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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 ACPI update from Borislav Petkov:
- Improve code generation in ACPI's global lock's acquisition function
* tag 'x86_acpi_for_v6.4_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/ACPI/boot: Improve __acpi_acquire_global_lock
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull RAS updates from Borislav Petkov:
- Just cleanups and fixes this time around: make threshold_ktype const,
an objtool fix and use proper size for a bitmap
* tag 'ras_core_for_v6.4_rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/MCE/AMD: Use an u64 for bank_map
x86/mce: Always inline old MCA stubs
x86/MCE/AMD: Make kobj_type structure constant
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Pull vfs fget updates from Al Viro:
"fget() to fdget() conversions"
* tag 'pull-fd' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
fuse_dev_ioctl(): switch to fdget()
cgroup_get_from_fd(): switch to fdget_raw()
bpf: switch to fdget_raw()
build_mount_idmapped(): switch to fdget()
kill the last remaining user of proc_ns_fget()
SVM-SEV: convert the rest of fget() uses to fdget() in there
convert sgx_set_attribute() to fdget()/fdput()
convert setns(2) to fdget()/fdput()
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Pull documentation updates from Jonathan Corbet:
"Commit volume in documentation is relatively low this time, but there
is still a fair amount going on, including:
- Reorganize the architecture-specific documentation under
Documentation/arch
This makes the structure match the source directory and helps to
clean up the mess that is the top-level Documentation directory a
bit. This work creates the new directory and moves x86 and most of
the less-active architectures there.
The current plan is to move the rest of the architectures in 6.5,
with the patches going through the appropriate subsystem trees.
- Some more Spanish translations and maintenance of the Italian
translation
- A new "Kernel contribution maturity model" document from Ted
- A new tutorial on quickly building a trimmed kernel from Thorsten
Plus the usual set of updates and fixes"
* tag 'docs-6.4' of git://git.lwn.net/linux: (47 commits)
media: Adjust column width for pdfdocs
media: Fix building pdfdocs
docs: clk: add documentation to log which clocks have been disabled
docs: trace: Fix typo in ftrace.rst
Documentation/process: always CC responsible lists
docs: kmemleak: adjust to config renaming
ELF: document some de-facto PT_* ABI quirks
Documentation: arm: remove stih415/stih416 related entries
docs: turn off "smart quotes" in the HTML build
Documentation: firmware: Clarify firmware path usage
docs/mm: Physical Memory: Fix grammar
Documentation: Add document for false sharing
dma-api-howto: typo fix
docs: move m68k architecture documentation under Documentation/arch/
docs: move parisc documentation under Documentation/arch/
docs: move ia64 architecture docs under Documentation/arch/
docs: Move arc architecture docs under Documentation/arch/
docs: move nios2 documentation under Documentation/arch/
docs: move openrisc documentation under Documentation/arch/
docs: move superh documentation under Documentation/arch/
...
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git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux
Pull RCU updates from Joel Fernandes:
- Updates and additions to MAINTAINERS files, with Boqun being added to
the RCU entry and Zqiang being added as an RCU reviewer.
I have also transitioned from reviewer to maintainer; however, Paul
will be taking over sending RCU pull-requests for the next merge
window.
- Resolution of hotplug warning in nohz code, achieved by fixing
cpu_is_hotpluggable() through interaction with the nohz subsystem.
Tick dependency modifications by Zqiang, focusing on fixing usage of
the TICK_DEP_BIT_RCU_EXP bitmask.
- Avoid needless calls to the rcu-lazy shrinker for CONFIG_RCU_LAZY=n
kernels, fixed by Zqiang.
- Improvements to rcu-tasks stall reporting by Neeraj.
- Initial renaming of k[v]free_rcu() to k[v]free_rcu_mightsleep() for
increased robustness, affecting several components like mac802154,
drbd, vmw_vmci, tracing, and more.
A report by Eric Dumazet showed that the API could be unknowingly
used in an atomic context, so we'd rather make sure they know what
they're asking for by being explicit:
https://lore.kernel.org/all/20221202052847.2623997-1-edumazet@google.com/
- Documentation updates, including corrections to spelling,
clarifications in comments, and improvements to the srcu_size_state
comments.
