[PATCH 2/2] iommu/vt-d: Remove private data use in fault message

From: Jingqi Liu
Date: Fri Mar 08 2024 - 05:41:05 EST


According to Intel VT-d specification revision 4.0, "Private Data"
field has been removed from Page Request/Response.

Since the private data field is not used in fault message, remove the
related definitions in page request descriptor and remove the related
code in page request/response handler, as Intel hasn't shipped any
products which support private data in the page request message.

Signed-off-by: Jingqi Liu <Jingqi.liu@xxxxxxxxx>
---
drivers/iommu/intel/iommu.h | 1 -
drivers/iommu/intel/svm.c | 75 ++++++++-----------------------------
include/linux/iommu.h | 3 +-
3 files changed, 16 insertions(+), 63 deletions(-)

diff --git a/drivers/iommu/intel/iommu.h b/drivers/iommu/intel/iommu.h
index 404d2476a877..9ee326f7bf62 100644
--- a/drivers/iommu/intel/iommu.h
+++ b/drivers/iommu/intel/iommu.h
@@ -455,7 +455,6 @@ enum {

/* Page group response descriptor QW0 */
#define QI_PGRP_PASID_P(p) (((u64)(p)) << 4)
-#define QI_PGRP_PDP(p) (((u64)(p)) << 5)
#define QI_PGRP_RESP_CODE(res) (((u64)(res)) << 12)
#define QI_PGRP_DID(rid) (((u64)(rid)) << 16)
#define QI_PGRP_PASID(pasid) (((u64)(pasid)) << 32)
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 4b2eeb55489d..699bef9b9197 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -418,8 +418,7 @@ struct page_req_dsc {
struct {
u64 type:8;
u64 pasid_present:1;
- u64 priv_data_present:1;
- u64 rsvd:6;
+ u64 rsvd:7;
u64 rid:16;
u64 pasid:20;
u64 exe_req:1;
@@ -438,7 +437,8 @@ struct page_req_dsc {
};
u64 qw_1;
};
- u64 priv_data[2];
+ u64 qw_2;
+ u64 qw_3;
};

static bool is_canonical_address(u64 addr)
@@ -572,18 +572,6 @@ static void intel_svm_prq_report(struct intel_iommu *iommu, struct device *dev,
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;
- event.fault.prm.private_data[0] = desc->priv_data[0];
- event.fault.prm.private_data[1] = desc->priv_data[1];
- }

iommu_report_device_fault(dev, &event);
}
@@ -591,39 +579,23 @@ static void intel_svm_prq_report(struct intel_iommu *iommu, struct device *dev,
static void handle_bad_prq_event(struct intel_iommu *iommu,
struct page_req_dsc *req, int result)
{
- struct qi_desc desc;
+ 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]);

- /*
- * 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.
- */
- if (!req->lpig && !req->priv_data_present)
+ 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_PDP(req->priv_data_present) |
QI_PGRP_RESP_CODE(result) |
QI_PGRP_RESP_TYPE;
desc.qw1 = QI_PGRP_IDX(req->prg_index) |
QI_PGRP_LPIG(req->lpig);

- if (req->priv_data_present) {
- desc.qw2 = req->priv_data[0];
- desc.qw3 = req->priv_data[1];
- } else {
- desc.qw2 = 0;
- desc.qw3 = 0;
- }
-
qi_submit_sync(iommu, &desc, 1, 0);
}

@@ -691,7 +663,7 @@ static irqreturn_t prq_event_thread(int irq, void *d)

intel_svm_prq_report(iommu, dev, req);
trace_prq_report(iommu, dev, req->qw_0, req->qw_1,
- req->priv_data[0], req->priv_data[1],
+ req->qw_2, req->qw_3,
iommu->prq_seq_number++);
mutex_unlock(&iommu->iopf_lock);
prq_advance:
@@ -730,7 +702,7 @@ void intel_svm_page_response(struct device *dev, struct iopf_fault *evt,
struct intel_iommu *iommu = info->iommu;
u8 bus = info->bus, devfn = info->devfn;
struct iommu_fault_page_request *prm;
- bool private_present;
+ struct qi_desc desc;
bool pasid_present;
bool last_page;
u16 sid;
@@ -738,34 +710,17 @@ void intel_svm_page_response(struct device *dev, struct iopf_fault *evt,
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;

- /*
- * 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) {
- desc.qw2 = prm->private_data[0];
- desc.qw3 = prm->private_data[1];
- }
+ 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);
- }
+ qi_submit_sync(iommu, &desc, 1, 0);
}

static void intel_svm_domain_free(struct iommu_domain *domain)
diff --git a/include/linux/iommu.h b/include/linux/iommu.h
index af6c367ed673..523bcb672efe 100644
--- a/include/linux/iommu.h
+++ b/include/linux/iommu.h
@@ -69,8 +69,7 @@ enum iommu_fault_type {
struct iommu_fault_page_request {
#define IOMMU_FAULT_PAGE_REQUEST_PASID_VALID (1 << 0)
#define IOMMU_FAULT_PAGE_REQUEST_LAST_PAGE (1 << 1)
-#define IOMMU_FAULT_PAGE_REQUEST_PRIV_DATA (1 << 2)
-#define IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID (1 << 3)
+#define IOMMU_FAULT_PAGE_RESPONSE_NEEDS_PASID (1 << 2)
u32 flags;
u32 pasid;
u32 grpid;
--
2.21.3