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1,447,411 commits

Author SHA1 Message Date
Danilo Krummrich
c1d4519e1c rust: driver: add DEVICE_DRIVER_OFFSET to the DriverLayout trait
Add an associated const DEVICE_DRIVER_OFFSET to the DriverLayout trait
indicating the offset of the embedded struct device_driver within
Self::DriverType, i.e. the specific driver structs, such as struct
pci_driver or struct platform_driver.

Acked-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Igor Korotin <igor.korotin.linux@gmail.com>
Link: https://patch.msgid.link/20260107103511.570525-5-dakr@kernel.org
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-01-16 01:17:29 +01:00
Danilo Krummrich
0af1a9e462 rust: driver: introduce a DriverLayout trait
The DriverLayout trait describes the layout of a specific driver
structure, such as `struct pci_driver` or `struct platform_driver`.

In a first step, this replaces the associated type RegType of the
RegistrationOps with the DriverLayout::DriverType associated type.

Acked-by: Alice Ryhl <aliceryhl@google.com>
Acked-by: Igor Korotin <igor.korotin.linux@gmail.com>
Link: https://patch.msgid.link/20260107103511.570525-4-dakr@kernel.org
[ Rename driver::Driver to driver::DriverLayout, as it represents the
  layout of a driver structure rather than the driver structure itself.
  - Danilo ]
Signed-off-by: Danilo Krummrich <dakr@kernel.org>
2026-01-16 01:16:44 +01:00
Jiri Olsa
934d9746ed selftests/bpf: Add test for bpf_override_return helper
We do not actually test the bpf_override_return helper functionality
itself at the moment, only the bpf program being able to attach it.

Adding test that override prctl syscall return value on top of
kprobe and kprobe.multi.

Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Acked-by: Song Liu <song@kernel.org>
Link: https://lore.kernel.org/bpf/20260112121157.854473-2-jolsa@kernel.org
2026-01-15 16:15:26 -08:00
Jiri Olsa
276f3b6daf arm64/ftrace,bpf: Fix partial regs after bpf_prog_run
Mahe reported issue with bpf_override_return helper not working when
executed from kprobe.multi bpf program on arm.

The problem is that on arm we use alternate storage for pt_regs object
that is passed to bpf_prog_run and if any register is changed (which
is the case of bpf_override_return) it's not propagated back to actual
pt_regs object.

Fixing this by introducing and calling ftrace_partial_regs_update function
to propagate the values of changed registers (ip and stack).

Reported-by: Mahe Tardy <mahe.tardy@gmail.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Signed-off-by: Andrii Nakryiko <andrii@kernel.org>
Reviewed-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/bpf/20260112121157.854473-1-jolsa@kernel.org
2026-01-15 16:15:25 -08:00
Linus Torvalds
88e490913f ftrace fixes for v6.19:
- Fix allocation accounting on boot up
 
   The ftrace records for each function that ftrace can attach to is
   done in a group of pages. At boot up, the number of pages are
   calculated and allocated. After that, the pages are filled with data.
   It may allocate more than needed due to some functions not being
   recorded (because they are unused weak functions), this too is
   recorded.
 
   After the data is filled in, a check is made to make sure the right
   number of pages were allocated. But this was off due to the
   assumption that the same number of entries fit per every page.
   Because the size of an entry does not evenly divide into PAGE_SIZE,
   there is a rounding error when a large number of pages is allocated
   to hold the events. This causes the check to fail and triggers a
   warning.
 
   Fix the accounting by finding out how many pages are actually
   allocated from the functions that allocate them and use that to see
   if all the pages allocated were used and the ones not used are
   properly freed.
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Merge tag 'ftrace-v6.19-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace

Pull ftrace fix from Steven Rostedt:

 - Fix allocation accounting on boot up

   The ftrace records for each function that ftrace can attach to is
   done in a group of pages. At boot up, the number of pages are
   calculated and allocated. After that, the pages are filled with data.
   It may allocate more than needed due to some functions not being
   recorded (because they are unused weak functions), this too is
   recorded.

   After the data is filled in, a check is made to make sure the right
   number of pages were allocated. But this was off due to the
   assumption that the same number of entries fit per every page.
   Because the size of an entry does not evenly divide into PAGE_SIZE,
   there is a rounding error when a large number of pages is allocated
   to hold the events. This causes the check to fail and triggers a
   warning.

   Fix the accounting by finding out how many pages are actually
   allocated from the functions that allocate them and use that to see
   if all the pages allocated were used and the ones not used are
   properly freed.

* tag 'ftrace-v6.19-rc5' of git://git.kernel.org/pub/scm/linux/kernel/git/trace/linux-trace:
  ftrace: Do not over-allocate ftrace memory
2026-01-15 15:13:05 -08:00
Jie Zhang
0df529f466 dt-bindings: display/msm/rgmu: Document A612 RGMU
RGMU a.k.a Reduced Graphics Management Unit is a small state machine
with the sole purpose of providing IFPC (Inter Frame Power Collapse)
support. Compared to GMU, it doesn't manage GPU clock, voltage
scaling, bw voting or any other functionalities. All it does is detect
an idle GPU and toggle the GDSC switch. As it doesn't access DDR space,
it doesn't require iommu.

So far, only Adreno 612 GPU has an RGMU core. Document it in
qcom,adreno-rgmu.yaml.

