2023-03-31 23:08:54

by Jacob Pan

[permalink] [raw]
Subject: [PATCH v3 0/7] Re-enable IDXD kernel workqueue under DMA API

Hi all,

IDXD kernel work queues were disabled due to the flawed use of kernel VA
and SVA API.
Link: https://lore.kernel.org/linux-iommu/[email protected]/

The solution is to enable it under DMA API where IDXD shared workqueue users
can use ENQCMDS to submit work on buffers mapped by DMA API.

This patchset adds support for attaching PASID to the device's default
domain and the ability to reserve global PASIDs from SVA APIs. We can then
re-enable the kernel work queues and use them under DMA API.

This depends on the IOASID removal series.
https://lore.kernel.org/all/[email protected]/


Thanks,

Jacob

---
Changelog:
v3:
- moved global PASID allocation API from SVA to IOMMU (Kevin)
- remove #ifdef around global PASID reservation during boot (Baolu)
- remove restriction on PASID 0 allocation (Baolu)
- fix a bug in sysfs domain change when attaching devices
- clear idxd user interrupt enable bit after disabling device( Fenghua)
v2:
- refactored device PASID attach domain ops based on Baolu's early patch
- addressed TLB flush gap
- explicitly reserve RID_PASID from SVA PASID number space
- get dma domain directly, avoid checking domain types



Jacob Pan (7):
iommu/vt-d: Use non-privileged mode for all PASIDs
iommu/vt-d: Remove PASID supervisor request support
iommu/sva: Support allocation of global PASIDs outside SVA
iommu/vt-d: Reserve RID_PASID from global PASID space
iommu/vt-d: Make device pasid attachment explicit
iommu/vt-d: Implement set_dev_pasid domain op
dmaengine/idxd: Re-enable kernel workqueue under DMA API

drivers/dma/idxd/device.c | 30 +-----
drivers/dma/idxd/init.c | 56 ++++++++++-
drivers/dma/idxd/sysfs.c | 7 --
drivers/iommu/intel/iommu.c | 180 +++++++++++++++++++++++++++++-------
drivers/iommu/intel/iommu.h | 8 ++
drivers/iommu/intel/pasid.c | 43 ---------
drivers/iommu/intel/pasid.h | 7 --
drivers/iommu/iommu-sva.c | 10 +-
drivers/iommu/iommu.c | 33 +++++++
include/linux/iommu.h | 10 ++
10 files changed, 257 insertions(+), 127 deletions(-)

--
2.25.1


2023-03-31 23:09:04

by Jacob Pan

[permalink] [raw]
Subject: [PATCH v3 6/7] iommu/vt-d: Implement set_dev_pasid domain op

Devices that use ENQCMDS to submit work on buffers mapped by DMA API
must attach a PASID to the default domain of the device. In preparation
for this use case, this patch implements set_dev_pasid() for the
default_domain_ops.

If the device context has not been set up prior to this call, this will
set up the device context in addition to PASID attachment.

Signed-off-by: Jacob Pan <[email protected]>
---
drivers/iommu/intel/iommu.c | 21 +++++++++++++++++++++
1 file changed, 21 insertions(+)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 52b9d0d3a02c..1ad9c5a4bd8f 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -4784,6 +4784,26 @@ static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
domain_detach_iommu(dmar_domain, info->iommu);
}

+static int intel_iommu_attach_device_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid)
+{
+ struct device_domain_info *info = dev_iommu_priv_get(dev);
+ struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+ struct intel_iommu *iommu = info->iommu;
+ int ret;
+
+ if (!pasid_supported(iommu))
+ return -ENODEV;
+
+ ret = prepare_domain_attach_device(domain, dev);
+ if (ret)
+ return ret;
+
+ return dmar_domain_attach_device_pasid(dmar_domain, dev, pasid);
+}
+
+
+
const struct iommu_ops intel_iommu_ops = {
.capable = intel_iommu_capable,
.domain_alloc = intel_iommu_domain_alloc,
@@ -4803,6 +4823,7 @@ const struct iommu_ops intel_iommu_ops = {
#endif
.default_domain_ops = &(const struct iommu_domain_ops) {
.attach_dev = intel_iommu_attach_device,
+ .set_dev_pasid = intel_iommu_attach_device_pasid,
.map_pages = intel_iommu_map_pages,
.unmap_pages = intel_iommu_unmap_pages,
.iotlb_sync_map = intel_iommu_iotlb_sync_map,
--
2.25.1

2023-03-31 23:09:16

by Jacob Pan

[permalink] [raw]
Subject: [PATCH v3 5/7] iommu/vt-d: Make device pasid attachment explicit

Currently, when a device is attached to its DMA domain, RID_PASID is
implicitly attached if VT-d is in scalable mode. To prepare for generic
PASID-device domain attachment, this patch parameterizes PASID such that
all PASIDs are attached explicitly.

It will allow code reuse for DMA API with PASID usage and makes no
assumptions of the ordering in which PASIDs and device are attached.
The same change applies to IOTLB invalidation and removing PASIDs.

