Commit Graph

1215427 Commits

Author SHA1 Message Date
Yi Liu
a2cdecdf9d iommu/vt-d: Enhance capability check for nested parent domain allocation
This adds the scalable mode check before allocating the nested parent domain
as checking nested capability is not enough. User may turn off scalable mode
which also means no nested support even if the hardware supports it.

Fixes: c97d1b20d3 ("iommu/vt-d: Add domain_alloc_user op")
Link: https://lore.kernel.org/r/20231024150011.44642-1-yi.l.liu@intel.com
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26 11:16:11 -03:00
Nicolin Chen
55a01657cb iommufd/selftest: Add coverage for IOMMU_HWPT_ALLOC with nested HWPTs
The IOMMU_HWPT_ALLOC ioctl now supports passing user_data to allocate a
user-managed domain for nested HWPTs. Add its coverage for that. Also,
update _test_cmd_hwpt_alloc() and add test_cmd/err_hwpt_alloc_nested().

Link: https://lore.kernel.org/r/20231026043938.63898-11-yi.l.liu@intel.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26 11:15:57 -03:00
Nicolin Chen
65fe32f7a4 iommufd/selftest: Add nested domain allocation for mock domain
Add nested domain support in the ->domain_alloc_user op with some proper
sanity checks. Then, add a domain_nested_ops for all nested domains and
split the get_md_pagetable helper into paging and nested helpers.

Also, add an iotlb as a testing property of a nested domain.

Link: https://lore.kernel.org/r/20231026043938.63898-10-yi.l.liu@intel.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26 11:15:57 -03:00
Nicolin Chen
e9d36c07bb iommu: Add iommu_copy_struct_from_user helper
Wrap up the data type/pointer/len sanity and a copy_struct_from_user call
for iommu drivers to copy driver specific data via struct iommu_user_data.
And expect it to be used in the domain_alloc_user op for example.

Link: https://lore.kernel.org/r/20231026043938.63898-9-yi.l.liu@intel.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Co-developed-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26 11:15:57 -03:00
Nicolin Chen
bd529dbb66 iommufd: Add a nested HW pagetable object
IOMMU_HWPT_ALLOC already supports iommu_domain allocation for usersapce.
But it can only allocate a hw_pagetable that associates to a given IOAS,
i.e. only a kernel-managed hw_pagetable of IOMMUFD_OBJ_HWPT_PAGING type.

IOMMU drivers can now support user-managed hw_pagetables, for two-stage
translation use cases that require user data input from the user space.

Add a new IOMMUFD_OBJ_HWPT_NESTED type with its abort/destroy(). Pair it
with a new iommufd_hwpt_nested structure and its to_hwpt_nested() helper.
Update the to_hwpt_paging() helper, so a NESTED-type hw_pagetable can be
handled in the callers, for example iommufd_hw_pagetable_enforce_rr().

Screen the inputs including the parent PAGING-type hw_pagetable that has
a need of a new nest_parent flag in the iommufd_hwpt_paging structure.

Extend the IOMMU_HWPT_ALLOC ioctl to accept an IOMMU driver specific data
input which is tagged by the enum iommu_hwpt_data_type. Also, update the
@pt_id to accept hwpt_id too besides an ioas_id. Then, use them to allocate
a hw_pagetable of IOMMUFD_OBJ_HWPT_NESTED type using the
iommufd_hw_pagetable_alloc_nested() allocator.

Link: https://lore.kernel.org/r/20231026043938.63898-8-yi.l.liu@intel.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Co-developed-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26 11:15:57 -03:00
Yi Liu
2bdabb8e82 iommu: Pass in parent domain with user_data to domain_alloc_user op
domain_alloc_user op already accepts user flags for domain allocation, add
a parent domain pointer and a driver specific user data support as well.
The user data would be tagged with a type for iommu drivers to add their
own driver specific user data per hw_pagetable.

Add a struct iommu_user_data as a bundle of data_ptr/data_len/type from an
iommufd core uAPI structure. Make the user data opaque to the core, since
a userspace driver must match the kernel driver. In the future, if drivers
share some common parameter, there would be a generic parameter as well.

Link: https://lore.kernel.org/r/20231026043938.63898-7-yi.l.liu@intel.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Co-developed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26 11:15:57 -03:00
Nicolin Chen
b5021cb264 iommufd: Share iommufd_hwpt_alloc with IOMMUFD_OBJ_HWPT_NESTED
Allow iommufd_hwpt_alloc() to have a common routine but jump to different
allocators corresponding to different user input pt_obj types, either an
IOMMUFD_OBJ_IOAS for a PAGING hwpt or an IOMMUFD_OBJ_HWPT_PAGING as the
parent for a NESTED hwpt.