Signed-off-by: Jie Zhang <jie.zhang@oss.qualcomm.com>
Signed-off-by: Akhil P Oommen <akhilpo@oss.qualcomm.com>
Reviewed-by: Krzysztof Kozlowski <krzk@kernel.org>
Patchwork: https://patchwork.freedesktop.org/patch/696679/
Message-ID: <20251231-qcs615-spin-2-v6-4-da87debf6883@oss.qualcomm.com>
Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
2026-01-15 14:12:33 -08:00
Akhil P Oommen
fa4525799d dt-bindings: display/msm: gpu: Document A612 GPU
A612 GPU has a new IP called RGMU (Reduced Graphics Management Unit)
which replaces GMU. But it doesn't do clock or voltage scaling. So we
need the gpu core clock in the GPU node along with the power domain to
do clock and voltage scaling from the kernel. Update the bindings to
describe this GPU.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Akhil P Oommen <akhilpo@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/696676/
Message-ID: <20251231-qcs615-spin-2-v6-3-da87debf6883@oss.qualcomm.com>
Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
2026-01-15 14:12:33 -08:00
Akhil P Oommen
158927e1f6 dt-bindings: display/msm: gpu: Simplify conditional schema logic
JSON Schema conditionals can become complex and error-prone when combined
with regex patterns. To improve readability and maintainability, replace
nested if-else blocks with a flattened structure using explicit enums.

Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Akhil P Oommen <akhilpo@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/696674/
Message-ID: <20251231-qcs615-spin-2-v6-2-da87debf6883@oss.qualcomm.com>
Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
2026-01-15 14:12:32 -08:00
Akhil P Oommen
e39333a81e drm/msm/a6xx: Retrieve gmu core range by index
Some GPUs like A612 doesn't use a named register range resource. This
is because the reg-name property is discouraged when there is just a
single resource.

To address this, retrieve the 'gmu' register range by its index. It is
always guaranteed to be at index 0.

Signed-off-by: Akhil P Oommen <akhilpo@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/696673/
Message-ID: <20251231-qcs615-spin-2-v6-1-da87debf6883@oss.qualcomm.com>
Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
2026-01-15 14:12:32 -08:00
Eric Biggers
fbfeca7404 lib/crypto: aes: Drop 'volatile' from aes_sbox and aes_inv_sbox
The volatile keyword is no longer necessary or useful on aes_sbox and
aes_inv_sbox, since the table prefetching is now done using a helper
function that casts to volatile itself and also includes an optimization
barrier.  Since it prevents some compiler optimizations, remove it.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-36-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:09:09 -08:00
Eric Biggers
953f2db0bf lib/crypto: aes: Remove old AES en/decryption functions
Now that all callers of the aes_encrypt() and aes_decrypt() type-generic
macros are using the new types, remove the old functions.

Then, replace the macro with direct calls to the new functions, dropping
the "_new" suffix from them.

This completes the change in the type of the key struct that is passed
to aes_encrypt() and aes_decrypt().

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-35-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:09:09 -08:00
Eric Biggers
bc79efa08c lib/crypto: aesgcm: Use new AES library API
Switch from the old AES library functions (which use struct
crypto_aes_ctx) to the new ones (which use struct aes_enckey).  This
eliminates the unnecessary computation and caching of the decryption
round keys.  The new AES en/decryption functions are also much faster
and use AES instructions when supported by the CPU.

Note that in addition to the change in the key preparation function and
the key struct type itself, the change in the type of the key struct
results in aes_encrypt() (which is temporarily a type-generic macro)
calling the new encryption function rather than the old one.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-34-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:09:09 -08:00
Eric Biggers
7fcb22dc77 lib/crypto: aescfb: Use new AES library API
Switch from the old AES library functions (which use struct
crypto_aes_ctx) to the new ones (which use struct aes_enckey).  This
eliminates the unnecessary computation and caching of the decryption
round keys.  The new AES en/decryption functions are also much faster
and use AES instructions when supported by the CPU.

Note that in addition to the change in the key preparation function and
the key struct type itself, the change in the type of the key struct
results in aes_encrypt() (which is temporarily a type-generic macro)
calling the new encryption function rather than the old one.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-33-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:09:08 -08:00
Eric Biggers
8612043471 crypto: omap - Use new AES library API
Switch from the old AES library functions (which use struct
crypto_aes_ctx) to the new ones (which use struct aes_enckey).  This
eliminates the unnecessary computation and caching of the decryption
round keys.  The new AES en/decryption functions are also much faster
and use AES instructions when supported by the CPU.

Note that in addition to the change in the key preparation function and
the key struct type itself, the change in the type of the key struct
results in aes_encrypt() (which is temporarily a type-generic macro)
calling the new encryption function rather than the old one.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-32-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:09:08 -08:00
Eric Biggers
65c7022be1 crypto: inside-secure - Use new AES library API
Switch from the old AES library functions (which use struct
crypto_aes_ctx) to the new ones (which use struct aes_enckey).  This
eliminates the unnecessary computation and caching of the decryption
round keys.  The new AES en/decryption functions are also much faster
and use AES instructions when supported by the CPU.

Note that in addition to the change in the key preparation function and
the key struct type itself, the change in the type of the key struct
results in aes_encrypt() (which is temporarily a type-generic macro)
calling the new encryption function rather than the old one.

This driver used crypto_aes_ctx::key_enc, but only to access the copy of
the raw key that is stored at the beginning of the expanded key.  To
eliminate the dependency on this field, instead just access the raw key
directly, which is already available in the relevant functions.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-31-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:09:08 -08:00
Eric Biggers
b2c15db74a crypto: drbg - Use new AES library API
Switch from the old AES library functions (which use struct
crypto_aes_ctx) to the new ones (which use struct aes_enckey).  This
eliminates the unnecessary computation and caching of the decryption
round keys.  The new AES en/decryption functions are also much faster
and use AES instructions when supported by the CPU.

