From: Joel Granados <j.granados@samsung.com>
IO page faults are no longer dependent on CONFIG_INTEL_IOMMU_SVM. Move
all Page Request Queue (PRQ) functions that handle prq events to a new
file in drivers/iommu/intel/prq.c. The page_req_des struct is now
declared in drivers/iommu/intel/prq.c.
No functional changes are intended. This is a preparation patch to
enable the use of IO page faults outside the SVM/PASID use cases.
Signed-off-by: Joel Granados <j.granados@samsung.com>
---
drivers/iommu/intel/Makefile | 2 +-
drivers/iommu/intel/iommu.c | 18 +-
drivers/iommu/intel/iommu.h | 14 +-
drivers/iommu/intel/prq.c | 410 +++++++++++++++++++++++++++++++++++++++++++
drivers/iommu/intel/svm.c | 397 -----------------------------------------
5 files changed, 423 insertions(+), 418 deletions(-)
diff --git a/drivers/iommu/intel/Makefile b/drivers/iommu/intel/Makefile
index c8beb0281559..d3bb0798092d 100644
--- a/drivers/iommu/intel/Makefile
+++ b/drivers/iommu/intel/Makefile
@@ -1,6 +1,6 @@
# SPDX-License-Identifier: GPL-2.0
obj-$(CONFIG_DMAR_TABLE) += dmar.o
-obj-$(CONFIG_INTEL_IOMMU) += iommu.o pasid.o nested.o cache.o
+obj-$(CONFIG_INTEL_IOMMU) += iommu.o pasid.o nested.o cache.o prq.o
obj-$(CONFIG_DMAR_TABLE) += trace.o cap_audit.o
obj-$(CONFIG_DMAR_PERF) += perf.o
obj-$(CONFIG_INTEL_IOMMU_DEBUGFS) += debugfs.o
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index 4aa070cf56e7..5acc52c62e8c 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -1487,12 +1487,10 @@ static void free_dmar_iommu(struct intel_iommu *iommu)
/* free context mapping */
free_context_table(iommu);
-#ifdef CONFIG_INTEL_IOMMU_SVM
if (pasid_supported(iommu)) {
if (ecap_prs(iommu->ecap))
- intel_svm_finish_prq(iommu);
+ intel_finish_prq(iommu);
}
-#endif
}
/*
@@ -2482,19 +2480,18 @@ static int __init init_dmars(void)
iommu_flush_write_buffer(iommu);
-#ifdef CONFIG_INTEL_IOMMU_SVM
if (pasid_supported(iommu) && ecap_prs(iommu->ecap)) {
/*
* Call dmar_alloc_hwirq() with dmar_global_lock held,
* could cause possible lock race condition.
*/
up_write(&dmar_global_lock);
- ret = intel_svm_enable_prq(iommu);
+ ret = intel_enable_prq(iommu);
down_write(&dmar_global_lock);
if (ret)
goto free_iommu;
}
-#endif
+
ret = dmar_set_interrupt(iommu);
if (ret)
goto free_iommu;
@@ -2924,13 +2921,12 @@ static int intel_iommu_add(struct dmar_drhd_unit *dmaru)
intel_iommu_init_qi(iommu);
iommu_flush_write_buffer(iommu);
-#ifdef CONFIG_INTEL_IOMMU_SVM
if (pasid_supported(iommu) && ecap_prs(iommu->ecap)) {
- ret = intel_svm_enable_prq(iommu);
+ ret = intel_enable_prq(iommu);
if (ret)
goto disable_iommu;
}
-#endif
+
ret = dmar_set_interrupt(iommu);
if (ret)
goto disable_iommu;
@@ -4673,9 +4669,7 @@ const struct iommu_ops intel_iommu_ops = {
.def_domain_type = device_def_domain_type,
.remove_dev_pasid = intel_iommu_remove_dev_pasid,
.pgsize_bitmap = SZ_4K,
-#ifdef CONFIG_INTEL_IOMMU_SVM
- .page_response = intel_svm_page_response,
-#endif
+ .page_response = intel_page_response,
.default_domain_ops = &(const struct iommu_domain_ops) {
.attach_dev = intel_iommu_attach_device,
.set_dev_pasid = intel_iommu_set_dev_pasid,
diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index a969be2258b1..3bce514e1d88 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -719,12 +719,10 @@ struct intel_iommu {
struct iommu_flush flush;
#endif
-#ifdef CONFIG_INTEL_IOMMU_SVM
struct page_req_dsc *prq;
unsigned char prq_name[16]; /* Name for PRQ interrupt */
unsigned long prq_seq_number;
struct completion prq_complete;
-#endif
struct iopf_queue *iopf_queue;
unsigned char iopfq_name[16];
/* Synchronization between fault report and iommu device release. */
@@ -1156,18 +1154,18 @@ void intel_context_flush_present(struct device_domain_info *info,
struct context_entry *context,
u16 did, bool affect_domains);
+int intel_enable_prq(struct intel_iommu *iommu);
+int intel_finish_prq(struct intel_iommu *iommu);
+void intel_page_response(struct device *dev, struct iopf_fault *evt,
+ struct iommu_page_response *msg);
+void intel_drain_pasid_prq(struct device *dev, u32 pasid);
+
#ifdef CONFIG_INTEL_IOMMU_SVM
void intel_svm_check(struct intel_iommu *iommu);
-int intel_svm_enable_prq(struct intel_iommu *iommu);
-int intel_svm_finish_prq(struct intel_iommu *iommu);
-void intel_svm_page_response(struct device *dev, struct iopf_fault *evt,
- struct iommu_page_response *msg);
struct iommu_domain *intel_svm_domain_alloc(struct device *dev,
struct mm_struct *mm);
-void intel_drain_pasid_prq(struct device *dev, u32 pasid);
#else
static inline void intel_svm_check(struct intel_iommu *iommu) {}
-static inline void intel_drain_pasid_prq(struct device *dev, u32 pasid) {}
static inline struct iommu_domain *intel_svm_domain_alloc(struct device *dev,
struct mm_struct *mm)
{
diff --git a/drivers/iommu/intel/prq.c b/drivers/iommu/intel/prq.c
new file mode 100644
index 000000000000..3376f60082b5
--- /dev/null
+++ b/drivers/iommu/intel/prq.c
@@ -0,0 +1,410 @@
+// SPDX-License-Identifier: GPL-2.0-only
+/*
+ * Copyright © 2015 Intel Corporation.
