Commit Graph

65 Commits

Author SHA1 Message Date
Linus Torvalds
c43267e679 arm64 updates for 7.1:
Core features:
 
  - Add support for FEAT_LSUI, allowing futex atomic operations without
    toggling Privileged Access Never (PAN)
 
  - Further refactor the arm64 exception handling code towards the
    generic entry infrastructure
 
  - Optimise __READ_ONCE() with CONFIG_LTO=y and allow alias analysis
    through it
 
 Memory management:
 
  - Refactor the arm64 TLB invalidation API and implementation for better
    control over barrier placement and level-hinted invalidation
 
  - Enable batched TLB flushes during memory hot-unplug
 
  - Fix rodata=full block mapping support for realm guests (when
    BBML2_NOABORT is available)
 
 Perf and PMU:
 
  - Add support for a whole bunch of system PMUs featured in NVIDIA's
    Tegra410 SoC (cspmu extensions for the fabric and PCIe, new drivers
    for CPU/C2C memory latency PMUs)
 
  - Clean up iomem resource handling in the Arm CMN driver
 
  - Fix signedness handling of AA64DFR0.{PMUVer,PerfMon}
 
 MPAM (Memory Partitioning And Monitoring):
 
  - Add architecture context-switch and hiding of the feature from KVM
 
  - Add interface to allow MPAM to be exposed to user-space using resctrl
 
  - Add errata workaround for some existing platforms
 
  - Add documentation for using MPAM and what shape of platforms can use
    resctrl
 
 Miscellaneous:
 
  - Check DAIF (and PMR, where relevant) at task-switch time
 
  - Skip TFSR_EL1 checks and barriers in synchronous MTE tag check mode
    (only relevant to asynchronous or asymmetric tag check modes)
 
  - Remove a duplicate allocation in the kexec code
 
  - Remove redundant save/restore of SCS SP on entry to/from EL0
 
  - Generate the KERNEL_HWCAP_ definitions from the arm64 hwcap
    descriptions
 
  - Add kselftest coverage for cmpbr_sigill()
 
  - Update sysreg definitions
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Catalin Marinas:
 "The biggest changes are MPAM enablement in drivers/resctrl and new PMU
  support under drivers/perf.

  On the core side, FEAT_LSUI lets futex atomic operations with EL0
  permissions, avoiding PAN toggling.

  The rest is mostly TLB invalidation refactoring, further generic entry
  work, sysreg updates and a few fixes.

  Core features:

   - Add support for FEAT_LSUI, allowing futex atomic operations without
     toggling Privileged Access Never (PAN)

   - Further refactor the arm64 exception handling code towards the
     generic entry infrastructure

   - Optimise __READ_ONCE() with CONFIG_LTO=y and allow alias analysis
     through it

  Memory management:

   - Refactor the arm64 TLB invalidation API and implementation for
     better control over barrier placement and level-hinted invalidation

   - Enable batched TLB flushes during memory hot-unplug

   - Fix rodata=full block mapping support for realm guests (when
     BBML2_NOABORT is available)

  Perf and PMU:

   - Add support for a whole bunch of system PMUs featured in NVIDIA's
     Tegra410 SoC (cspmu extensions for the fabric and PCIe, new drivers
     for CPU/C2C memory latency PMUs)

   - Clean up iomem resource handling in the Arm CMN driver

   - Fix signedness handling of AA64DFR0.{PMUVer,PerfMon}

  MPAM (Memory Partitioning And Monitoring):

   - Add architecture context-switch and hiding of the feature from KVM

   - Add interface to allow MPAM to be exposed to user-space using
     resctrl

   - Add errata workaround for some existing platforms

   - Add documentation for using MPAM and what shape of platforms can
     use resctrl

  Miscellaneous:

   - Check DAIF (and PMR, where relevant) at task-switch time

   - Skip TFSR_EL1 checks and barriers in synchronous MTE tag check mode
     (only relevant to asynchronous or asymmetric tag check modes)

   - Remove a duplicate allocation in the kexec code

   - Remove redundant save/restore of SCS SP on entry to/from EL0

   - Generate the KERNEL_HWCAP_ definitions from the arm64 hwcap
     descriptions

   - Add kselftest coverage for cmpbr_sigill()