Note that in addition to the change in the key preparation function and
the key struct type itself, the change in the type of the key struct
results in aes_encrypt() (which is temporarily a type-generic macro)
calling the new encryption function rather than the old one.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-30-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:09:08 -08:00
Eric Biggers
9b95f3a4c9 crypto: crypto4xx - Use new AES library API
Switch from the old AES library functions (which use struct
crypto_aes_ctx) to the new ones (which use struct aes_enckey).  This
eliminates the unnecessary computation and caching of the decryption
round keys.  The new AES en/decryption functions are also much faster
and use AES instructions when supported by the CPU.

Note that in addition to the change in the key preparation function and
the key struct type itself, the change in the type of the key struct
results in aes_encrypt() (which is temporarily a type-generic macro)
calling the new encryption function rather than the old one.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-29-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:09:08 -08:00
Eric Biggers
cafa7a0b6c crypto: chelsio - Use new AES library API
Switch from the old AES library functions (which use struct
crypto_aes_ctx) to the new ones (which use struct aes_key and struct
aes_enckey).  In encryption-only use cases, this eliminates the
unnecessary computation and caching of the decryption round keys.  The
new AES en/decryption functions are also much faster and use AES
instructions when supported by the CPU.

Note that in addition to the change in the key preparation function and
the key struct type itself, the change in the type of the key struct
results in aes_encrypt() (which is temporarily a type-generic macro)
calling the new encryption function rather than the old one.  Likewise
for decryption.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-28-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:09:08 -08:00
Eric Biggers
0f5f4961ae crypto: ccp - Use new AES library API
Switch from the old AES library functions (which use struct
crypto_aes_ctx) to the new ones (which use struct aes_enckey).  This
eliminates the unnecessary computation and caching of the decryption
round keys.  The new AES en/decryption functions are also much faster
and use AES instructions when supported by the CPU.

Note that in addition to the change in the key preparation function and
the key struct type itself, the change in the type of the key struct
results in aes_encrypt() (which is temporarily a type-generic macro)
calling the new encryption function rather than the old one.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-27-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:09:08 -08:00
Eric Biggers
104a9526e1 crypto: x86/aes-gcm - Use new AES library API
Switch from the old AES library functions (which use struct
crypto_aes_ctx) to the new ones (which use struct aes_enckey).  This
eliminates the unnecessary computation and caching of the decryption
round keys.  The new AES en/decryption functions are also much faster
and use AES instructions when supported by the CPU.

Since this changes the format of the AES-GCM key structures that are
used by the AES-GCM assembly code, the offsets in the assembly code had
to be updated to match.  Note that the new key structures are smaller,
since the decryption round keys are no longer unnecessarily included.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-26-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:09:08 -08:00
Eric Biggers
370960c153 crypto: arm64/ghash - Use new AES library API
Switch from the old AES library functions (which use struct
crypto_aes_ctx) to the new ones (which use struct aes_enckey).  This
eliminates the unnecessary computation and caching of the decryption
round keys.  The new AES en/decryption functions are also much faster
and use AES instructions when supported by the CPU.

Note that in addition to the change in the key preparation function and
the key struct type itself, the change in the type of the key struct
results in aes_encrypt() (which is temporarily a type-generic macro)
calling the new encryption function rather than the old one.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-25-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:09:08 -08:00
Eric Biggers
cf4b7b99a6 crypto: arm/ghash - Use new AES library API
Switch from the old AES library functions (which use struct
crypto_aes_ctx) to the new ones (which use struct aes_enckey).  This
eliminates the unnecessary computation and caching of the decryption
round keys.  The new AES en/decryption functions are also much faster
and use AES instructions when supported by the CPU.

Note that in addition to the change in the key preparation function and
the key struct type itself, the change in the type of the key struct
results in aes_encrypt() (which is temporarily a type-generic macro)
calling the new encryption function rather than the old one.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-24-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:09:08 -08:00
Eric Biggers
60fb28ca02 staging: rtl8723bs: core: Use new AES library API
Switch from the old AES library functions (which use struct
crypto_aes_ctx) to the new ones (which use struct aes_enckey).  This
eliminates the unnecessary computation and caching of the decryption
round keys.  The new AES en/decryption functions are also much faster
and use AES instructions when supported by the CPU.

Note that in addition to the change in the key preparation function and
the key struct type itself, the change in the type of the key struct
results in aes_encrypt() (which is temporarily a type-generic macro)
calling the new encryption function rather than the old one.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-23-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:09:07 -08:00
Eric Biggers
12b03936a0 net: phy: mscc: macsec: Use new AES library API
Switch from the old AES library functions (which use struct
crypto_aes_ctx) to the new ones (which use struct aes_enckey).  This
eliminates the unnecessary computation and caching of the decryption
round keys.  The new AES en/decryption functions are also much faster
and use AES instructions when supported by the CPU.

Note that in addition to the change in the key preparation function and
the key struct type itself, the change in the type of the key struct
results in aes_encrypt() (which is temporarily a type-generic macro)
calling the new encryption function rather than the old one.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-22-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:09:07 -08:00
Eric Biggers
1f161437c6 chelsio: Use new AES library API
Switch from the old AES library functions (which use struct
crypto_aes_ctx) to the new ones (which use struct aes_enckey).  This
eliminates the unnecessary computation and caching of the decryption
round keys.  The new AES en/decryption functions are also much faster
and use AES instructions when supported by the CPU.