Also, move the "flags" validation to the hwpt allocator (paging), so that
later the hwpt_nested allocator can do its own separate flags validation.

Link: https://lore.kernel.org/r/20231026043938.63898-6-yi.l.liu@intel.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26 11:15:57 -03:00
Nicolin Chen
89db31635c iommufd: Derive iommufd_hwpt_paging from iommufd_hw_pagetable
To prepare for IOMMUFD_OBJ_HWPT_NESTED, derive struct iommufd_hwpt_paging
from struct iommufd_hw_pagetable, by leaving the common members in struct
iommufd_hw_pagetable. Add a __iommufd_object_alloc and to_hwpt_paging()
helpers for the new structure.

Then, update "hwpt" to "hwpt_paging" throughout the files, accordingly.

Link: https://lore.kernel.org/r/20231026043938.63898-5-yi.l.liu@intel.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26 11:15:56 -03:00
Jason Gunthorpe
58d84f430d iommufd/device: Wrap IOMMUFD_OBJ_HWPT_PAGING-only configurations
Some of the configurations during the attach/replace() should only apply
to IOMMUFD_OBJ_HWPT_PAGING. Once IOMMUFD_OBJ_HWPT_NESTED gets introduced
in a following patch, keeping them unconditionally in the common routine
will not work.

Wrap all of those PAGING-only configurations together into helpers. Do a
hwpt_is_paging check whenever calling them or their fallback routines.

Link: https://lore.kernel.org/r/20231026043938.63898-4-yi.l.liu@intel.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26 11:15:56 -03:00
Jason Gunthorpe
9744a7ab62 iommufd: Rename IOMMUFD_OBJ_HW_PAGETABLE to IOMMUFD_OBJ_HWPT_PAGING
To add a new IOMMUFD_OBJ_HWPT_NESTED, rename the HWPT object to confine
it to PAGING hwpts/domains. The following patch will separate the hwpt
structure as well.

Link: https://lore.kernel.org/r/20231026043938.63898-3-yi.l.liu@intel.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26 11:15:56 -03:00
Lu Baolu
54d606816b iommu: Add IOMMU_DOMAIN_NESTED
Introduce a new domain type for a user I/O page table, which is nested on
top of another user space address represented by a PAGING domain. This
new domain can be allocated by the domain_alloc_user op, and attached to
a device through the existing iommu_attach_device/group() interfaces.

The mappings of a nested domain are managed by user space software, so it
is not necessary to have map/unmap callbacks.

Link: https://lore.kernel.org/r/20231026043938.63898-2-yi.l.liu@intel.com
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-26 11:15:56 -03:00
Nicolin Chen
2ccabf81dd iommufd: Only enforce cache coherency in iommufd_hw_pagetable_alloc
According to the conversation in the following link:
https://lore.kernel.org/linux-iommu/20231020135501.GG3952@nvidia.com/

The enforce_cache_coherency should be set/enforced in the hwpt allocation
routine. The iommu driver in its attach_dev() op should decide whether to
reject or not a device that doesn't match with the configuration of cache
coherency. Drop the enforce_cache_coherency piece in the attach/replace()
and move the remaining "num_devices" piece closer to the refcount that is
using it.

Accordingly drop its function prototype in the header and mark it static.
Also add some extra comments to clarify the expected behaviors.

Link: https://lore.kernel.org/r/20231024012958.30842-1-nicolinc@nvidia.com
Suggested-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 12:56:37 -03:00
Joao Martins
0795b305da iommufd/selftest: Test IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR flag
Change test_mock_dirty_bitmaps() to pass a flag where it specifies the flag
under test. The test does the same thing as the GET_DIRTY_BITMAP regular
test. Except that it tests whether the dirtied bits are fetched all the
same a second time, as opposed to observing them cleared.

Link: https://lore.kernel.org/r/20231024135109.73787-19-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:44 -03:00
Joao Martins
ae36fe70ce iommufd/selftest: Test out_capabilities in IOMMU_GET_HW_INFO
Enumerate the capabilities from the mock device and test whether it
advertises as expected. Include it as part of the iommufd_dirty_tracking
fixture.

Link: https://lore.kernel.org/r/20231024135109.73787-18-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:44 -03:00
Joao Martins
a9af47e382 iommufd/selftest: Test IOMMU_HWPT_GET_DIRTY_BITMAP
Add a new test ioctl for simulating the dirty IOVAs in the mock domain, and
implement the mock iommu domain ops that get the dirty tracking supported.

The selftest exercises the usual main workflow of:

1) Setting dirty tracking from the iommu domain
2) Read and clear dirty IOPTEs

Different fixtures will test different IOVA range sizes, that exercise
corner cases of the bitmaps.

