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VFIO updates for v4.17-rc1

Browse source 
- Adopt iommu_unmap_fast() interface to type1 backend
    (Suravee Suthikulpanit)
 
  - mdev sample driver fixup (Shunyong Yang)
 
  - More efficient PFN mapping handling in type1 backend
    (Jason Cai)
 
  - VFIO device ioeventfd interface (Alex Williamson)
 
  - Tag new vfio-platform sub-maintainer (Alex Williamson)
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Merge tag 'vfio-v4.17-rc1' of git://github.com/awilliam/linux-vfio

Pull VFIO updates from Alex Williamson:

 - Adopt iommu_unmap_fast() interface to type1 backend
   (Suravee Suthikulpanit)

 - mdev sample driver fixup (Shunyong Yang)

 - More efficient PFN mapping handling in type1 backend
   (Jason Cai)

 - VFIO device ioeventfd interface (Alex Williamson)

 - Tag new vfio-platform sub-maintainer (Alex Williamson)

* tag 'vfio-v4.17-rc1' of git://github.com/awilliam/linux-vfio:
  MAINTAINERS: vfio/platform: Update sub-maintainer
  vfio/pci: Add ioeventfd support
  vfio/pci: Use endian neutral helpers
  vfio/pci: Pull BAR mapping setup from read-write path
  vfio/type1: Improve memory pinning process for raw PFN mapping
  vfio-mdev/samples: change RDI interrupt condition
  vfio/type1: Adopt fast IOTLB flush interface when unmap IOVAs
This commit is contained in:
Linus Torvalds 2018-04-06 19:44:27 -07:00
commit f605ba97fb
7 changed files with 377 additions and 43 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

2
MAINTAINERS
View file

@ -14797,7 +14797,7 @@ F: include/linux/mdev.h
F: samples/vfio-mdev/
VFIO PLATFORM DRIVER
M: Baptiste Reynal <b.reynal@virtualopensystems.com>
M: Eric Auger <eric.auger@redhat.com>
L: kvm@vger.kernel.org
S: Maintained
F: drivers/vfio/platform/

35
drivers/vfio/pci/vfio_pci.c
View file

@ -302,6 +302,7 @@ static void vfio_pci_disable(struct vfio_pci_device *vdev)
{
struct pci_dev *pdev = vdev->pdev;
struct vfio_pci_dummy_resource *dummy_res, *tmp;
struct vfio_pci_ioeventfd *ioeventfd, *ioeventfd_tmp;
int i, bar;
/* Stop the device from further DMA */
@ -311,6 +312,15 @@ static void vfio_pci_disable(struct vfio_pci_device *vdev)
VFIO_IRQ_SET_ACTION_TRIGGER,
vdev->irq_type, 0, 0, NULL);
/* Device closed, don't need mutex here */
list_for_each_entry_safe(ioeventfd, ioeventfd_tmp,
&vdev->ioeventfds_list, next) {
vfio_virqfd_disable(&ioeventfd->virqfd);
list_del(&ioeventfd->next);
kfree(ioeventfd);
}
vdev->ioeventfds_nr = 0;
vdev->virq_disabled = false;
for (i = 0; i < vdev->num_regions; i++)
@ -1009,6 +1019,28 @@ static long vfio_pci_ioctl(void *device_data,
kfree(groups);
return ret;
} else if (cmd == VFIO_DEVICE_IOEVENTFD) {
struct vfio_device_ioeventfd ioeventfd;
int count;
minsz = offsetofend(struct vfio_device_ioeventfd, fd);
if (copy_from_user(&ioeventfd, (void __user *)arg, minsz))
return -EFAULT;
if (ioeventfd.argsz < minsz)
return -EINVAL;
if (ioeventfd.flags & ~VFIO_DEVICE_IOEVENTFD_SIZE_MASK)
return -EINVAL;
count = ioeventfd.flags & VFIO_DEVICE_IOEVENTFD_SIZE_MASK;
if (hweight8(count) != 1 || ioeventfd.fd < -1)
return -EINVAL;
return vfio_pci_ioeventfd(vdev, ioeventfd.offset,
ioeventfd.data, count, ioeventfd.fd);
}
return -ENOTTY;
@ -1171,6 +1203,8 @@ static int vfio_pci_probe(struct pci_dev *pdev, const struct pci_device_id *id)
vdev->irq_type = VFIO_PCI_NUM_IRQS;
mutex_init(&vdev->igate);
spin_lock_init(&vdev->irqlock);
mutex_init(&vdev->ioeventfds_lock);
INIT_LIST_HEAD(&vdev->ioeventfds_list);
ret = vfio_add_group_dev(&pdev->dev, &vfio_pci_ops, vdev);
if (ret) {
@ -1212,6 +1246,7 @@ static void vfio_pci_remove(struct pci_dev *pdev)
vfio_iommu_group_put(pdev->dev.iommu_group, &pdev->dev);
kfree(vdev->region);
mutex_destroy(&vdev->ioeventfds_lock);
kfree(vdev);
if (vfio_pci_is_vga(pdev)) {