Note that in addition to the change in the key preparation function and
the key struct type itself, the change in the type of the key struct
results in aes_encrypt() (which is temporarily a type-generic macro)
calling the new encryption function rather than the old one.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-21-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:09:07 -08:00
Eric Biggers
7f6dfeb943 Bluetooth: SMP: Use new AES library API
Switch from the old AES library functions (which use struct
crypto_aes_ctx) to the new ones (which use struct aes_enckey).  This
eliminates the unnecessary computation and caching of the decryption
round keys.  The new AES en/decryption functions are also much faster
and use AES instructions when supported by the CPU.

Note that in addition to the change in the key preparation function and
the key struct type itself, the change in the type of the key struct
results in aes_encrypt() (which is temporarily a type-generic macro)
calling the new encryption function rather than the old one.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-20-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:09:07 -08:00
Eric Biggers
9c941c94bc crypto: x86/aes - Remove the superseded AES-NI crypto_cipher
Remove the "aes-aesni" crypto_cipher algorithm and the code specific to
its implementation.  It is no longer necessary because the AES library
is now optimized with x86 AES-NI, and crypto/aes.c exposes the AES
library via the crypto_cipher API.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-19-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:09:07 -08:00
Eric Biggers
24eb22d816 lib/crypto: x86/aes: Add AES-NI optimization
Optimize the AES library with x86 AES-NI instructions.

The relevant existing assembly functions, aesni_set_key(), aesni_enc(),
and aesni_dec(), are a bit difficult to extract into the library:

- They're coupled to the code for the AES modes.
- They operate on struct crypto_aes_ctx.  The AES library now uses
  different structs.
- They assume the key is 16-byte aligned.  The AES library only
  *prefers* 16-byte alignment; it doesn't require it.

Moreover, they're not all that great in the first place:

- They use unrolled loops, which isn't a great choice on x86.
- They use the 'aeskeygenassist' instruction, which is unnecessary, is
  slow on Intel CPUs, and forces the loop to be unrolled.
- They have special code for AES-192 key expansion, despite that being
  kind of useless.  AES-128 and AES-256 are the ones used in practice.

These are small functions anyway.

Therefore, I opted to just write replacements of these functions for the
library.  They address all the above issues.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-18-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:09:07 -08:00
Eric Biggers
293c7cd5c6 lib/crypto: sparc/aes: Migrate optimized code into library
Move the SPARC64 AES assembly code into lib/crypto/, wire the key
expansion and single-block en/decryption functions up to the AES library
API, and remove the "aes-sparc64" crypto_cipher algorithm.

The result is that both the AES library and crypto_cipher APIs use the
SPARC64 AES opcodes, whereas previously only crypto_cipher did (and it
wasn't enabled by default, which this commit fixes as well).

Note that some of the functions in the SPARC64 AES assembly code are
still used by the AES mode implementations in
arch/sparc/crypto/aes_glue.c.  For now, just export these functions.
These exports will go away once the AES mode implementations are
migrated to the library as well.  (Trying to split up the assembly file
seemed like much more trouble than it would be worth.)

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Link: https://lore.kernel.org/r/20260112192035.10427-17-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:09:07 -08:00
Eric Biggers
0cab15611e lib/crypto: s390/aes: Migrate optimized code into library
Implement aes_preparekey_arch(), aes_encrypt_arch(), and
aes_decrypt_arch() using the CPACF AES instructions.

Then, remove the superseded "aes-s390" crypto_cipher.

The result is that both the AES library and crypto_cipher APIs use the
CPACF AES instructions, whereas previously only crypto_cipher did (and
it wasn't enabled by default, which this commit fixes as well).

Note that this preserves the optimization where the AES key is stored in
raw form rather than expanded form.  CPACF just takes the raw key.

Acked-by: Ard Biesheuvel <ardb@kernel.org>
Tested-by: Holger Dengler <dengler@linux.ibm.com>
Reviewed-by: Holger Dengler <dengler@linux.ibm.com>
Link: https://lore.kernel.org/r/20260112192035.10427-16-ebiggers@kernel.org
Signed-off-by: Eric Biggers <ebiggers@kernel.org>
2026-01-15 14:08:55 -08:00
Rob Clark
dc220915dd drm/msm: Fix GMEM_BASE for gen8
This should also be zero for gen8.  This does change a7xx-gen1 to zero.
It was almost certainly incorrect before, but we have no such devices in
CI currently.

Fixes: 288a932008 ("drm/msm/adreno: Introduce A8x GPU Support")
Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/697779/
Message-ID: <20260109153730.130462-3-robin.clark@oss.qualcomm.com>
2026-01-15 14:06:28 -08:00
Rob Clark
56cd8adff8 drm/msm: Fix x2-85 TPL1_DBG_ECO_CNTL1
We actually need to set b26, just claiming to do so is not enough :-)

Fixes: 01ff3bf272 ("drm/msm/a8xx: Add support for Adreno X2-85 GPU")
Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@oss.qualcomm.com>
Patchwork: https://patchwork.freedesktop.org/patch/697778/
Message-ID: <20260109153730.130462-2-robin.clark@oss.qualcomm.com>
2026-01-15 14:06:12 -08:00
Johan Hovold
dcbd2f8280 drm/msm/a6xx: fix bogus hwcg register updates
The hw clock gating register sequence consists of register value pairs
that are written to the GPU during initialisation.

