Re: [PATCH v2 4/4] iommu/vt-d: Add page response ops support
Hi Kevin,
On 7/6/20 9:47 AM, Tian, Kevin wrote:
From: Lu Baolu
Sent: Monday, July 6, 2020 8:26 AM
After a page request is handled, software must response the device which
raised the page request with the handling result. This is done through
'response' is a noun.
Yes.
the iommu ops.page_response if the request was reported to outside of
vendor iommu driver through iommu_report_device_fault(). This adds the
VT-d implementation of page_response ops.
Co-developed-by: Jacob Pan
Signed-off-by: Jacob Pan
Co-developed-by: Liu Yi L
Signed-off-by: Liu Yi L
Signed-off-by: Lu Baolu
---
drivers/iommu/intel/iommu.c | 1 +
drivers/iommu/intel/svm.c | 74
+
include/linux/intel-iommu.h | 3 ++
3 files changed, 78 insertions(+)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index de17952ed133..7eb29167e8f9 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -6057,6 +6057,7 @@ const struct iommu_ops intel_iommu_ops = {
.sva_bind = intel_svm_bind,
.sva_unbind = intel_svm_unbind,
.sva_get_pasid = intel_svm_get_pasid,
+ .page_response = intel_svm_page_response,
#endif
};
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 08c58c2b1a06..1c7d8a9ea124 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -1078,3 +1078,77 @@ int intel_svm_get_pasid(struct iommu_sva *sva)
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;
+ struct intel_iommu *iommu;
+ struct intel_svm *svm;
+ 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;
but we didn't do same check when reporting fault?
For now, we only support PCI devices, so I will add this check in report
as well.
+
+ iommu = device_to_iommu(dev, , );
+ if (!iommu)
+ return -ENODEV;
+
+ if (!msg || !evt)
+ return -EINVAL;
+
+ mutex_lock(_mutex);
+
+ prm = >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) {
+ if (prm->pasid == 0 || prm->pasid >= PASID_MAX) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = pasid_to_svm_sdev(dev, prm->pasid, , );
+ if (ret || !sdev) {
+ ret = -ENODEV;
+ goto out;
+ }
+ }
what about pasid_present==0? Do we support recoverable fault now
with this patch?
For now, we don't support reporting a prq without pasid to outside.
prq_event_thread() handles such requests explicitly. I will add a
check in response ops.
and who guarantees that the external fault handler (e.g. guest)
cannot do bad thing with this interface, e.g. by specifying a PASID
belonging to other guests (when Scalable IOV is enabled)?
I will check below if the response is from user space.
(svm->mm == get_task_mm(current))
Thanks
Kevin
Best regards,
baolu
+
+ /*
+* 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(, prm->private_data,
+ sizeof(prm->private_data));
+
+ qi_submit_sync(iommu, , 1, 0);
+ }
+out:
+ mutex_unlock(_mutex);
+ return ret;
+}
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index fc2cfc3db6e1..bf6009a344f5 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -741,6 +741,9 @@ struct iommu_sva *intel_svm_bind(struct device
*dev, struct mm_struct *mm,
RE: [PATCH v2 4/4] iommu/vt-d: Add page response ops support
> From: Lu Baolu
> Sent: Monday, July 6, 2020 8:26 AM
>
> After a page request is handled, software must response the device which
> raised the page request with the handling result. This is done through
'response' is a noun.
> the iommu ops.page_response if the request was reported to outside of
> vendor iommu driver through iommu_report_device_fault(). This adds the
> VT-d implementation of page_response ops.
>
> Co-developed-by: Jacob Pan
> Signed-off-by: Jacob Pan
> Co-developed-by: Liu Yi L
> Signed-off-by: Liu Yi L
> Signed-off-by: Lu Baolu
> ---
> drivers/iommu/intel/iommu.c | 1 +
> drivers/iommu/intel/svm.c | 74
> +
> include/linux/intel-iommu.h | 3 ++
> 3 files changed, 78 insertions(+)
>
> diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
> index de17952ed133..7eb29167e8f9 100644
> --- a/drivers/iommu/intel/iommu.c
> +++ b/drivers/iommu/intel/iommu.c
> @@ -6057,6 +6057,7 @@ const struct iommu_ops intel_iommu_ops = {
> .sva_bind = intel_svm_bind,
> .sva_unbind = intel_svm_unbind,
> .sva_get_pasid = intel_svm_get_pasid,
> + .page_response = intel_svm_page_response,
> #endif
> };
>
> diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
> index 08c58c2b1a06..1c7d8a9ea124 100644
> --- a/drivers/iommu/intel/svm.c
> +++ b/drivers/iommu/intel/svm.c
> @@ -1078,3 +1078,77 @@ int intel_svm_get_pasid(struct iommu_sva *sva)
>
> 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;
> + struct intel_iommu *iommu;
> + struct intel_svm *svm;
> + 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;
but we didn't do same check when reporting fault?