19
drivers/vfio/pci/vfio_pci_private.h
View file

@ -29,6 +29,19 @@
#define PCI_CAP_ID_INVALID 0xFF /* default raw access */
#define PCI_CAP_ID_INVALID_VIRT 0xFE /* default virt access */
/* Cap maximum number of ioeventfds per device (arbitrary) */
#define VFIO_PCI_IOEVENTFD_MAX 1000
struct vfio_pci_ioeventfd {
struct list_head next;
struct virqfd *virqfd;
void __iomem *addr;
uint64_t data;
loff_t pos;
int bar;
int count;
};
struct vfio_pci_irq_ctx {
struct eventfd_ctx *trigger;
struct virqfd *unmask;
@ -92,9 +105,12 @@ struct vfio_pci_device {
bool nointx;
struct pci_saved_state *pci_saved_state;
int refcnt;
int ioeventfds_nr;
struct eventfd_ctx *err_trigger;
struct eventfd_ctx *req_trigger;
struct list_head dummy_resources_list;
struct mutex ioeventfds_lock;
struct list_head ioeventfds_list;
};
#define is_intx(vdev) (vdev->irq_type == VFIO_PCI_INTX_IRQ_INDEX)
@ -120,6 +136,9 @@ extern ssize_t vfio_pci_bar_rw(struct vfio_pci_device *vdev, char __user *buf,
extern ssize_t vfio_pci_vga_rw(struct vfio_pci_device *vdev, char __user *buf,
size_t count, loff_t *ppos, bool iswrite);
extern long vfio_pci_ioeventfd(struct vfio_pci_device *vdev, loff_t offset,
uint64_t data, int count, int fd);
extern int vfio_pci_init_perm_bits(void);
extern void vfio_pci_uninit_perm_bits(void);