Extracted common code based on Baolu's patch:

Link:https://lore.kernel.org/linux-iommu/[email protected]/
Signed-off-by: Lu Baolu <[email protected]>
Signed-off-by: Jacob Pan <[email protected]>
---
drivers/iommu/intel/iommu.c | 153 ++++++++++++++++++++++++++++--------
drivers/iommu/intel/iommu.h | 8 ++
2 files changed, 128 insertions(+), 33 deletions(-)

diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index cbb2670f88ca..52b9d0d3a02c 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -278,6 +278,8 @@ static LIST_HEAD(dmar_satc_units);
list_for_each_entry(rmrr, &dmar_rmrr_units, list)

static void device_block_translation(struct device *dev);
+static void intel_iommu_detach_device_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid);
static void intel_iommu_domain_free(struct iommu_domain *domain);

int dmar_disabled = !IS_ENABLED(CONFIG_INTEL_IOMMU_DEFAULT_ON);
@@ -1365,6 +1367,7 @@ domain_lookup_dev_info(struct dmar_domain *domain,

static void domain_update_iotlb(struct dmar_domain *domain)
{
+ struct device_pasid_info *dev_pasid;
struct device_domain_info *info;
bool has_iotlb_device = false;
unsigned long flags;
@@ -1376,6 +1379,14 @@ static void domain_update_iotlb(struct dmar_domain *domain)
break;
}
}
+
+ list_for_each_entry(dev_pasid, &domain->dev_pasids, link_domain) {
+ info = dev_iommu_priv_get(dev_pasid->dev);
+ if (info->ats_enabled) {
+ has_iotlb_device = true;
+ break;
+ }
+ }
domain->has_iotlb_device = has_iotlb_device;
spin_unlock_irqrestore(&domain->lock, flags);
}
@@ -1486,6 +1497,7 @@ static void __iommu_flush_dev_iotlb(struct device_domain_info *info,
static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
u64 addr, unsigned mask)
{
+ struct device_pasid_info *dev_pasid;
struct device_domain_info *info;
unsigned long flags;

@@ -1495,6 +1507,39 @@ static void iommu_flush_dev_iotlb(struct dmar_domain *domain,
spin_lock_irqsave(&domain->lock, flags);
list_for_each_entry(info, &domain->devices, link)
__iommu_flush_dev_iotlb(info, addr, mask);
+
+ list_for_each_entry(dev_pasid, &domain->dev_pasids, link_domain) {
+ /* device TLB is not aware of the use of RID PASID is for DMA w/o PASID */
+ if (dev_pasid->pasid == PASID_RID2PASID)
+ continue;
+
+ info = dev_iommu_priv_get(dev_pasid->dev);
+ qi_flush_dev_iotlb_pasid(info->iommu,
+ PCI_DEVID(info->bus, info->devfn),
+ info->pfsid, dev_pasid->pasid,
+ info->ats_qdep, addr,
+ mask);
+ }
+ spin_unlock_irqrestore(&domain->lock, flags);
+}
+
+/*
+ * The VT-d spec requires to use PASID-based-IOTLB Invalidation to
+ * invalidate IOTLB and the paging-structure-caches for a first-stage
+ * page table.
+ */
+static void domain_flush_pasid_iotlb(struct intel_iommu *iommu,
+ struct dmar_domain *domain, u64 addr,
+ unsigned long npages, bool ih)
+{
+ u16 did = domain_id_iommu(domain, iommu);
+ struct device_pasid_info *dev_pasid;
+ unsigned long flags;
+
+ spin_lock_irqsave(&domain->lock, flags);
+ list_for_each_entry(dev_pasid, &domain->dev_pasids, link_domain)
+ qi_flush_piotlb(iommu, did, dev_pasid->pasid, addr, npages, ih);
+
spin_unlock_irqrestore(&domain->lock, flags);
}

@@ -1514,7 +1559,7 @@ static void iommu_flush_iotlb_psi(struct intel_iommu *iommu,
ih = 1 << 6;

if (domain->use_first_level) {
- qi_flush_piotlb(iommu, did, PASID_RID2PASID, addr, pages, ih);
+ domain_flush_pasid_iotlb(iommu, domain, addr, pages, ih);
} else {
unsigned long bitmask = aligned_pages - 1;

@@ -1584,7 +1629,7 @@ static void intel_flush_iotlb_all(struct iommu_domain *domain)
u16 did = domain_id_iommu(dmar_domain, iommu);

if (dmar_domain->use_first_level)
- qi_flush_piotlb(iommu, did, PASID_RID2PASID, 0, -1, 0);
+ domain_flush_pasid_iotlb(iommu, dmar_domain, 0, -1, 0);
else
iommu->flush.flush_iotlb(iommu, did, 0, 0,
DMA_TLB_DSI_FLUSH);
@@ -1756,6 +1801,7 @@ static struct dmar_domain *alloc_domain(unsigned int type)
domain->use_first_level = true;
domain->has_iotlb_device = false;
INIT_LIST_HEAD(&domain->devices);
+ INIT_LIST_HEAD(&domain->dev_pasids);
spin_lock_init(&domain->lock);
xa_init(&domain->iommu_array);

@@ -2429,10 +2475,11 @@ static int __init si_domain_init(int hw)
return 0;
}

-static int dmar_domain_attach_device(struct dmar_domain *domain,
- struct device *dev)
+static int dmar_domain_attach_device_pasid(struct dmar_domain *domain,
+ struct device *dev, ioasid_t pasid)
{
struct device_domain_info *info = dev_iommu_priv_get(dev);
+ struct device_pasid_info *dev_pasid;
struct intel_iommu *iommu;
unsigned long flags;
u8 bus, devfn;
@@ -2442,43 +2489,57 @@ static int dmar_domain_attach_device(struct dmar_domain *domain,
if (!iommu)
return -ENODEV;