- Better srcu_struct cache locality for readers, by adjusting the size
of srcu_struct in support of SRCU usage by Christoph Hellwig.
- Teach lockdep to detect deadlocks between srcu_read_lock() vs
synchronize_srcu() contributed by Boqun.
Previously lockdep could not detect such deadlocks, now it can.
- Integration of rcutorture and rcu-related tools, targeted for v6.4
from Boqun's tree, featuring new SRCU deadlock scenarios, test_nmis
module parameter, and more
- Miscellaneous changes, various code cleanups and comment improvements
* tag 'rcu.6.4.april5.2023.3' of git://git.kernel.org/pub/scm/linux/kernel/git/jfern/linux: (71 commits)
checkpatch: Error out if deprecated RCU API used
mac802154: Rename kfree_rcu() to kvfree_rcu_mightsleep()
rcuscale: Rename kfree_rcu() to kfree_rcu_mightsleep()
ext4/super: Rename kfree_rcu() to kfree_rcu_mightsleep()
net/mlx5: Rename kfree_rcu() to kfree_rcu_mightsleep()
net/sysctl: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
lib/test_vmalloc.c: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
tracing: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
misc: vmw_vmci: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
drbd: Rename kvfree_rcu() to kvfree_rcu_mightsleep()
rcu: Protect rcu_print_task_exp_stall() ->exp_tasks access
rcu: Avoid stack overflow due to __rcu_irq_enter_check_tick() being kprobe-ed
rcu-tasks: Report stalls during synchronize_srcu() in rcu_tasks_postscan()
rcu: Permit start_poll_synchronize_rcu_expedited() to be invoked early
rcu: Remove never-set needwake assignment from rcu_report_qs_rdp()
rcu: Register rcu-lazy shrinker only for CONFIG_RCU_LAZY=y kernels
rcu: Fix missing TICK_DEP_MASK_RCU_EXP dependency check
rcu: Fix set/clear TICK_DEP_BIT_RCU_EXP bitmask race
rcu/trace: use strscpy() to instead of strncpy()
tick/nohz: Fix cpu_is_hotpluggable() by checking with nohz subsystem
...
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Merge my x86 user copy updates branch.
This cleans up a lot of our x86 memory copy code, particularly for user
accesses. I've been pushing for microarchitectural support for good
memory copying and clearing for a long while, and it's been visible in
how the kernel has aggressively used 'rep movs' and 'rep stos' whenever
possible.
And that micro-architectural support has been improving over the years,
to the point where on modern CPU's the best option for a memory copy
that would become a function call (as opposed to being something that
can just be turned into individual 'mov' instructions) is now to inline
the string instruction sequence instead.
However, that only makes sense when we have the modern markers for this:
the x86 FSRM and FSRS capabilities ("Fast Short REP MOVS/STOS").
So this cleans up a lot of our historical code, gets rid of the legacy
marker use ("REP_GOOD" and "ERMS") from the memcpy/memset cases, and
replaces it with that modern reality. Note that REP_GOOD and ERMS end
up still being used by the known large cases (ie page copyin gand
clearing).
The reason much of this ends up being about user memory accesses is that
the normal in-kernel cases are done by the compiler (__builtin_memcpy()
and __builtin_memset()) and getting to the point where we can use our
instruction rewriting to inline those to be string instructions will
need some compiler support.
In contrast, the user accessor functions are all entirely controlled by
the kernel code, so we can change those arbitrarily.
Thanks to Borislav Petkov for feedback on the series, and Jens testing
some of this on micro-architectures I didn't personally have access to.
* x86-rep-insns:
x86: rewrite '__copy_user_nocache' function
x86: remove 'zerorest' argument from __copy_user_nocache()
x86: set FSRS automatically on AMD CPUs that have FSRM
x86: improve on the non-rep 'copy_user' function
x86: improve on the non-rep 'clear_user' function
x86: inline the 'rep movs' in user copies for the FSRM case
x86: move stac/clac from user copy routines into callers
x86: don't use REP_GOOD or ERMS for user memory clearing
x86: don't use REP_GOOD or ERMS for user memory copies
x86: don't use REP_GOOD or ERMS for small memory clearing
x86: don't use REP_GOOD or ERMS for small memory copies
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Add missing clockticks and cas_count_* events for Intel SapphireRapids IMC
PMU. These events are useful to measure memory bandwidth.
