
deassign_host_irq(kvm, assigned_dev);
if (guest_irq_type)
deassign_guest_irq(kvm, assigned_dev);
return 0;
}
static void kvm_free_assigned_irq(struct kvm *kvm,
struct kvm_assigned_dev_kernel *assigned_dev)
{
kvm_deassign_irq(kvm, assigned_dev, assigned_dev->irq_requested_type);
}
static void kvm_free_assigned_device(struct kvm *kvm,
struct kvm_assigned_dev_kernel
*assigned_dev)
{
kvm_free_assigned_irq(kvm, assigned_dev);
pci_reset_function(assigned_dev->dev);
pci_release_regions(assigned_dev->dev);
pci_disable_device(assigned_dev->dev);
pci_dev_put(assigned_dev->dev);
list_del(&assigned_dev->list);
kfree(assigned_dev);
}
void kvm_free_all_assigned_devices(struct kvm *kvm)
{
struct list_head *ptr, *ptr2;
struct kvm_assigned_dev_kernel *assigned_dev;
list_for_each_safe(ptr, ptr2, &kvm->arch.assigned_dev_head) {
assigned_dev = list_entry(ptr,
struct kvm_assigned_dev_kernel,
list);
kvm_free_assigned_device(kvm, assigned_dev);
}
}
static int assigned_device_enable_host_intx(struct kvm *kvm,
struct kvm_assigned_dev_kernel *dev)
{
dev->host_irq = dev->dev->irq;
/* Even though this is PCI, we don't want to use shared
* interrupts. Sharing host devices with guest-assigned devices
* on the same interrupt line is not a happy situation: there
* are going to be long delays in accepting, acking, etc.
*/
if (request_threaded_irq(dev->host_irq, NULL, kvm_assigned_dev_thread,
IRQF_ONESHOT, dev->irq_name, (void *)dev))
return -EIO;
return 0;
}
#ifdef __KVM_HAVE_MSI
static int assigned_device_enable_host_msi(struct kvm *kvm,
struct kvm_assigned_dev_kernel *dev)
{
int r;
if (!dev->dev->msi_enabled) {
r = pci_enable_msi(dev->dev);
if (r)
return r;
}
dev->host_irq = dev->dev->irq;
if (request_threaded_irq(dev->host_irq, NULL, kvm_assigned_dev_thread,
0, dev->irq_name, (void *)dev)) {
pci_disable_msi(dev->dev);
return -EIO;
}
return 0;
}
#endif
#ifdef __KVM_HAVE_MSIX
static int assigned_device_enable_host_msix(struct kvm *kvm,
struct kvm_assigned_dev_kernel *dev)
{
int i, r = -EINVAL;
/* host_msix_entries and guest_msix_entries should have been
* initialized */
if (dev->entries_nr == 0)
return r;
r = pci_enable_msix(dev->dev, dev->host_msix_entries, dev->entries_nr);
if (r)
return r;
for (i = 0; i < dev->entries_nr; i++) {
r = request_threaded_irq(dev->host_msix_entries[i].vector,
NULL, kvm_assigned_dev_thread,
0, dev->irq_name, (void *)dev);
if (r)
goto err;
}
return 0;
err:
for (i -= 1; i >= 0; i--)
free_irq(dev->host_msix_entries[i].vector, (void *)dev);
pci_disable_msix(dev->dev);
return r;
}
#endif
static int assigned_device_enable_guest_intx(struct kvm *kvm,
struct kvm_assigned_dev_kernel *dev,
struct kvm_assigned_irq *irq)
{
dev->guest_irq = irq->guest_irq;
dev->ack_notifier.gsi = irq->guest_irq;
return 0;
}
#ifdef __KVM_HAVE_MSI
static int assigned_device_enable_guest_msi(struct kvm *kvm,
struct kvm_assigned_dev_kernel *dev,
struct kvm_assigned_irq *irq)
{
dev->guest_irq = irq->guest_irq;
dev->ack_notifier.gsi = -1;
dev->host_irq_disabled = false;
return 0;
}
#endif
#ifdef __KVM_HAVE_MSIX
static int assigned_device_enable_guest_msix(struct kvm *kvm,
struct kvm_assigned_dev_kernel *dev,
struct kvm_assigned_irq *irq)
{
dev->guest_irq = irq->guest_irq;
dev->ack_notifier.gsi = -1;
