Pull RISC-V updates from Paul Walmsley:
- Add support for control flow integrity for userspace processes.
This is based on the standard RISC-V ISA extensions Zicfiss and
Zicfilp
- Improve ptrace behavior regarding vector registers, and add some
selftests
- Optimize our strlen() assembly
- Enable the ISO-8859-1 code page as built-in, similar to ARM64, for
EFI volume mounting
- Clean up some code slightly, including defining copy_user_page() as
copy_page() rather than memcpy(), aligning us with other
architectures; and using max3() to slightly simplify an expression
in riscv_iommu_init_check()
* tag 'riscv-for-linus-7.0-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux: (42 commits)
riscv: lib: optimize strlen loop efficiency
selftests: riscv: vstate_exec_nolibc: Use the regular prctl() function
selftests: riscv: verify ptrace accepts valid vector csr values
selftests: riscv: verify ptrace rejects invalid vector csr inputs
selftests: riscv: verify syscalls discard vector context
selftests: riscv: verify initial vector state with ptrace
selftests: riscv: test ptrace vector interface
riscv: ptrace: validate input vector csr registers
riscv: csr: define vtype register elements
riscv: vector: init vector context with proper vlenb
riscv: ptrace: return ENODATA for inactive vector extension
kselftest/riscv: add kselftest for user mode CFI
riscv: add documentation for shadow stack
riscv: add documentation for landing pad / indirect branch tracking
riscv: create a Kconfig fragment for shadow stack and landing pad support
arch/riscv: add dual vdso creation logic and select vdso based on hw
arch/riscv: compile vdso with landing pad and shadow stack note
riscv: enable kernel access to shadow stack memory via the FWFT SBI call
riscv: add kernel command line option to opt out of user CFI
riscv/hwprobe: add zicfilp / zicfiss enumeration in hwprobe
...
RISC-V Devicetrees for v6.20 (or v7.0)
Anlogic:
Minor change to the extension information, to add the "b" extension
that's a catch-all for 3 of the extensions already in the dts.
Starfive:
Append the jh7110 compatible to jh7110s devicetrees, as that will enable
OpenSBI etc to run without adding support for this minor variant. The
"s" device differs from the non "s" device only in
thermal limits and voltage/frequency characteristics.
Microchip:
Redo the mpfs clock setup yet again, to something approaching correct.
The original binding conjured up for the platform was wildly inaccurate,
and even with the original improvements, a bigger change to using
syscons was required to support several peripherals that also inhabit
the memory regions that the clocks lie in. The damage to the dts isn't
that bad in the end, and of course the whole thing has been done in a
backwards compatible manner, with the code changes being merged a cycle
or two ago in the kernel and like a year ago in U-Boot (the only other
user that I am aware of).
Generic:
Additions to extensions.yaml, mainly for things in the "rva23" profile
that appear for the first time on the Spacemit K3 SoC.
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
* tag 'riscv-dt-for-v6.20' of https://git.kernel.org/pub/scm/linux/kernel/git/conor/linux:
riscv: dts: anlogic: dr1v90: Add "b" ISA extension
dt-bindings: riscv: extensions: Drop unnecessary select schema
dt-bindings: riscv: Add Sha and its comprised extensions
dt-bindings: riscv: Add Ssccptr, Sscounterenw, Sstvala, Sstvecd, Ssu64xl
dt-bindings: riscv: Add descriptions for Za64rs, Ziccamoa, Ziccif, and Zicclsm
dt-bindings: riscv: Add B ISA extension description
dt-bindings: riscv: update ratified version of h, svinval, svnapot, svpbmt
riscv: dts: starfive: Append JH-7110 SoC compatible to VisionFive 2 Lite eMMC board
riscv: dts: starfive: Append JH-7110 SoC compatible to VisionFive 2 Lite board
dt-bindings: riscv: starfive: Append JH-7110 SoC compatible to VisionFive 2 Lite board
riscv: dts: microchip: convert clock and reset to use syscon
riscv: dts: microchip: fix mailbox description
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
The "select" schema is not necessary because this schema is referenced by
riscv/cpus.yaml schema.