+ dev_pasid = kzalloc(sizeof(*dev_pasid), GFP_KERNEL);
+ if (!dev_pasid)
+ return -ENOMEM;
+
ret = domain_attach_iommu(domain, iommu);
if (ret)
- return ret;
+ goto exit_free;
+
info->domain = domain;
+ dev_pasid->pasid = pasid;
+ dev_pasid->dev = dev;
spin_lock_irqsave(&domain->lock, flags);
- list_add(&info->link, &domain->devices);
+ if (!info->dev_attached)
+ list_add(&info->link, &domain->devices);
+
+ list_add(&dev_pasid->link_domain, &domain->dev_pasids);
spin_unlock_irqrestore(&domain->lock, flags);

/* PASID table is mandatory for a PCI device in scalable mode. */
if (sm_supported(iommu) && !dev_is_real_dma_subdevice(dev)) {
/* Setup the PASID entry for requests without PASID: */
if (hw_pass_through && domain_type_is_si(domain))
- ret = intel_pasid_setup_pass_through(iommu, domain,
- dev, PASID_RID2PASID);
+ ret = intel_pasid_setup_pass_through(iommu, domain, dev, pasid);
else if (domain->use_first_level)
- ret = domain_setup_first_level(iommu, domain, dev,
- PASID_RID2PASID);
+ ret = domain_setup_first_level(iommu, domain, dev, pasid);
else
- ret = intel_pasid_setup_second_level(iommu, domain,
- dev, PASID_RID2PASID);
+ ret = intel_pasid_setup_second_level(iommu, domain, dev, pasid);
if (ret) {
- dev_err(dev, "Setup RID2PASID failed\n");
+ dev_err(dev, "Setup PASID %d failed\n", pasid);
device_block_translation(dev);
- return ret;
+ goto exit_free;
}
}
+ /* device context already activated, we are done */
+ if (info->dev_attached)
+ goto exit;

ret = domain_context_mapping(domain, dev);
if (ret) {
dev_err(dev, "Domain context map failed\n");
device_block_translation(dev);
- return ret;
+ goto exit_free;
}

iommu_enable_pci_caps(info);
-
+ info->dev_attached = 1;
+exit:
return 0;
+exit_free:
+ kfree(dev_pasid);
+ return ret;
}

static bool device_has_rmrr(struct device *dev)
@@ -4029,8 +4090,7 @@ static void device_block_translation(struct device *dev)
iommu_disable_pci_caps(info);
if (!dev_is_real_dma_subdevice(dev)) {
if (sm_supported(iommu))
- intel_pasid_tear_down_entry(iommu, dev,
- PASID_RID2PASID, false);
+ intel_iommu_detach_device_pasid(&info->domain->domain, dev, PASID_RID2PASID);
else
domain_context_clear(info);
}
@@ -4040,6 +4100,7 @@ static void device_block_translation(struct device *dev)

spin_lock_irqsave(&info->domain->lock, flags);
list_del(&info->link);
+ info->dev_attached = 0;
spin_unlock_irqrestore(&info->domain->lock, flags);

domain_detach_iommu(info->domain, iommu);
@@ -4186,7 +4247,7 @@ static int intel_iommu_attach_device(struct iommu_domain *domain,
if (ret)
return ret;

- return dmar_domain_attach_device(to_dmar_domain(domain), dev);
+ return dmar_domain_attach_device_pasid(to_dmar_domain(domain), dev, PASID_RID2PASID);
}

static int intel_iommu_map(struct iommu_domain *domain,
@@ -4675,26 +4736,52 @@ static void intel_iommu_iotlb_sync_map(struct iommu_domain *domain,
__mapping_notify_one(info->iommu, dmar_domain, pfn, pages);
}

-static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
+static void intel_iommu_detach_device_pasid(struct iommu_domain *domain,
+ struct device *dev, ioasid_t pasid)
{
- struct intel_iommu *iommu = device_to_iommu(dev, NULL, NULL);
- struct iommu_domain *domain;
+ struct device_domain_info *info = dev_iommu_priv_get(dev);
+ struct dmar_domain *dmar_domain = to_dmar_domain(domain);
+ struct device_pasid_info *i, *dev_pasid = NULL;
+ struct intel_iommu *iommu = info->iommu;
+ unsigned long flags;

- /* Domain type specific cleanup: */
- domain = iommu_get_domain_for_dev_pasid(dev, pasid, 0);
- if (domain) {
- switch (domain->type) {
- case IOMMU_DOMAIN_SVA:
- intel_svm_remove_dev_pasid(dev, pasid);
- break;
- default:
- /* should never reach here */
- WARN_ON(1);
+ spin_lock_irqsave(&dmar_domain->lock, flags);
+ list_for_each_entry(i, &dmar_domain->dev_pasids, link_domain) {
+ if (i->dev == dev && i->pasid == pasid) {
+ list_del(&i->link_domain);
+ dev_pasid = i;
break;
}
}
+ spin_unlock_irqrestore(&dmar_domain->lock, flags);
+ if (WARN_ON(!dev_pasid))
+ return;
+
+ /* PASID entry already cleared during SVA unbind */
+ if (domain->type != IOMMU_DOMAIN_SVA)
+ intel_pasid_tear_down_entry(iommu, dev, pasid, false);
+
+ kfree(dev_pasid);
+}
+
+static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
+{
+ struct device_domain_info *info = dev_iommu_priv_get(dev);
+ struct dmar_domain *dmar_domain;
+ struct iommu_domain *domain;
+
+ domain = iommu_get_domain_for_dev_pasid(dev, pasid, 0);
+ dmar_domain = to_dmar_domain(domain);
+
+ /*
+ * SVA Domain type specific cleanup: Not ideal but not until we have
+ * IOPF capable domain specific ops, we need this special case.
+ */
+ if (domain->type == IOMMU_DOMAIN_SVA)
+ return intel_svm_remove_dev_pasid(dev, pasid);

