linux/drivers/iommu/intel/svm.c
Lu Baolu 3aa7c62cb7 iommu/vt-d: Use INVALID response code instead of FAILURE
The VT-d IOMMU response RESPONSE_FAILURE for a page request in below
cases:

- When it gets a Page_Request with no PASID;
- When it gets a Page_Request with PASID that is not in use for this
  device.

This is allowed by the spec, but IOMMU driver doesn't support such cases
today. When the device receives RESPONSE_FAILURE, it sends the device
state machine to HALT state. Now if we try to unload the driver, it hangs
since the device doesn't send any outbound transactions to host when the
driver is trying to clear things up. The only possible responses would be
for invalidation requests.

Let's use RESPONSE_INVALID instead for now, so that the device state
machine doesn't enter HALT state.

Suggested-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/20210126080730.2232859-3-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
2021-01-29 09:25:24 +01:00

1211 lines
30 KiB
C

// SPDX-License-Identifier: GPL-2.0-only
/*
* Copyright © 2015 Intel Corporation.
*
* Authors: David Woodhouse <dwmw2@infradead.org>
*/
#include <linux/intel-iommu.h>
#include <linux/mmu_notifier.h>
#include <linux/sched.h>
#include <linux/sched/mm.h>
#include <linux/slab.h>
#include <linux/intel-svm.h>
#include <linux/rculist.h>
#include <linux/pci.h>
#include <linux/pci-ats.h>
#include <linux/dmar.h>
#include <linux/interrupt.h>
#include <linux/mm_types.h>
#include <linux/ioasid.h>
#include <asm/page.h>
#include <asm/fpu/api.h>
#include "pasid.h"
static irqreturn_t prq_event_thread(int irq, void *d);
static void intel_svm_drain_prq(struct device *dev, u32 pasid);
#define PRQ_ORDER 0
int intel_svm_enable_prq(struct intel_iommu *iommu)
{
struct page *pages;
int irq, ret;
pages = alloc_pages(GFP_KERNEL | __GFP_ZERO, PRQ_ORDER);
if (!pages) {
pr_warn("IOMMU: %s: Failed to allocate page request queue\n",
iommu->name);
return -ENOMEM;
}
iommu->prq = page_address(pages);
irq = dmar_alloc_hwirq(DMAR_UNITS_SUPPORTED + iommu->seq_id, iommu->node, iommu);
if (irq <= 0) {
pr_err("IOMMU: %s: Failed to create IRQ vector for page request queue\n",
iommu->name);
ret = -EINVAL;
err:
free_pages((unsigned long)iommu->prq, PRQ_ORDER);
iommu->prq = NULL;
return ret;
}
iommu->pr_irq = irq;
snprintf(iommu->prq_name, sizeof(iommu->prq_name), "dmar%d-prq", iommu->seq_id);
ret = request_threaded_irq(irq, NULL, prq_event_thread, IRQF_ONESHOT,
iommu->prq_name, iommu);
if (ret) {
pr_err("IOMMU: %s: Failed to request IRQ for page request queue\n",
iommu->name);
dmar_free_hwirq(irq);
iommu->pr_irq = 0;
goto err;
}
dmar_writeq(iommu->reg + DMAR_PQH_REG, 0ULL);
dmar_writeq(iommu->reg + DMAR_PQT_REG, 0ULL);
dmar_writeq(iommu->reg + DMAR_PQA_REG, virt_to_phys(iommu->prq) | PRQ_ORDER);
init_completion(&iommu->prq_complete);
return 0;
}
int intel_svm_finish_prq(struct intel_iommu *iommu)
{
dmar_writeq(iommu->reg + DMAR_PQH_REG, 0ULL);
dmar_writeq(iommu->reg + DMAR_PQT_REG, 0ULL);
dmar_writeq(iommu->reg + DMAR_PQA_REG, 0ULL);
if (iommu->pr_irq) {
free_irq(iommu->pr_irq, iommu);
dmar_free_hwirq(iommu->pr_irq);
iommu->pr_irq = 0;
}
free_pages((unsigned long)iommu->prq, PRQ_ORDER);
iommu->prq = NULL;
return 0;
}
static inline bool intel_svm_capable(struct intel_iommu *iommu)
{
return iommu->flags & VTD_FLAG_SVM_CAPABLE;
}
void intel_svm_check(struct intel_iommu *iommu)
{
if (!pasid_supported(iommu))
return;
if (cpu_feature_enabled(X86_FEATURE_GBPAGES) &&
!cap_fl1gp_support(iommu->cap)) {
pr_err("%s SVM disabled, incompatible 1GB page capability\n",
iommu->name);
return;
}