Signed-off-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Reviewed-by: Kan Liang <kan.liang@linux.intel.com>
Link: https://lore.kernel.org/r/20230419214241.2310385-1-eranian@google.com
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* kvm-arm64/smccc-filtering:
: .
: SMCCC call filtering and forwarding to userspace, courtesy of
: Oliver Upton. From the cover letter:
:
: "The Arm SMCCC is rather prescriptive in regards to the allocation of
: SMCCC function ID ranges. Many of the hypercall ranges have an
: associated specification from Arm (FF-A, PSCI, SDEI, etc.) with some
: room for vendor-specific implementations.
:
: The ever-expanding SMCCC surface leaves a lot of work within KVM for
: providing new features. Furthermore, KVM implements its own
: vendor-specific ABI, with little room for other implementations (like
: Hyper-V, for example). Rather than cramming it all into the kernel we
: should provide a way for userspace to handle hypercalls."
: .
KVM: selftests: Fix spelling mistake "KVM_HYPERCAL_EXIT_SMC" -> "KVM_HYPERCALL_EXIT_SMC"
KVM: arm64: Test that SMC64 arch calls are reserved
KVM: arm64: Prevent userspace from handling SMC64 arch range
KVM: arm64: Expose SMC/HVC width to userspace
KVM: selftests: Add test for SMCCC filter
KVM: selftests: Add a helper for SMCCC calls with SMC instruction
KVM: arm64: Let errors from SMCCC emulation to reach userspace
KVM: arm64: Return NOT_SUPPORTED to guest for unknown PSCI version
KVM: arm64: Introduce support for userspace SMCCC filtering
KVM: arm64: Add support for KVM_EXIT_HYPERCALL
KVM: arm64: Use a maple tree to represent the SMCCC filter
KVM: arm64: Refactor hvc filtering to support different actions
KVM: arm64: Start handling SMCs from EL1
KVM: arm64: Rename SMC/HVC call handler to reflect reality
KVM: arm64: Add vm fd device attribute accessors
KVM: arm64: Add a helper to check if a VM has ran once
KVM: x86: Redefine 'longmode' as a flag for KVM_EXIT_HYPERCALL
Signed-off-by: Marc Zyngier <maz@kernel.org>
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Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
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I didn't really want to do this, but as part of all the other changes to
the user copy loops, I've been looking at this horror.
I tried to clean it up multiple times, but every time I just found more
problems, and the way it's written, it's just too hard to fix them.
For example, the code is written to do quad-word alignment, and will use
regular byte accesses to get to that point. That's fairly simple, but
it means that any initial 8-byte alignment will be done with cached
copies.
However, the code then is very careful to do any 4-byte _tail_ accesses
using an uncached 4-byte write, and that was claimed to be relevant in
commit a82eee742452 ("x86/uaccess/64: Handle the caching of 4-byte
nocache copies properly in __copy_user_nocache()").
So if you do a 4-byte copy using that function, it carefully uses a
4-byte 'movnti' for the destination. But if you were to do a 12-byte
copy that is 4-byte aligned, it would _not_ do a 4-byte 'movnti'
followed by a 8-byte 'movnti' to keep it all uncached.
Instead, it would align the destination to 8 bytes using a
byte-at-a-time loop, and then do a 8-byte 'movnti' for the final 8
bytes.
The main caller that cares is __copy_user_flushcache(), which knows
about this insanity, and has odd cases for it all. But I just can't
deal with looking at this kind of "it does one case right, and another
related case entirely wrong".
And the code really wasn't fixable without hard drugs, which I try to
avoid.
So instead, rewrite it in a form that hopefully not only gets this
right, but is a bit more maintainable. Knock wood.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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There's a lot of code here that hard-codes that the
data is a single page, and right now that seems to
be sufficient, but to make it easier to change this
in the future, add a new STUB_DATA_PAGES constant
and use it throughout the code.