Link: https://lore.kernel.org/r/20231024135109.73787-17-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:44 -03:00
Joao Martins
7adf267d66 iommufd/selftest: Test IOMMU_HWPT_SET_DIRTY_TRACKING
Change mock_domain to supporting dirty tracking and add tests to exercise
the new SET_DIRTY_TRACKING API in the iommufd_dirty_tracking selftest
fixture.

Link: https://lore.kernel.org/r/20231024135109.73787-16-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:44 -03:00
Joao Martins
266ce58989 iommufd/selftest: Test IOMMU_HWPT_ALLOC_DIRTY_TRACKING
In order to selftest the iommu domain dirty enforcing implement the
mock_domain necessary support and add a new dev_flags to test that the
hwpt_alloc/attach_device fails as expected.

Expand the existing mock_domain fixture with a enforce_dirty test that
exercises the hwpt_alloc and device attachment.

Link: https://lore.kernel.org/r/20231024135109.73787-15-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:44 -03:00
Joao Martins
e04b23c8d4 iommufd/selftest: Expand mock_domain with dev_flags
Expand mock_domain test to be able to manipulate the device capabilities.
This allows testing with mockdev without dirty tracking support advertised
and thus make sure enforce_dirty test does the expected.

To avoid breaking IOMMUFD_TEST UABI replicate the mock_domain struct and
thus add an input dev_flags at the end.

Link: https://lore.kernel.org/r/20231024135109.73787-14-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:44 -03:00
Joao Martins
f35f22cc76 iommu/vt-d: Access/Dirty bit support for SS domains
IOMMU advertises Access/Dirty bits for second-stage page table if the
extended capability DMAR register reports it (ECAP, mnemonic ECAP.SSADS).
The first stage table is compatible with CPU page table thus A/D bits are
implicitly supported. Relevant Intel IOMMU SDM ref for first stage table
"3.6.2 Accessed, Extended Accessed, and Dirty Flags" and second stage table
"3.7.2 Accessed and Dirty Flags".

First stage page table is enabled by default so it's allowed to set dirty
tracking and no control bits needed, it just returns 0. To use SSADS, set
bit 9 (SSADE) in the scalable-mode PASID table entry and flush the IOTLB
via pasid_flush_caches() following the manual. Relevant SDM refs:

"3.7.2 Accessed and Dirty Flags"
"6.5.3.3 Guidance to Software for Invalidations,
 Table 23. Guidance to Software for Invalidations"

PTE dirty bit is located in bit 9 and it's cached in the IOTLB so flush
IOTLB to make sure IOMMU attempts to set the dirty bit again. Note that
iommu_dirty_bitmap_record() will add the IOVA to iotlb_gather and thus the
caller of the iommu op will flush the IOTLB. Relevant manuals over the
hardware translation is chapter 6 with some special mention to:

"6.2.3.1 Scalable-Mode PASID-Table Entry Programming Considerations"
"6.2.4 IOTLB"

Select IOMMUFD_DRIVER only if IOMMUFD is enabled, given that IOMMU dirty
tracking requires IOMMUFD.

Link: https://lore.kernel.org/r/20231024135109.73787-13-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:43 -03:00
Joao Martins
421a511a29 iommu/amd: Access/Dirty bit support in IOPTEs
IOMMU advertises Access/Dirty bits if the extended feature register reports
it. Relevant AMD IOMMU SDM ref[0] "1.3.8 Enhanced Support for Access and
Dirty Bits"

To enable it set the DTE flag in bits 7 and 8 to enable access, or
access+dirty. With that, the IOMMU starts marking the D and A flags on
every Memory Request or ATS translation request. It is on the VMM side to
steer whether to enable dirty tracking or not, rather than wrongly doing in
IOMMU. Relevant AMD IOMMU SDM ref [0], "Table 7. Device Table Entry (DTE)
Field Definitions" particularly the entry "HAD".

To actually toggle on and off it's relatively simple as it's setting 2 bits
on DTE and flush the device DTE cache.

To get what's dirtied use existing AMD io-pgtable support, by walking the
pagetables over each IOVA, with fetch_pte().  The IOTLB flushing is left to
the caller (much like unmap), and iommu_dirty_bitmap_record() is the one
adding page-ranges to invalidate. This allows caller to batch the flush
over a big span of IOVA space, without the iommu wondering about when to
flush.