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Add descriptions for the Sha extension and the seven extensions it
comprises: Shcounterenw, Shgatpa, Shtvala, Shvsatpa, Shvstvala, Shvstvecd,
and Ssstateen.
Sha is ratified in the RVA23 Profiles Version 1.0 (commit 0273f3c921b6
"rva23/rvb23 ratified") as a new profile-defined extension that captures
the full set of features that are mandated to be supported along with
the H extension.
Extensions Shcounterenw, Shgatpa, Shtvala, Shvsatpa, Shvstvala, Shvstvecd,
and Ssstateen are ratified in the RISC-V Profiles Version 1.0 (commit
b1d806605f87 "Updated to ratified state").
The requirement status for Sha and its comprised extension in RISC-V
Profiles are:
- Sha: Mandatory in RVA23S64
- H: Optional in RVA22S64; Mandatory in RVA23S64
- Shcounterenw: Optional in RVA22S64; Mandatory in RVA23S64
- Shgatpa: Optional in RVA22S64; Mandatory in RVA23S64
- Shtvala: Optional in RVA22S64; Mandatory in RVA23S64
- Shvsatpa: Optional in RVA22S64; Mandatory in RVA23S64
- Shvstvala: Optional in RVA22S64; Mandatory in RVA23S64
- Shvstvecd: Optional in RVA22S64; Mandatory in RVA23S64
- Ssstateen: Optional in RVA22S64; Mandatory in RVA23S64
Signed-off-by: Guodong Xu <guodong@riscstar.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Add descriptions for five new extensions: Ssccptr, Sscounterenw, Sstvala,
Sstvecd, and Ssu64xl. These extensions are ratified in RISC-V Profiles
Version 1.0 (commit b1d806605f87 "Updated to ratified state.").
They are introduced as new extension names for existing features and
regulate implementation details for RISC-V Profile compliance. According
to RISC-V Profiles Version 1.0 and RVA23 Profiles Version 1.0, their
requirement status are:
- Ssccptr: Mandatory in RVA20S64, RVA22S64, RVA23S64
- Sscounterenw: Mandatory in RVA22S64, RVA23S64
- Sstvala: Mandatory in RVA20S64, RVA22S64, RVA23S64
- Sstvecd: Mandatory in RVA20S64, RVA22S64, RVA23S64
- Ssu64xl: Optional in RVA20S64, RVA22S64; Mandatory in RVA23S64
Signed-off-by: Guodong Xu <guodong@riscstar.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Add descriptions for four extensions: Za64rs, Ziccamoa, Ziccif, and
Zicclsm. These extensions are ratified in RISC-V Profiles Version 1.0
(commit b1d806605f87 "Updated to ratified state.").
They are introduced as new extension names for existing features and
regulate implementation details for RISC-V Profile compliance. According
to RISC-V Profiles Version 1.0 and RVA23 Profiles Version 1.0, they are
mandatory for the following profiles:
- za64rs: Mandatory in RVA22U64, RVA23U64
- ziccamoa: Mandatory in RVA20U64, RVA22U64, RVA23U64
- ziccif: Mandatory in RVA20U64, RVA22U64, RVA23U64
- zicclsm: Mandatory in RVA20U64, RVA22U64, RVA23U64
Ziccrse specifies the main memory must support "RsrvEventual", which is
one (totally there are four) of the support level for Load-Reserved/
Store-Conditional (LR/SC) atomic instructions. Thus it depends on Zalrsc.
Ziccamoa specifies the main memory must support AMOArithmetic, among the
four levels of PMA support defined for AMOs in the A extension. Thus it
depends on Zaamo.
Za64rs defines reservation sets are contiguous, naturally aligned, and a
maximum of 64 bytes. Za64rs is consumed by two extensions: Zalrsc and
Zawrs. Zawrs itself depends on Zalrsc too.
Based on the relationship that "A" = Zaamo + Zalrsc, add the following
dependencies checks:
Za64rs -> Zalrsc or A
Ziccrse -> Zalrsc or A
Ziccamoa -> Zaamo or A
Signed-off-by: Guodong Xu <guodong@riscstar.com>
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Add description of the single-letter B extension for Bit Manipulation.
B is mandatory for RVA23U64.
