Write protect bit, when set, inhibits supervisor writes to the read-only
pages. In guest supervisor shared virtual addressing (SVA), write-protect
should be honored upon guest bind supervisor PASID request.
This patch extends the VT-d portion of the IOMMU UAPI to include WP bit.
WPE bit of the supervisor PASID entry will be set to match CPU CR0.WP bit.
Signed-off-by: Sanjay Kumar <sanjay.k.kumar@intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Acked-by: Lu Baolu <baolu.lu@linux.intel.com>
Link: https://lore.kernel.org/r/1614680040-1989-3-git-send-email-jacob.jun.pan@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
IOMMU generic layer already does sanity checks on UAPI data for version
match and argsz range based on generic information.
This patch adjusts the following data checking responsibilities:
- removes the redundant version check from VT-d driver
- removes the check for vendor specific data size
- adds check for the use of reserved/undefined flags
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/1601051567-54787-7-git-send-email-jacob.jun.pan@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
IOMMU user APIs are responsible for processing user data. This patch
changes the interface such that user pointers can be passed into IOMMU
code directly. Separate kernel APIs without user pointers are introduced
for in-kernel users of the UAPI functionality.
IOMMU UAPI data has a user filled argsz field which indicates the data
length of the structure. User data is not trusted, argsz must be
validated based on the current kernel data size, mandatory data size,
and feature flags.
User data may also be extended, resulting in possible argsz increase.
Backward compatibility is ensured based on size and flags (or
the functional equivalent fields) checking.
This patch adds sanity checks in the IOMMU layer. In addition to argsz,
reserved/unused fields in padding, flags, and version are also checked.
Details are documented in Documentation/userspace-api/iommu.rst
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/1601051567-54787-6-git-send-email-jacob.jun.pan@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
IOMMU UAPI data size is filled by the user space which must be validated
by the kernel. To ensure backward compatibility, user data can only be
extended by either re-purpose padding bytes or extend the variable sized
union at the end. No size change is allowed before the union. Therefore,
the minimum size is the offset of the union.
To use offsetof() on the union, we must make it named.
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/linux-iommu/20200611145518.0c2817d6@x1.home/
Link: https://lore.kernel.org/r/1601051567-54787-4-git-send-email-jacob.jun.pan@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
As IOMMU UAPI gets extended, user data size may increase. To support
backward compatibiliy, this patch introduces a size field to each UAPI
data structures. It is *always* the responsibility for the user to fill in
the correct size. Padding fields are adjusted to ensure 8 byte alignment.
Specific scenarios for user data handling are documented in:
Documentation/userspace-api/iommu.rst
As there is no current users of the API, struct version is not
incremented.
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/1601051567-54787-3-git-send-email-jacob.jun.pan@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Some PCIe devices do not expect a PASID value in PRI Page Responses.
If the "PRG Response PASID Required" bit in the PRI capability is zero,
then the OS should not set the PASID field. Similarly on Arm SMMU,
responses to stall events do not have a PASID.
Currently iommu_page_response() systematically checks that the PASID in
the page response corresponds to the one in the page request. This can't
work with virtualization because a page response coming from a guest OS
won't have a PASID if the passed-through device does not require one.
Add a flag to page requests that declares whether the corresponding
response needs to have a PASID. When this flag isn't set, allow page
responses without PASID.
Reported-by: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Link: https://lore.kernel.org/r/20200616144712.748818-1-jean-philippe@linaro.org
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Nested translation mode is supported in VT-d 3.0 Spec.CH 3.8.
With PASID granular translation type set to 0x11b, translation
result from the first level(FL) also subject to a second level(SL)
page table translation. This mode is used for SVA virtualization,
where FL performs guest virtual to guest physical translation and
SL performs guest physical to host physical translation.
This patch adds a helper function for setting up nested translation
where second level comes from a domain and first level comes from
a guest PGD.