Worthwhile sections from AMD IOMMU SDM:

"2.2.3.1 Host Access Support"
"2.2.3.2 Host Dirty Support"

For details on how IOMMU hardware updates the dirty bit see, and expects
from its consequent clearing by CPU:

"2.2.7.4 Updating Accessed and Dirty Bits in the Guest Address Tables"
"2.2.7.5 Clearing Accessed and Dirty Bits"

Quoting the SDM:

"The setting of accessed and dirty status bits in the page tables is
visible to both the CPU and the peripheral when sharing guest page tables.
The IOMMU interlocked operations to update A and D bits must be 64-bit
operations and naturally aligned on a 64-bit boundary"

.. and for the IOMMU update sequence to Dirty bit, essentially is states:

1. Decodes the read and write intent from the memory access.
2. If P=0 in the page descriptor, fail the access.
3. Compare the A & D bits in the descriptor with the read and write
intent in the request.
4. If the A or D bits need to be updated in the descriptor:
* Start atomic operation.
* Read the descriptor as a 64-bit access.
* If the descriptor no longer appears to require an update, release the
atomic lock with
no further action and continue to step 5.
* Calculate the new A & D bits.
* Write the descriptor as a 64-bit access.
* End atomic operation.
5. Continue to the next stage of translation or to the memory access.

Access/Dirty bits readout also need to consider the non-default page-sizes
(aka replicated PTEs as mentined by manual), as AMD supports all powers of
two (except 512G) page sizes.

Select IOMMUFD_DRIVER only if IOMMUFD is enabled considering that IOMMU
dirty tracking requires IOMMUFD.

Link: https://lore.kernel.org/r/20231024135109.73787-12-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:43 -03:00
Joao Martins
134288158a iommu/amd: Add domain_alloc_user based domain allocation
Add the domain_alloc_user op implementation. To that end, refactor
amd_iommu_domain_alloc() to receive a dev pointer and flags, while renaming
it too, such that it becomes a common function shared with
domain_alloc_user() implementation. The sole difference with
domain_alloc_user() is that we initialize also other fields that
iommu_domain_alloc() does. It lets it return the iommu domain correctly
initialized in one function.

This is in preparation to add dirty enforcement on AMD implementation of
domain_alloc_user.

Link: https://lore.kernel.org/r/20231024135109.73787-11-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Suravee Suthikulpanit <suravee.suthikulpanit@amd.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:43 -03:00
Joao Martins
609848132c iommufd: Add a flag to skip clearing of IOPTE dirty
VFIO has an operation where it unmaps an IOVA while returning a bitmap with
the dirty data. In reality the operation doesn't quite query the IO
pagetables that the PTE was dirty or not. Instead it marks as dirty on
anything that was mapped, and doing so in one syscall.

In IOMMUFD the equivalent is done in two operations by querying with
GET_DIRTY_IOVA followed by UNMAP_IOVA. However, this would incur two TLB
flushes given that after clearing dirty bits IOMMU implementations require
invalidating their IOTLB, plus another invalidation needed for the UNMAP.
To allow dirty bits to be queried faster, add a flag
(IOMMU_HWPT_GET_DIRTY_BITMAP_NO_CLEAR) that requests to not clear the dirty
bits from the PTE (but just reading them), under the expectation that the
next operation is the unmap. An alternative is to unmap and just
perpectually mark as dirty as that's the same behaviour as today. So here
equivalent functionally can be provided with unmap alone, and if real dirty
info is required it will amortize the cost while querying.

There's still a race against DMA where in theory the unmap of the IOVA
(when the guest invalidates the IOTLB via emulated iommu) would race
against the VF performing DMA on the same IOVA. As discussed in [0], we are
accepting to resolve this race as throwing away the DMA and it doesn't
matter if it hit physical DRAM or not, the VM can't tell if we threw it
away because the DMA was blocked or because we failed to copy the DRAM.

[0] https://lore.kernel.org/linux-iommu/20220502185239.GR8364@nvidia.com/

Link: https://lore.kernel.org/r/20231024135109.73787-10-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:43 -03:00
Joao Martins
7623683857 iommufd: Add capabilities to IOMMU_GET_HW_INFO
Extend IOMMUFD_CMD_GET_HW_INFO op to query generic iommu capabilities for a
given device.

Capabilities are IOMMU agnostic and use device_iommu_capable() API passing
one of the IOMMU_CAP_*. Enumerate IOMMU_CAP_DIRTY_TRACKING for now in the
out_capabilities field returned back to userspace.

Link: https://lore.kernel.org/r/20231024135109.73787-9-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:43 -03:00
Joao Martins
b9a60d6f85 iommufd: Add IOMMU_HWPT_GET_DIRTY_BITMAP
Connect a hw_pagetable to the IOMMU core dirty tracking
read_and_clear_dirty iommu domain op. It exposes all of the functionality
for the UAPI that read the dirtied IOVAs while clearing the Dirty bits from
the PTEs.