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Signed-off-by: Richard Weinberger <richard@nod.at>
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Avoid cluttering up the kallsyms symbol table with entries that should
not end up in things like backtraces, as they have undescriptive and
generated identifiers.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Avoid cluttering up the kallsyms symbol table with entries that should
not end up in things like backtraces, as they have undescriptive and
generated identifiers.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Avoid cluttering up the kallsyms symbol table with entries that should
not end up in things like backtraces, as they have undescriptive and
generated identifiers.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Prefer RIP-relative addressing where possible, which removes the need
for boot time relocation fixups.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Prefer RIP-relative addressing where possible, which removes the need
for boot time relocation fixups.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Prefer RIP-relative addressing where possible, which removes the need
for boot time relocation fixups.
Co-developed-by: Thomas Garnier <thgarnie@chromium.org>
Signed-off-by: Thomas Garnier <thgarnie@chromium.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Prefer RIP-relative addressing where possible, which removes the need
for boot time relocation fixups.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Prefer RIP-relative addressing where possible, which removes the need
for boot time relocation fixups.
Co-developed-by: Thomas Garnier <thgarnie@chromium.org>
Signed-off-by: Thomas Garnier <thgarnie@chromium.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Prefer RIP-relative addressing where possible, which removes the need
for boot time relocation fixups.
Co-developed-by: Thomas Garnier <thgarnie@chromium.org>
Signed-off-by: Thomas Garnier <thgarnie@chromium.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Prefer RIP-relative addressing where possible, which removes the need
for boot time relocation fixups.
Co-developed-by: Thomas Garnier <thgarnie@chromium.org>
Signed-off-by: Thomas Garnier <thgarnie@chromium.org>
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Prefer RIP-relative addressing where possible, which removes the need
for boot time relocation fixups.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Prefer RIP-relative addressing where possible, which removes the need
for boot time relocation fixups. In the GCM case, we can get rid of the
oversized permutation array entirely while at it.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Prefer RIP-relative addressing where possible, which removes the need
for boot time relocation fixups.
Signed-off-by: Ard Biesheuvel <ardb@kernel.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
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Every caller passes in zero, meaning they don't want any partial copy to
zero the remainder of the destination buffer.
Which is just as well, because the implementation of that function
didn't actually even look at that argument, and wasn't even aware it
existed, although some misleading comments did mention it still.
The 'zerorest' thing is a historical artifact of how "copy_from_user()"
worked, in that it would zero the rest of the kernel buffer that it
copied into.
That zeroing still exists, but it's long since been moved to generic
code, and the raw architecture-specific code doesn't do it. See
_copy_from_user() in lib/usercopy.c for this all.
However, while __copy_user_nocache() shares some history and superficial
other similarities with copy_from_user(), it is in many ways also very
different.
In particular, while the code makes it *look* similar to the generic
user copy functions that can copy both to and from user space, and take
faults on both reads and writes as a result, __copy_user_nocache() does
no such thing at all.
__copy_user_nocache() always copies to kernel space, and will never take
a page fault on the destination. What *can* happen, though, is that the
non-temporal stores take a machine check because one of the use cases is
for writing to stable memory, and any memory errors would then take
synchronous faults.
So __copy_user_nocache() does look a lot like copy_from_user(), but has
faulting behavior that is more akin to our old copy_in_user() (which no
longer exists, but copied from user space to user space and could fault
on both source and destination).
And it very much does not have the "zero the end of the destination
buffer", since a problem with the destination buffer is very possibly
the very source of the partial copy.
So this whole thing was just a confusing historical artifact from having
shared some code with a completely different function with completely
different use cases.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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So Intel introduced the FSRS ("Fast Short REP STOS") CPU capability bit,
because they seem to have done the (much simpler) REP STOS optimizations
separately and later than the REP MOVS one.
In contrast, when AMD introduced support for FSRM ("Fast Short REP
MOVS"), in the Zen 3 core, it appears to have improved the REP STOS case
at the same time, and since the FSRS bit was added by Intel later, it
doesn't show up on those AMD Zen 3 cores.
And now that we made use of FSRS for the "rep stos" conditional, that
made those AMD machines unnecessarily slower. The Intel situation where
"rep movs" is fast, but "rep stos" isn't, is just odd. The 'stos' case
is a lot simpler with no aliasing, no mutual alignment issues, no
complicated cases.
So this just sets FSRS automatically when FSRM is available on AMD
machines, to get back all the nice REP STOS goodness in Zen 3.