   - Update sysreg definitions"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (109 commits)
  arm64: rsi: use linear-map alias for realm config buffer
  arm64: Kconfig: fix duplicate word in CMDLINE help text
  arm64: mte: Skip TFSR_EL1 checks and barriers in synchronous tag check mode
  arm64/sysreg: Update ID_AA64SMFR0_EL1 description to DDI0601 2025-12
  arm64/sysreg: Update ID_AA64ZFR0_EL1 description to DDI0601 2025-12
  arm64/sysreg: Update ID_AA64FPFR0_EL1 description to DDI0601 2025-12
  arm64/sysreg: Update ID_AA64ISAR2_EL1 description to DDI0601 2025-12
  arm64/sysreg: Update ID_AA64ISAR0_EL1 description to DDI0601 2025-12
  arm64/hwcap: Generate the KERNEL_HWCAP_ definitions for the hwcaps
  arm64: kexec: Remove duplicate allocation for trans_pgd
  ACPI: AGDI: fix missing newline in error message
  arm64: Check DAIF (and PMR) at task-switch time
  arm64: entry: Use split preemption logic
  arm64: entry: Use irqentry_{enter_from,exit_to}_kernel_mode()
  arm64: entry: Consistently prefix arm64-specific wrappers
  arm64: entry: Don't preempt with SError or Debug masked
  entry: Split preemption from irqentry_exit_to_kernel_mode()
  entry: Split kernel mode logic from irqentry_{enter,exit}()
  entry: Move irqentry_enter() prototype later
  entry: Remove local_irq_{enable,disable}_exit_to_user()
  ...
2026-04-14 16:48:56 -07:00
Yeoreum Yun
16dbe77a5b KVM: arm64: Use CAST instruction for swapping guest descriptor
Use the CAST instruction to swap the guest descriptor when FEAT_LSUI
is enabled, avoiding the need to clear the PAN bit.

FEAT_LSUI is introduced in Armv9.6, where FEAT_PAN is mandatory. However,
this assumption may not always hold:

 - Some CPUs may advertise FEAT_LSUI but lack FEAT_PAN.
 - Virtualization or ID register overrides may expose invalid feature
   combinations.

Therefore, instead of disabling FEAT_LSUI when FEAT_PAN is absent, wrap
LSUI instructions with uaccess_ttbr0_enable()/disable() when
ARM64_SW_TTBR0_PAN is enabled.

Signed-off-by: Yeoreum Yun <yeoreum.yun@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2026-03-27 12:52:45 +00:00
Zenghui Yu (Huawei)
0496acc42f KVM: arm64: Fix the descriptor address in __kvm_at_swap_desc()
Using "(u64 __user *)hva + offset" to get the virtual addresses of S1/S2
descriptors looks really wrong, if offset is not zero. What we want to get
for swapping is hva + offset, not hva + offset*8. ;-)

Fix it.

Fixes: f6927b41d5 ("KVM: arm64: Add helper for swapping guest descriptor")
Signed-off-by: Zenghui Yu (Huawei) <zenghui.yu@linux.dev>
Link: https://patch.msgid.link/20260317115748.47332-1-zenghui.yu@linux.dev
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: stable@vger.kernel.org
2026-03-17 13:40:00 +00:00
Zenghui Yu (Huawei)
3599c714c0 KVM: arm64: Remove the redundant ISB in __kvm_at_s1e2()
We already have an ISB in __kvm_at() to make the address translation result
visible to subsequent reads of PAR_EL1. Remove the redundant one right
after it.

Signed-off-by: Zenghui Yu (Huawei) <zenghui.yu@linux.dev>
Link: https://patch.msgid.link/20260306074422.47694-1-zenghui.yu@linux.dev
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-03-06 10:42:21 +00:00
Marc Zyngier
54e367cb94 KVM: arm64: Deduplicate ASID retrieval code
We currently have three versions of the ASID retrieval code, one
in the S1 walker, and two in the VNCR handling (although the last
two are limited to the EL2&0 translation regime).

Make this code common, and take this opportunity to also simplify
the code a bit while switching over to the TTBRx_EL1_ASID macro.