dev->host_irq_disabled = false;
return 0;
}
#endif
static int assign_host_irq(struct kvm *kvm,
struct kvm_assigned_dev_kernel *dev,
__u32 host_irq_type)
{
int r = -EEXIST;
if (dev->irq_requested_type & KVM_DEV_IRQ_HOST_MASK)
return r;
snprintf(dev->irq_name, sizeof(dev->irq_name), "kvm:%s",
pci_name(dev->dev));
switch (host_irq_type) {
case KVM_DEV_IRQ_HOST_INTX:
r = assigned_device_enable_host_intx(kvm, dev);
break;
#ifdef __KVM_HAVE_MSI
case KVM_DEV_IRQ_HOST_MSI:
r = assigned_device_enable_host_msi(kvm, dev);
break;
#endif
#ifdef __KVM_HAVE_MSIX
case KVM_DEV_IRQ_HOST_MSIX:
r = assigned_device_enable_host_msix(kvm, dev);
break;
#endif
default:
r = -EINVAL;
}
if (!r)
dev->irq_requested_type |= host_irq_type;
return r;
}
static int assign_guest_irq(struct kvm *kvm,
struct kvm_assigned_dev_kernel *dev,
struct kvm_assigned_irq *irq,
unsigned long guest_irq_type)
{
int id;
int r = -EEXIST;
if (dev->irq_requested_type & KVM_DEV_IRQ_GUEST_MASK)
return r;
id = kvm_request_irq_source_id(kvm);
if (id < 0)
return id;
dev->irq_source_id = id;
switch (guest_irq_type) {
case KVM_DEV_IRQ_GUEST_INTX:
r = assigned_device_enable_guest_intx(kvm, dev, irq);
break;
#ifdef __KVM_HAVE_MSI
case KVM_DEV_IRQ_GUEST_MSI:
r = assigned_device_enable_guest_msi(kvm, dev, irq);
break;
#endif
#ifdef __KVM_HAVE_MSIX
case KVM_DEV_IRQ_GUEST_MSIX:
r = assigned_device_enable_guest_msix(kvm, dev, irq);
break;
#endif
default:
r = -EINVAL;
}
if (!r) {
dev->irq_requested_type |= guest_irq_type;
kvm_register_irq_ack_notifier(kvm, &dev->ack_notifier);
} else
kvm_free_irq_source_id(kvm, dev->irq_source_id);
return r;
}
/* TODO Deal with KVM_DEV_IRQ_ASSIGNED_MASK_MSIX */
static int kvm_vm_ioctl_assign_irq(struct kvm *kvm,
struct kvm_assigned_irq *assigned_irq)
{
int r = -EINVAL;
struct kvm_assigned_dev_kernel *match;
unsigned long host_irq_type, guest_irq_type;
if (!irqchip_in_kernel(kvm))
return r;
mutex_lock(&kvm->lock);
r = -ENODEV;
match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
assigned_irq->assigned_dev_id);
if (!match)
goto out;
host_irq_type = (assigned_irq->flags & KVM_DEV_IRQ_HOST_MASK);
guest_irq_type = (assigned_irq->flags & KVM_DEV_IRQ_GUEST_MASK);
r = -EINVAL;
/* can only assign one type at a time */
if (hweight_long(host_irq_type) > 1)
goto out;
if (hweight_long(guest_irq_type) > 1)
goto out;
if (host_irq_type == 0 && guest_irq_type == 0)
goto out;
r = 0;
if (host_irq_type)
r = assign_host_irq(kvm, match, host_irq_type);
if (r)
goto out;
if (guest_irq_type)
r = assign_guest_irq(kvm, match, assigned_irq, guest_irq_type);
out:
mutex_unlock(&kvm->lock);
return r;
}
static int kvm_vm_ioctl_deassign_dev_irq(struct kvm *kvm,
struct kvm_assigned_irq
*assigned_irq)
{
int r = -ENODEV;
struct kvm_assigned_dev_kernel *match;
mutex_lock(&kvm->lock);
match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
assigned_irq->assigned_dev_id);
if (!match)
goto out;
r = kvm_deassign_irq(kvm, match, assigned_irq->flags);
out:
mutex_unlock(&kvm->lock);
return r;
}
static int kvm_vm_ioctl_assign_device(struct kvm *kvm,
struct kvm_assigned_pci_dev *assigned_dev)
{
int r = 0, idx;
struct kvm_assigned_dev_kernel *match;
struct pci_dev *dev;
mutex_lock(&kvm->lock);
idx = srcu_read_lock(&kvm->srcu);