Reported-and-tested-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The old 'copy_user_generic_unrolled' function was oddly implemented for
largely historical reasons: it had been largely based on the uncached
copy case, which has some other concerns.
For example, the __copy_user_nocache() function uses 'movnti' for the
destination stores, and those want the destination to be aligned. In
contrast, the regular copy function doesn't really care, and trying to
align things only complicates matters.
Also, like the clear_user function, the copy function had some odd
handling of the repeat counts, complicating the exception handling for
no really good reason. So as with clear_user, just write it to keep all
the byte counts in the %rcx register, exactly like the 'rep movs'
functionality that this replaces.
Unlike a real 'rep movs', we do allow for this to trash a few temporary
registers to not have to unnecessarily save/restore registers on the
stack.
And like the clearing case, rename this to what it now clearly is:
'rep_movs_alternative', and make it one coherent function, so that it
shows up as such in profiles (instead of the odd split between
"copy_user_generic_unrolled" and "copy_user_short_string", the latter of
which was not about strings at all, and which was shared with the
uncached case).
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The old version was oddly written to have the repeat count in multiple
registers. So instead of taking advantage of %rax being zero, it had
some sub-counts in it. All just for a "single word clearing" loop,
which isn't even efficient to begin with.
So get rid of those games, and just keep all the state in the same
registers we got it in (and that we should return things in). That not
only makes this act much more like 'rep stos' (which this function is
replacing), but makes it much easier to actually do the obvious loop
unrolling.
Also rename the function from the now nonsensical 'clear_user_original'
to what it now clearly is: 'rep_stos_alternative'.
End result: if we don't have a fast 'rep stosb', at least we can have a
fast fallback for it.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This does the same thing for the user copies as commit 0db7058e8e23
("x86/clear_user: Make it faster") did for clear_user(). In other
words, it inlines the "rep movs" case when X86_FEATURE_FSRM is set,
avoiding the function call entirely.
In order to do that, it makes the calling convention for the out-of-line
case ("copy_user_generic_unrolled") match the 'rep movs' calling
convention, although it does also end up clobbering a number of
additional registers.
Also, to simplify code sharing in the low-level assembly with the
__copy_user_nocache() function (that uses the normal C calling
convention), we end up with a kind of mixed return value for the
low-level asm code: it will return the result in both %rcx (to work as
an alternative for the 'rep movs' case), _and_ in %rax (for the nocache
case).
We could avoid this by wrapping __copy_user_nocache() callers in an
inline asm, but since the cost is just an extra register copy, it's
probably not worth it.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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This is preparatory work for inlining the 'rep movs' case, but also a
cleanup. The __copy_user_nocache() function was mis-used by the rdma
code to do uncached kernel copies that don't actually want user copies
at all, and as a result doesn't want the stac/clac either.
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The modern target to use is FSRS (Fast Short REP STOS), and the other
cases should only be used for bigger areas (ie mainly things like page
clearing).
Note! This changes the conditional for the inlining from FSRM ("fast
short rep movs") to FSRS ("fast short rep stos").
We'll have a separate fixup for AMD microarchitectures that have a good
'rep stosb' yet do not set the new Intel-specific FSRS bit (because FSRM
was there first).
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The modern target to use is FSRM (Fast Short REP MOVS), and the other
cases should only be used for bigger areas (ie mainly things like page
clearing).
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The modern target to use is FSRS (Fast Short REP STOS), and the other
cases should only be used for bigger areas (ie mainly things like page
clearing).
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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The modern target to use is FSRM (Fast Short REP MOVS), and the other
cases should only be used for bigger areas (ie mainly things like page
copying and clearing).
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Now we use ARCH_WANT_HUGETLB_PAGE_OPTIMIZE_VMEMMAP config option to
indicate devdax and hugetlb vmemmap optimization support. Hence rename
that to a generic ARCH_WANT_OPTIMIZE_VMEMMAP
Link: https://lkml.kernel.org/r/20230412050025.84346-2-aneesh.kumar@linux.ibm.com
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.ibm.com>
Reviewed-by: Muchun Song <songmuchun@bytedance.com>
Cc: Joao Martins <joao.m.martins@oracle.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Mike Kravetz <mike.kravetz@oracle.com>
Cc: Tarun Sahu <tsahu@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
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Fundamentally semaphores are a counted primitive, but
DEFINE_SEMAPHORE() does not expose this and explicitly creates a
binary semaphore.