- intel_pasid_tear_down_entry(iommu, dev, pasid, false);
+ intel_iommu_detach_device_pasid(domain, dev, pasid);
+ domain_detach_iommu(dmar_domain, info->iommu);
}

const struct iommu_ops intel_iommu_ops = {
diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index 65b15be72878..b6c26f25d1ba 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -595,6 +595,7 @@ struct dmar_domain {

spinlock_t lock; /* Protect device tracking lists */
struct list_head devices; /* all devices' list */
+ struct list_head dev_pasids; /* all attached pasids */

struct dma_pte *pgd; /* virtual address */
int gaw; /* max guest address width */
@@ -708,6 +709,7 @@ struct device_domain_info {
u8 ats_supported:1;
u8 ats_enabled:1;
u8 dtlb_extra_inval:1; /* Quirk for devices need extra flush */
+ u8 dev_attached:1; /* Device context activated */
u8 ats_qdep;
struct device *dev; /* it's NULL for PCIe-to-PCI bridge */
struct intel_iommu *iommu; /* IOMMU used by this device */
@@ -715,6 +717,12 @@ struct device_domain_info {
struct pasid_table *pasid_table; /* pasid table */
};

+struct device_pasid_info {
+ struct list_head link_domain; /* link to domain siblings */
+ struct device *dev; /* physical device derived from */
+ ioasid_t pasid; /* PASID on physical device */
+};
+
static inline void __iommu_flush_cache(
struct intel_iommu *iommu, void *addr, int size)
{
--
2.25.1

2023-03-31 23:09:50

by Jacob Pan

[permalink] [raw]
Subject: [PATCH v3 7/7] dmaengine/idxd: Re-enable kernel workqueue under DMA API

Kernel workqueues were disabled due to flawed use of kernel VA and SVA
API. Now That we have the support for attaching PASID to the device's
default domain and the ability to reserve global PASIDs from SVA APIs,
we can re-enable the kernel work queues and use them under DMA API.

We also use non-privileged access for in-kernel DMA to be consistent
with the IOMMU settings. Consequently, interrupt for user privilege is
enabled for work completion IRQs.

Link:https://lore.kernel.org/linux-iommu/[email protected]/
Reviewed-by: Dave Jiang <[email protected]>
Signed-off-by: Jacob Pan <[email protected]>
---
drivers/dma/idxd/device.c | 30 ++++-----------------
drivers/dma/idxd/init.c | 56 ++++++++++++++++++++++++++++++++++++---
drivers/dma/idxd/sysfs.c | 7 -----
3 files changed, 57 insertions(+), 36 deletions(-)

diff --git a/drivers/dma/idxd/device.c b/drivers/dma/idxd/device.c
index 6fca8fa8d3a8..f6b133d61a04 100644
--- a/drivers/dma/idxd/device.c
+++ b/drivers/dma/idxd/device.c
@@ -299,21 +299,6 @@ void idxd_wqs_unmap_portal(struct idxd_device *idxd)
}
}

-static void __idxd_wq_set_priv_locked(struct idxd_wq *wq, int priv)
-{
- struct idxd_device *idxd = wq->idxd;
- union wqcfg wqcfg;
- unsigned int offset;
-
- offset = WQCFG_OFFSET(idxd, wq->id, WQCFG_PRIVL_IDX);
- spin_lock(&idxd->dev_lock);
- wqcfg.bits[WQCFG_PRIVL_IDX] = ioread32(idxd->reg_base + offset);
- wqcfg.priv = priv;
- wq->wqcfg->bits[WQCFG_PRIVL_IDX] = wqcfg.bits[WQCFG_PRIVL_IDX];
- iowrite32(wqcfg.bits[WQCFG_PRIVL_IDX], idxd->reg_base + offset);
- spin_unlock(&idxd->dev_lock);
-}
-
static void __idxd_wq_set_pasid_locked(struct idxd_wq *wq, int pasid)
{
struct idxd_device *idxd = wq->idxd;
@@ -1324,15 +1309,14 @@ int drv_enable_wq(struct idxd_wq *wq)
}

/*
- * In the event that the WQ is configurable for pasid and priv bits.
- * For kernel wq, the driver should setup the pasid, pasid_en, and priv bit.
- * However, for non-kernel wq, the driver should only set the pasid_en bit for
- * shared wq. A dedicated wq that is not 'kernel' type will configure pasid and
+ * In the event that the WQ is configurable for pasid, the driver
+ * should setup the pasid, pasid_en bit. This is true for both kernel
+ * and user shared workqueues. There is no need to setup priv bit in
+ * that in-kernel DMA will also do user privileged requests.
+ * A dedicated wq that is not 'kernel' type will configure pasid and
* pasid_en later on so there is no need to setup.
*/
if (test_bit(IDXD_FLAG_CONFIGURABLE, &idxd->flags)) {
- int priv = 0;
-
if (wq_pasid_enabled(wq)) {
if (is_idxd_wq_kernel(wq) || wq_shared(wq)) {
u32 pasid = wq_dedicated(wq) ? idxd->pasid : 0;
@@ -1340,10 +1324,6 @@ int drv_enable_wq(struct idxd_wq *wq)
__idxd_wq_set_pasid_locked(wq, pasid);
}
}
-
- if (is_idxd_wq_kernel(wq))
- priv = 1;
- __idxd_wq_set_priv_locked(wq, priv);
}