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Link: https://lore.kernel.org/r/20200516062101.29541-4-baolu.lu@linux.intel.com
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Guest shared virtual address (SVA) may require host to shadow guest
PASID tables. Guest PASID can also be allocated from the host via
enlightened interfaces. In this case, guest needs to bind the guest
mm, i.e. cr3 in guest physical address to the actual PASID table in
the host IOMMU. Nesting will be turned on such that guest virtual
address can go through a two level translation:
- 1st level translates GVA to GPA
- 2nd level translates GPA to HPA
This patch introduces APIs to bind guest PASID data to the assigned
device entry in the physical IOMMU. See the diagram below for usage
explanation.
.-------------. .---------------------------.
| vIOMMU | | Guest process mm, FL only |
| | '---------------------------'
.----------------/
| PASID Entry |--- PASID cache flush -
'-------------' |
| | V
| | GP
'-------------'
Guest
------| Shadow |----------------------- GP->HP* ---------
v v |
Host v
.-------------. .----------------------.
| pIOMMU | | Bind FL for GVA-GPA |
| | '----------------------'
.----------------/ |
| PASID Entry | V (Nested xlate)
'----------------\.---------------------.
| | |Set SL to GPA-HPA |
| | '---------------------'
'-------------'
Where:
- FL = First level/stage one page tables
- SL = Second level/stage two page tables
- GP = Guest PASID
- HP = Host PASID
* Conversion needed if non-identity GP-HP mapping option is chosen.
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Liu Yi L <yi.l.liu@intel.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
In any virtualization use case, when the first translation stage
is "owned" by the guest OS, the host IOMMU driver has no knowledge
of caching structure updates unless the guest invalidation activities
are trapped by the virtualizer and passed down to the host.
Since the invalidation data can be obtained from user space and will be
written into physical IOMMU, we must allow security check at various
layers. Therefore, generic invalidation data format are proposed here,
model specific IOMMU drivers need to convert them into their own format.
Signed-off-by: Yi L Liu <yi.l.liu@intel.com>
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe@linaro.com>
Reviewed-by: Jean-Philippe Brucker <jean-philippe@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Ease future extensions of struct iommu_fault_page_request and struct
iommu_fault_unrecoverable by adding a few bytes of padding. That way, a
new field can be added to either of these structures by simply introducing
a new flag. To extend it after the size limit is reached, a new fault
reporting structure will have to be negotiated with userspace.
With 56 bytes of padding, the total size of iommu_fault is 64 bytes and
fits in a cache line on a lot of contemporary machines, while providing 16
and 24 bytes of extension to structures iommu_fault_page_request and
iommu_fault_unrecoverable respectively.
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Acked-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Some IOMMU hardware features, for example PCI PRI and Arm SMMU Stall,
enable recoverable I/O page faults. Allow IOMMU drivers to report PRI Page
Requests and Stall events through the new fault reporting API. The
consumer of the fault can be either an I/O page fault handler in the host,
or a guest OS.
Once handled, the fault must be completed by sending a page response back
to the IOMMU. Add an iommu_page_response() function to complete a page
fault.
There are two ways to extend the userspace API:
* Add a field to iommu_page_response and a flag to
iommu_page_response::flags describing the validity of this field.
* Introduce a new iommu_page_response_X structure with a different version
number. The kernel must then support both versions.
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Device faults detected by IOMMU can be reported outside the IOMMU
subsystem for further processing. This patch introduces
a generic device fault data structure.
The fault can be either an unrecoverable fault or a page request,
also referred to as a recoverable fault.
We only care about non internal faults that are likely to be reported
to an external subsystem.
Signed-off-by: Jacob Pan <jacob.jun.pan@linux.intel.com>
Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Signed-off-by: Liu, Yi L <yi.l.liu@linux.intel.com>
Signed-off-by: Ashok Raj <ashok.raj@intel.com>
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Joerg Roedel <jroedel@suse.de>
Jacob Pan