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Jonathan Cameron <jonathan.cameron@huawei.com>
Link: https://patch.msgid.link/20260225104718.14209-1-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-02-25 12:19:33 +00:00
Marc Zyngier
1c07f35ff7 Merge branch kvm-arm64/vtcr into kvmarm-master/next
* kvm-arm64/vtcr:
  : .
  : VTCR_EL2 conversion to the configuration-driven RESx framework,
  : fixing a couple of UXN/PXN/XN bugs in the process.
  : .
  KVM: arm64: nv: Return correct RES0 bits for FGT registers
  KVM: arm64: Always populate FGT masks at boot time
  KVM: arm64: Honor UX/PX attributes for EL2 S1 mappings
  KVM: arm64: Convert VTCR_EL2 to config-driven sanitisation
  KVM: arm64: Account for RES1 bits in DECLARE_FEAT_MAP() and co
  arm64: Convert VTCR_EL2 to sysreg infratructure
  arm64: Convert ID_AA64MMFR0_EL1.TGRAN{4,16,64}_2 to UnsignedEnum
  KVM: arm64: Invert KVM_PGTABLE_WALK_HANDLE_FAULT to fix pKVM walkers
  KVM: arm64: Don't blindly set set PSTATE.PAN on guest exit
  KVM: arm64: nv: Respect stage-2 write permssion when setting stage-1 AF
  KVM: arm64: Remove unused vcpu_{clear,set}_wfx_traps()
  KVM: arm64: Remove unused parameter in synchronize_vcpu_pstate()
  KVM: arm64: Remove extra argument for __pvkm_host_{share,unshare}_hyp()
  KVM: arm64: Inject UNDEF for a register trap without accessor
  KVM: arm64: Copy FGT traps to unprotected pKVM VCPU on VCPU load
  KVM: arm64: Fix EL2 S1 XN handling for hVHE setups
  KVM: arm64: gic: Check for vGICv3 when clearing TWI

Signed-off-by: Marc Zyngier <maz@kernel.org>
2026-01-23 10:03:03 +00:00
Marc Zyngier
6191b25d8b arm64: Unconditionally enable LSE support
LSE atomics have been in the architecture since ARMv8.1 (released in
2014), and are hopefully supported by all modern toolchains.

Drop the optional nature of LSE support in the kernel, and always
compile the support in, as this really is very little code. LL/SC
still is the default, and the switch to LSE is done dynamically.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Will Deacon <will@kernel.org>
2026-01-22 10:16:41 +00:00
Oliver Upton
9e27085c33 KVM: arm64: nv: Respect stage-2 write permssion when setting stage-1 AF
Naturally, updating the Access Flag in a stage-1 descriptor requires
write permission at stage-2, although this isn't actually enforced in
KVM's software PTW.

Generate a stage-2 permission fault if the stage-1 walk attempts to
update the descriptor and its corresponding stage-2 translation lacks
write permission.

Fixes: bff8aa213d ("KVM: arm64: Implement HW access flag management in stage-1 SW PTW")
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://msgid.link/20260108204230.677172-1-oupton@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2026-01-09 15:40:34 -08:00
Alexandru Elisei
d52aca1635 KVM: arm64: at: Update AF on software walk only if VM has FEAT_HAFDBS
A guest can write 1 to TCR_ELx.HA, making the KVM software walker update
the access flag in a table descriptor even if FEAT_HAFDBS is not present.
Avoid this by making wi->ha depend on FEAT_HAFDBS being enabled in the VM,
similar to how the software walker treats FEAT_HPDS.

This is not needed for VTCR_EL2.HA, since a guest will always write to
the in-memory copy of the register, where the HA bit is masked (set to
0) by KVM if the VM doesn't have FEAT_HAFDBS.

Fixes: c59ca4b5b0c3 ("KVM: arm64: Implement HW access flag management in stage-1 SW PTW")
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://msgid.link/20251128100946.74210-5-alexandru.elisei@arm.com
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-12-01 00:44:55 -08:00
Alexandru Elisei
e88d60c0aa KVM: arm64: at: Use correct HA bit in TCR_EL2 when regime is EL2
According to ARM DDI 0487L.b, the HA bit in TCR_EL2 when the translation
regime is EL2 (or !ELIsInHost(EL2)) is bit 21, not 39.