if (cpu_feature_enabled(X86_FEATURE_LA57) &&
!cap_5lp_support(iommu->cap)) {
pr_err("%s SVM disabled, incompatible paging mode\n",
iommu->name);
return;
}
iommu->flags |= VTD_FLAG_SVM_CAPABLE;
}
static void __flush_svm_range_dev(struct intel_svm *svm,
struct intel_svm_dev *sdev,
unsigned long address,
unsigned long pages, int ih)
{
struct device_domain_info *info = get_domain_info(sdev->dev);
if (WARN_ON(!pages))
return;
qi_flush_piotlb(sdev->iommu, sdev->did, svm->pasid, address, pages, ih);
if (info->ats_enabled)
qi_flush_dev_iotlb_pasid(sdev->iommu, sdev->sid, info->pfsid,
svm->pasid, sdev->qdep, address,
order_base_2(pages));
}
static void intel_flush_svm_range_dev(struct intel_svm *svm,
struct intel_svm_dev *sdev,
unsigned long address,
unsigned long pages, int ih)
{
unsigned long shift = ilog2(__roundup_pow_of_two(pages));
unsigned long align = (1ULL << (VTD_PAGE_SHIFT + shift));
unsigned long start = ALIGN_DOWN(address, align);
unsigned long end = ALIGN(address + (pages << VTD_PAGE_SHIFT), align);
while (start < end) {
__flush_svm_range_dev(svm, sdev, start, align >> VTD_PAGE_SHIFT, ih);
start += align;
}
}
static void intel_flush_svm_range(struct intel_svm *svm, unsigned long address,
unsigned long pages, int ih)
{
struct intel_svm_dev *sdev;
rcu_read_lock();
list_for_each_entry_rcu(sdev, &svm->devs, list)
intel_flush_svm_range_dev(svm, sdev, address, pages, ih);
rcu_read_unlock();
}
/* Pages have been freed at this point */
static void intel_invalidate_range(struct mmu_notifier *mn,
struct mm_struct *mm,
unsigned long start, unsigned long end)
{
struct intel_svm *svm = container_of(mn, struct intel_svm, notifier);
intel_flush_svm_range(svm, start,
(end - start + PAGE_SIZE - 1) >> VTD_PAGE_SHIFT, 0);
}
static void intel_mm_release(struct mmu_notifier *mn, struct mm_struct *mm)
{
struct intel_svm *svm = container_of(mn, struct intel_svm, notifier);
struct intel_svm_dev *sdev;
/* This might end up being called from exit_mmap(), *before* the page
* tables are cleared. And __mmu_notifier_release() will delete us from
* the list of notifiers so that our invalidate_range() callback doesn't
* get called when the page tables are cleared. So we need to protect
* against hardware accessing those page tables.
*
* We do it by clearing the entry in the PASID table and then flushing
* the IOTLB and the PASID table caches. This might upset hardware;
* perhaps we'll want to point the PASID to a dummy PGD (like the zero
* page) so that we end up taking a fault that the hardware really
* *has* to handle gracefully without affecting other processes.
*/
rcu_read_lock();
list_for_each_entry_rcu(sdev, &svm->devs, list)
intel_pasid_tear_down_entry(sdev->iommu, sdev->dev,
svm->pasid, true);
rcu_read_unlock();
}
static const struct mmu_notifier_ops intel_mmuops = {
.release = intel_mm_release,
.invalidate_range = intel_invalidate_range,
};
static DEFINE_MUTEX(pasid_mutex);
static LIST_HEAD(global_svm_list);
#define for_each_svm_dev(sdev, svm, d) \
list_for_each_entry((sdev), &(svm)->devs, list) \
if ((d) != (sdev)->dev) {} else
static int pasid_to_svm_sdev(struct device *dev, unsigned int pasid,
struct intel_svm **rsvm,
struct intel_svm_dev **rsdev)
{
struct intel_svm_dev *d, *sdev = NULL;
struct intel_svm *svm;
/* The caller should hold the pasid_mutex lock */
if (WARN_ON(!mutex_is_locked(&pasid_mutex)))
return -EINVAL;
if (pasid == INVALID_IOASID || pasid >= PASID_MAX)
return -EINVAL;
svm = ioasid_find(NULL, pasid, NULL);
if (IS_ERR(svm))
return PTR_ERR(svm);
if (!svm)
goto out;
/*
* If we found svm for the PASID, there must be at least one device
* bond.