+ *
+ * Originally split from drivers/iommu/intel/svm.c
+ */
+
+#include <linux/pci.h>
+#include <linux/pci-ats.h>
+
+#include "iommu.h"
+#include "../iommu-pages.h"
+#include "trace.h"
+
+/* Page request queue descriptor */
+struct page_req_dsc {
+ union {
+ struct {
+ u64 type:8;
+ u64 pasid_present:1;
+ u64 rsvd:7;
+ 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 qw_2;
+ u64 qw_3;
+};
+
+/**
+ * intel_drain_pasid_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.
+ */
+void intel_drain_pasid_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 = dev_iommu_priv_get(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_id_iommu(domain, iommu);
+ 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;
+ }
+
+ iopf_queue_flush_dev(dev);
+
+ /*
+ * 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 bool is_canonical_address(u64 addr)
+{
+ int shift = 64 - (__VIRTUAL_MASK_SHIFT + 1);
+ long saddr = (long) addr;
+
+ return (((saddr << shift) >> shift) == saddr);
+}
+
+static void handle_bad_prq_event(struct intel_iommu *iommu,
+ struct page_req_dsc *req, int result)
+{
+ struct qi_desc desc = { };
+
+ pr_err("%s: Invalid page request: %08llx %08llx\n",
+ iommu->name, ((unsigned long long *)req)[0],
+ ((unsigned long long *)req)[1]);
+
+ if (!req->lpig)
+ return;
+
+ desc.qw0 = QI_PGRP_PASID(req->pasid) |
+ QI_PGRP_DID(req->rid) |
+ QI_PGRP_PASID_P(req->pasid_present) |
+ QI_PGRP_RESP_CODE(result) |
+ QI_PGRP_RESP_TYPE;
+ desc.qw1 = QI_PGRP_IDX(req->prg_index) |
+ QI_PGRP_LPIG(req->lpig);
+
+ qi_submit_sync(iommu, &desc, 1, 0);
+}
+
+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 void intel_prq_report(struct intel_iommu *iommu, struct device *dev,
+ struct page_req_dsc *desc)
+{
+ struct iopf_fault event = { };
+
+ /* Fill in event data for device specific processing */
+ event.fault.type = IOMMU_FAULT_PAGE_REQ;
+ event.fault.prm.addr = (u64)desc->addr << VTD_PAGE_SHIFT;
+ 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;
+ }
+
+ iommu_report_device_fault(dev, &event);
+}
+
+static irqreturn_t prq_event_thread(int irq, void *d)
+{
+ struct intel_iommu *iommu = d;
+ struct page_req_dsc *req;
+ int head, tail, handled;
+ struct device *dev;
+ u64 address;
+
+ /*
+ * 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;
+ handled = (head != tail);
+ while (head != tail) {
+ req = &iommu->prq[head / sizeof(*req)];
+ address = (u64)req->addr << VTD_PAGE_SHIFT;
+
+ if (unlikely(!req->pasid_present)) {
+ pr_err("IOMMU: %s: Page request without PASID\n",
+ iommu->name);
+bad_req:
+ handle_bad_prq_event(iommu, req, QI_RESP_INVALID);
+ goto prq_advance;
+ }
+
+ if (unlikely(!is_canonical_address(address))) {
+ pr_err("IOMMU: %s: Address is not canonical\n",
+ iommu->name);
+ goto bad_req;
+ }
+
+ if (unlikely(req->pm_req && (req->rd_req | req->wr_req))) {
+ pr_err("IOMMU: %s: Page request in Privilege Mode\n",
+ iommu->name);
+ goto bad_req;
+ }
+
+ if (unlikely(req->exe_req && req->rd_req)) {
+ pr_err("IOMMU: %s: Execution request not supported\n",
+ iommu->name);
+ goto bad_req;
+ }
+
+ /* Drop Stop Marker message. No need for a response. */
+ if (unlikely(req->lpig && !req->rd_req && !req->wr_req))
+ goto prq_advance;
+
+ /*
+ * If prq is to be handled outside iommu driver via receiver of
+ * the fault notifiers, we skip the page response here.