Fixes: c59ca4b5b0c3 ("KVM: arm64: Implement HW access flag management in stage-1 SW PTW")
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://msgid.link/20251128100946.74210-3-alexandru.elisei@arm.com
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-12-01 00:44:03 -08:00
Marc Zyngier
b0fc8329ec KVM: arm64: Add endian casting to kvm_swap_s[12]_desc()
Keep sparse quiet by explicitly casting endianness conversion
when swapping S1 and S2 descriptors.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202511260246.JQDGsQKa-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202511260344.9XehvH5Q-lkp@intel.com/
Fixes: c59ca4b5b0c3f ("KVM: arm64: Implement HW access flag management in stage-1 SW PTW")
Fixes: 39db933ba67f8 ("KVM: arm64: nv: Implement HW access flag management in stage-2 SW PTW")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://msgid.link/20251125204848.1136383-1-maz@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-12-01 00:44:02 -08:00
Oliver Upton
36fe022f88 KVM: arm64: Fix compilation when CONFIG_ARM64_USE_LSE_ATOMICS=n
__lse_swap_desc() is compiled unconditionally, even if LSE is disabled
using the config option. Align with the spirit of the config option and
fix some build errors due to __LSE_PREAMBLE being undefined with the
application of some ifdeffery.

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202511250700.kAutzJFm-lkp@intel.com/
Link: https://msgid.link/20251124235409.1731253-1-oupton@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-12-01 00:44:02 -08:00
Oliver Upton
bff8aa213d KVM: arm64: Implement HW access flag management in stage-1 SW PTW
Atomically update the Access flag at stage-1 when the guest has
configured the MMU to do so. Make the implementation choice (and liberal
interpretation of speculation) that any access type updates the Access
flag, including AT and CMO instructions.

Restart the entire walk by returning to the exception-generating
instruction in the case of a failed Access flag update.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Link: https://msgid.link/20251124190158.177318-13-oupton@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-12-01 00:44:02 -08:00
Oliver Upton
92c6443222 KVM: arm64: Propagate PTW errors up to AT emulation
KVM's software PTW will soon support 'hardware' updates to the access
flag. Similar to fault handling, races to update the descriptor will be
handled by restarting the instruction. Prepare for this by propagating
errors up to the AT emulation, only retiring the instruction if the walk
succeeds.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Link: https://msgid.link/20251124190158.177318-12-oupton@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-12-01 00:44:02 -08:00
Oliver Upton
f6927b41d5 KVM: arm64: Add helper for swapping guest descriptor
Implementing FEAT_HAFDBS in KVM's software PTWs requires the ability to
CAS a descriptor to update the in-memory value. Add an accessor to do
exactly that, coping with the fact that guest descriptors are in user
memory (duh).

While FEAT_LSE required on any system that implements NV, KVM now uses
the stage-1 PTW for non-nested use cases meaning an LL/SC implementation
is necessary as well.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Link: https://msgid.link/20251124190158.177318-11-oupton@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-12-01 00:44:02 -08:00
Oliver Upton
fabf321cba KVM: arm64: Handle endianness in read helper for emulated PTW
Implementing FEAT_HAFDBS means adding another descriptor accessor that
needs to deal with the guest-configured endianness. Prepare by moving
the endianness handling into the read accessor and out of the main body
of the S1/S2 PTWs.

Reviewed-by: Marc Zyngier <maz@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Link: https://msgid.link/20251124190158.177318-9-oupton@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
2025-12-01 00:44:02 -08:00
Osama Abdelkader
05a02490fa KVM: arm64: Remove unreachable break after return
Remove an unnecessary 'break' statement that follows a 'return'
in arch/arm64/kvm/at.c. The break is unreachable.

Signed-off-by: Osama Abdelkader <osama.abdelkader@gmail.com>
Reviewed-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-10-13 14:17:03 +01:00
Oliver Upton
a46c09b382 KVM: arm64: Use the in-context stage-1 in __kvm_find_s1_desc_level()
Running the external_aborts selftest at EL2 leads to an ugly splat due
to the stage-1 MMU being disabled for the walked context, owing to the
fact that __kvm_find_s1_desc_level() is hardcoded to the EL1&0 regime.