The B extension is ratified in the 20240411 version of the unprivileged
ISA specification. According to the ratified spec, the B standard
extension comprises instructions provided by the Zba, Zbb, and Zbs
extensions.
Add two-way dependency check to enforce that B implies Zba/Zbb/Zbs; and
when Zba/Zbb/Zbs (all of them) are specified, then B must be added too.
The reason why B/Zba/Zbb/Zbs must coexist at the same time is that
unlike other single-letter extensions, B was ratified (Apr/2024) much
later than its component extensions Zba/Zbb/Zbs (Jun/2021).
When "b" is specified, zba/zbb/zbs must be present to ensure
backward compatibility with existing software and kernels that only
look for the explicit component strings.
When all three components zba/zbb/zbs are specified, "b" should also be
present. Making "b" mandatory when all three components are present.
Existing devicetrees with zba/zbb/zbs but without "b" will generate
warnings that can be fixed in follow-up patches.
Signed-off-by: Guodong Xu <guodong@riscstar.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
The descriptions for h, svinval, svnapot, and svpbmt extensions currently
reference the "20191213 version of the privileged ISA specification".
While an Unprivileged ISA document exists with that date, there is no
corresponding ratified Privileged ISA specification.
These extensions were ratified in the RISC-V Instruction Set Manual,
Volume II: Privileged Architecture, Version 20211203. Update the
descriptions to reference the correct specification version.
RISC-V International hosts a website [1] for ratified specifications.
Following the "Ratified ISA Specifications", historical versions of
Volume II Privileged ISA can be found.
Link: https://riscv.org/specifications/ratified/ [1]
Fixes: aeb71e42ca ("dt-bindings: riscv: deprecate riscv,isa")
Acked-by: Conor Dooley <conor.dooley@microchip.com>
Signed-off-by: Guodong Xu <guodong@riscstar.com>
Signed-off-by: Conor Dooley <conor.dooley@microchip.com>
Pull RISC-V updates from Paul Walmsley:
- Enable parallel hotplug for RISC-V
- Optimize vector regset allocation for ptrace()
- Add a kernel selftest for the vector ptrace interface
- Enable the userspace RAID6 test to build and run using RISC-V vectors
- Add initial support for the Zalasr RISC-V ratified ISA extension
- For the Zicbop RISC-V ratified ISA extension to userspace, expose
hardware and kernel support to userspace and add a kselftest for
Zicbop
- Convert open-coded instances of 'asm goto's that are controlled by
runtime ALTERNATIVEs to use riscv_has_extension_{un,}likely(),
following arm64's alternative_has_cap_{un,}likely()
- Remove an unnecessary mask in the GFP flags used in some calls to
pagetable_alloc()
* tag 'riscv-for-linus-6.19-mw1' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
selftests/riscv: Add Zicbop prefetch test
riscv: hwprobe: Expose Zicbop extension and its block size
riscv: Introduce Zalasr instructions
riscv: hwprobe: Export Zalasr extension
dt-bindings: riscv: Add Zalasr ISA extension description
riscv: Add ISA extension parsing for Zalasr
selftests: riscv: Add test for the Vector ptrace interface
riscv: ptrace: Optimize the allocation of vector regset
raid6: test: Add support for RISC-V
raid6: riscv: Allow code to be compiled in userspace
raid6: riscv: Prevent compiler from breaking inline vector assembly code
riscv: cmpxchg: Use riscv_has_extension_likely
riscv: bitops: Use riscv_has_extension_likely
riscv: hweight: Use riscv_has_extension_likely
riscv: checksum: Use riscv_has_extension_likely
riscv: pgtable: Use riscv_has_extension_unlikely
riscv: Remove __GFP_HIGHMEM masking
RISC-V: Enable HOTPLUG_PARALLEL for secondary CPUs
Pull SoC dt updates from Arnd Bergmann:
"There are five sets of new SoCs that get added in existing families,
all of them being either upgrades or cut-down versions of the older
chips:
- Apple M2 Pro, M2 Max and M2 Ultra, used in the 2022/2023 generation
of high-end workstations and laptops from Apple. Linux has been
working on these for a while but stil requires patches.
- Axis Artpec8 is an Armv8 chip based on Samsung Exynos design,
unlike the earlier Armv7 Artpec6 from the same company that was
part of a separate family of chips.