*/
if (WARN_ON(list_empty(&svm->devs)))
return -EINVAL;
rcu_read_lock();
list_for_each_entry_rcu(d, &svm->devs, list) {
if (d->dev == dev) {
sdev = d;
break;
}
}
rcu_read_unlock();
out:
*rsvm = svm;
*rsdev = sdev;
return 0;
}
int intel_svm_bind_gpasid(struct iommu_domain *domain, struct device *dev,
struct iommu_gpasid_bind_data *data)
{
struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL);
struct intel_svm_dev *sdev = NULL;
struct dmar_domain *dmar_domain;
struct device_domain_info *info;
struct intel_svm *svm = NULL;
unsigned long iflags;
int ret = 0;
if (WARN_ON(!iommu) || !data)
return -EINVAL;
if (data->format != IOMMU_PASID_FORMAT_INTEL_VTD)
return -EINVAL;
/* IOMMU core ensures argsz is more than the start of the union */
if (data->argsz < offsetofend(struct iommu_gpasid_bind_data, vendor.vtd))
return -EINVAL;
/* Make sure no undefined flags are used in vendor data */
if (data->vendor.vtd.flags & ~(IOMMU_SVA_VTD_GPASID_LAST - 1))
return -EINVAL;
if (!dev_is_pci(dev))
return -ENOTSUPP;
/* VT-d supports devices with full 20 bit PASIDs only */
if (pci_max_pasids(to_pci_dev(dev)) != PASID_MAX)
return -EINVAL;
/*
* We only check host PASID range, we have no knowledge to check
* guest PASID range.
*/
if (data->hpasid <= 0 || data->hpasid >= PASID_MAX)
return -EINVAL;
info = get_domain_info(dev);
if (!info)
return -EINVAL;
dmar_domain = to_dmar_domain(domain);
mutex_lock(&pasid_mutex);
ret = pasid_to_svm_sdev(dev, data->hpasid, &svm, &sdev);
if (ret)
goto out;
if (sdev) {
/*
* Do not allow multiple bindings of the same device-PASID since
* there is only one SL page tables per PASID. We may revisit
* once sharing PGD across domains are supported.
*/
dev_warn_ratelimited(dev, "Already bound with PASID %u\n",
svm->pasid);
ret = -EBUSY;
goto out;
}
if (!svm) {
/* We come here when PASID has never been bond to a device. */
svm = kzalloc(sizeof(*svm), GFP_KERNEL);
if (!svm) {
ret = -ENOMEM;
goto out;
}
/* REVISIT: upper layer/VFIO can track host process that bind
* the PASID. ioasid_set = mm might be sufficient for vfio to
* check pasid VMM ownership. We can drop the following line
* once VFIO and IOASID set check is in place.
*/
svm->mm = get_task_mm(current);
svm->pasid = data->hpasid;
if (data->flags & IOMMU_SVA_GPASID_VAL) {
svm->gpasid = data->gpasid;
svm->flags |= SVM_FLAG_GUEST_PASID;
}
ioasid_set_data(data->hpasid, svm);
INIT_LIST_HEAD_RCU(&svm->devs);
mmput(svm->mm);
}
sdev = kzalloc(sizeof(*sdev), GFP_KERNEL);
if (!sdev) {
ret = -ENOMEM;
goto out;
}
sdev->dev = dev;
sdev->sid = PCI_DEVID(info->bus, info->devfn);
sdev->iommu = iommu;
/* Only count users if device has aux domains */
if (iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX))
sdev->users = 1;
/* Set up device context entry for PASID if not enabled already */
ret = intel_iommu_enable_pasid(iommu, sdev->dev);
if (ret) {
dev_err_ratelimited(dev, "Failed to enable PASID capability\n");
kfree(sdev);
goto out;
}
/*
* PASID table is per device for better security. Therefore, for
* each bind of a new device even with an existing PASID, we need to
* call the nested mode setup function here.
*/
spin_lock_irqsave(&iommu->lock, iflags);
ret = intel_pasid_setup_nested(iommu, dev,
(pgd_t *)(uintptr_t)data->gpgd,
data->hpasid, &data->vendor.vtd, dmar_domain,
data->addr_width);
spin_unlock_irqrestore(&iommu->lock, iflags);
if (ret) {
dev_err_ratelimited(dev, "Failed to set up PASID %llu in nested mode, Err %d\n",
data->hpasid, ret);
/*
* PASID entry should be in cleared state if nested mode
* set up failed. So we only need to clear IOASID tracking
* data such that free call will succeed.
*/
kfree(sdev);
goto out;
}
svm->flags |= SVM_FLAG_GUEST_MODE;
init_rcu_head(&sdev->rcu);
list_add_rcu(&sdev->list, &svm->devs);
out:
if (!IS_ERR_OR_NULL(svm) && list_empty(&svm->devs)) {
ioasid_set_data(data->hpasid, NULL);
kfree(svm);
}
mutex_unlock(&pasid_mutex);
return ret;
}
int intel_svm_unbind_gpasid(struct device *dev, u32 pasid)
{
struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL);
struct intel_svm_dev *sdev;
struct intel_svm *svm;
int ret;
if (WARN_ON(!iommu))
return -EINVAL;
mutex_lock(&pasid_mutex);
ret = pasid_to_svm_sdev(dev, pasid, &svm, &sdev);
if (ret)
goto out;
if (sdev) {
if (iommu_dev_feature_enabled(dev, IOMMU_DEV_FEAT_AUX))
sdev->users--;
if (!sdev->users) {
list_del_rcu(&sdev->list);
intel_pasid_tear_down_entry(iommu, dev,
svm->pasid, false);
intel_svm_drain_prq(dev, svm->pasid);
kfree_rcu(sdev, rcu);
if (list_empty(&svm->devs)) {
/*
* We do not free the IOASID here in that
* IOMMU driver did not allocate it.