rc = 0;
diff --git a/drivers/dma/idxd/init.c b/drivers/dma/idxd/init.c
index e6ee267da0ff..6f7778e1e936 100644
--- a/drivers/dma/idxd/init.c
+++ b/drivers/dma/idxd/init.c
@@ -506,14 +506,61 @@ static struct idxd_device *idxd_alloc(struct pci_dev *pdev, struct idxd_driver_d

static int idxd_enable_system_pasid(struct idxd_device *idxd)
{
- return -EOPNOTSUPP;
+ struct pci_dev *pdev = idxd->pdev;
+ struct device *dev = &pdev->dev;
+ struct iommu_domain *domain;
+ union gencfg_reg gencfg;
+ ioasid_t pasid;
+ int ret;
+
+ /*
+ * Attach a global PASID to the DMA domain so that we can use ENQCMDS
+ * to submit work on buffers mapped by DMA API.
+ */
+ domain = iommu_get_domain_for_dev(dev);
+ if (!domain)
+ return -EPERM;
+
+ pasid = iommu_alloc_global_pasid(0, dev->iommu->max_pasids);
+ if (!pasid_valid(pasid))
+ return -ENOSPC;
+
+ ret = iommu_attach_device_pasid(domain, dev, pasid);
+ if (ret) {
+ dev_err(dev, "failed to attach device pasid %d, domain type %d",
+ pasid, domain->type);
+ iommu_free_global_pasid(pasid);
+ return ret;
+ }
+
+ /* Since we set user privilege for kernel DMA, enable completion IRQ */
+ gencfg.bits = ioread32(idxd->reg_base + IDXD_GENCFG_OFFSET);
+ gencfg.user_int_en = 1;
+ iowrite32(gencfg.bits, idxd->reg_base + IDXD_GENCFG_OFFSET);
+ idxd->pasid = pasid;
+
+ return ret;
}

static void idxd_disable_system_pasid(struct idxd_device *idxd)
{
+ struct pci_dev *pdev = idxd->pdev;
+ struct device *dev = &pdev->dev;
+ struct iommu_domain *domain;
+ union gencfg_reg gencfg;
+
+ domain = iommu_get_domain_for_dev(dev);
+ if (!domain || domain->type == IOMMU_DOMAIN_BLOCKED)
+ return;
+
+ iommu_detach_device_pasid(domain, dev, idxd->pasid);
+ iommu_free_global_pasid(idxd->pasid);

- iommu_sva_unbind_device(idxd->sva);
+ gencfg.bits = ioread32(idxd->reg_base + IDXD_GENCFG_OFFSET);
+ gencfg.user_int_en = 0;
+ iowrite32(gencfg.bits, idxd->reg_base + IDXD_GENCFG_OFFSET);
idxd->sva = NULL;
+ idxd->pasid = IOMMU_PASID_INVALID;
}

static int idxd_probe(struct idxd_device *idxd)
@@ -535,8 +582,9 @@ static int idxd_probe(struct idxd_device *idxd)
} else {
set_bit(IDXD_FLAG_USER_PASID_ENABLED, &idxd->flags);

- if (idxd_enable_system_pasid(idxd))
- dev_warn(dev, "No in-kernel DMA with PASID.\n");
+ rc = idxd_enable_system_pasid(idxd);
+ if (rc)
+ dev_warn(dev, "No in-kernel DMA with PASID. %d\n", rc);
else
set_bit(IDXD_FLAG_PASID_ENABLED, &idxd->flags);
}
diff --git a/drivers/dma/idxd/sysfs.c b/drivers/dma/idxd/sysfs.c
index 18cd8151dee0..c5561c00a503 100644
--- a/drivers/dma/idxd/sysfs.c
+++ b/drivers/dma/idxd/sysfs.c
@@ -944,13 +944,6 @@ static ssize_t wq_name_store(struct device *dev,
if (strlen(buf) > WQ_NAME_SIZE || strlen(buf) == 0)
return -EINVAL;

- /*
- * This is temporarily placed here until we have SVM support for
- * dmaengine.
- */
- if (wq->type == IDXD_WQT_KERNEL && device_pasid_enabled(wq->idxd))
- return -EOPNOTSUPP;
-
input = kstrndup(buf, count, GFP_KERNEL);
if (!input)
return -ENOMEM;
--
2.25.1

2023-03-31 23:45:33

by Fenghua Yu

[permalink] [raw]
Subject: RE: [PATCH v3 7/7] dmaengine/idxd: Re-enable kernel workqueue under DMA API

Hi, Jacob,

> Kernel workqueues were disabled due to flawed use of kernel VA and SVA API.
> Now That we have the support for attaching PASID to the device's default

s/That/that/

> domain and the ability to reserve global PASIDs from SVA APIs, we can re-enable
> the kernel work queues and use them under DMA API.
>
> We also use non-privileged access for in-kernel DMA to be consistent with the
> IOMMU settings. Consequently, interrupt for user privilege is enabled for work
> completion IRQs.
>
> Link:https://lore.kernel.org/linux-
> iommu/[email protected]/
> Reviewed-by: Dave Jiang <[email protected]>
> Signed-off-by: Jacob Pan <[email protected]>

Other than the typo,

Reviewed-by: Fenghua Yu <[email protected]>

Thanks.