- NXP i.MX91 is a cut-down version of i.MX93, using only a single
Cortex-A55 core.
- Qualcomm Lemans Auto is a variant of the Lemans SoC that was
originally merged under the sa8775p name, the differences being
mostly the firmware configuration of the platform.
- Four new Renesas SoCs RZ/T2H (r9a09g077m44), RZ/N2H (r9a09g087m44),
RZ/T2H (r9a09g077), and RZ/N2H (r9a09g087) are all industrial
bedded SoCs based on Cortex-A55 cores
In total, there are 65 new machines, including:
- Industrial embedded system and single-board computers based on NXP,
Allwinner, TI, Rockchips, Marvell, Xilinx Spacemit, Starfive chips.
- Reference boards for the newly added Renesas, Qualcomm, NXP and
Axis ARMv8 chips as well as Microchip's MPFS RISC-V SoC
- Laptops and Workstations using Apple M2 and Qualcomm Snapdragon X1
chips.
- Several Samsung phones using Qualcomm Snapdragon chips
- Set-top boxes based on Allwinner H313
- Five BMC boards using 32-bit ASpeed SoCs
- Three network routers using IXP4xx (ARMv5!) and Broadcom bcm4708
(ARMv7) SoCs
Two machines get phased out because they were available only in small
quantities but never made it into products: one STi407 based reference
board, and a Snapdragon 845 based Chromebook.
Aside from the newly added machines, a lot of work went into improving
hardware support on the existing machines and cleaning up contents for
validation"
* tag 'soc-dt-6.18' of git://git.kernel.org/pub/scm/linux/kernel/git/soc/soc: (931 commits)
arm64: dts: apm-shadowcat: Drop "apm,xgene2-pcie" compatible
arm64: dts: apm-shadowcat: Move slimpro nodes out of "simple-bus" node
ARM: dts: microchip: sam9x7: Add qspi controller
arm64: dts: qcom: Add MST pixel streams for displayport
arm64: dts: qcom: sm6350: correct DP compatibility strings
arm64: dts: qcom: monaco-evk: Enable Adreno 623 GPU
arm64: dts: qcom: qcs8300-ride: Enable Adreno 623 GPU
arm64: dts: qcom: qcs8300: Add gpu and gmu nodes
arm64: dts: allwinner: h313: Add Amediatech X96Q
dt-bindings: arm: sunxi: Add Amediatech X96Q
arm64: dts: apple: t8015: Add SPMI node
arm64: dts: apple: t8012: Add SPMI node
arm64: dts: apple: Add J180d (Mac Pro, M2 Ultra, 2023) device tree
arm64: dts: rockchip: Add devicetree for the ROC-RK3588-RT
dt-bindings: arm: rockchip: Add Firefly ROC-RK3588-RT
arm64: dts: rockchip: update pinctrl names for Radxa E52C
arm64: dts: rockchip: remove vcc_3v3_pmu regulator for Radxa E52C
arm64: dts: apple: Add J474s, J475c and J475d device trees
arm64: dts: apple: Add J414 and J416 Macbook Pro device trees
arm64: dts: apple: Add initial t6020/t6021/t6022 DTs
...
Conor Dooley <conor@kernel.org> says:
From: Conor Dooley <conor.dooley@microchip.com>
Yo,
This series is partly leveraging Clement's work adding a validate
callback in the extension detection code so that things like checking
for whether a vector crypto extension is usable can be done like:
has_extension(<vector crypto>)
rather than
has_vector() && has_extension(<vector crypto>)
which Eric pointed out was a poor design some months ago.
The rest of this is adding some requirements to the bindings that
prevent combinations of extensions disallowed by the ISA.
There's a bunch of over-long lines in here, but I thought that the
over-long lines were clearer than breaking them up.
Cheers,
Conor.