+ */
+ mutex_lock(&iommu->iopf_lock);
+ dev = device_rbtree_find(iommu, req->rid);
+ if (!dev) {
+ mutex_unlock(&iommu->iopf_lock);
+ goto bad_req;
+ }
+
+ intel_prq_report(iommu, dev, req);
+ trace_prq_report(iommu, dev, req->qw_0, req->qw_1,
+ req->qw_2, req->qw_3,
+ iommu->prq_seq_number++);
+ mutex_unlock(&iommu->iopf_lock);
+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) {
+ iopf_queue_discard_partial(iommu->iopf_queue);
+ 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);
+}
+
+int intel_enable_prq(struct intel_iommu *iommu)
+{
+ struct iopf_queue *iopfq;
+ int irq, ret;
+
+ iommu->prq = iommu_alloc_pages_node(iommu->node, GFP_KERNEL, PRQ_ORDER);
+ if (!iommu->prq) {
+ pr_warn("IOMMU: %s: Failed to allocate page request queue\n",
+ iommu->name);
+ return -ENOMEM;
+ }
+
+ irq = dmar_alloc_hwirq(IOMMU_IRQ_ID_OFFSET_PRQ + 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;
+ goto free_prq;
+ }
+ iommu->pr_irq = irq;
+
+ snprintf(iommu->iopfq_name, sizeof(iommu->iopfq_name),
+ "dmar%d-iopfq", iommu->seq_id);
+ iopfq = iopf_queue_alloc(iommu->iopfq_name);
+ if (!iopfq) {
+ pr_err("IOMMU: %s: Failed to allocate iopf queue\n", iommu->name);
+ ret = -ENOMEM;
+ goto free_hwirq;
+ }
+ iommu->iopf_queue = iopfq;
+
+ 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);
+ goto free_iopfq;
+ }
+ 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;
+
+free_iopfq:
+ iopf_queue_free(iommu->iopf_queue);
+ iommu->iopf_queue = NULL;
+free_hwirq:
+ dmar_free_hwirq(irq);
+ iommu->pr_irq = 0;
+free_prq:
+ iommu_free_pages(iommu->prq, PRQ_ORDER);
+ iommu->prq = NULL;
+
+ return ret;
+}
+
+int intel_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;
+ }
+
+ if (iommu->iopf_queue) {
+ iopf_queue_free(iommu->iopf_queue);
+ iommu->iopf_queue = NULL;
+ }
+
+ iommu_free_pages(iommu->prq, PRQ_ORDER);
+ iommu->prq = NULL;
+
+ return 0;
+}
+
+void intel_page_response(struct device *dev, struct iopf_fault *evt,
+ struct iommu_page_response *msg)
+{
+ struct device_domain_info *info = dev_iommu_priv_get(dev);
+ struct intel_iommu *iommu = info->iommu;
+ u8 bus = info->bus, devfn = info->devfn;
+ struct iommu_fault_page_request *prm;
+ struct qi_desc desc;
+ bool pasid_present;
+ bool last_page;
+ u16 sid;
+
+ prm = &evt->fault.prm;
+ sid = PCI_DEVID(bus, devfn);
+ pasid_present = prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID;
+ last_page = prm->flags & IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE;
+
+ desc.qw0 = QI_PGRP_PASID(prm->pasid) | QI_PGRP_DID(sid) |
+ QI_PGRP_PASID_P(pasid_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;
+
+ qi_submit_sync(iommu, &desc, 1, 0);
+}
+
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 0e3a9b38bef2..6ab7d9d03d3d 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -25,92 +25,6 @@
#include "../iommu-pages.h"
#include "trace.h"
-static irqreturn_t prq_event_thread(int irq, void *d);
-
-int intel_svm_enable_prq(struct intel_iommu *iommu)
-{
- struct iopf_queue *iopfq;
- int irq, ret;
-
- iommu->prq = iommu_alloc_pages_node(iommu->node, GFP_KERNEL, PRQ_ORDER);
- if (!iommu->prq) {
- pr_warn("IOMMU: %s: Failed to allocate page request queue\n",
- iommu->name);
- return -ENOMEM;
- }
-
- irq = dmar_alloc_hwirq(IOMMU_IRQ_ID_OFFSET_PRQ + 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;
- goto free_prq;
- }
- iommu->pr_irq = irq;
-
- snprintf(iommu->iopfq_name, sizeof(iommu->iopfq_name),
- "dmar%d-iopfq", iommu->seq_id);
- iopfq = iopf_queue_alloc(iommu->iopfq_name);
- if (!iopfq) {
- pr_err("IOMMU: %s: Failed to allocate iopf queue\n", iommu->name);
- ret = -ENOMEM;
- goto free_hwirq;
- }
- iommu->iopf_queue = iopfq;
-
- 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);
- goto free_iopfq;
- }
- 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;
-
-free_iopfq:
- iopf_queue_free(iommu->iopf_queue);
- iommu->iopf_queue = NULL;
-free_hwirq:
- dmar_free_hwirq(irq);
- iommu->pr_irq = 0;
-free_prq:
- iommu_free_pages(iommu->prq, PRQ_ORDER);
- iommu->prq = NULL;
-
- return ret;
-}
-
-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;
- }
-
- if (iommu->iopf_queue) {
- iopf_queue_free(iommu->iopf_queue);
- iommu->iopf_queue = NULL;
- }
-
- iommu_free_pages(iommu->prq, PRQ_ORDER);
- iommu->prq = NULL;
-
- return 0;
-}
-
void intel_svm_check(struct intel_iommu *iommu)
{
if (!pasid_supported(iommu))
@@ -237,317 +151,6 @@ static int intel_svm_set_dev_pasid(struct iommu_domain *domain,
return ret;
}
-/* Page request queue descriptor */
-struct page_req_dsc {
- union {
- struct {
- u64 type:8;
- u64 pasid_present:1;
- u64 rsvd:7;
- 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 qw_2;
- u64 qw_3;
-};
-
-static bool is_canonical_address(u64 addr)
-{
- int shift = 64 - (__VIRTUAL_MASK_SHIFT + 1);
- long saddr = (long) addr;
-
- return (((saddr << shift) >> shift) == saddr);
-}
-
-/**
- * intel_drain_pasid_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.