-Fenghua

2023-04-01 13:47:00

by Baolu Lu

[permalink] [raw]
Subject: Re: [PATCH v3 7/7] dmaengine/idxd: Re-enable kernel workqueue under DMA API

On 2023/4/1 7:11, Jacob Pan wrote:
> static void idxd_disable_system_pasid(struct idxd_device *idxd)
> {
> + struct pci_dev *pdev = idxd->pdev;
> + struct device *dev = &pdev->dev;
> + struct iommu_domain *domain;
> + union gencfg_reg gencfg;
> +
> + domain = iommu_get_domain_for_dev(dev);
> + if (!domain || domain->type == IOMMU_DOMAIN_BLOCKED)
> + return;

Out of curiosity, why do you need to check the domain type? And, in
which case could the domain for the device be changed to a blocking one?

Once a driver is bound to the device, the driver "owns" the DMA of the
device. No one else could change the domain except the driver itself.

> +
> + iommu_detach_device_pasid(domain, dev, idxd->pasid);
> + iommu_free_global_pasid(idxd->pasid);
>
> - iommu_sva_unbind_device(idxd->sva);
> + gencfg.bits = ioread32(idxd->reg_base + IDXD_GENCFG_OFFSET);
> + gencfg.user_int_en = 0;
> + iowrite32(gencfg.bits, idxd->reg_base + IDXD_GENCFG_OFFSET);
> idxd->sva = NULL;
> + idxd->pasid = IOMMU_PASID_INVALID;
> }

Best regards,
baolu

2023-04-01 14:04:58

by Baolu Lu

[permalink] [raw]
Subject: Re: [PATCH v3 6/7] iommu/vt-d: Implement set_dev_pasid domain op

On 2023/4/1 7:11, Jacob Pan wrote:
> Devices that use ENQCMDS to submit work on buffers mapped by DMA API
> must attach a PASID to the default domain of the device. In preparation
> for this use case, this patch implements set_dev_pasid() for the
> default_domain_ops.
>
> If the device context has not been set up prior to this call, this will
> set up the device context in addition to PASID attachment.
>
> Signed-off-by: Jacob Pan <[email protected]>
> ---
> drivers/iommu/intel/iommu.c | 21 +++++++++++++++++++++
> 1 file changed, 21 insertions(+)
>
> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> index 52b9d0d3a02c..1ad9c5a4bd8f 100644
> --- a/drivers/iommu/intel/iommu.c
> +++ b/drivers/iommu/intel/iommu.c
> @@ -4784,6 +4784,26 @@ static void intel_iommu_remove_dev_pasid(struct device *dev, ioasid_t pasid)
> domain_detach_iommu(dmar_domain, info->iommu);
> }
>
> +static int intel_iommu_attach_device_pasid(struct iommu_domain *domain,
> + struct device *dev, ioasid_t pasid)
> +{
> + struct device_domain_info *info = dev_iommu_priv_get(dev);
> + struct dmar_domain *dmar_domain = to_dmar_domain(domain);
> + struct intel_iommu *iommu = info->iommu;
> + int ret;
> +
> + if (!pasid_supported(iommu))
> + return -ENODEV;

As the domain ID will be set to the pasid entry, need to get a refcount
of the domain ID. Call domain_attach_iommu() here, and release it after
the pasid entry is torn down.

> + ret = prepare_domain_attach_device(domain, dev);
> + if (ret)
> + return ret;
> +
> + return dmar_domain_attach_device_pasid(dmar_domain, dev, pasid);
> +}
> +
> +
> +
> const struct iommu_ops intel_iommu_ops = {
> .capable = intel_iommu_capable,
> .domain_alloc = intel_iommu_domain_alloc,
> @@ -4803,6 +4823,7 @@ const struct iommu_ops intel_iommu_ops = {
> #endif
> .default_domain_ops = &(const struct iommu_domain_ops) {
> .attach_dev = intel_iommu_attach_device,
> + .set_dev_pasid = intel_iommu_attach_device_pasid,
> .map_pages = intel_iommu_map_pages,
> .unmap_pages = intel_iommu_unmap_pages,
> .iotlb_sync_map = intel_iommu_iotlb_sync_map,

Best regards,
baolu

2023-04-03 21:49:17

by Jacob Pan

[permalink] [raw]
Subject: Re: [PATCH v3 6/7] iommu/vt-d: Implement set_dev_pasid domain op

Hi Baolu,

On Sat, 1 Apr 2023 21:48:36 +0800, Baolu Lu <[email protected]>
wrote:

> On 2023/4/1 7:11, Jacob Pan wrote:
> > Devices that use ENQCMDS to submit work on buffers mapped by DMA API
> > must attach a PASID to the default domain of the device. In preparation
> > for this use case, this patch implements set_dev_pasid() for the
> > default_domain_ops.
> >
> > If the device context has not been set up prior to this call, this will
> > set up the device context in addition to PASID attachment.
> >
> > Signed-off-by: Jacob Pan <[email protected]>
> > ---
> > drivers/iommu/intel/iommu.c | 21 +++++++++++++++++++++
> > 1 file changed, 21 insertions(+)
> >
> > diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> > index 52b9d0d3a02c..1ad9c5a4bd8f 100644
> > --- a/drivers/iommu/intel/iommu.c
> > +++ b/drivers/iommu/intel/iommu.c
> > @@ -4784,6 +4784,26 @@ static void intel_iommu_remove_dev_pasid(struct
> > device *dev, ioasid_t pasid) domain_detach_iommu(dmar_domain,
> > info->iommu); }
> >
> > +static int intel_iommu_attach_device_pasid(struct iommu_domain *domain,
> > + struct device *dev,
> > ioasid_t pasid) +{
> > + struct device_domain_info *info = dev_iommu_priv_get(dev);
> > + struct dmar_domain *dmar_domain = to_dmar_domain(domain);
> > + struct intel_iommu *iommu = info->iommu;
> > + int ret;
> > +
> > + if (!pasid_supported(iommu))
> > + return -ENODEV;
>
> As the domain ID will be set to the pasid entry, need to get a refcount
> of the domain ID. Call domain_attach_iommu() here, and release it after
> the pasid entry is torn down.
dmar_domain_attach_device_pasid() below will call domain_attach_iommu() and
release in intel_iommu_remove_dev_pasid(). The previous patch has
consolidated the code path with device attachment.
would it be sufficient?