* patches from https://lore.kernel.org/r/20250312-abide-pancreas-3576b8c44d2c@spud:
dt-bindings: riscv: document vector crypto requirements
dt-bindings: riscv: add vector sub-extension dependencies
dt-bindings: riscv: d requires f
RISC-V: add f & d extension validation checks
RISC-V: add vector crypto extension validation checks
RISC-V: add vector extension validation checks
Link: https://lore.kernel.org/r/20250312-abide-pancreas-3576b8c44d2c@spud
Signed-off-by: Alexandre Ghiti <alexghiti@rivosinc.com>
Charlie Jenkins <charlie@rivosinc.com> says:
xtheadvector is a custom extension that is based upon riscv vector
version 0.7.1 [1]. All of the vector routines have been modified to
support this alternative vector version based upon whether xtheadvector
was determined to be supported at boot.
vlenb is not supported on the existing xtheadvector hardware, so a
devicetree property thead,vlenb is added to provide the vlenb to Linux.
There is a new hwprobe key RISCV_HWPROBE_KEY_VENDOR_EXT_THEAD_0 that is
used to request which thead vendor extensions are supported on the
current platform. This allows future vendors to allocate hwprobe keys
for their vendor.
Support for xtheadvector is also added to the vector kselftests.
[1] 95358cb2cc/xtheadvector.adoc
* b4-shazam-merge:
riscv: Add ghostwrite vulnerability
selftests: riscv: Support xtheadvector in vector tests
selftests: riscv: Fix vector tests
riscv: hwprobe: Document thead vendor extensions and xtheadvector extension
riscv: hwprobe: Add thead vendor extension probing
riscv: vector: Support xtheadvector save/restore
riscv: Add xtheadvector instruction definitions
riscv: csr: Add CSR encodings for CSR_VXRM/CSR_VXSAT
RISC-V: define the elements of the VCSR vector CSR
riscv: vector: Use vlenb from DT for thead
riscv: Add thead and xtheadvector as a vendor extension
riscv: dts: allwinner: Add xtheadvector to the D1/D1s devicetree
dt-bindings: cpus: add a thead vlen register length property
dt-bindings: riscv: Add xtheadvector ISA extension description
Signed-off-by: Charlie Jenkins <charlie@rivosinc.com>
Link: https://lore.kernel.org/r/20241113-xtheadvector-v11-0-236c22791ef9@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Alexandre Ghiti <alexghiti@rivosinc.com> says:
This implements [cmp]xchgXX() macros using Zacas and Zabha extensions
and finally uses those newly introduced macros to add support for
qspinlocks: note that this implementation of qspinlocks satisfies the
forward progress guarantee.
It also uses Ziccrse to provide the qspinlock implementation.
Thanks to Guo and Leonardo for their work!
* b4-shazam-merge: (1314 commits)
riscv: Add qspinlock support
dt-bindings: riscv: Add Ziccrse ISA extension description
riscv: Add ISA extension parsing for Ziccrse
asm-generic: ticket-lock: Add separate ticket-lock.h
asm-generic: ticket-lock: Reuse arch_spinlock_t of qspinlock
riscv: Implement xchg8/16() using Zabha
riscv: Implement arch_cmpxchg128() using Zacas
riscv: Improve zacas fully-ordered cmpxchg()
riscv: Implement cmpxchg8/16() using Zabha
dt-bindings: riscv: Add Zabha ISA extension description
riscv: Implement cmpxchg32/64() using Zacas
riscv: Do not fail to build on byte/halfword operations with Zawrs
riscv: Move cpufeature.h macros into their own header
Link: https://lore.kernel.org/r/20241103145153.105097-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Alexandre Ghiti <alexghiti@rivosinc.com> says:
In RISC-V, after a new mapping is established, a sfence.vma needs to be
emitted for different reasons:
- if the uarch caches invalid entries, we need to invalidate it otherwise
we would trap on this invalid entry,
- if the uarch does not cache invalid entries, a reordered access could fail
to see the new mapping and then trap (sfence.vma acts as a fence).
We can actually avoid emitting those (mostly) useless and costly sfence.vma
by handling the traps instead:
- for new kernel mappings: only vmalloc mappings need to be taken care of,
other new mapping are rare and already emit the required sfence.vma if
needed.
That must be achieved very early in the exception path as explained in
patch 3, and this also fixes our fragile way of dealing with vmalloc faults.
- for new user mappings: Svvptc makes update_mmu_cache() a no-op but we can
take some gratuitous page faults (which are very unlikely though).