- */
-void intel_drain_pasid_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 = dev_iommu_priv_get(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_id_iommu(domain, iommu);
- 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;
- }
-
- iopf_queue_flush_dev(dev);
-
- /*
- * 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 void intel_svm_prq_report(struct intel_iommu *iommu, struct device *dev,
- struct page_req_dsc *desc)
-{
- struct iopf_fault event = { };
-
- /* Fill in event data for device specific processing */
- event.fault.type = IOMMU_FAULT_PAGE_REQ;
- event.fault.prm.addr = (u64)desc->addr << VTD_PAGE_SHIFT;
- 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;
- }
-
- iommu_report_device_fault(dev, &event);
-}
-
-static void handle_bad_prq_event(struct intel_iommu *iommu,
- struct page_req_dsc *req, int result)
-{
- struct qi_desc desc = { };
-
- pr_err("%s: Invalid page request: %08llx %08llx\n",
- iommu->name, ((unsigned long long *)req)[0],
- ((unsigned long long *)req)[1]);
-
- if (!req->lpig)
- return;
-
- desc.qw0 = QI_PGRP_PASID(req->pasid) |
- QI_PGRP_DID(req->rid) |
- QI_PGRP_PASID_P(req->pasid_present) |
- QI_PGRP_RESP_CODE(result) |
- QI_PGRP_RESP_TYPE;
- desc.qw1 = QI_PGRP_IDX(req->prg_index) |
- QI_PGRP_LPIG(req->lpig);
-
- qi_submit_sync(iommu, &desc, 1, 0);
-}
-
-static irqreturn_t prq_event_thread(int irq, void *d)
-{
- struct intel_iommu *iommu = d;
- struct page_req_dsc *req;
- int head, tail, handled;
- struct device *dev;
- u64 address;
-
- /*
- * 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;
- handled = (head != tail);
- while (head != tail) {
- req = &iommu->prq[head / sizeof(*req)];
- address = (u64)req->addr << VTD_PAGE_SHIFT;
-
- if (unlikely(!req->pasid_present)) {
- pr_err("IOMMU: %s: Page request without PASID\n",
- iommu->name);
-bad_req:
- handle_bad_prq_event(iommu, req, QI_RESP_INVALID);
- goto prq_advance;
- }
-
- if (unlikely(!is_canonical_address(address))) {
- pr_err("IOMMU: %s: Address is not canonical\n",
- iommu->name);
- goto bad_req;
- }
-
- if (unlikely(req->pm_req && (req->rd_req | req->wr_req))) {
- pr_err("IOMMU: %s: Page request in Privilege Mode\n",
- iommu->name);
- goto bad_req;
- }
-
- if (unlikely(req->exe_req && req->rd_req)) {
- pr_err("IOMMU: %s: Execution request not supported\n",
- iommu->name);
- goto bad_req;
- }
-
- /* Drop Stop Marker message. No need for a response. */
- if (unlikely(req->lpig && !req->rd_req && !req->wr_req))
- goto prq_advance;
-
- /*
- * If prq is to be handled outside iommu driver via receiver of
- * the fault notifiers, we skip the page response here.
- */
- mutex_lock(&iommu->iopf_lock);
- dev = device_rbtree_find(iommu, req->rid);
- if (!dev) {
- mutex_unlock(&iommu->iopf_lock);
- goto bad_req;
- }
-
- intel_svm_prq_report(iommu, dev, req);
- trace_prq_report(iommu, dev, req->qw_0, req->qw_1,
- req->qw_2, req->qw_3,
- iommu->prq_seq_number++);
- mutex_unlock(&iommu->iopf_lock);
-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) {
- iopf_queue_discard_partial(iommu->iopf_queue);
- 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);
-}
-
-void intel_svm_page_response(struct device *dev, struct iopf_fault *evt,
- struct iommu_page_response *msg)
-{
- struct device_domain_info *info = dev_iommu_priv_get(dev);
- struct intel_iommu *iommu = info->iommu;
- u8 bus = info->bus, devfn = info->devfn;
- struct iommu_fault_page_request *prm;
- struct qi_desc desc;
- bool pasid_present;
- bool last_page;
- u16 sid;
-
- prm = &evt->fault.prm;
- sid = PCI_DEVID(bus, devfn);
- pasid_present = prm->flags & IOMMU_FAULT_PAGE_REQUEST_PASID_VALID;
- last_page = prm->flags & IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE;
-
- desc.qw0 = QI_PGRP_PASID(prm->pasid) | QI_PGRP_DID(sid) |
- QI_PGRP_PASID_P(pasid_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;
-
- qi_submit_sync(iommu, &desc, 1, 0);
-}
-
static void intel_svm_domain_free(struct iommu_domain *domain)
{
struct dmar_domain *dmar_domain = to_dmar_domain(domain);
--
2.43.0
> From: Joel Granados via B4 Relay
> <devnull+j.granados.samsung.com@kernel.org>
>
> From: Joel Granados <j.granados@samsung.com>
>
> IO page faults are no longer dependent on CONFIG_INTEL_IOMMU_SVM.
> Move
> all Page Request Queue (PRQ) functions that handle prq events to a new
> file in drivers/iommu/intel/prq.c. The page_req_des struct is now
> declared in drivers/iommu/intel/prq.c.
>
> No functional changes are intended. This is a preparation patch to
> enable the use of IO page faults outside the SVM/PASID use cases.
Do we want to guard it under a new config option e.g.
CONFIG_INTEL_IOMMU_IOPF? it's unnecessary to allocate resources
for the majority usages which don't require IOPF.
Baolu?