match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
assigned_dev->assigned_dev_id);
if (match) {
/* device already assigned */
r = -EEXIST;
goto out;
}
match = kzalloc(sizeof(struct kvm_assigned_dev_kernel), GFP_KERNEL);
if (match == NULL) {
printk(KERN_INFO "%s: Couldn't allocate memory\n",
__func__);
r = -ENOMEM;
goto out;
}
dev = pci_get_domain_bus_and_slot(assigned_dev->segnr,
assigned_dev->busnr,
assigned_dev->devfn);
if (!dev) {
printk(KERN_INFO "%s: host device not found\n", __func__);
r = -EINVAL;
goto out_free;
}
if (pci_enable_device(dev)) {
printk(KERN_INFO "%s: Could not enable PCI device\n", __func__);
r = -EBUSY;
goto out_put;
}
r = pci_request_regions(dev, "kvm_assigned_device");
if (r) {
printk(KERN_INFO "%s: Could not get access to device regions\n",
__func__);
goto out_disable;
}
pci_reset_function(dev);
match->assigned_dev_id = assigned_dev->assigned_dev_id;
match->host_segnr = assigned_dev->segnr;
match->host_busnr = assigned_dev->busnr;
match->host_devfn = assigned_dev->devfn;
match->flags = assigned_dev->flags;
match->dev = dev;
spin_lock_init(&match->intx_lock);
match->irq_source_id = -1;
match->kvm = kvm;
match->ack_notifier.irq_acked = kvm_assigned_dev_ack_irq;
list_add(&match->list, &kvm->arch.assigned_dev_head);
if (assigned_dev->flags & KVM_DEV_ASSIGN_ENABLE_IOMMU) {
if (!kvm->arch.iommu_domain) {
r = kvm_iommu_map_guest(kvm);
if (r)
goto out_list_del;
}
r = kvm_assign_device(kvm, match);
if (r)
goto out_list_del;
}
out:
srcu_read_unlock(&kvm->srcu, idx);
mutex_unlock(&kvm->lock);
return r;
out_list_del:
list_del(&match->list);
pci_release_regions(dev);
out_disable:
pci_disable_device(dev);
out_put:
pci_dev_put(dev);
out_free:
kfree(match);
srcu_read_unlock(&kvm->srcu, idx);
mutex_unlock(&kvm->lock);
return r;
}
static int kvm_vm_ioctl_deassign_device(struct kvm *kvm,
struct kvm_assigned_pci_dev *assigned_dev)
{
int r = 0;
struct kvm_assigned_dev_kernel *match;
mutex_lock(&kvm->lock);
match = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
assigned_dev->assigned_dev_id);
if (!match) {
printk(KERN_INFO "%s: device hasn't been assigned before, "
"so cannot be deassigned\n", __func__);
r = -EINVAL;
goto out;
}
if (match->flags & KVM_DEV_ASSIGN_ENABLE_IOMMU)
kvm_deassign_device(kvm, match);
kvm_free_assigned_device(kvm, match);
out:
mutex_unlock(&kvm->lock);
return r;
}
#ifdef __KVM_HAVE_MSIX
static int kvm_vm_ioctl_set_msix_nr(struct kvm *kvm,
struct kvm_assigned_msix_nr *entry_nr)
{
int r = 0;
struct kvm_assigned_dev_kernel *adev;
mutex_lock(&kvm->lock);
adev = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
entry_nr->assigned_dev_id);
if (!adev) {
r = -EINVAL;
goto msix_nr_out;
}
if (adev->entries_nr == 0) {
adev->entries_nr = entry_nr->entry_nr;
if (adev->entries_nr == 0 ||
adev->entries_nr >= KVM_MAX_MSIX_PER_DEV) {
r = -EINVAL;
goto msix_nr_out;
}
adev->host_msix_entries = kzalloc(sizeof(struct msix_entry) *
entry_nr->entry_nr,
GFP_KERNEL);
if (!adev->host_msix_entries) {
r = -ENOMEM;
goto msix_nr_out;
}
adev->guest_msix_entries =
kzalloc(sizeof(struct msix_entry) * entry_nr->entry_nr,
GFP_KERNEL);
if (!adev->guest_msix_entries) {
kfree(adev->host_msix_entries);
r = -ENOMEM;
goto msix_nr_out;
}