184
drivers/vfio/pci/vfio_pci_rdwr.c
View file

@ -17,10 +17,29 @@
#include <linux/pci.h>
#include <linux/uaccess.h>
#include <linux/io.h>
#include <linux/vfio.h>
#include <linux/vgaarb.h>
#include "vfio_pci_private.h"
#ifdef __LITTLE_ENDIAN
#define vfio_ioread64 ioread64
#define vfio_iowrite64 iowrite64
#define vfio_ioread32 ioread32
#define vfio_iowrite32 iowrite32
#define vfio_ioread16 ioread16
#define vfio_iowrite16 iowrite16
#else
#define vfio_ioread64 ioread64be
#define vfio_iowrite64 iowrite64be
#define vfio_ioread32 ioread32be
#define vfio_iowrite32 iowrite32be
#define vfio_ioread16 ioread16be
#define vfio_iowrite16 iowrite16be
#endif
#define vfio_ioread8 ioread8
#define vfio_iowrite8 iowrite8
/*
* Read or write from an __iomem region (MMIO or I/O port) with an excluded
* range which is inaccessible. The excluded range drops writes and fills
@ -44,15 +63,15 @@ static ssize_t do_io_rw(void __iomem *io, char __user *buf,
fillable = 0;
if (fillable >= 4 && !(off % 4)) {
__le32 val;
u32 val;
if (iswrite) {
if (copy_from_user(&val, buf, 4))
return -EFAULT;
iowrite32(le32_to_cpu(val), io + off);
vfio_iowrite32(val, io + off);
} else {
val = cpu_to_le32(ioread32(io + off));
val = vfio_ioread32(io + off);
if (copy_to_user(buf, &val, 4))
return -EFAULT;
@ -60,15 +79,15 @@ static ssize_t do_io_rw(void __iomem *io, char __user *buf,
filled = 4;
} else if (fillable >= 2 && !(off % 2)) {
__le16 val;
u16 val;
if (iswrite) {
if (copy_from_user(&val, buf, 2))
return -EFAULT;
iowrite16(le16_to_cpu(val), io + off);
vfio_iowrite16(val, io + off);
} else {
val = cpu_to_le16(ioread16(io + off));
val = vfio_ioread16(io + off);
if (copy_to_user(buf, &val, 2))
return -EFAULT;
@ -82,9 +101,9 @@ static ssize_t do_io_rw(void __iomem *io, char __user *buf,
if (copy_from_user(&val, buf, 1))
return -EFAULT;
iowrite8(val, io + off);
vfio_iowrite8(val, io + off);
} else {
val = ioread8(io + off);
val = vfio_ioread8(io + off);
if (copy_to_user(buf, &val, 1))
return -EFAULT;
@ -113,6 +132,30 @@ static ssize_t do_io_rw(void __iomem *io, char __user *buf,
return done;
}
static int vfio_pci_setup_barmap(struct vfio_pci_device *vdev, int bar)
{
struct pci_dev *pdev = vdev->pdev;
int ret;
void __iomem *io;
if (vdev->barmap[bar])
return 0;
ret = pci_request_selected_regions(pdev, 1 << bar, "vfio");
if (ret)
return ret;
io = pci_iomap(pdev, bar, 0);
if (!io) {
pci_release_selected_regions(pdev, 1 << bar);
return -ENOMEM;
}
vdev->barmap[bar] = io;
return 0;
}
ssize_t vfio_pci_bar_rw(struct vfio_pci_device *vdev, char __user *buf,
size_t count, loff_t *ppos, bool iswrite)
{
@ -147,22 +190,13 @@ ssize_t vfio_pci_bar_rw(struct vfio_pci_device *vdev, char __user *buf,
if (!io)
return -ENOMEM;
x_end = end;