The a690 hwcg sequence has two GMU registers in it that used to amount
to random writes in the GPU mapping, but since commit 188db3d7fe
("drm/msm/a6xx: Rebase GMU register offsets") they trigger a fault as
the updated offsets now lie outside the mapping. This in turn breaks
boot of machines like the Lenovo ThinkPad X13s.

Note that the updates of these GMU registers is already taken care of
properly since commit 40c297eb24 ("drm/msm/a6xx: Set GMU CGC
properties on a6xx too"), but for some reason these two entries were
left in the table.

Fixes: 5e7665b5e4 ("drm/msm/adreno: Add Adreno A690 support")
Cc: stable@vger.kernel.org	# 6.5
Cc: Bjorn Andersson <andersson@kernel.org>
Cc: Konrad Dybcio <konradybcio@kernel.org>
Signed-off-by: Johan Hovold <johan@kernel.org>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Reviewed-by: Akhil P Oommen <akhilpo@oss.qualcomm.com>
Fixes: 188db3d7fe ("drm/msm/a6xx: Rebase GMU register offsets")
Patchwork: https://patchwork.freedesktop.org/patch/695778/
Message-ID: <20251221164552.19990-1-johan@kernel.org>
Signed-off-by: Rob Clark <robin.clark@oss.qualcomm.com>
2026-01-15 14:06:06 -08:00
Shrikanth Hegde
5d86d542f6 sched/fair: Remove nohz.nr_cpus and use weight of cpumask instead
nohz.nr_cpus was observed as contended cacheline when running
enterprise workload on large systems.

Fundamental scalability challenge with nohz.idle_cpus_mask
and nohz.nr_cpus is the following:

 (1) nohz_balancer_kick() observes (reads) nohz.nr_cpus
     (or nohz.idle_cpu_mask) and nohz.has_blocked to  see whether there's
     any nohz balancing work to do, in every scheduler tick.

 (2) nohz_balance_enter_idle() and nohz_balance_exit_idle()
     (through nohz_balancer_kick() via sched_tick()) modify (write)
     nohz.nr_cpus (and/or nohz.idle_cpu_mask) and nohz.has_blocked.

The characteristic frequencies are the following:

 (1) nohz_balancer_kick() happens at scheduler (busy)tick frequency
     on CPU(which has not gone idle). This is a relatively constant
     frequency  in the ~1 kHz range or lower.

 (2) happens at idle enter/exit frequency on every CPU that goes to idle.
     This is workload dependent, but can easily be hundreds of kHz for
     IO-bound loads and high CPU counts. Ie. can be orders of magnitude
     higher than (1), in which case a cachemiss at every invocation of (1)
     is almost inevitable. idle exit will trigger (1) on the CPU
     which is coming out of idle.

There's two types of costs from these functions:

 (A) scheduler tick cost via (1): this happens on busy CPUs too, and is
     thus a primary scalability cost. But the rate here is constant and
     typically much lower than (B), hence the absolute benefit to workload
     scalability will be lower as well.

 (B) idle cost via (2): going-to-idle and coming-from-idle costs are
     secondary concerns, because they impact power efficiency more than
     they impact scalability. But in terms of absolute cost this scales
     up with nr_cpus as well, and a much faster rate, and thus may also
     approach and negatively impact system limits like
     memory bus/fabric bandwidth.

Note that nohz.idle_cpus_mask and nohz.nr_cpus may appear to reside in the
same cacheline, however under CONFIG_CPUMASK_OFFSTACK=y the backing storage
for nohz.idle_cpus_mask will be elsewhere. With CPUMASK_OFFSTACK=n,
the nohz.idle_cpus_mask and rest of nohz fields are in different cachelines
under typical NR_CPUS=512/2048. This implies two separate cachelines
being dirtied upon idle entry / exit.

nohz.nr_cpus can be derived from the mask itself. Its usage doesn't warrant
a functionally correct value. This means one less cacheline being dirtied in
idle entry/exit path which helps to save some bus bandwidth w.r.t to those
nohz functions(approx 50%). This in turn helps to improve enterprise
workload throughput.

On system with 480 CPUs, running "hackbench 40 process 10000 loops"
(Avg of 3 runs)
baseline:
     0.81%  hackbench          [k] nohz_balance_exit_idle
     0.21%  hackbench          [k] nohz_balancer_kick
     0.09%  swapper            [k] nohz_run_idle_balance

With patch:
     0.35%  hackbench          [k] nohz_balance_exit_idle
     0.09%  hackbench          [k] nohz_balancer_kick
     0.07%  swapper            [k] nohz_run_idle_balance

[Ingo Molnar: scalability analysis changlog]

Reviewed-and-tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Valentin Schneider <vschneid@redhat.com>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://patch.msgid.link/20260115073524.376643-4-sshegde@linux.ibm.com
2026-01-15 22:41:27 +01:00
Shrikanth Hegde
94e70734b4 sched/fair: Change likelyhood of nohz.nr_cpus
These days most of the system have multi cores. The likelyhood of
at least one or more CPUs in nohz (idle state) is higher.

Give accurate hint to the branch predictor.

Reviewed-and-tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://patch.msgid.link/20260115073524.376643-3-sshegde@linux.ibm.com
2026-01-15 22:41:27 +01:00
Shrikanth Hegde
6b67c8a72e sched/fair: Move checking for nohz cpus after time check
Current code does.
- Read nohz.nr_cpus
- Check if the time has passed to do NOHZ idle balance

Instead do this.
- Check if the time has passed to do NOHZ idle balance
- Read nohz.nr_cpus

This will skip the read most of the time in normal system usage.
i.e when there are nohz.nr_cpus (system is not 100% busy).