> > + ret = prepare_domain_attach_device(domain, dev);
> > + if (ret)
> > + return ret;
> > +
> > + return dmar_domain_attach_device_pasid(dmar_domain, dev,
> > pasid); +}
> > +
> > +
> > +
> > const struct iommu_ops intel_iommu_ops = {
> > .capable = intel_iommu_capable,
> > .domain_alloc = intel_iommu_domain_alloc,
> > @@ -4803,6 +4823,7 @@ const struct iommu_ops intel_iommu_ops = {
> > #endif
> > .default_domain_ops = &(const struct iommu_domain_ops) {
> > .attach_dev =
> > intel_iommu_attach_device,
> > + .set_dev_pasid =
> > intel_iommu_attach_device_pasid, .map_pages =
> > intel_iommu_map_pages, .unmap_pages =
> > intel_iommu_unmap_pages, .iotlb_sync_map =
> > intel_iommu_iotlb_sync_map,
>
> Best regards,
> baolu


Thanks,

Jacob

2023-04-03 21:51:47

by Jacob Pan

[permalink] [raw]
Subject: Re: [PATCH v3 7/7] dmaengine/idxd: Re-enable kernel workqueue under DMA API

Hi Baolu,

On Sat, 1 Apr 2023 21:39:32 +0800, Baolu Lu <[email protected]>
wrote:

> On 2023/4/1 7:11, Jacob Pan wrote:
> > static void idxd_disable_system_pasid(struct idxd_device *idxd)
> > {
> > + struct pci_dev *pdev = idxd->pdev;
> > + struct device *dev = &pdev->dev;
> > + struct iommu_domain *domain;
> > + union gencfg_reg gencfg;
> > +
> > + domain = iommu_get_domain_for_dev(dev);
> > + if (!domain || domain->type == IOMMU_DOMAIN_BLOCKED)
> > + return;
>
> Out of curiosity, why do you need to check the domain type? And, in
> which case could the domain for the device be changed to a blocking one?
>
> Once a driver is bound to the device, the driver "owns" the DMA of the
> device. No one else could change the domain except the driver itself.
nothing particular just for precaution, I can drop the check or add a
warn_on.

> > +
> > + iommu_detach_device_pasid(domain, dev, idxd->pasid);
> > + iommu_free_global_pasid(idxd->pasid);
> >
> > - iommu_sva_unbind_device(idxd->sva);
> > + gencfg.bits = ioread32(idxd->reg_base + IDXD_GENCFG_OFFSET);
> > + gencfg.user_int_en = 0;
> > + iowrite32(gencfg.bits, idxd->reg_base + IDXD_GENCFG_OFFSET);
> > idxd->sva = NULL;
> > + idxd->pasid = IOMMU_PASID_INVALID;
> > }
>
> Best regards,
> baolu


Thanks,

Jacob

2023-04-03 21:53:20

by Jacob Pan

[permalink] [raw]
Subject: Re: [PATCH v3 7/7] dmaengine/idxd: Re-enable kernel workqueue under DMA API

Hi Fenghua,

On Fri, 31 Mar 2023 23:31:13 +0000, "Yu, Fenghua" <[email protected]>
wrote:

> Hi, Jacob,
>
> > Kernel workqueues were disabled due to flawed use of kernel VA and SVA
> > API. Now That we have the support for attaching PASID to the device's
> > default
>
> s/That/that/
will fix, for real this time :) you pointed it out before.

> > domain and the ability to reserve global PASIDs from SVA APIs, we can
> > re-enable the kernel work queues and use them under DMA API.
> >
> > We also use non-privileged access for in-kernel DMA to be consistent
> > with the IOMMU settings. Consequently, interrupt for user privilege is
> > enabled for work completion IRQs.
> >
> > Link:https://lore.kernel.org/linux-
> > iommu/[email protected]/
> > Reviewed-by: Dave Jiang <[email protected]>
> > Signed-off-by: Jacob Pan <[email protected]>
>
> Other than the typo,
>
> Reviewed-by: Fenghua Yu <[email protected]>
>
> Thanks.
>
> -Fenghua


Thanks,

Jacob

2023-04-04 05:27:36

by Baolu Lu

[permalink] [raw]
Subject: Re: [PATCH v3 6/7] iommu/vt-d: Implement set_dev_pasid domain op