> -#ifdef CONFIG_INTEL_IOMMU_SVM
> if (pasid_supported(iommu)) {
> if (ecap_prs(iommu->ecap))
> - intel_svm_finish_prq(iommu);
> + intel_finish_prq(iommu);
> }
> -#endif
either intel_iommu_finish_prq() or intel_prq_finish().
same for other helpers.
On Sat, Sep 14, 2024 at 12:52:22AM +0000, Tian, Kevin wrote:
> > From: Joel Granados via B4 Relay
> > <devnull+j.granados.samsung.com@kernel.org>
> >
> > From: Joel Granados <j.granados@samsung.com>
> >
> > IO page faults are no longer dependent on CONFIG_INTEL_IOMMU_SVM.
> > Move
> > all Page Request Queue (PRQ) functions that handle prq events to a new
> > file in drivers/iommu/intel/prq.c. The page_req_des struct is now
> > declared in drivers/iommu/intel/prq.c.
> >
> > No functional changes are intended. This is a preparation patch to
> > enable the use of IO page faults outside the SVM/PASID use cases.
>
> Do we want to guard it under a new config option e.g.
> CONFIG_INTEL_IOMMU_IOPF? it's unnecessary to allocate resources
> for the majority usages which don't require IOPF.
>
> Baolu?
>
> > -#ifdef CONFIG_INTEL_IOMMU_SVM
> > if (pasid_supported(iommu)) {
> > if (ecap_prs(iommu->ecap))
> > - intel_svm_finish_prq(iommu);
> > + intel_finish_prq(iommu);
> > }
> > -#endif
>
> either intel_iommu_finish_prq() or intel_prq_finish().
Thx; I see the pattern now! The first (Adding "_iommu_" to the name)
makes more sense to me as I see some intel_iommu_* function further down
in the iommu.h file.
>
> same for other helpers.
Will change for the next version
Best
--
Joel Granados
On 9/14/24 8:52 AM, Tian, Kevin wrote: >> From: Joel Granados via B4 Relay >> <devnull+j.granados.samsung.com@kernel.org> >> >> From: Joel Granados<j.granados@samsung.com> >> >> IO page faults are no longer dependent on CONFIG_INTEL_IOMMU_SVM. >> Move >> all Page Request Queue (PRQ) functions that handle prq events to a new >> file in drivers/iommu/intel/prq.c. The page_req_des struct is now >> declared in drivers/iommu/intel/prq.c. >> >> No functional changes are intended. This is a preparation patch to >> enable the use of IO page faults outside the SVM/PASID use cases. > Do we want to guard it under a new config option e.g. > CONFIG_INTEL_IOMMU_IOPF? it's unnecessary to allocate resources > for the majority usages which don't require IOPF. > > Baolu? The OS builder doesn't know if Linux will run on a platform with PRI- capable devices. They'll probably always enable this option if we provide it. This option could be useful for embedded systems, but I'm not sure if any embedded systems have VT-d hardware, which is mainly for high-end PCs or cloud servers. So, maybe we could leave it as is for now and add it later if we see a real use case. Thanks, baolu
> From: Baolu Lu <baolu.lu@linux.intel.com> > Sent: Saturday, September 14, 2024 9:18 AM > > On 9/14/24 8:52 AM, Tian, Kevin wrote: > >> From: Joel Granados via B4 Relay > >> <devnull+j.granados.samsung.com@kernel.org> > >> > >> From: Joel Granados<j.granados@samsung.com> > >> > >> IO page faults are no longer dependent on CONFIG_INTEL_IOMMU_SVM. > >> Move > >> all Page Request Queue (PRQ) functions that handle prq events to a new > >> file in drivers/iommu/intel/prq.c. The page_req_des struct is now > >> declared in drivers/iommu/intel/prq.c. > >> > >> No functional changes are intended. This is a preparation patch to > >> enable the use of IO page faults outside the SVM/PASID use cases. > > Do we want to guard it under a new config option e.g. > > CONFIG_INTEL_IOMMU_IOPF? it's unnecessary to allocate resources > > for the majority usages which don't require IOPF. > > > > Baolu? > > The OS builder doesn't know if Linux will run on a platform with PRI- > capable devices. They'll probably always enable this option if we > provide it. hmm then why do we need a SVM option? In reality I haven't seen a platform which supports IOPF but no pasid/SVM. so the reason for whether to have an option should be same between IOPF/SVM. IMHO the point of options is to allow reducing footprint of the kernel image and many options are probably always enabled in distributions... > > This option could be useful for embedded systems, but I'm not sure if > any embedded systems have VT-d hardware, which is mainly for high-end > PCs or cloud servers. > > So, maybe we could leave it as is for now and add it later if we see a > real use case. >
On 2024/9/14 10:53, Tian, Kevin wrote: >> From: Baolu Lu<baolu.lu@linux.intel.com> >> Sent: Saturday, September 14, 2024 9:18 AM >> >> On 9/14/24 8:52 AM, Tian, Kevin wrote: >>>> From: Joel Granados via B4 Relay >>>> <devnull+j.granados.samsung.com@kernel.org> >>>> >>>> From: Joel Granados<j.granados@samsung.com> >>>> >>>> IO page faults are no longer dependent on CONFIG_INTEL_IOMMU_SVM. >>>> Move >>>> all Page Request Queue (PRQ) functions that handle prq events to a new >>>> file in drivers/iommu/intel/prq.c. The page_req_des struct is now >>>> declared in drivers/iommu/intel/prq.c. >>>> >>>> No functional changes are intended. This is a preparation patch to >>>> enable the use of IO page faults outside the SVM/PASID use cases. >>> Do we want to guard it under a new config option e.g. >>> CONFIG_INTEL_IOMMU_IOPF? it's unnecessary to