In doing so, add an IO pagetable API iopt_read_and_clear_dirty_data() that
performs the reading of dirty IOPTEs for a given IOVA range and then
copying back to userspace bitmap.

Underneath it uses the IOMMU domain kernel API which will read the dirty
bits, as well as atomically clearing the IOPTE dirty bit and flushing the
IOTLB at the end. The IOVA bitmaps usage takes care of the iteration of the
bitmaps user pages efficiently and without copies. Within the iterator
function we iterate over io-pagetable contigous areas that have been
mapped.

Contrary to past incantation of a similar interface in VFIO the IOVA range
to be scanned is tied in to the bitmap size, thus the application needs to
pass a appropriately sized bitmap address taking into account the iova
range being passed *and* page size ... as opposed to allowing bitmap-iova
!= iova.

Link: https://lore.kernel.org/r/20231024135109.73787-8-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:43 -03:00
Joao Martins
e2a4b29478 iommufd: Add IOMMU_HWPT_SET_DIRTY_TRACKING
Every IOMMU driver should be able to implement the needed iommu domain ops
to control dirty tracking.

Connect a hw_pagetable to the IOMMU core dirty tracking ops, specifically
the ability to enable/disable dirty tracking on an IOMMU domain
(hw_pagetable id). To that end add an io_pagetable kernel API to toggle
dirty tracking:

* iopt_set_dirty_tracking(iopt, [domain], state)

The intended caller of this is via the hw_pagetable object that is created.

Internally it will ensure the leftover dirty state is cleared /right
before/ dirty tracking starts. This is also useful for iommu drivers which
may decide that dirty tracking is always-enabled at boot without wanting to
toggle dynamically via corresponding iommu domain op.

Link: https://lore.kernel.org/r/20231024135109.73787-7-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:43 -03:00
Joao Martins
5f9bdbf4c6 iommufd: Add a flag to enforce dirty tracking on attach
Throughout IOMMU domain lifetime that wants to use dirty tracking, some
guarantees are needed such that any device attached to the iommu_domain
supports dirty tracking.

The idea is to handle a case where IOMMU in the system are assymetric
feature-wise and thus the capability may not be supported for all devices.
The enforcement is done by adding a flag into HWPT_ALLOC namely:

	IOMMU_HWPT_ALLOC_DIRTY_TRACKING

.. Passed in HWPT_ALLOC ioctl() flags. The enforcement is done by creating
a iommu_domain via domain_alloc_user() and validating the requested flags
with what the device IOMMU supports (and failing accordingly) advertised).
Advertising the new IOMMU domain feature flag requires that the individual
iommu driver capability is supported when a future device attachment
happens.

Link: https://lore.kernel.org/r/20231024135109.73787-6-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:42 -03:00
Joao Martins
750e2e902b iommu: Add iommu_domain ops for dirty tracking
Add to iommu domain operations a set of callbacks to perform dirty
tracking, particulary to start and stop tracking and to read and clear the
dirty data.

Drivers are generally expected to dynamically change its translation
structures to toggle the tracking and flush some form of control state
structure that stands in the IOVA translation path. Though it's not
mandatory, as drivers can also enable dirty tracking at boot, and just
clear the dirty bits before setting dirty tracking. For each of the newly
added IOMMU core APIs:

iommu_cap::IOMMU_CAP_DIRTY_TRACKING: new device iommu_capable value when
probing for capabilities of the device.

.set_dirty_tracking(): an iommu driver is expected to change its
translation structures and enable dirty tracking for the devices in the
iommu_domain. For drivers making dirty tracking always-enabled, it should
just return 0.

.read_and_clear_dirty(): an iommu driver is expected to walk the pagetables
for the iova range passed in and use iommu_dirty_bitmap_record() to record
dirty info per IOVA. When detecting that a given IOVA is dirty it should
also clear its dirty state from the PTE, *unless* the flag
IOMMU_DIRTY_NO_CLEAR is passed in -- flushing is steered from the caller of
the domain_op via iotlb_gather. The iommu core APIs use the same data
structure in use for dirty tracking for VFIO device dirty (struct
iova_bitmap) abstracted by iommu_dirty_bitmap_record() helper function.

domain::dirty_ops: IOMMU domains will store the dirty ops depending on
whether the iommu device supports dirty tracking or not. iommu drivers can
then use this field to figure if the dirty tracking is supported+enforced
on attach. The enforcement is enable via domain_alloc_user() which is done
via IOMMUFD hwpt flag introduced later.