* Unlike native SVM, IOASID for guest use was
* allocated prior to the bind call.
* In any case, if the free call comes before
* the unbind, IOMMU driver will get notified
* and perform cleanup.
*/
ioasid_set_data(pasid, NULL);
kfree(svm);
}
}
}
out:
mutex_unlock(&pasid_mutex);
return ret;
}
static void _load_pasid(void *unused)
{
update_pasid();
}
static void load_pasid(struct mm_struct *mm, u32 pasid)
{
mutex_lock(&mm->context.lock);
/* Synchronize with READ_ONCE in update_pasid(). */
smp_store_release(&mm->pasid, pasid);
/* Update PASID MSR on all CPUs running the mm's tasks. */
on_each_cpu_mask(mm_cpumask(mm), _load_pasid, NULL, true);
mutex_unlock(&mm->context.lock);
}
/* Caller must hold pasid_mutex, mm reference */
static int
intel_svm_bind_mm(struct device *dev, unsigned int flags,
struct svm_dev_ops *ops,
struct mm_struct *mm, struct intel_svm_dev **sd)
{
struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL);
struct device_domain_info *info;
struct intel_svm_dev *sdev;
struct intel_svm *svm = NULL;
unsigned long iflags;
int pasid_max;
int ret;
if (!iommu || dmar_disabled)
return -EINVAL;
if (!intel_svm_capable(iommu))
return -ENOTSUPP;
if (dev_is_pci(dev)) {
pasid_max = pci_max_pasids(to_pci_dev(dev));
if (pasid_max < 0)
return -EINVAL;
} else
pasid_max = 1 << 20;
/* Bind supervisor PASID shuld have mm = NULL */
if (flags & SVM_FLAG_SUPERVISOR_MODE) {
if (!ecap_srs(iommu->ecap) || mm) {
pr_err("Supervisor PASID with user provided mm.\n");
return -EINVAL;
}
}
if (!(flags & SVM_FLAG_PRIVATE_PASID)) {
struct intel_svm *t;
list_for_each_entry(t, &global_svm_list, list) {
if (t->mm != mm || (t->flags & SVM_FLAG_PRIVATE_PASID))
continue;
svm = t;
if (svm->pasid >= pasid_max) {
dev_warn(dev,
"Limited PASID width. Cannot use existing PASID %d\n",
svm->pasid);
ret = -ENOSPC;
goto out;
}
/* Find the matching device in svm list */
for_each_svm_dev(sdev, svm, dev) {
if (sdev->ops != ops) {
ret = -EBUSY;
goto out;
}
sdev->users++;
goto success;
}
break;
}
}
sdev = kzalloc(sizeof(*sdev), GFP_KERNEL);
if (!sdev) {
ret = -ENOMEM;
goto out;
}
sdev->dev = dev;
sdev->iommu = iommu;
ret = intel_iommu_enable_pasid(iommu, dev);
if (ret) {
kfree(sdev);
goto out;
}
info = get_domain_info(dev);
sdev->did = FLPT_DEFAULT_DID;
sdev->sid = PCI_DEVID(info->bus, info->devfn);
if (info->ats_enabled) {
sdev->dev_iotlb = 1;
sdev->qdep = info->ats_qdep;
if (sdev->qdep >= QI_DEV_EIOTLB_MAX_INVS)
sdev->qdep = 0;
}
/* Finish the setup now we know we're keeping it */
sdev->users = 1;
sdev->ops = ops;
init_rcu_head(&sdev->rcu);
if (!svm) {
svm = kzalloc(sizeof(*svm), GFP_KERNEL);
if (!svm) {
ret = -ENOMEM;
kfree(sdev);
goto out;
}
if (pasid_max > intel_pasid_max_id)
pasid_max = intel_pasid_max_id;
/* Do not use PASID 0, reserved for RID to PASID */
svm->pasid = ioasid_alloc(NULL, PASID_MIN,
pasid_max - 1, svm);
if (svm->pasid == INVALID_IOASID) {
kfree(svm);
kfree(sdev);
ret = -ENOSPC;
goto out;
}
svm->notifier.ops = &intel_mmuops;
svm->mm = mm;
svm->flags = flags;
INIT_LIST_HEAD_RCU(&svm->devs);
INIT_LIST_HEAD(&svm->list);
ret = -ENOMEM;
if (mm) {
ret = mmu_notifier_register(&svm->notifier, mm);
if (ret) {
ioasid_put(svm->pasid);
kfree(svm);
kfree(sdev);
goto out;
}
}
spin_lock_irqsave(&iommu->lock, iflags);
ret = intel_pasid_setup_first_level(iommu, dev,
mm ? mm->pgd : init_mm.pgd,
svm->pasid, FLPT_DEFAULT_DID,
(mm ? 0 : PASID_FLAG_SUPERVISOR_MODE) |
(cpu_feature_enabled(X86_FEATURE_LA57) ?