allocate resources >>> for the majority usages which don't require IOPF. >>> >>> Baolu? >> The OS builder doesn't know if Linux will run on a platform with PRI- >> capable devices. They'll probably always enable this option if we >> provide it. > hmm then why do we need a SVM option? In reality I haven't seen > a platform which supports IOPF but no pasid/SVM. so the reason > for whether to have an option should be same between IOPF/SVM. > > IMHO the point of options is to allow reducing footprint of the kernel > image and many options are probably always enabled in distributions... To be honest, I would hope to remove the SVM option some day. It's nothing special except listening to an external notification and synchronize the caches when the page table is updated. It's common to all cases where a page table is shared between the IOMMU and another component. As for CONFIG_INTEL_IOMMU_IOPF, my suggestion is that we don't need to add any unnecessary options unless we see a real need. Thanks, baolu
> From: Baolu Lu <baolu.lu@linux.intel.com> > Sent: Saturday, September 14, 2024 1:50 PM > > On 2024/9/14 10:53, Tian, Kevin wrote: > >> From: Baolu Lu<baolu.lu@linux.intel.com> > >> Sent: Saturday, September 14, 2024 9:18 AM > >> > >> On 9/14/24 8:52 AM, Tian, Kevin wrote: > >>>> From: Joel Granados via B4 Relay > >>>> <devnull+j.granados.samsung.com@kernel.org> > >>>> > >>>> From: Joel Granados<j.granados@samsung.com> > >>>> > >>>> IO page faults are no longer dependent on > CONFIG_INTEL_IOMMU_SVM. > >>>> Move > >>>> all Page Request Queue (PRQ) functions that handle prq events to a > new > >>>> file in drivers/iommu/intel/prq.c. The page_req_des struct is now > >>>> declared in drivers/iommu/intel/prq.c. > >>>> > >>>> No functional changes are intended. This is a preparation patch to > >>>> enable the use of IO page faults outside the SVM/PASID use cases. > >>> Do we want to guard it under a new config option e.g. > >>> CONFIG_INTEL_IOMMU_IOPF? it's unnecessary to allocate resources > >>> for the majority usages which don't require IOPF. > >>> > >>> Baolu? > >> The OS builder doesn't know if Linux will run on a platform with PRI- > >> capable devices. They'll probably always enable this option if we > >> provide it. > > hmm then why do we need a SVM option? In reality I haven't seen > > a platform which supports IOPF but no pasid/SVM. so the reason > > for whether to have an option should be same between IOPF/SVM. > > > > IMHO the point of options is to allow reducing footprint of the kernel > > image and many options are probably always enabled in distributions... > > To be honest, I would hope to remove the SVM option some day. It's > nothing special except listening to an external notification and > synchronize the caches when the page table is updated. more than that... for each IOMMU the current code allocates 16 pages and 1 hwirq. Those are unnecessary burdens in majority deployments which don't support/require I/O page faults. > It's common to > all cases where a page table is shared between the IOMMU and another > component. but "all cases" with shared page table is actually a small group now. > > As for CONFIG_INTEL_IOMMU_IOPF, my suggestion is that we don't need to > add any unnecessary options unless we see a real need. > so I was thinking the opposite, i.e. keeping the option until doing so becomes a real burden.😊
On 2024/9/18 16:20, Tian, Kevin wrote:
>> From: Baolu Lu<baolu.lu@linux.intel.com>
>> Sent: Saturday, September 14, 2024 1:50 PM
>>
>> On 2024/9/14 10:53, Tian, Kevin wrote:
>>>> From: Baolu Lu<baolu.lu@linux.intel.com>
>>>> Sent: Saturday, September 14, 2024 9:18 AM
>>>>
>>>> On 9/14/24 8:52 AM, Tian, Kevin wrote:
>>>>>> From: Joel Granados via B4 Relay
>>>>>> <devnull+j.granados.samsung.com@kernel.org>
>>>>>>
>>>>>> From: Joel Granados<j.granados@samsung.com>
>>>>>>
>>>>>> IO page faults are no longer dependent on
>> CONFIG_INTEL_IOMMU_SVM.
>>>>>> Move
>>>>>> all Page Request Queue (PRQ) functions that handle prq events to a
>> new
>>>>>> file in drivers/iommu/intel/prq.c. The page_req_des struct is now
>>>>>> declared in drivers/iommu/intel/prq.c.
>>>>>>
>>>>>> No functional changes are intended. This is a preparation patch to
>>>>>> enable the use of IO page faults outside the SVM/PASID use cases.
>>>>> Do we want to guard it under a new config option e.g.
>>>>> CONFIG_INTEL_IOMMU_IOPF? it's unnecessary to allocate resources
>>>>> for the majority usages which don't require IOPF.
>>>>>
>>>>> Baolu?
>>>> The OS builder doesn't know if Linux will run on a platform with PRI-
>>>> capable devices. They'll probably always enable this option if we
>>>> provide it.
>>> hmm then why do we need a SVM option? In reality I haven't seen
>>> a platform which supports IOPF but no pasid/SVM. so the reason
>>> for whether to have an option should be same between IOPF/SVM.
>>>
>>> IMHO the point of options is to allow reducing footprint of the kernel
>>> image and many options are probably always enabled in distributions...
>> To be honest, I would hope to remove the SVM option some day. It's
>> nothing special except listening to an external notification and
>> synchronize the caches when the page table is updated.