Link: https://lore.kernel.org/r/20231024135109.73787-5-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:42 -03:00
Joao Martins
13578d4ebe iommufd/iova_bitmap: Move symbols to IOMMUFD namespace
Have the IOVA bitmap exported symbols adhere to the IOMMUFD symbol
export convention i.e. using the IOMMUFD namespace. In doing so,
import the namespace in the current users. This means VFIO and the
vfio-pci drivers that use iova_bitmap_set().

Link: https://lore.kernel.org/r/20231024135109.73787-4-joao.m.martins@oracle.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:42 -03:00
Joao Martins
8c9c727b61 vfio: Move iova_bitmap into iommufd
Both VFIO and IOMMUFD will need iova bitmap for storing dirties and walking
the user bitmaps, so move to the common dependency into IOMMUFD.  In doing
so, create the symbol IOMMUFD_DRIVER which designates the builtin code that
will be used by drivers when selected. Today this means MLX5_VFIO_PCI and
PDS_VFIO_PCI. IOMMU drivers will do the same (in future patches) when
supporting dirty tracking and select IOMMUFD_DRIVER accordingly.

Given that the symbol maybe be disabled, add header definitions in
iova_bitmap.h for when IOMMUFD_DRIVER=n

Link: https://lore.kernel.org/r/20231024135109.73787-3-joao.m.martins@oracle.com
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Brett Creeley <brett.creeley@amd.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:42 -03:00
Joao Martins
53f0b02021 vfio/iova_bitmap: Export more API symbols
In preparation to move iova_bitmap into iommufd, export the rest of API
symbols that will be used in what could be used by modules, namely:

	iova_bitmap_alloc
	iova_bitmap_free
	iova_bitmap_for_each

Link: https://lore.kernel.org/r/20231024135109.73787-2-joao.m.martins@oracle.com
Suggested-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Joao Martins <joao.m.martins@oracle.com>
Reviewed-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Alex Williamson <alex.williamson@redhat.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-24 11:58:42 -03:00
Nicolin Chen
b5f9e63278 iommufd: Correct IOMMU_HWPT_ALLOC_NEST_PARENT description
The IOMMU_HWPT_ALLOC_NEST_PARENT flag is used to allocate a HWPT. Though
a HWPT holds a domain in the core structure, it is still quite confusing
to describe it using "domain" in the uAPI kdoc. Correct it to "HWPT".

Fixes: 4ff5421633 ("iommufd: Support allocating nested parent domain")
Link: https://lore.kernel.org/r/20231017181552.12667-1-nicolinc@nvidia.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-21 13:16:16 -03:00
Nicolin Chen
266dcae34d iommufd/selftest: Rework TEST_LENGTH to test min_size explicitly
TEST_LENGTH passing ".size = sizeof(struct _struct) - 1" expects -EINVAL
from "if (ucmd.user_size < op->min_size)" check in iommufd_fops_ioctl().
This has been working when min_size is exactly the size of the structure.

However, if the size of the structure becomes larger than min_size, i.e.
the passing size above is larger than min_size, that min_size sanity no
longer works.

Since the first test in TEST_LENGTH() was to test that min_size sanity
routine, rework it to support a min_size calculation, rather than using
the full size of the structure.

Link: https://lore.kernel.org/r/20231015074648.24185-1-nicolinc@nvidia.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-16 11:05:51 -03:00
Yi Liu
c97d1b20d3 iommu/vt-d: Add domain_alloc_user op
Add the domain_alloc_user() op implementation. It supports allocating
domains to be used as parent under nested translation.

Unlike other drivers VT-D uses only a single page table format so it only
needs to check if the HW can support nesting.

Link: https://lore.kernel.org/r/20230928071528.26258-7-yi.l.liu@intel.com
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-10 13:31:24 -03:00
Yi Liu
408663619f iommufd/selftest: Add domain_alloc_user() support in iommu mock
Add mock_domain_alloc_user() and a new test case for
IOMMU_HWPT_ALLOC_NEST_PARENT.

Link: https://lore.kernel.org/r/20230928071528.26258-6-yi.l.liu@intel.com
Co-developed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-10 13:31:24 -03:00
Yi Liu
4ff5421633 iommufd: Support allocating nested parent domain
Extend IOMMU_HWPT_ALLOC to allocate domains to be used as parent (stage-2)
in nested translation.

Add IOMMU_HWPT_ALLOC_NEST_PARENT to the uAPI.

Link: https://lore.kernel.org/r/20230928071528.26258-5-yi.l.liu@intel.com
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-10 13:31:24 -03:00
Yi Liu
89d63875d8 iommufd: Flow user flags for domain allocation to domain_alloc_user()
Extends iommufd_hw_pagetable_alloc() to accept user flags, the uAPI will
provide the flags.