} else if (!vdev->barmap[bar]) {
int ret;
ret = pci_request_selected_regions(pdev, 1 << bar, "vfio");
} else {
int ret = vfio_pci_setup_barmap(vdev, bar);
if (ret)
return ret;
io = pci_iomap(pdev, bar, 0);
if (!io) {
pci_release_selected_regions(pdev, 1 << bar);
return -ENOMEM;
}
vdev->barmap[bar] = io;
} else
io = vdev->barmap[bar];
}
if (bar == vdev->msix_bar) {
x_start = vdev->msix_offset;
@ -242,3 +276,113 @@ ssize_t vfio_pci_vga_rw(struct vfio_pci_device *vdev, char __user *buf,
return done;
}
static int vfio_pci_ioeventfd_handler(void *opaque, void *unused)
{
struct vfio_pci_ioeventfd *ioeventfd = opaque;
switch (ioeventfd->count) {
case 1:
vfio_iowrite8(ioeventfd->data, ioeventfd->addr);
break;
case 2:
vfio_iowrite16(ioeventfd->data, ioeventfd->addr);
break;
case 4:
vfio_iowrite32(ioeventfd->data, ioeventfd->addr);
break;
#ifdef iowrite64
case 8:
vfio_iowrite64(ioeventfd->data, ioeventfd->addr);
break;
#endif
}
return 0;
}
long vfio_pci_ioeventfd(struct vfio_pci_device *vdev, loff_t offset,
uint64_t data, int count, int fd)
{
struct pci_dev *pdev = vdev->pdev;
loff_t pos = offset & VFIO_PCI_OFFSET_MASK;
int ret, bar = VFIO_PCI_OFFSET_TO_INDEX(offset);
struct vfio_pci_ioeventfd *ioeventfd;
/* Only support ioeventfds into BARs */
if (bar > VFIO_PCI_BAR5_REGION_INDEX)
return -EINVAL;
if (pos + count > pci_resource_len(pdev, bar))
return -EINVAL;
/* Disallow ioeventfds working around MSI-X table writes */
if (bar == vdev->msix_bar &&
!(pos + count <= vdev->msix_offset ||
pos >= vdev->msix_offset + vdev->msix_size))
return -EINVAL;
#ifndef iowrite64
if (count == 8)
return -EINVAL;
#endif
ret = vfio_pci_setup_barmap(vdev, bar);
if (ret)
return ret;
mutex_lock(&vdev->ioeventfds_lock);
list_for_each_entry(ioeventfd, &vdev->ioeventfds_list, next) {
if (ioeventfd->pos == pos && ioeventfd->bar == bar &&
ioeventfd->data == data && ioeventfd->count == count) {
if (fd == -1) {
vfio_virqfd_disable(&ioeventfd->virqfd);
list_del(&ioeventfd->next);
vdev->ioeventfds_nr--;
kfree(ioeventfd);
ret = 0;
} else
ret = -EEXIST;
goto out_unlock;
}
}
if (fd < 0) {
ret = -ENODEV;
goto out_unlock;
}
if (vdev->ioeventfds_nr >= VFIO_PCI_IOEVENTFD_MAX) {
ret = -ENOSPC;
goto out_unlock;
}
ioeventfd = kzalloc(sizeof(*ioeventfd), GFP_KERNEL);
if (!ioeventfd) {
ret = -ENOMEM;
goto out_unlock;
}
ioeventfd->addr = vdev->barmap[bar] + pos;
ioeventfd->data = data;
ioeventfd->pos = pos;
ioeventfd->bar = bar;
ioeventfd->count = count;
ret = vfio_virqfd_enable(ioeventfd, vfio_pci_ioeventfd_handler,
NULL, NULL, &ioeventfd->virqfd, fd);
if (ret) {
kfree(ioeventfd);
goto out_unlock;
}
list_add(&ioeventfd->next, &vdev->ioeventfds_list);
vdev->ioeventfds_nr++;
out_unlock:
mutex_unlock(&vdev->ioeventfds_lock);
return ret;
}