PASID_FLAG_FL5LP : 0));
spin_unlock_irqrestore(&iommu->lock, iflags);
if (ret) {
if (mm)
mmu_notifier_unregister(&svm->notifier, mm);
ioasid_put(svm->pasid);
kfree(svm);
kfree(sdev);
goto out;
}
list_add_tail(&svm->list, &global_svm_list);
if (mm) {
/* The newly allocated pasid is loaded to the mm. */
load_pasid(mm, svm->pasid);
}
} else {
/*
* Binding a new device with existing PASID, need to setup
* the PASID entry.
*/
spin_lock_irqsave(&iommu->lock, iflags);
ret = intel_pasid_setup_first_level(iommu, dev,
mm ? mm->pgd : init_mm.pgd,
svm->pasid, FLPT_DEFAULT_DID,
(mm ? 0 : PASID_FLAG_SUPERVISOR_MODE) |
(cpu_feature_enabled(X86_FEATURE_LA57) ?
PASID_FLAG_FL5LP : 0));
spin_unlock_irqrestore(&iommu->lock, iflags);
if (ret) {
kfree(sdev);
goto out;
}
}
list_add_rcu(&sdev->list, &svm->devs);
success:
sdev->pasid = svm->pasid;
sdev->sva.dev = dev;
if (sd)
*sd = sdev;
ret = 0;
out:
return ret;
}
/* Caller must hold pasid_mutex */
static int intel_svm_unbind_mm(struct device *dev, u32 pasid)
{
struct intel_svm_dev *sdev;
struct intel_iommu *iommu;
struct intel_svm *svm;
int ret = -EINVAL;
iommu = device_to_iommu(dev, NULL, NULL);
if (!iommu)
goto out;
ret = pasid_to_svm_sdev(dev, pasid, &svm, &sdev);
if (ret)
goto out;
if (sdev) {
sdev->users--;
if (!sdev->users) {
list_del_rcu(&sdev->list);
/* Flush the PASID cache and IOTLB for this device.
* Note that we do depend on the hardware *not* using
* the PASID any more. Just as we depend on other
* devices never using PASIDs that they have no right
* to use. We have a *shared* PASID table, because it's
* large and has to be physically contiguous. So it's
* hard to be as defensive as we might like. */
intel_pasid_tear_down_entry(iommu, dev,
svm->pasid, false);
intel_svm_drain_prq(dev, svm->pasid);
kfree_rcu(sdev, rcu);
if (list_empty(&svm->devs)) {
ioasid_put(svm->pasid);
if (svm->mm) {
mmu_notifier_unregister(&svm->notifier, svm->mm);
/* Clear mm's pasid. */
load_pasid(svm->mm, PASID_DISABLED);
}
list_del(&svm->list);
/* We mandate that no page faults may be outstanding
* for the PASID when intel_svm_unbind_mm() is called.
* If that is not obeyed, subtle errors will happen.
* Let's make them less subtle... */
memset(svm, 0x6b, sizeof(*svm));
kfree(svm);
}
}
}
out:
return ret;
}
/* Page request queue descriptor */
struct page_req_dsc {
union {
struct {
u64 type:8;
u64 pasid_present:1;
u64 priv_data_present:1;
u64 rsvd:6;
u64 rid:16;
u64 pasid:20;
u64 exe_req:1;
u64 pm_req:1;
u64 rsvd2:10;
};
u64 qw_0;
};
union {
struct {
u64 rd_req:1;
u64 wr_req:1;
u64 lpig:1;
u64 prg_index:9;
u64 addr:52;
};
u64 qw_1;
};
u64 priv_data[2];
};
#define PRQ_RING_MASK ((0x1000 << PRQ_ORDER) - 0x20)
static bool access_error(struct vm_area_struct *vma, struct page_req_dsc *req)
{
unsigned long requested = 0;
if (req->exe_req)
requested |= VM_EXEC;
if (req->rd_req)
requested |= VM_READ;
if (req->wr_req)
requested |= VM_WRITE;
return (requested & ~vma->vm_flags) != 0;
}
static bool is_canonical_address(u64 addr)
{
int shift = 64 - (__VIRTUAL_MASK_SHIFT + 1);
long saddr = (long) addr;
return (((saddr << shift) >> shift) == saddr);
}
/**
* intel_svm_drain_prq - Drain page requests and responses for a pasid
* @dev: target device
* @pasid: pasid for draining
*
* Drain all pending page requests and responses related to @pasid in both
* software and hardware. This is supposed to be called after the device
* driver has stopped DMA, the pasid entry has been cleared, and both IOTLB
* and DevTLB have been invalidated.