Change DEFINE_SEMAPHORE() to take a number argument and use that in the
few places that open-coded it using __SEMAPHORE_INITIALIZER().
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
[mcgrof: add some tribal knowledge about why some folks prefer
binary sempahores over mutexes]
Reviewed-by: Sergey Senozhatsky <senozhatsky@chromium.org>
Reviewed-by: Davidlohr Bueso <dave@stgolabs.net>
Signed-off-by: Luis Chamberlain <mcgrof@kernel.org>
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Virtual Trust Levels (VTL) helps enable Hyper-V Virtual Secure Mode (VSM)
feature. VSM is a set of hypervisor capabilities and enlightenments
offered to host and guest partitions which enable the creation and
management of new security boundaries within operating system software.
VSM achieves and maintains isolation through VTLs.
Add early initialization for Virtual Trust Levels (VTL). This includes
initializing the x86 platform for VTL and enabling boot support for
secondary CPUs to start in targeted VTL context. For now, only enable
the code for targeted VTL level as 2.
When starting an AP at a VTL other than VTL0, the AP must start directly
in 64-bit mode, bypassing the usual 16-bit -> 32-bit -> 64-bit mode
transition sequence that occurs after waking up an AP with SIPI whose
vector points to the 16-bit AP startup trampoline code.
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Stanislav Kinsburskii <stanislav.kinsburskii@gmail.com>
Link: https://lore.kernel.org/r/1681192532-15460-6-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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Move hv_get_nmi_reason to .h file so it can be used in other
modules as well.
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1681192532-15460-4-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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Add structs and hypercalls required to enable VTL support on x86.
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Stanislav Kinsburskii <stanislav.kinsburskii@gmail.com>
Link: https://lore.kernel.org/r/1681192532-15460-3-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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Make get/set_rtc_noop() to be public so that they can be used
in other modules as well.
Co-developed-by: Tianyu Lan <tiala@microsoft.com>
Signed-off-by: Tianyu Lan <tiala@microsoft.com>
Signed-off-by: Saurabh Sengar <ssengar@linux.microsoft.com>
Reviewed-by: Wei Liu <wei.liu@kernel.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/1681192532-15460-2-git-send-email-ssengar@linux.microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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The usage of the BIT() macro in inline asm code was introduced in 6.3 by
the commit in the Fixes tag. However, this macro uses "1UL" for integer
constant suffixes in its shift operation, while gas before 2.28 does not
support the "L" suffix after a number, and gas before 2.27 does not
support the "U" suffix, resulting in build errors such as the following
with such versions:
./arch/x86/include/asm/uaccess_64.h:124: Error: found 'L', expected: ')'
./arch/x86/include/asm/uaccess_64.h:124: Error: junk at end of line,
first unrecognized character is `L'
However, the currently minimal binutils version the kernel supports is
2.25.
There's a single use of this macro here, revert to (1 << 0) that works
with such older binutils.
As an additional info, the binutils PRs which add support for those
suffixes are:
https://sourceware.org/bugzilla/show_bug.cgi?id=19910
https://sourceware.org/bugzilla/show_bug.cgi?id=20732
[ bp: Massage and extend commit message. ]
Fixes: 5d1dd961e743 ("x86/alternatives: Add alt_instr.flags")
Signed-off-by: Willy Tarreau <w@1wt.eu>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Tested-by: Jingbo Xu <jefflexu@linux.alibaba.com>
Link: https://lore.kernel.org/lkml/a9aae568-3046-306c-bd71-92c1fc8eeddc@linux.alibaba.com/
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In the case where page tables are not freed, native_flush_tlb_multi()
does not do a remote TLB flush on CPUs in lazy TLB mode because the
CPU will flush itself at the next context switch. By comparison, the
Hyper-V enlightened TLB flush does not exclude CPUs in lazy TLB mode
and so performs unnecessary flushes.
If we're not freeing page tables, add logic to test for lazy TLB
mode when adding CPUs to the input argument to the Hyper-V TLB
flush hypercall. Exclude lazy TLB mode CPUs so the behavior
matches native_flush_tlb_multi() and the unnecessary flushes are
avoided. Handle both the <=64 vCPU case and the _ex case for >64
vCPUs.