151
drivers/vfio/vfio_iommu_type1.c
View file

@ -102,6 +102,13 @@ struct vfio_pfn {
atomic_t ref_count;
};
struct vfio_regions {
struct list_head list;
dma_addr_t iova;
phys_addr_t phys;
size_t len;
};
#define IS_IOMMU_CAP_DOMAIN_IN_CONTAINER(iommu) \
(!list_empty(&iommu->domain_list))
@ -397,7 +404,6 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
{
unsigned long pfn = 0;
long ret, pinned = 0, lock_acct = 0;
bool rsvd;
dma_addr_t iova = vaddr - dma->vaddr + dma->iova;
/* This code path is only user initiated */
@ -408,14 +414,23 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
if (ret)
return ret;
if (is_invalid_reserved_pfn(*pfn_base)) {
struct vm_area_struct *vma;
down_read(&current->mm->mmap_sem);
vma = find_vma_intersection(current->mm, vaddr, vaddr + 1);
pinned = min_t(long, npage, vma_pages(vma));
up_read(&current->mm->mmap_sem);
return pinned;
}
pinned++;
rsvd = is_invalid_reserved_pfn(*pfn_base);
/*
* Reserved pages aren't counted against the user, externally pinned
* pages are already counted against the user.
*/
if (!rsvd && !vfio_find_vpfn(dma, iova)) {
if (!vfio_find_vpfn(dma, iova)) {
if (!lock_cap && current->mm->locked_vm + 1 > limit) {
put_pfn(*pfn_base, dma->prot);
pr_warn("%s: RLIMIT_MEMLOCK (%ld) exceeded\n", __func__,
@ -435,13 +450,12 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
if (ret)
break;
if (pfn != *pfn_base + pinned ||
rsvd != is_invalid_reserved_pfn(pfn)) {
if (pfn != *pfn_base + pinned) {
put_pfn(pfn, dma->prot);
break;
}
if (!rsvd && !vfio_find_vpfn(dma, iova)) {
if (!vfio_find_vpfn(dma, iova)) {
if (!lock_cap &&
current->mm->locked_vm + lock_acct + 1 > limit) {
put_pfn(pfn, dma->prot);
@ -459,10 +473,8 @@ static long vfio_pin_pages_remote(struct vfio_dma *dma, unsigned long vaddr,
unpin_out:
if (ret) {
if (!rsvd) {
for (pfn = *pfn_base ; pinned ; pfn++, pinned--)
put_pfn(pfn, dma->prot);
}
for (pfn = *pfn_base ; pinned ; pfn++, pinned--)
put_pfn(pfn, dma->prot);
return ret;
}
@ -660,11 +672,102 @@ static int vfio_iommu_type1_unpin_pages(void *iommu_data,
return i > npage ? npage : (i > 0 ? i : -EINVAL);
}
static long vfio_sync_unpin(struct vfio_dma *dma, struct vfio_domain *domain,
struct list_head *regions)
{
long unlocked = 0;
struct vfio_regions *entry, *next;
iommu_tlb_sync(domain->domain);
list_for_each_entry_safe(entry, next, regions, list) {
unlocked += vfio_unpin_pages_remote(dma,
entry->iova,
entry->phys >> PAGE_SHIFT,
entry->len >> PAGE_SHIFT,
false);
list_del(&entry->list);
kfree(entry);
}
cond_resched();
return unlocked;
}
/*
* Generally, VFIO needs to unpin remote pages after each IOTLB flush.
* Therefore, when using IOTLB flush sync interface, VFIO need to keep track
* of these regions (currently using a list).
*
* This value specifies maximum number of regions for each IOTLB flush sync.
*/
#define VFIO_IOMMU_TLB_SYNC_MAX 512
static size_t unmap_unpin_fast(struct vfio_domain *domain,
struct vfio_dma *dma, dma_addr_t *iova,
size_t len, phys_addr_t phys, long *unlocked,
struct list_head *unmapped_list,
int *unmapped_cnt)
{
size_t unmapped = 0;
struct vfio_regions *entry = kzalloc(sizeof(*entry), GFP_KERNEL);
if (entry) {
unmapped = iommu_unmap_fast(domain->domain, *iova, len);
if (!unmapped) {
kfree(entry);
} else {
iommu_tlb_range_add(domain->domain, *iova, unmapped);
entry->iova = *iova;
entry->phys = phys;
entry->len = unmapped;
list_add_tail(&entry->list, unmapped_list);
*iova += unmapped;
(*unmapped_cnt)++;
}
}
/*
* Sync if the number of fast-unmap regions hits the limit
* or in case of errors.
*/
if (*unmapped_cnt >= VFIO_IOMMU_TLB_SYNC_MAX || !unmapped) {
*unlocked += vfio_sync_unpin(dma, domain,
unmapped_list);
*unmapped_cnt = 0;
}
return unmapped;
}
static size_t unmap_unpin_slow(struct vfio_domain *domain,
struct vfio_dma *dma, dma_addr_t *iova,
size_t len, phys_addr_t phys,
long *unlocked)
{
size_t unmapped = iommu_unmap(domain->domain, *iova, len);
if (unmapped) {
*unlocked += vfio_unpin_pages_remote(dma, *iova,
phys >> PAGE_SHIFT,
unmapped >> PAGE_SHIFT,
false);
*iova += unmapped;
cond_resched();
}
return unmapped;
}
static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma,
bool do_accounting)
{
dma_addr_t iova = dma->iova, end = dma->iova + dma->size;
struct vfio_domain *domain, *d;
LIST_HEAD(unmapped_region_list);
int unmapped_region_cnt = 0;
long unlocked = 0;
if (!dma->size)
@ -710,20 +813,26 @@ static long vfio_unmap_unpin(struct vfio_iommu *iommu, struct vfio_dma *dma,
break;
}
unmapped = iommu_unmap(domain->domain, iova, len);
if (WARN_ON(!unmapped))
break;
unlocked += vfio_unpin_pages_remote(dma, iova,
phys >> PAGE_SHIFT,
unmapped >> PAGE_SHIFT,
false);
iova += unmapped;
cond_resched();
/*
* First, try to use fast unmap/unpin. In case of failure,
* switch to slow unmap/unpin path.
*/
unmapped = unmap_unpin_fast(domain, dma, &iova, len, phys,
&unlocked, &unmapped_region_list,
&unmapped_region_cnt);
if (!unmapped) {
unmapped = unmap_unpin_slow(domain, dma, &iova, len,
phys, &unlocked);
if (WARN_ON(!unmapped))
break;
}
}
dma->iommu_mapped = false;
if (unmapped_region_cnt)
unlocked += vfio_sync_unpin(dma, domain, &unmapped_region_list);
if (do_accounting) {
vfio_lock_acct(dma->task, -unlocked, NULL);
return 0;