*
* It waits until all pending page requests for @pasid in the page fault
* queue are completed by the prq handling thread. Then follow the steps
* described in VT-d spec CH7.10 to drain all page requests and page
* responses pending in the hardware.
*/
static void intel_svm_drain_prq(struct device *dev, u32 pasid)
{
struct device_domain_info *info;
struct dmar_domain *domain;
struct intel_iommu *iommu;
struct qi_desc desc[3];
struct pci_dev *pdev;
int head, tail;
u16 sid, did;
int qdep;
info = get_domain_info(dev);
if (WARN_ON(!info || !dev_is_pci(dev)))
return;
if (!info->pri_enabled)
return;
iommu = info->iommu;
domain = info->domain;
pdev = to_pci_dev(dev);
sid = PCI_DEVID(info->bus, info->devfn);
did = domain->iommu_did[iommu->seq_id];
qdep = pci_ats_queue_depth(pdev);
/*
* Check and wait until all pending page requests in the queue are
* handled by the prq handling thread.
*/
prq_retry:
reinit_completion(&iommu->prq_complete);
tail = dmar_readq(iommu->reg + DMAR_PQT_REG) & PRQ_RING_MASK;
head = dmar_readq(iommu->reg + DMAR_PQH_REG) & PRQ_RING_MASK;
while (head != tail) {
struct page_req_dsc *req;
req = &iommu->prq[head / sizeof(*req)];
if (!req->pasid_present || req->pasid != pasid) {
head = (head + sizeof(*req)) & PRQ_RING_MASK;
continue;
}
wait_for_completion(&iommu->prq_complete);
goto prq_retry;
}
/*
* Perform steps described in VT-d spec CH7.10 to drain page
* requests and responses in hardware.
*/
memset(desc, 0, sizeof(desc));
desc[0].qw0 = QI_IWD_STATUS_DATA(QI_DONE) |
QI_IWD_FENCE |
QI_IWD_TYPE;
desc[1].qw0 = QI_EIOTLB_PASID(pasid) |
QI_EIOTLB_DID(did) |
QI_EIOTLB_GRAN(QI_GRAN_NONG_PASID) |
QI_EIOTLB_TYPE;
desc[2].qw0 = QI_DEV_EIOTLB_PASID(pasid) |
QI_DEV_EIOTLB_SID(sid) |
QI_DEV_EIOTLB_QDEP(qdep) |
QI_DEIOTLB_TYPE |
QI_DEV_IOTLB_PFSID(info->pfsid);
qi_retry:
reinit_completion(&iommu->prq_complete);
qi_submit_sync(iommu, desc, 3, QI_OPT_WAIT_DRAIN);
if (readl(iommu->reg + DMAR_PRS_REG) & DMA_PRS_PRO) {
wait_for_completion(&iommu->prq_complete);
goto qi_retry;
}
}
static int prq_to_iommu_prot(struct page_req_dsc *req)
{
int prot = 0;
if (req->rd_req)
prot |= IOMMU_FAULT_PERM_READ;
if (req->wr_req)
prot |= IOMMU_FAULT_PERM_WRITE;
if (req->exe_req)
prot |= IOMMU_FAULT_PERM_EXEC;
if (req->pm_req)
prot |= IOMMU_FAULT_PERM_PRIV;
return prot;
}
static int
intel_svm_prq_report(struct device *dev, struct page_req_dsc *desc)
{
struct iommu_fault_event event;
if (!dev || !dev_is_pci(dev))
return -ENODEV;
/* Fill in event data for device specific processing */
memset(&event, 0, sizeof(struct iommu_fault_event));
event.fault.type = IOMMU_FAULT_PAGE_REQ;
event.fault.prm.addr = desc->addr;
event.fault.prm.pasid = desc->pasid;
event.fault.prm.grpid = desc->prg_index;
event.fault.prm.perm = prq_to_iommu_prot(desc);
if (desc->lpig)
event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE;
if (desc->pasid_present) {
event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_PASID_VALID;
event.fault.prm.flags |= IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID;
}
if (desc->priv_data_present) {
/*
* Set last page in group bit if private data is present,
* page response is required as it does for LPIG.
* iommu_report_device_fault() doesn't understand this vendor
* specific requirement thus we set last_page as a workaround.