On 4/4/23 5:48 AM, Jacob Pan wrote:
> On Sat, 1 Apr 2023 21:48:36 +0800, Baolu Lu<[email protected]>
> wrote:
>
>> On 2023/4/1 7:11, Jacob Pan wrote:
>>> Devices that use ENQCMDS to submit work on buffers mapped by DMA API
>>> must attach a PASID to the default domain of the device. In preparation
>>> for this use case, this patch implements set_dev_pasid() for the
>>> default_domain_ops.
>>>
>>> If the device context has not been set up prior to this call, this will
>>> set up the device context in addition to PASID attachment.
>>>
>>> Signed-off-by: Jacob Pan<[email protected]>
>>> ---
>>> drivers/iommu/intel/iommu.c | 21 +++++++++++++++++++++
>>> 1 file changed, 21 insertions(+)
>>>
>>> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
>>> index 52b9d0d3a02c..1ad9c5a4bd8f 100644
>>> --- a/drivers/iommu/intel/iommu.c
>>> +++ b/drivers/iommu/intel/iommu.c
>>> @@ -4784,6 +4784,26 @@ static void intel_iommu_remove_dev_pasid(struct
>>> device *dev, ioasid_t pasid) domain_detach_iommu(dmar_domain,
>>> info->iommu); }
>>>
>>> +static int intel_iommu_attach_device_pasid(struct iommu_domain *domain,
>>> + struct device *dev,
>>> ioasid_t pasid) +{
>>> + struct device_domain_info *info = dev_iommu_priv_get(dev);
>>> + struct dmar_domain *dmar_domain = to_dmar_domain(domain);
>>> + struct intel_iommu *iommu = info->iommu;
>>> + int ret;
>>> +
>>> + if (!pasid_supported(iommu))
>>> + return -ENODEV;
>> As the domain ID will be set to the pasid entry, need to get a refcount
>> of the domain ID. Call domain_attach_iommu() here, and release it after
>> the pasid entry is torn down.
> dmar_domain_attach_device_pasid() below will call domain_attach_iommu() and
> release in intel_iommu_remove_dev_pasid(). The previous patch has
> consolidated the code path with device attachment.
> would it be sufficient?

It's fine. Sorry, I overlooked this.

Best regards,
baolu

2023-04-05 12:21:01

by Jason Gunthorpe

[permalink] [raw]
Subject: Re: [PATCH v3 7/7] dmaengine/idxd: Re-enable kernel workqueue under DMA API

On Fri, Mar 31, 2023 at 04:11:37PM -0700, Jacob Pan wrote:
> static void idxd_disable_system_pasid(struct idxd_device *idxd)
> {
> + struct pci_dev *pdev = idxd->pdev;
> + struct device *dev = &pdev->dev;
> + struct iommu_domain *domain;
> + union gencfg_reg gencfg;
> +
> + domain = iommu_get_domain_for_dev(dev);
> + if (!domain || domain->type == IOMMU_DOMAIN_BLOCKED)
> + return;
> +
> + iommu_detach_device_pasid(domain, dev, idxd->pasid);

This sequence is kinda weird, we shouldn't pass in domain to
detach_device_pasid, IMHO. We already know the domain because we store
it in an xarray, it just creates weirdness if the user passes in the
wrong domain.

Jason

2023-04-06 02:52:57

by Baolu Lu

[permalink] [raw]
Subject: Re: [PATCH v3 7/7] dmaengine/idxd: Re-enable kernel workqueue under DMA API

On 4/5/23 8:15 PM, Jason Gunthorpe wrote:
> On Fri, Mar 31, 2023 at 04:11:37PM -0700, Jacob Pan wrote:
>> static void idxd_disable_system_pasid(struct idxd_device *idxd)
>> {
>> + struct pci_dev *pdev = idxd->pdev;
>> + struct device *dev = &pdev->dev;
>> + struct iommu_domain *domain;
>> + union gencfg_reg gencfg;
>> +
>> + domain = iommu_get_domain_for_dev(dev);
>> + if (!domain || domain->type == IOMMU_DOMAIN_BLOCKED)
>> + return;
>> +
>> + iommu_detach_device_pasid(domain, dev, idxd->pasid);
> This sequence is kinda weird, we shouldn't pass in domain to
> detach_device_pasid, IMHO. We already know the domain because we store
> it in an xarray, it just creates weirdness if the user passes in the
> wrong domain.

The initial idea was that the driver has a domain and it wants to attach
the domain to a pasid of the device. During attaching, iommu core will
save the domain in its xarray.

After use, driver want to detach the domain from the pasid by calling
iommu_detach_device_pasid(). The iommu core will compare the input
domain and the one it saved. A warning will be triggered if they are
different.

WARN_ON(xa_erase(&group->pasid_array, pasid) != domain);

Logically speaking, @domain for detach_device_pasid is unnecessary,
because the pasid array is essentially per-device (as we discussed
before. the pci_enable_pasid() ensures this), although it is currently
placed in the group structure. In that case, the driver can and should
own everything about the pasid and domain. The roles of the iommu core
and the individual driver are only to handle requests of installing or
withdrawing a domain on/from a device's pasid.

Best regards,
baolu

2023-04-06 12:41:00

by Baolu Lu

[permalink] [raw]
Subject: Re: [PATCH v3 0/7] Re-enable IDXD kernel workqueue under DMA API

Hi Jacob,

On 2023/4/1 7:11, Jacob Pan wrote:
> Jacob Pan (7):
> iommu/vt-d: Use non-privileged mode for all PASIDs
> iommu/vt-d: Remove PASID supervisor request support

Above two patches are vt-d cleanups after

942fd5435dcc iommu: Remove SVM_FLAG_SUPERVISOR_MODE support

I will queue them as vt-d updates for v6.4 if no objection.

Best regards,
baolu