> more than that... for each IOMMU the current code allocates 16 pages
> and 1 hwirq. Those are unnecessary burdens in majority deployments
> which don't support/require I/O page faults.
Yeah! I only focused on the kernel binary size but ignored these system
resources consumed by IOPF. Then, perhaps
diff --git a/drivers/iommu/intel/Kconfig b/drivers/iommu/intel/Kconfig
index f52fb39c968e..847a5c43c9dc 100644
--- a/drivers/iommu/intel/Kconfig
+++ b/drivers/iommu/intel/Kconfig
@@ -97,4 +97,7 @@ config INTEL_IOMMU_PERF_EVENTS
to aid performance tuning and debug. These are available on
modern
processors which support Intel VT-d 4.0 and later.
+config INTEL_IOMMU_IOPF
+ depends on IOMMUFD || INTEL_IOMMU_SVM
+
endif # INTEL_IOMMU
diff --git a/drivers/iommu/intel/Makefile b/drivers/iommu/intel/Makefile
index c8beb0281559..c382307ae7aa 100644
--- a/drivers/iommu/intel/Makefile
+++ b/drivers/iommu/intel/Makefile
@@ -5,6 +5,7 @@ obj-$(CONFIG_DMAR_TABLE) += trace.o cap_audit.o
obj-$(CONFIG_DMAR_PERF) += perf.o
obj-$(CONFIG_INTEL_IOMMU_DEBUGFS) += debugfs.o
obj-$(CONFIG_INTEL_IOMMU_SVM) += svm.o
+obj-$(CONFIG_INTEL_IOMMU_IOPF) += prq.o
ifdef CONFIG_INTEL_IOMMU
obj-$(CONFIG_IRQ_REMAP) += irq_remapping.o
endif
?
Thanks,
baolu
On Wed, Sep 18, 2024 at 07:17:32PM +0800, Baolu Lu wrote: > > more than that... for each IOMMU the current code allocates 16 pages > > and 1 hwirq. Those are unnecessary burdens in majority deployments > > which don't support/require I/O page faults. > > Yeah! I only focused on the kernel binary size but ignored these system > resources consumed by IOPF. Then, perhaps If you care about runtime overhead it should be delt with by dynamically allocating the memory and enabling it, not via kconfig We can dynmaically add IRQS in some cases now for instance Jason
On Fri, Sep 20, 2024 at 09:54:34AM -0300, Jason Gunthorpe wrote: > On Wed, Sep 18, 2024 at 07:17:32PM +0800, Baolu Lu wrote: > > > more than that... for each IOMMU the current code allocates 16 pages > > > and 1 hwirq. Those are unnecessary burdens in majority deployments > > > which don't support/require I/O page faults. > > > > Yeah! I only focused on the kernel binary size but ignored these system > > resources consumed by IOPF. Then, perhaps > > If you care about runtime overhead it should be delt with by > dynamically allocating the memory and enabling it, not via kconfig > > We can dynmaically add IRQS in some cases now for instance > > Jason Summary (Please correct if inaccurate): 1. Kevin Tian & Baolu Lu have proposed a kconfig guard (INTEL_IOMMU_IOPF) to avoid unnecessary resource allocation (of 16 pages and 1 hwirq). It can be keep it until it becomes a burden. 2. Jason Gunthorp: runtime overhead should be handled by dynamically allocating memory and enabling it. Not via Kconfig. There was no real consensus reached here. I'll leave IOMMU_IOPF guarded under INTEL_IOMMU (no changes from V2), two reasons for this IMO: 1. The reasoning being that any system that has the resources for INTEL_IOMMU has them for IOMMU_IOPF. 2. If the IOPF resources are a burden, they should be solved by changing the way we allocate memory instead of hiding them behind a kconfig. Quick Note: I am adding my new email to the thread so I get the responses routed to the correct inbox. Best -- Joel Granados
On Sat, Sep 14, 2024 at 01:49:44PM +0800, Baolu Lu wrote: > On 2024/9/14 10:53, Tian, Kevin wrote: > > > From: Baolu Lu<baolu.lu@linux.intel.com> > > > Sent: Saturday, September 14, 2024 9:18 AM > > > > > > On 9/14/24 8:52 AM, Tian, Kevin wrote: > > > > > From: Joel Granados via B4 Relay > > > > > <devnull+j.granados.samsung.com@kernel.org> > > > > > > > > > > From: Joel Granados<j.granados@samsung.com> > > > > > > > > > > IO page faults are no longer dependent on CONFIG_INTEL_IOMMU_SVM. > > > > > Move > > > > > all Page Request Queue (PRQ) functions that handle prq events to a new > > > > > file in drivers/iommu/intel/prq.c. The page_req_des struct is now > > > > > declared in drivers/iommu/intel/prq.c. > > > > > > > > > > No functional changes are intended. This is a preparation patch to > > > > > enable the use of IO page faults outside the SVM/PASID use cases. > > > > Do we want to guard it under a new config option e.g. > > > > CONFIG_INTEL_IOMMU_IOPF? it's unnecessary to allocate resources > > > > for the majority usages which don't require IOPF. > > > > > > > > Baolu? > > > The OS builder doesn't know if Linux will run on a platform with PRI- > > > capable devices. They'll probably always enable this option if we > > > provide it. > > hmm then why do we need a SVM option? In reality I haven't seen > > a platform which supports IOPF but no pasid/SVM. so the reason > > for whether to have an option should be same between IOPF/SVM. > > > > IMHO the point of options is to allow reducing footprint of the kernel > > image and many options are probably always enabled in distributions... > > To be honest, I would hope to remove the SVM option some day. It's > nothing special except listening to an external notification and > synchronize the caches when the page table is updated. It's common to > all cases where a page table is shared between the IOMMU and another > component. > > As for CONFIG_INTEL_IOMMU_IOPF, my suggestion is that we don't need to > add any unnecessary options unless we see a real need. You could possibly bundle the SVA and IOPF options together I called the new option on the ARM side CONFIG_ARM_SMMU_V3_IOMMUFD which seems like a reasonable cut point against embedded vs server. Jason