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1679922967-26582-3-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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When copying CPUs from a Linux cpumask to a Hyper-V VPset,
cpumask_to_vpset() currently has a "_noself" variant that doesn't copy
the current CPU to the VPset. Generalize this variant by replacing it
with a "_skip" variant having a callback function that is invoked for
each CPU to decide if that CPU should be copied. Update the one caller
of cpumask_to_vpset_noself() to use the new "_skip" variant instead.
No functional change.
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/1679922967-26582-2-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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For PCI pass-thru devices in a Confidential VM, Hyper-V requires
that PCI config space be accessed via hypercalls. In normal VMs,
config space accesses are trapped to the Hyper-V host and emulated.
But in a confidential VM, the host can't access guest memory to
decode the instruction for emulation, so an explicit hypercall must
be used.
Add functions to make the new MMIO read and MMIO write hypercalls.
Update the PCI config space access functions to use the hypercalls
when such use is indicated by Hyper-V flags. Also, set the flag to
allow the Hyper-V PCI driver to be loaded and used in a Confidential
VM (a.k.a., "Isolation VM"). The driver has previously been hardened
against a malicious Hyper-V host[1].
[1] https://lore.kernel.org/all/20220511223207.3386-2-parri.andrea@gmail.com/
Co-developed-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Dexuan Cui <decui@microsoft.com>
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Boqun Feng <boqun.feng@gmail.com>
Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>
Link: https://lore.kernel.org/r/1679838727-87310-13-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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With the vTOM bit now treated as a protection flag and not part of
the physical address, avoid remapping physical addresses with vTOM set
since technically such addresses aren't valid. Use ioremap_cache()
instead of memremap() to ensure that the mapping provides decrypted
access, which will correctly set the vTOM bit as a protection flag.
While this change is not required for correctness with the current
implementation of memremap(), for general code hygiene it's better to
not depend on the mapping functions doing something reasonable with
a physical address that is out-of-range.
While here, fix typos in two error messages.
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/1679838727-87310-12-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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With changes to how Hyper-V guest VMs flip memory between private
(encrypted) and shared (decrypted), creating a second kernel virtual
mapping for shared memory is no longer necessary. Everything needed
for the transition to shared is handled by set_memory_decrypted().
As such, remove the code to create and manage the second
mapping for the pre-allocated send and recv buffers. This mapping
is the last user of hv_map_memory()/hv_unmap_memory(), so delete
these functions as well. Finally, hv_map_memory() is the last
user of vmap_pfn() in Hyper-V guest code, so remove the Kconfig
selection of VMAP_PFN.
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Reviewed-by: Tianyu Lan <Tianyu.Lan@microsoft.com>
Link: https://lore.kernel.org/r/1679838727-87310-11-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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With changes to how Hyper-V guest VMs flip memory between private
(encrypted) and shared (decrypted), creating a second kernel virtual
mapping for shared memory is no longer necessary. Everything needed
for the transition to shared is handled by set_memory_decrypted().
As such, remove swiotlb_unencrypted_base and the associated
code.
Signed-off-by: Michael Kelley <mikelley@microsoft.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/1679838727-87310-8-git-send-email-mikelley@microsoft.com
Signed-off-by: Wei Liu <wei.liu@kernel.org>
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Merge the following 6 patches from tip/x86/sev, which are taken from
Michael Kelley's series [0]. The rest of Michael's series depend on
them.
x86/hyperv: Change vTOM handling to use standard coco mechanisms
init: Call mem_encrypt_init() after Hyper-V hypercall init is done
x86/mm: Handle decryption/re-encryption of bss_decrypted consistently
Drivers: hv: Explicitly request decrypted in vmap_pfn() calls
x86/hyperv: Reorder code to facilitate future work
x86/ioremap: Add hypervisor callback for private MMIO mapping in coco VM
0: https://lore.kernel.org/linux-hyperv/1679838727-87310-1-git-send-email-mikelley@microsoft.com/
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git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull x86 fix from Borislav Petkov:
- Drop __init annotation from two rtc functions which get called after
boot is done, in order to prevent a crash
* tag 'x86_urgent_for_v6.3_rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
x86/rtc: Remove __init for runtime functions
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