27
include/uapi/linux/vfio.h
View file

@ -575,6 +575,33 @@ struct vfio_device_gfx_plane_info {
#define VFIO_DEVICE_GET_GFX_DMABUF _IO(VFIO_TYPE, VFIO_BASE + 15)
/**
* VFIO_DEVICE_IOEVENTFD - _IOW(VFIO_TYPE, VFIO_BASE + 16,
* struct vfio_device_ioeventfd)
*
* Perform a write to the device at the specified device fd offset, with
* the specified data and width when the provided eventfd is triggered.
* vfio bus drivers may not support this for all regions, for all widths,
* or at all. vfio-pci currently only enables support for BAR regions,
* excluding the MSI-X vector table.
*
* Return: 0 on success, -errno on failure.
*/
struct vfio_device_ioeventfd {
__u32 argsz;
__u32 flags;
#define VFIO_DEVICE_IOEVENTFD_8 (1 << 0) /* 1-byte write */
#define VFIO_DEVICE_IOEVENTFD_16 (1 << 1) /* 2-byte write */
#define VFIO_DEVICE_IOEVENTFD_32 (1 << 2) /* 4-byte write */
#define VFIO_DEVICE_IOEVENTFD_64 (1 << 3) /* 8-byte write */
#define VFIO_DEVICE_IOEVENTFD_SIZE_MASK (0xf)
__u64 offset; /* device fd offset of write */
__u64 data; /* data to be written */
__s32 fd; /* -1 for de-assignment */
};
#define VFIO_DEVICE_IOEVENTFD _IO(VFIO_TYPE, VFIO_BASE + 16)
/* -------- API for Type1 VFIO IOMMU -------- */
/**

2
samples/vfio-mdev/mtty.c
View file

@ -534,7 +534,7 @@ static void handle_bar_read(unsigned int index, struct mdev_state *mdev_state,
/* Interrupt priority 2: Fifo trigger level reached */
if ((ier & UART_IER_RDI) &&
(mdev_state->s[index].rxtx.count ==
(mdev_state->s[index].rxtx.count >=
mdev_state->s[index].intr_trigger_level))
*buf |= UART_IIR_RDI;