On 9/15/24 9:49 PM, Jason Gunthorpe wrote: > On Sat, Sep 14, 2024 at 01:49:44PM +0800, Baolu Lu wrote: >> On 2024/9/14 10:53, Tian, Kevin wrote: >>>> From: Baolu Lu<baolu.lu@linux.intel.com> >>>> Sent: Saturday, September 14, 2024 9:18 AM >>>> >>>> On 9/14/24 8:52 AM, Tian, Kevin wrote: >>>>>> From: Joel Granados via B4 Relay >>>>>> <devnull+j.granados.samsung.com@kernel.org> >>>>>> >>>>>> From: Joel Granados<j.granados@samsung.com> >>>>>> >>>>>> IO page faults are no longer dependent on CONFIG_INTEL_IOMMU_SVM. >>>>>> Move >>>>>> all Page Request Queue (PRQ) functions that handle prq events to a new >>>>>> file in drivers/iommu/intel/prq.c. The page_req_des struct is now >>>>>> declared in drivers/iommu/intel/prq.c. >>>>>> >>>>>> No functional changes are intended. This is a preparation patch to >>>>>> enable the use of IO page faults outside the SVM/PASID use cases. >>>>> Do we want to guard it under a new config option e.g. >>>>> CONFIG_INTEL_IOMMU_IOPF? it's unnecessary to allocate resources >>>>> for the majority usages which don't require IOPF. >>>>> >>>>> Baolu? >>>> The OS builder doesn't know if Linux will run on a platform with PRI- >>>> capable devices. They'll probably always enable this option if we >>>> provide it. >>> hmm then why do we need a SVM option? In reality I haven't seen >>> a platform which supports IOPF but no pasid/SVM. so the reason >>> for whether to have an option should be same between IOPF/SVM. >>> >>> IMHO the point of options is to allow reducing footprint of the kernel >>> image and many options are probably always enabled in distributions... >> To be honest, I would hope to remove the SVM option some day. It's >> nothing special except listening to an external notification and >> synchronize the caches when the page table is updated. It's common to >> all cases where a page table is shared between the IOMMU and another >> component. >> >> As for CONFIG_INTEL_IOMMU_IOPF, my suggestion is that we don't need to >> add any unnecessary options unless we see a real need. > You could possibly bundle the SVA and IOPF options together > > I called the new option on the ARM side CONFIG_ARM_SMMU_V3_IOMMUFD > which seems like a reasonable cut point against embedded vs server. Probably I will consider this after this series. This is not intel iommu specific, hence it's better to make it consistent for all drivers. Thanks, baolu
On Sun, Sep 15, 2024 at 10:49:28AM -0300, Jason Gunthorpe wrote: > On Sat, Sep 14, 2024 at 01:49:44PM +0800, Baolu Lu wrote: > > On 2024/9/14 10:53, Tian, Kevin wrote: > > > > From: Baolu Lu<baolu.lu@linux.intel.com> > > > > Sent: Saturday, September 14, 2024 9:18 AM > > > > > > > > On 9/14/24 8:52 AM, Tian, Kevin wrote: > > > > > > From: Joel Granados via B4 Relay > > > > > > <devnull+j.granados.samsung.com@kernel.org> > > > > > > > > > > > > From: Joel Granados<j.granados@samsung.com> > > > > > > > > > > > > IO page faults are no longer dependent on CONFIG_INTEL_IOMMU_SVM. > > > > > > Move > > > > > > all Page Request Queue (PRQ) functions that handle prq events to a new > > > > > > file in drivers/iommu/intel/prq.c. The page_req_des struct is now > > > > > > declared in drivers/iommu/intel/prq.c. > > > > > > > > > > > > No functional changes are intended. This is a preparation patch to > > > > > > enable the use of IO page faults outside the SVM/PASID use cases. > > > > > Do we want to guard it under a new config option e.g. > > > > > CONFIG_INTEL_IOMMU_IOPF? it's unnecessary to allocate resources > > > > > for the majority usages which don't require IOPF. > > > > > > > > > > Baolu? > > > > The OS builder doesn't know if Linux will run on a platform with PRI- > > > > capable devices. They'll probably always enable this option if we > > > > provide it. > > > hmm then why do we need a SVM option? In reality I haven't seen > > > a platform which supports IOPF but no pasid/SVM. so the reason > > > for whether to have an option should be same between IOPF/SVM. > > > > > > IMHO the point of options is to allow reducing footprint of the kernel > > > image and many options are probably always enabled in distributions... > > > > To be honest, I would hope to remove the SVM option some day. It's > > nothing special except listening to an external notification and > > synchronize the caches when the page table is updated. It's common to > > all cases where a page table is shared between the IOMMU and another > > component. > > > > As for CONFIG_INTEL_IOMMU_IOPF, my suggestion is that we don't need to > > add any unnecessary options unless we see a real need. > > You could possibly bundle the SVA and IOPF options together > > I called the new option on the ARM side CONFIG_ARM_SMMU_V3_IOMMUFD > which seems like a reasonable cut point against embedded vs server. I'll go with Baolu's suggestion of leaving as is for my V3. Thx for the review -- Joel Granados
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