Note that when there are no idle CPUs(100% busy), even if the flag gets
set to NOHZ_STATS_KICK | NOHZ_NEXT_KICK, find_new_ilb will fail and
there will be no NOHZ idle balance. In such cases there will be a very
narrow window where, kick_ilb will be called un-necessarily.
However current functionality is still retained.

Note: This patch doesn't solve any cacheline overheads. No improvement
in performance apart from saving a few cycles of reading nohz.nr_cpus

Reviewed-and-tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Shrikanth Hegde <sshegde@linux.ibm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Vincent Guittot <vincent.guittot@linaro.org>
Link: https://patch.msgid.link/20260115073524.376643-2-sshegde@linux.ibm.com
2026-01-15 22:41:26 +01:00
Zhan Xusheng
553255cc85 sched/fair: Fix math notation errors in avg_vruntime comment
The avg_vruntime comment contains a couple of mathematical notation
issues:

 - The summation over w_i * (V - v_i) is written in an ambiguous form
 - The delta term refers to v instead of v0, which is inconsistent
   with the code and preceding explanation

Fix these to make the comment mathematically correct and consistent
with the implementation.

Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://patch.msgid.link/20260114090035.19033-1-zhanxusheng@xiaomi.com
2026-01-15 22:41:26 +01:00
Gabriele Monaco
8d73732016 sched: Fix build for modules using set_tsk_need_resched()
Commit adcc3bfa88 ("sched: Adapt sched tracepoints for RV task model")
added a tracepoint to the need_resched action that can be triggered also
by set_tsk_need_resched.
This function was previously accessible from out-of-tree modules but
it's no longer available because the __trace_set_need_resched() symbol
is not exported (together with the tracepoint itself, which was exported
in a separate patch) and building such modules fails.

Export __trace_set_need_resched to modules to fix those build issues.

Fixes: adcc3bfa88 ("sched: Adapt sched tracepoints for RV task model")
Signed-off-by: Gabriele Monaco <gmonaco@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Phil Auld <pauld@redhat.com>
Link: https://patch.msgid.link/20260112140413.362202-1-gmonaco@redhat.com
2026-01-15 22:41:26 +01:00
Mukesh Ojha
d27267558f arm64: dts: qcom: lemans; Add EL2 overlay
All the Lemans IOT variants boards are using Gunyah hypervisor which
means that, so far, Linux-based OS could only boot in EL1 on those
devices.  However, it is possible for us to boot Linux at EL2 on these
devices [1].

When running under Gunyah, the remote processor firmware IOMMU streams
are controlled by Gunyah. However, without Gunyah, the IOMMU is managed
by the consumer of this DeviceTree. Therefore, describe the firmware
streams for each remote processor.

Add a EL2-specific DT overlay and apply it to Lemans IOT variant
devices to create -el2.dtb for each of them alongside "normal" dtb.

[1]
https://docs.qualcomm.com/bundle/publicresource/topics/80-70020-4/boot-developer-touchpoints.html#uefi

Signed-off-by: Mukesh Ojha <mukesh.ojha@oss.qualcomm.com>
Link: https://lore.kernel.org/r/20260105-kvmrprocv10-v10-14-022e96815380@oss.qualcomm.com
Signed-off-by: Bjorn Andersson <andersson@kernel.org>
2026-01-15 15:08:20 -06:00
Peter Zijlstra
627cc25f84 sched/deadline: Use ENQUEUE_MOVE to allow priority change
Pierre reported hitting balance callback warnings for deadline tasks
after commit 6455ad5346 ("sched: Move sched_class::prio_changed()
into the change pattern").

It turns out that DEQUEUE_SAVE+ENQUEUE_RESTORE does not preserve DL
priority and subsequently trips a balance pass -- where one was not
expected.

From discussion with Juri and Luca, the purpose of this clause was to
deal with tasks new to DL and all those sites will have MOVE set (as
well as CLASS, but MOVE is move conservative at this point).

Per the previous patches MOVE is audited to always run the balance
callbacks, so switch enqueue_dl_entity() to use MOVE for this case.

Fixes: 6455ad5346 ("sched: Move sched_class::prio_changed() into the change pattern")
Reported-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Pierre Gondois <pierre.gondois@arm.com>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://patch.msgid.link/20260114130528.GB831285@noisy.programming.kicks-ass.net
2026-01-15 21:57:53 +01:00
Peter Zijlstra
e008ec6c79 sched: Deadline has dynamic priority
While FIFO/RR have static priority, DEADLINE is a dynamic priority
scheme. Notably it has static priority -1. Do not assume the priority
doesn't change for deadline tasks just because the static priority
doesn't change.

This ensures DL always sees {DE,EN}QUEUE_MOVE where appropriate.

Fixes: ff77e46853 ("sched/rt: Fix PI handling vs. sched_setscheduler()")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Pierre Gondois <pierre.gondois@arm.com>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://patch.msgid.link/20260114130528.GB831285@noisy.programming.kicks-ass.net
2026-01-15 21:57:53 +01:00
Peter Zijlstra
53439363c0 sched: Audit MOVE vs balance_callbacks
The {DE,EN}QUEUE_MOVE flag indicates a task is allowed to change
priority, which means there could be balance callbacks queued.