Link: https://lore.kernel.org/r/20230928071528.26258-4-yi.l.liu@intel.com
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-10 13:31:24 -03:00
Yi Liu
7975b72208 iommufd: Use the domain_alloc_user() op for domain allocation
Make IOMMUFD use iommu_domain_alloc_user() by default for iommu_domain
creation. IOMMUFD needs to support iommu_domain allocation with parameters
from userspace in nested support, and a driver is expected to implement
everything under this op.

If the iommu driver doesn't provide domain_alloc_user callback then
IOMMUFD falls back to use iommu_domain_alloc() with an UNMANAGED type if
possible.

Link: https://lore.kernel.org/r/20230928071528.26258-3-yi.l.liu@intel.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Reviewed-by: Lu Baolu <baolu.lu@linux.intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Co-developed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-10 13:31:24 -03:00
Yi Liu
909f4abd10 iommu: Add new iommu op to create domains owned by userspace
Introduce a new iommu_domain op to create domains owned by userspace,
e.g. through IOMMUFD. These domains have a few different properties
compares to kernel owned domains:

 - They may be PAGING domains, but created with special parameters.
   For instance aperture size changes/number of levels, different
   IOPTE formats, or other things necessary to make a vIOMMU work

 - We have to track all the memory allocations with GFP_KERNEL_ACCOUNT
   to make the cgroup sandbox stronger

 - Device-specialty domains, such as NESTED domains can be created by
   IOMMUFD.

The new op clearly says the domain is being created by IOMMUFD, that the
domain is intended for userspace use, and it provides a way to pass user
flags or a driver specific uAPI structure to customize the created domain
to exactly what the vIOMMU userspace driver requires.

iommu drivers that cannot support VFIO/IOMMUFD should not support this
op. This includes any driver that cannot provide a fully functional PAGING
domain.

This new op for now is only supposed to be used by IOMMUFD, hence no
wrapper for it. IOMMUFD would call the callback directly. As for domain
free, IOMMUFD would use iommu_domain_free().

Link: https://lore.kernel.org/r/20230928071528.26258-2-yi.l.liu@intel.com
Suggested-by: Jason Gunthorpe <jgg@nvidia.com>
Signed-off-by: Lu Baolu <baolu.lu@linux.intel.com>
Co-developed-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Signed-off-by: Yi Liu <yi.l.liu@intel.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-10-10 13:30:22 -03:00
Nicolin Chen
bb812e0069 iommufd/selftest: Iterate idev_ids in mock_domain's alloc_hwpt test
The point in iterating variant->mock_domains is to test the idev_ids[0]
and idev_ids[1]. So use it instead of keeping testing idev_ids[0] only.

Link: https://lore.kernel.org/r/20230919011637.16483-1-nicolinc@nvidia.com
Signed-off-by: Nicolin Chen <nicolinc@nvidia.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-09-26 13:07:02 -03:00
GuokaiXu
474d9f3276 iommufd: Fix spelling errors in comments
requres -> requires
dramtically -> dramatically

Link: https://lore.kernel.org/r/31680D47D9533D91+20230904023236.GA12494@xgk8823
Signed-off-by: GuokaiXu <xuguokai@ucas.com.cn>
Signed-off-by: Jason Gunthorpe <jgg@nvidia.com>
2023-09-19 09:09:22 -03:00
Linus Torvalds
ce9ecca023 Linux 6.6-rc2 v6.6-rc2 2023-09-17 14:40:24 -07:00
Linus Torvalds
e789286468 Merge tag 'x86-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fixes from Ingo Molnar:
 "Misc fixes:

   - Fix an UV boot crash

   - Skip spurious ENDBR generation on _THIS_IP_

   - Fix ENDBR use in putuser() asm methods

   - Fix corner case boot crashes on 5-level paging

   - and fix a false positive WARNING on LTO kernels"

* tag 'x86-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/purgatory: Remove LTO flags
  x86/boot/compressed: Reserve more memory for page tables
  x86/ibt: Avoid duplicate ENDBR in __put_user_nocheck*()
  x86/ibt: Suppress spurious ENDBR
  x86/platform/uv: Use alternate source for socket to node data
2023-09-17 11:13:37 -07:00
Linus Torvalds
e5a710d132 Merge tag 'sched-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull scheduler fixes from Ingo Molnar:
 "Fix a performance regression on large SMT systems, an Intel SMT4
  balancing bug, and a topology setup bug on (Intel) hybrid processors"

* tag 'sched-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/sched: Restore the SD_ASYM_PACKING flag in the DIE domain
  sched/fair: Fix SMT4 group_smt_balance handling
  sched/fair: Optimize should_we_balance() for large SMT systems
2023-09-17 11:10:23 -07:00
Linus Torvalds
e54ca3c81f Merge tag 'objtool-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull objtool fix from Ingo Molnar:
 "Fix a cold functions related false-positive objtool warning that
  triggers on Clang"