Patch 1 and 2 introduce Svvptc extension probing.
On our uarch that does not cache invalid entries and a 6.5 kernel, the
gains are measurable:
* Kernel boot: 6%
* ltp - mmapstress01: 8%
* lmbench - lat_pagefault: 20%
* lmbench - lat_mmap: 5%
Here are the corresponding numbers of sfence.vma emitted:
* Ubuntu boot to login:
Before: ~630k sfence.vma
After: ~200k sfence.vma
* ltp - mmapstress01
Before: ~45k
After: ~6.3k
* lmbench - lat_pagefault
Before: ~665k
After: 832 (!)
* lmbench - lat_mmap
Before: ~546k
After: 718 (!)
Thanks to Ved and Matt Evans for triggering the discussion that led to
this patchset!
* b4-shazam-merge:
riscv: Stop emitting preventive sfence.vma for new userspace mappings with Svvptc
riscv: Stop emitting preventive sfence.vma for new vmalloc mappings
dt-bindings: riscv: Add Svvptc ISA extension description
riscv: Add ISA extension parsing for Svvptc
Link: https://lore.kernel.org/r/20240717060125.139416-1-alexghiti@rivosinc.com
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
Andrew Jones <ajones@ventanamicro.com> says:
Zawrs provides two instructions (wrs.nto and wrs.sto), where both are
meant to allow the hart to enter a low-power state while waiting on a
store to a memory location. The instructions also both wait an
implementation-defined "short" duration (unless the implementation
terminates the stall for another reason). The difference is that while
wrs.sto will terminate when the duration elapses, wrs.nto, depending on
configuration, will either just keep waiting or an ILL exception will be
raised. Linux will use wrs.nto, so if platforms have an implementation
which falls in the "just keep waiting" category (which is not expected),
then it should _not_ advertise Zawrs in the hardware description.
Like wfi (and with the same {m,h}status bits to configure it), when
wrs.nto is configured to raise exceptions it's expected that the higher
privilege level will see the instruction was a wait instruction, do
something, and then resume execution following the instruction. For
example, KVM does configure exceptions for wfi (hstatus.VTW=1) and
therefore also for wrs.nto. KVM does this for wfi since it's better to
allow other tasks to be scheduled while a VCPU waits for an interrupt.
For waits such as those where wrs.nto/sto would be used, which are
typically locks, it is also a good idea for KVM to be involved, as it
can attempt to schedule the lock holding VCPU.
This series starts with Christoph's addition of the riscv
smp_cond_load_relaxed function which applies wrs.sto when available.
That patch has been reworked to use wrs.nto and to use the same approach
as Arm for the wait loop, since we can't have arbitrary C code between
the load-reserved and the wrs. Then, hwprobe support is added (since the
instructions are also usable from usermode), and finally KVM is
taught about wrs.nto, allowing guests to see and use the Zawrs
extension.
We still don't have test results from hardware, and it's not possible to
prove that using Zawrs is a win when testing on QEMU, not even when
oversubscribing VCPUs to guests. However, it is possible to use KVM
selftests to force a scenario where we can prove Zawrs does its job and
does it well. [4] is a test which does this and, on my machine, without
Zawrs it takes 16 seconds to complete and with Zawrs it takes 0.25
seconds.
This series is also available here [1]. In order to use QEMU for testing
a build with [2] is needed. In order to enable guests to use Zawrs with
KVM using kvmtool, the branch at [3] may be used.
[1] https://github.com/jones-drew/linux/commits/riscv/zawrs-v3/
[2] https://lore.kernel.org/all/20240312152901.512001-2-ajones@ventanamicro.com/
[3] https://github.com/jones-drew/kvmtool/commits/riscv/zawrs/
[4] cb2beccebc
Link: https://lore.kernel.org/r/20240426100820.14762-8-ajones@ventanamicro.com
* b4-shazam-merge:
KVM: riscv: selftests: Add Zawrs extension to get-reg-list test
KVM: riscv: Support guest wrs.nto
riscv: hwprobe: export Zawrs ISA extension
riscv: Add Zawrs support for spinlocks
dt-bindings: riscv: Add Zawrs ISA extension description
riscv: Provide a definition for 'pause'
Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>