> +
> + iommu = device_to_iommu(dev, , );
> + if (!iommu)
> + return -ENODEV;
> +
> + if (!msg || !evt)
> + return -EINVAL;
> +
> + mutex_lock(_mutex);
> +
> + prm = >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) {
> + if (prm->pasid == 0 || prm->pasid >= PASID_MAX) {
> + ret = -EINVAL;
> + goto out;
> + }
> +
> + ret = pasid_to_svm_sdev(dev, prm->pasid, , );
> + if (ret || !sdev) {
> + ret = -ENODEV;
> + goto out;
> + }
> + }
what about pasid_present==0? Do we support recoverable fault now
with this patch?
and who guarantees that the external fault handler (e.g. guest)
cannot do bad thing with this interface, e.g. by specifying a PASID
belonging to other guests (when Scalable IOV is enabled)?
Thanks
Kevin
> +
> + /*
> + * 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(, prm->private_data,
> +sizeof(prm->private_data));
> +
> + qi_submit_sync(iommu, , 1, 0);
> + }
> +out:
> + mutex_unlock(_mutex);
> + return ret;
> +}
> diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
> index fc2cfc3db6e1..bf6009a344f5 100644
> --- a/include/linux/intel-iommu.h
> +++ b/include/linux/intel-iommu.h
> @@ -741,6 +741,9 @@ struct iommu_sva *intel_svm_bind(struct device
> *dev, struct mm_struct *mm,
>void *drvdata);
> void intel_svm_unbind(struct iommu_sva *handle);
> int intel_svm_get_pasid(struct iommu_sva *handle);
> +int intel_svm_page_response(struct device *dev, struct iommu_fault_event
> *evt,
> + struct iommu_page_response *msg);
> +
> struct
[PATCH v2 4/4] iommu/vt-d: Add page response ops support
After a page request is handled, software must response the device which
raised the page request with the handling result. This is done through
the iommu ops.page_response if the request was reported to outside of
vendor iommu driver through iommu_report_device_fault(). This adds the
VT-d implementation of page_response ops.
Co-developed-by: Jacob Pan
Signed-off-by: Jacob Pan
Co-developed-by: Liu Yi L
Signed-off-by: Liu Yi L
Signed-off-by: Lu Baolu
---
drivers/iommu/intel/iommu.c | 1 +
drivers/iommu/intel/svm.c | 74 +
include/linux/intel-iommu.h | 3 ++
3 files changed, 78 insertions(+)
diff --git a/drivers/iommu/intel/iommu.c b/drivers/iommu/intel/iommu.c
index de17952ed133..7eb29167e8f9 100644
--- a/drivers/iommu/intel/iommu.c
+++ b/drivers/iommu/intel/iommu.c
@@ -6057,6 +6057,7 @@ const struct iommu_ops intel_iommu_ops = {
.sva_bind = intel_svm_bind,
.sva_unbind = intel_svm_unbind,
.sva_get_pasid = intel_svm_get_pasid,
+ .page_response = intel_svm_page_response,
#endif
};
diff --git a/drivers/iommu/intel/svm.c b/drivers/iommu/intel/svm.c
index 08c58c2b1a06..1c7d8a9ea124 100644
--- a/drivers/iommu/intel/svm.c
+++ b/drivers/iommu/intel/svm.c
@@ -1078,3 +1078,77 @@ int intel_svm_get_pasid(struct iommu_sva *sva)
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;
+ struct intel_iommu *iommu;
+ struct intel_svm *svm;
+ 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, , );
+ if (!iommu)
+ return -ENODEV;
+
+ if (!msg || !evt)
+ return -EINVAL;
+
+ mutex_lock(_mutex);
+
+ prm = >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) {
+ if (prm->pasid == 0 || prm->pasid >= PASID_MAX) {
+ ret = -EINVAL;
+ goto out;
+ }
+
+ ret = pasid_to_svm_sdev(dev, prm->pasid, , );
+ if (ret || !sdev) {
+ ret = -ENODEV;
+ goto out;
+ }
+ }
+
+ /*
+* 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(, prm->private_data,
+ sizeof(prm->private_data));
+
+ qi_submit_sync(iommu, , 1, 0);
+ }
+out:
+ mutex_unlock(_mutex);
+ return ret;
+}
diff --git a/include/linux/intel-iommu.h b/include/linux/intel-iommu.h
index fc2cfc3db6e1..bf6009a344f5 100644
--- a/include/linux/intel-iommu.h
+++ b/include/linux/intel-iommu.h
@@ -741,6 +741,9 @@ struct iommu_sva *intel_svm_bind(struct device *dev, struct
mm_struct *mm,
void *drvdata);
void intel_svm_unbind(struct iommu_sva *handle);
int intel_svm_get_pasid(struct iommu_sva *handle);
+int intel_svm_page_response(struct device *dev, struct iommu_fault_event *evt,
+ struct iommu_page_response *msg);
+
struct svm_dev_ops;
struct intel_svm_dev {
--
2.17.1
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