*/
event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE;
event.fault.prm.flags |= IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA;
memcpy(event.fault.prm.private_data, desc->priv_data,
sizeof(desc->priv_data));
}
return iommu_report_device_fault(dev, &event);
}
static irqreturn_t prq_event_thread(int irq, void *d)
{
struct intel_svm_dev *sdev = NULL;
struct intel_iommu *iommu = d;
struct intel_svm *svm = NULL;
int head, tail, handled = 0;
/* Clear PPR bit before reading head/tail registers, to
* ensure that we get a new interrupt if needed. */
writel(DMA_PRS_PPR, iommu->reg + DMAR_PRS_REG);
tail = dmar_readq(iommu->reg + DMAR_PQT_REG) & PRQ_RING_MASK;
head = dmar_readq(iommu->reg + DMAR_PQH_REG) & PRQ_RING_MASK;
while (head != tail) {
struct vm_area_struct *vma;
struct page_req_dsc *req;
struct qi_desc resp;
int result;
vm_fault_t ret;
u64 address;
handled = 1;
req = &iommu->prq[head / sizeof(*req)];
result = QI_RESP_INVALID;
address = (u64)req->addr << VTD_PAGE_SHIFT;
if (!req->pasid_present) {
pr_err("%s: Page request without PASID: %08llx %08llx\n",
iommu->name, ((unsigned long long *)req)[0],
((unsigned long long *)req)[1]);
goto no_pasid;
}
if (!svm || svm->pasid != req->pasid) {
rcu_read_lock();
svm = ioasid_find(NULL, req->pasid, NULL);
/* It *can't* go away, because the driver is not permitted
* to unbind the mm while any page faults are outstanding.
* So we only need RCU to protect the internal idr code. */
rcu_read_unlock();
if (IS_ERR_OR_NULL(svm)) {
pr_err("%s: Page request for invalid PASID %d: %08llx %08llx\n",
iommu->name, req->pasid, ((unsigned long long *)req)[0],
((unsigned long long *)req)[1]);
goto no_pasid;
}
}
if (!sdev || sdev->sid != req->rid) {
struct intel_svm_dev *t;
sdev = NULL;
rcu_read_lock();
list_for_each_entry_rcu(t, &svm->devs, list) {
if (t->sid == req->rid) {
sdev = t;
break;
}
}
rcu_read_unlock();
}
/* Since we're using init_mm.pgd directly, we should never take
* any faults on kernel addresses. */
if (!svm->mm)
goto bad_req;
/* If address is not canonical, return invalid response */
if (!is_canonical_address(address))
goto bad_req;
/*
* If prq is to be handled outside iommu driver via receiver of
* the fault notifiers, we skip the page response here.
*/
if (svm->flags & SVM_FLAG_GUEST_MODE) {
if (sdev && !intel_svm_prq_report(sdev->dev, req))
goto prq_advance;
else
goto bad_req;
}
/* If the mm is already defunct, don't handle faults. */
if (!mmget_not_zero(svm->mm))
goto bad_req;
mmap_read_lock(svm->mm);
vma = find_extend_vma(svm->mm, address);
if (!vma || address < vma->vm_start)
goto invalid;
if (access_error(vma, req))
goto invalid;
ret = handle_mm_fault(vma, address,
req->wr_req ? FAULT_FLAG_WRITE : 0,
NULL);
if (ret & VM_FAULT_ERROR)
goto invalid;
result = QI_RESP_SUCCESS;
invalid:
mmap_read_unlock(svm->mm);
mmput(svm->mm);
bad_req:
WARN_ON(!sdev);
if (sdev && sdev->ops && sdev->ops->fault_cb) {
int rwxp = (req->rd_req << 3) | (req->wr_req << 2) |
(req->exe_req << 1) | (req->pm_req);
sdev->ops->fault_cb(sdev->dev, req->pasid, req->addr,
req->priv_data, rwxp, result);
}
/* We get here in the error case where the PASID lookup failed,
and these can be NULL. Do not use them below this point! */
sdev = NULL;
svm = NULL;
no_pasid:
if (req->lpig || req->priv_data_present) {
/*
* Per VT-d spec. v3.0 ch7.7, system software must
* respond with page group response if private data
* is present (PDP) or last page in group (LPIG) bit
* is set. This is an additional VT-d feature beyond
* PCI ATS spec.
*/
resp.qw0 = QI_PGRP_PASID(req->pasid) |
QI_PGRP_DID(req->rid) |
QI_PGRP_PASID_P(req->pasid_present) |
QI_PGRP_PDP(req->priv_data_present) |
QI_PGRP_RESP_CODE(result) |
QI_PGRP_RESP_TYPE;
resp.qw1 = QI_PGRP_IDX(req->prg_index) |
QI_PGRP_LPIG(req->lpig);
if (req->priv_data_present)
memcpy(&resp.qw2, req->priv_data,
sizeof(req->priv_data));
resp.qw2 = 0;
resp.qw3 = 0;
qi_submit_sync(iommu, &resp, 1, 0);
}
prq_advance:
head = (head + sizeof(*req)) & PRQ_RING_MASK;
}
dmar_writeq(iommu->reg + DMAR_PQH_REG, tail);
/*
* Clear the page request overflow bit and wake up all threads that
* are waiting for the completion of this handling.