Therefore audit all MOVE users and make sure they do run balance
callbacks before dropping rq-lock.

Fixes: 6455ad5346 ("sched: Move sched_class::prio_changed() into the change pattern")
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Pierre Gondois <pierre.gondois@arm.com>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://patch.msgid.link/20260114130528.GB831285@noisy.programming.kicks-ass.net
2026-01-15 21:57:53 +01:00
Peter Zijlstra
49041e87f9 sched: Fold rq-pin swizzle into __balance_callbacks()
Prepare for more users needing the rq-pin swizzle.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Pierre Gondois <pierre.gondois@arm.com>
Tested-by: Juri Lelli <juri.lelli@redhat.com>
Link: https://patch.msgid.link/20260114130528.GB831285@noisy.programming.kicks-ass.net
2026-01-15 21:57:52 +01:00
Peter Zijlstra
4de9ff7606 sched/deadline: Avoid double update_rq_clock()
When setup_new_dl_entity() is called from enqueue_task_dl() ->
enqueue_dl_entity(), the rq-clock should already be updated, and
calling update_rq_clock() again is not right.

Move the update_rq_clock() to the one other caller of
setup_new_dl_entity(): sched_init_dl_server().

Fixes: 9f239df555 ("sched/deadline: Initialize dl_servers after SMP")
Reported-by: Pierre Gondois <pierre.gondois@arm.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Tested-by: Pierre Gondois <pierre.gondois@arm.com>
Link: https://patch.msgid.link/20260113115622.GA831285@noisy.programming.kicks-ass.net
2026-01-15 21:57:52 +01:00
Peter Zijlstra
375410bb9a sched/deadline: Ensure get_prio_dl() is up-to-date
Pratheek tripped a WARN and noted the following issue:

> Inspecting the set of events that led to the warning being triggered
> showed the following:
>
>     systemd-1  [008] dN.31 ...: do_set_cpus_allowed: set_cpus_allowed begin!
>
>     systemd-1  [008] dN.31 ...: sched_change_begin: Begin!
>     systemd-1  [008] dN.31 ...: sched_change_begin: Before dequeue_task()!
>     systemd-1  [008] dN.31 ...: update_curr_dl_se: update_curr_dl_se: ENQUEUE_REPLENISH
>     systemd-1  [008] dN.31 ...: enqueue_dl_entity: enqueue_dl_entity: ENQUEUE_REPLENISH
>     systemd-1  [008] dN.31 ...: replenish_dl_entity: Replenish before: 14815760217
>     systemd-1  [008] dN.31 ...: replenish_dl_entity: Replenish after: 14816960047
>     systemd-1  [008] dN.31 ...: sched_change_begin: Before put_prev_task()!
>
>     systemd-1  [008] dN.31 ...: sched_change_end: Before enqueue_task()!
>     systemd-1  [008] dN.31 ...: sched_change_end: Before put_prev_task()!
>     systemd-1  [008] dN.31 ...: prio_changed_dl: Queuing pull task on prio change: 14815760217 -> 14816960047
>     systemd-1  [008] dN.31 ...: prio_changed_dl: Queuing balance callback!
>     systemd-1  [008] dN.31 ...: sched_change_end: End!
>
>     systemd-1  [008] dN.31 ...: do_set_cpus_allowed: set_cpus_allowed end!
>     systemd-1  [008] dN.21 ...: __schedule: Woops! Balance callback found!
>
> 1. sched_change_begin() from guard(sched_change) in
>    do_set_cpus_allowed() stashes the priority, which for the deadline
>    task, is "p->dl.deadline".
> 2. The dequeue of the deadline task replenishes the deadline.
> 3. The task is enqueued back after guard's scope ends and since there is
>    no *_CLASS flags set, sched_change_end() calls
>    dl_sched_class->prio_changed() which compares the deadline.
> 4. Since deadline was moved on dequeue, prio_changed_dl() sees the value
>    differ from the stashed value and queues a balance pull callback.
> 5. do_set_cpus_allowed() finishes and drops the rq_lock without doing a
>    do_balance_callbacks().
> 6. Grabbing the rq_lock() at subsequent __schedule() triggers the
>    warning since the balance pull callback was never executed before
>    dropping the lock.

Meaning get_prio_dl() ought to update current and return an up-to-date
value.

Fixes: 6455ad5346 ("sched: Move sched_class::prio_changed() into the change pattern")
Reported-by: K Prateek Nayak <kprateek.nayak@amd.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: K Prateek Nayak <kprateek.nayak@amd.com>
Tested-by: K Prateek Nayak <kprateek.nayak@amd.com>
Link: https://patch.msgid.link/20260106104113.GX3707891@noisy.programming.kicks-ass.net
2026-01-15 21:57:52 +01:00
Nakshtra Goyal
c51595b3d2 drm/xe/xe_query: Remove check for gt
There's no need to check a userspace-provided GT ID (which may come from
any tile) against the number of GTs that can be present on a single
tile. The xe_device_get_gt() lookup already checks that the GT ID passed
is valid for the current device.(Matt Roper)

Signed-off-by: Nakshtra Goyal <nakshtra.goyal@intel.com>
Reviewed-by: Matt Roper <matthew.d.roper@intel.com>
Link: https://patch.msgid.link/20260113091928.67446-1-nakshtra.goyal@intel.com
Signed-off-by: Matt Roper <matthew.d.roper@intel.com>
2026-01-15 12:57:25 -08:00
Michael Roth
2a62345b30 KVM: guest_memfd: GUP source pages prior to populating guest memory
Currently the post-populate callbacks handle copying source pages into
private GPA ranges backed by guest_memfd, where kvm_gmem_populate()
acquires the filemap invalidate lock, then calls a post-populate
callback which may issue a get_user_pages() on the source pages prior to
copying them into the private GPA (e.g. TDX).