} else /* Not allowed set MSI-X number twice */
r = -EINVAL;
msix_nr_out:
mutex_unlock(&kvm->lock);
return r;
}
static int kvm_vm_ioctl_set_msix_entry(struct kvm *kvm,
struct kvm_assigned_msix_entry *entry)
{
int r = 0, i;
struct kvm_assigned_dev_kernel *adev;
mutex_lock(&kvm->lock);
adev = kvm_find_assigned_dev(&kvm->arch.assigned_dev_head,
entry->assigned_dev_id);
if (!adev) {
r = -EINVAL;
goto msix_entry_out;
}
for (i = 0; i < adev->entries_nr; i++)
if (adev->guest_msix_entries[i].vector == 0 ||
adev->guest_msix_entries[i].entry == entry->entry) {
adev->guest_msix_entries[i].entry = entry->entry;
adev->guest_msix_entries[i].vector = entry->gsi;
adev->host_msix_entries[i].entry = entry->entry;
break;
}
if (i == adev->entries_nr) {
r = -ENOSPC;
goto msix_entry_out;
}
msix_entry_out:
mutex_unlock(&kvm->lock);
return r;
}
#endif
long kvm_vm_ioctl_assigned_device(struct kvm *kvm, unsigned ioctl,
unsigned long arg)
{
void __user *argp = (void __user *)arg;
int r = -ENOTTY;
switch (ioctl) {
case KVM_ASSIGN_PCI_DEVICE: {
struct kvm_assigned_pci_dev assigned_dev;
r = -EFAULT;
if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev))
goto out;
r = kvm_vm_ioctl_assign_device(kvm, &assigned_dev);
if (r)
goto out;
break;
}
case KVM_ASSIGN_IRQ: {
r = -EOPNOTSUPP;
break;
}
#ifdef KVM_CAP_ASSIGN_DEV_IRQ
case KVM_ASSIGN_DEV_IRQ: {
struct kvm_assigned_irq assigned_irq;
r = -EFAULT;
if (copy_from_user(&assigned_irq, argp, sizeof assigned_irq))
goto out;
r = kvm_vm_ioctl_assign_irq(kvm, &assigned_irq);
if (r)
goto out;
break;
}
case KVM_DEASSIGN_DEV_IRQ: {
struct kvm_assigned_irq assigned_irq;
r = -EFAULT;
if (copy_from_user(&assigned_irq, argp, sizeof assigned_irq))
goto out;
r = kvm_vm_ioctl_deassign_dev_irq(kvm, &assigned_irq);
if (r)
goto out;
break;
}
#endif
#ifdef KVM_CAP_DEVICE_DEASSIGNMENT
case KVM_DEASSIGN_PCI_DEVICE: {
struct kvm_assigned_pci_dev assigned_dev;
r = -EFAULT;
if (copy_from_user(&assigned_dev, argp, sizeof assigned_dev))
goto out;
r = kvm_vm_ioctl_deassign_device(kvm, &assigned_dev);
if (r)
goto out;
break;
}
#endif
#ifdef KVM_CAP_IRQ_ROUTING
case KVM_SET_GSI_ROUTING: {
struct kvm_irq_routing routing;
struct kvm_irq_routing __user *urouting;
struct kvm_irq_routing_entry *entries;
r = -EFAULT;
if (copy_from_user(&routing, argp, sizeof(routing)))
goto out;
r = -EINVAL;
if (routing.nr >= KVM_MAX_IRQ_ROUTES)
goto out;
if (routing.flags)
goto out;
r = -ENOMEM;
entries = vmalloc(routing.nr * sizeof(*entries));
if (!entries)
goto out;
r = -EFAULT;
urouting = argp;
if (copy_from_user(entries, urouting->entries,
routing.nr * sizeof(*entries)))
goto out_free_irq_routing;
r = kvm_set_irq_routing(kvm, entries, routing.nr,
routing.flags);
out_free_irq_routing:
vfree(entries);
break;
}
#endif /* KVM_CAP_IRQ_ROUTING */
#ifdef __KVM_HAVE_MSIX
case KVM_ASSIGN_SET_MSIX_NR: {
struct kvm_assigned_msix_nr entry_nr;
r = -EFAULT;
if (copy_from_user(&entry_nr, argp, sizeof entry_nr))
goto out;
r = kvm_vm_ioctl_set_msix_nr(kvm, &entry_nr);
if (r)
goto out;
break;
}
case KVM_ASSIGN_SET_MSIX_ENTRY: {
struct kvm_assigned_msix_entry entry;
r = -EFAULT;
if (copy_from_user(&entry, argp, sizeof entry))
goto out;
r = kvm_vm_ioctl_set_msix_entry(kvm, &entry);
if (r)
goto out;
break;
}
#endif
}
out:
return r;
}