*/
if (readl(iommu->reg + DMAR_PRS_REG) & DMA_PRS_PRO) {
pr_info_ratelimited("IOMMU: %s: PRQ overflow detected\n",
iommu->name);
head = dmar_readq(iommu->reg + DMAR_PQH_REG) & PRQ_RING_MASK;
tail = dmar_readq(iommu->reg + DMAR_PQT_REG) & PRQ_RING_MASK;
if (head == tail) {
writel(DMA_PRS_PRO, iommu->reg + DMAR_PRS_REG);
pr_info_ratelimited("IOMMU: %s: PRQ overflow cleared",
iommu->name);
}
}
if (!completion_done(&iommu->prq_complete))
complete(&iommu->prq_complete);
return IRQ_RETVAL(handled);
}
#define to_intel_svm_dev(handle) container_of(handle, struct intel_svm_dev, sva)
struct iommu_sva *
intel_svm_bind(struct device *dev, struct mm_struct *mm, void *drvdata)
{
struct iommu_sva *sva = ERR_PTR(-EINVAL);
struct intel_svm_dev *sdev = NULL;
unsigned int flags = 0;
int ret;
/*
* TODO: Consolidate with generic iommu-sva bind after it is merged.
* It will require shared SVM data structures, i.e. combine io_mm
* and intel_svm etc.
*/
if (drvdata)
flags = *(unsigned int *)drvdata;
mutex_lock(&pasid_mutex);
ret = intel_svm_bind_mm(dev, flags, NULL, mm, &sdev);
if (ret)
sva = ERR_PTR(ret);
else if (sdev)
sva = &sdev->sva;
else
WARN(!sdev, "SVM bind succeeded with no sdev!\n");
mutex_unlock(&pasid_mutex);
return sva;
}
void intel_svm_unbind(struct iommu_sva *sva)
{
struct intel_svm_dev *sdev;
mutex_lock(&pasid_mutex);
sdev = to_intel_svm_dev(sva);
intel_svm_unbind_mm(sdev->dev, sdev->pasid);
mutex_unlock(&pasid_mutex);
}
u32 intel_svm_get_pasid(struct iommu_sva *sva)
{
struct intel_svm_dev *sdev;
u32 pasid;
mutex_lock(&pasid_mutex);
sdev = to_intel_svm_dev(sva);
pasid = sdev->pasid;
mutex_unlock(&pasid_mutex);
return pasid;
}
int intel_svm_page_response(struct device *dev,
struct iommu_fault_event *evt,
struct iommu_page_response *msg)
{
struct iommu_fault_page_request *prm;
struct intel_svm_dev *sdev = NULL;
struct intel_svm *svm = NULL;
struct intel_iommu *iommu;
bool private_present;
bool pasid_present;
bool last_page;
u8 bus, devfn;
int ret = 0;
u16 sid;
if (!dev || !dev_is_pci(dev))
return -ENODEV;
iommu = device_to_iommu(dev, &bus, &devfn);
if (!iommu)
return -ENODEV;
if (!msg || !evt)
return -EINVAL;
mutex_lock(&pasid_mutex);
prm = &evt->fault.prm;
sid = PCI_DEVID(bus, devfn);
pasid_present = prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID;
private_present = prm->flags & IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA;
last_page = prm->flags & IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE;
if (!pasid_present) {
ret = -EINVAL;
goto out;
}
if (prm->pasid == 0 || prm->pasid >= PASID_MAX) {
ret = -EINVAL;
goto out;
}
ret = pasid_to_svm_sdev(dev, prm->pasid, &svm, &sdev);
if (ret || !sdev) {
ret = -ENODEV;
goto out;
}
/*
* For responses from userspace, need to make sure that the
* pasid has been bound to its mm.
*/
if (svm->flags & SVM_FLAG_GUEST_MODE) {
struct mm_struct *mm;
mm = get_task_mm(current);
if (!mm) {
ret = -EINVAL;
goto out;
}
if (mm != svm->mm) {
ret = -ENODEV;
mmput(mm);
goto out;
}
mmput(mm);
}
/*
* Per VT-d spec. v3.0 ch7.7, system software must respond
* with page group response if private data is present (PDP)
* or last page in group (LPIG) bit is set. This is an
* additional VT-d requirement beyond PCI ATS spec.
*/
if (last_page || private_present) {
struct qi_desc desc;
desc.qw0 = QI_PGRP_PASID(prm->pasid) | QI_PGRP_DID(sid) |
QI_PGRP_PASID_P(pasid_present) |
QI_PGRP_PDP(private_present) |
QI_PGRP_RESP_CODE(msg->code) |
QI_PGRP_RESP_TYPE;
desc.qw1 = QI_PGRP_IDX(prm->grpid) | QI_PGRP_LPIG(last_page);
desc.qw2 = 0;
desc.qw3 = 0;
if (private_present)
memcpy(&desc.qw2, prm->private_data,
sizeof(prm->private_data));
qi_submit_sync(iommu, &desc, 1, 0);
}
out:
mutex_unlock(&pasid_mutex);
return ret;
}