This will not be compatible with in-place conversion, where the
userspace page fault path will attempt to acquire the filemap invalidate
lock while holding the mm->mmap_lock, leading to a potential ABBA
deadlock.

Address this by hoisting the GUP above the filemap invalidate lock so
that these page faults path can be taken early, prior to acquiring the
filemap invalidate lock.

It's not currently clear whether this issue is reachable with the
current implementation of guest_memfd, which doesn't support in-place
conversion, however it does provide a consistent mechanism to provide
stable source/target PFNs to callbacks rather than punting to
vendor-specific code, which allows for more commonality across
architectures, which may be worthwhile even without in-place conversion.

As part of this change, also begin enforcing that the 'src' argument to
kvm_gmem_populate() must be page-aligned, as this greatly reduces the
complexity around how the post-populate callbacks are implemented, and
since no current in-tree users support using a non-page-aligned 'src'
argument.

Suggested-by: Sean Christopherson <seanjc@google.com>
Co-developed-by: Sean Christopherson <seanjc@google.com>
Co-developed-by: Vishal Annapurve <vannapurve@google.com>
Signed-off-by: Vishal Annapurve <vannapurve@google.com>
Tested-by: Vishal Annapurve <vannapurve@google.com>
Tested-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Tested-by: Yan Zhao <yan.y.zhao@intel.com>
Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Link: https://patch.msgid.link/20260108214622.1084057-7-michael.roth@amd.com
[sean: avoid local "p" variable]
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-15 12:31:17 -08:00
Michael Roth
189fd1b059 KVM: TDX: Document alignment requirements for KVM_TDX_INIT_MEM_REGION
Since it was never possible to use a non-PAGE_SIZE-aligned @source_addr,
go ahead and document this as a requirement. This is in preparation for
enforcing page-aligned @source_addr for all architectures in
guest_memfd.

Reviewed-by: Vishal Annapurve <vannapurve@google.com>
Tested-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Reviewed-by: Yan Zhao <yan.y.zhao@intel.com>
Link: https://patch.msgid.link/20260108214622.1084057-6-michael.roth@amd.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-15 12:31:17 -08:00
Michael Roth
dcbcc2323c KVM: SEV: Document/enforce page-alignment for KVM_SEV_SNP_LAUNCH_UPDATE
In the past, KVM_SEV_SNP_LAUNCH_UPDATE accepted a non-page-aligned
'uaddr' parameter to copy data from, but continuing to support this with
new functionality like in-place conversion and hugepages in the pipeline
has proven to be more trouble than it is worth, since there are no known
users that have been identified who use a non-page-aligned 'uaddr'
parameter.

Rather than locking guest_memfd into continuing to support this, go
ahead and document page-alignment as a requirement and begin enforcing
this in the handling function.

Reviewed-by: Vishal Annapurve <vannapurve@google.com>
Tested-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Link: https://patch.msgid.link/20260108214622.1084057-5-michael.roth@amd.com
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-15 12:31:16 -08:00
Michael Roth
8622ef0570 KVM: guest_memfd: Remove preparation tracking
guest_memfd currently uses the folio uptodate flag to track:

  1) whether or not a page has been cleared before initial usage
  2) whether or not the architecture hooks have been issued to put the
     page in a private state as defined by the architecture

In practice, (2) is only actually being tracked for SEV-SNP VMs, and
there do not seem to be any plans/reasons that would suggest this will
change in the future, so this additional tracking/complexity is not
really providing any general benefit to guest_memfd users.  On the other
hand, future plans around in-place conversion and hugepage support will
make the burden of tracking this information within guest_memfd even more
complex.

With in-place conversion and hugepage support, the plan is to use the
per-folio uptodate flag purely to track the initial clearing of folios,
whereas conversion operations could trigger multiple transitions between
'prepared' and 'unprepared' and thus need separate tracking.  Since
preparation generally happens during fault time, i.e. on the "read-side"
of any VM-wide locks that might protect state tracked by guest_memfd,
supporting concurrent handling of page faults would likely require more
complex locking schemes if the "preparedness" state were tracked by
guest_memfd, i.e. if it needs to be updated as part of handling the fault.

Instead of keeping this current/future complexity within guest_memfd for
what is essentially just SEV-SNP, just drop the tracking for (2) and have
the arch-specific preparation hooks get triggered unconditionally on
every fault so the arch-specific hooks can check the preparation state
directly and decide whether or not a folio still needs additional
preparation. In the case of SEV-SNP, the preparation state is already
checked again via the preparation hooks to avoid double-preparation, so
nothing extra needs to be done to update the handling of things there.

Reviewed-by: Vishal Annapurve <vannapurve@google.com>
Tested-by: Vishal Annapurve <vannapurve@google.com>
Reviewed-by: Pankaj Gupta <pankaj.gupta@amd.com>
Tested-by: Kai Huang <kai.huang@intel.com>
Signed-off-by: Michael Roth <michael.roth@amd.com>
Link: https://patch.msgid.link/20260108214622.1084057-4-michael.roth@amd.com
[sean: massage changelog]
Signed-off-by: Sean Christopherson <seanjc@google.com>
2026-01-15 12:31:15 -08:00