* tag 'objtool-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  objtool: Fix _THIS_IP_ detection for cold functions
2023-09-17 10:59:37 -07:00
Linus Torvalds
99a73f9e8d Merge tag 'core-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull WARN fix from Ingo Molnar:
 "Fix a missing preempt-enable in the WARN() slowpath"

* tag 'core-urgent-2023-09-17' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  panic: Reenable preemption in WARN slowpath
2023-09-17 10:55:35 -07:00
Linus Torvalds
42aadec8c7 stat: remove no-longer-used helper macros
The choose_32_64() macros were added to deal with an odd inconsistency
between the 32-bit and 64-bit layout of 'struct stat' way back when in
commit a52dd971f9 ("vfs: de-crapify "cp_new_stat()" function").

Then a decade later Mikulas noticed that said inconsistency had been a
mistake in the early x86-64 port, and shouldn't have existed in the
first place.  So commit 932aba1e16 ("stat: fix inconsistency between
struct stat and struct compat_stat") removed the uses of the helpers.

But the helpers remained around, unused.

Get rid of them.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2023-09-17 10:46:12 -07:00
Linus Torvalds
45c3c62722 Merge tag '6.6-rc1-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6
Pull smb client fixes from Steve French:
 "Three small SMB3 client fixes, one to improve a null check and two
  minor cleanups"

* tag '6.6-rc1-smb3-client-fixes' of git://git.samba.org/sfrench/cifs-2.6:
  smb3: fix some minor typos and repeated words
  smb3: correct places where ENOTSUPP is used instead of preferred EOPNOTSUPP
  smb3: move server check earlier when setting channel sequence number
2023-09-17 10:41:42 -07:00
Linus Torvalds
39e0c8afdc Merge tag '6.6-rc1-ksmbd' of git://git.samba.org/ksmbd
Pull smb server fixes from Steve French:
 "Two ksmbd server fixes"

* tag '6.6-rc1-ksmbd' of git://git.samba.org/ksmbd:
  ksmbd: fix passing freed memory 'aux_payload_buf'
  ksmbd: remove unneeded mark_inode_dirty in set_info_sec()
2023-09-17 10:38:01 -07:00
Linus Torvalds
3fde3003ca Merge tag 'ext4_for_linus-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 fixes from Ted Ts'o:
 "Regression and bug fixes for ext4"

* tag 'ext4_for_linus-6.6-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4:
  ext4: fix rec_len verify error
  ext4: do not let fstrim block system suspend
  ext4: move setting of trimmed bit into ext4_try_to_trim_range()
  jbd2: Fix memory leak in journal_init_common()
  jbd2: Remove page size assumptions
  buffer: Make bh_offset() work for compound pages
2023-09-17 10:33:53 -07:00
Song Liu
75b2f7e4c9 x86/purgatory: Remove LTO flags
-flto* implies -ffunction-sections. With LTO enabled, ld.lld generates
multiple .text sections for purgatory.ro:

  $ readelf -S purgatory.ro  | grep " .text"
    [ 1] .text             PROGBITS         0000000000000000  00000040
    [ 7] .text.purgatory   PROGBITS         0000000000000000  000020e0
    [ 9] .text.warn        PROGBITS         0000000000000000  000021c0
    [13] .text.sha256_upda PROGBITS         0000000000000000  000022f0
    [15] .text.sha224_upda PROGBITS         0000000000000000  00002be0
    [17] .text.sha256_fina PROGBITS         0000000000000000  00002bf0
    [19] .text.sha224_fina PROGBITS         0000000000000000  00002cc0

This causes WARNING from kexec_purgatory_setup_sechdrs():

  WARNING: CPU: 26 PID: 110894 at kernel/kexec_file.c:919
  kexec_load_purgatory+0x37f/0x390

Fix this by disabling LTO for purgatory.

[ AFAICT, x86 is the only arch that supports LTO and purgatory. ]

We could also fix this with an explicit linker script to rejoin .text.*
sections back into .text. However, given the benefit of LTOing purgatory
is small, simply disable the production of more .text.* sections for now.

Fixes: b33fff07e3 ("x86, build: allow LTO to be selected")
Signed-off-by: Song Liu <song@kernel.org>
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Reviewed-by: Nick Desaulniers <ndesaulniers@google.com>
Reviewed-by: Sami Tolvanen <samitolvanen@google.com>
Link: https://lore.kernel.org/r/20230914170138.995606-1-song@kernel.org
2023-09-17 09:49:03 +02:00