Select the appropriate translation regime for the stage-1 walk based on
the current vCPU context.

Fixes: b8e625167a ("KVM: arm64: Add S1 IPA to page table level walker")
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-10-13 14:17:03 +01:00
Marc Zyngier
b8e625167a KVM: arm64: Add S1 IPA to page table level walker
Use the filtering hook infrastructure to implement a new walker
that, for a given VA and an IPA, returns the level of the first
occurence of this IPA in the walk from that VA.

This will be used to improve our SEA syndrome reporting.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-20 11:05:14 +01:00
Marc Zyngier
0c5471408c KVM: arm64: Add filtering hook to S1 page table walk
Add a filtering hook that can get called on each level of the
walk, and providing access to the full state.

Crucially, this is called *before* the access is made, so that
it is possible to track down the level of a faulting access.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-20 11:05:13 +01:00
Marc Zyngier
61b0280a67 KVM: arm64: Don't switch MMU on translation from non-NV context
If calling into the AT code from guest EL1, there is no need
to consider any context switch, as we are guaranteed to be
in the correct context.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-20 11:05:13 +01:00
Marc Zyngier
cb1762904c KVM: arm64: Allow EL1 control registers to be accessed from the CPU state
As we are about to plug the SW PTW into the EL1-only code, we can
no longer assume that the EL1 state is not resident on the CPU,
as we don't necessarily get there from EL2 traps.

Turn the __vcpu_sys_reg() access on the EL1 state into calls to
the vcpu_read_sys_reg() helper, which is guaranteed to do the
right thing.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-20 11:05:13 +01:00
Marc Zyngier
14d4802dc2 KVM: arm64: Allow use of S1 PTW for non-NV vcpus
As we are about to use the S1 PTW in non-NV contexts, we must make
sure that we don't evaluate the EL2 state when dealing with the EL1&0
translation regime.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-20 11:05:13 +01:00
Marc Zyngier
dabf9f73fe KVM: arm64: Report faults from S1 walk setup at the expected start level
Translation faults from TTBR must be reported on the start level,
and not level-0. Enforcing this requires moving quite a lot of
code around so that the start level can be computed early enough
that it is usable.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-20 11:05:13 +01:00
Marc Zyngier
5da3a3b27a KVM: arm64: Expand valid block mappings to FEAT_LPA/LPA2 support
With 52bit PAs, block mappings can exist at different levels (such
as level 0 for 4kB pages, or level 1 for 16kB and 64kB pages).

Account for this in walk_s1().

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-20 11:05:13 +01:00
Marc Zyngier
dd82412c2b KVM: arm64: Populate PAR_EL1 with 52bit addresses
Expand the output address populated in PAR_EL1 to 52bit addresses.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-20 11:05:13 +01:00
Marc Zyngier
c0cc438046 KVM: arm64: Compute shareability for LPA2
LPA2 gets the memory access shareability from TCR_ELx instead of
getting it form the descriptors. Store it in the walk info struct
so that it is passed around and evaluated as required.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-20 11:05:12 +01:00
Marc Zyngier
e4bd479884 KVM: arm64: Pass the walk_info structure to compute_par_s1()
Instead of just passing the translation regime, pass the full
walk_info structure to compute_par_s1(). This will help further
chamges that will require it.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-20 11:05:12 +01:00
Marc Zyngier
df1d0197a2 KVM: arm64: Decouple output address from the PT descriptor
Add a helper converting the descriptor into a nicely formed OA,
irrespective of the in-descriptor representation (< 52bit, LPA
or LPA2).

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-20 11:05:12 +01:00
Marc Zyngier
e645226a9c KVM: arm64: Compute 52bit TTBR address and alignment
52bit addresses from TTBR need extra adjustment and alignment
checks. Implement the requirements of the architecture.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-20 11:05:12 +01:00
Marc Zyngier
23cf13def0 KVM: arm64: Account for 52bit when computing maximum OA
Adjust the computation of the max OA to account for 52bit PAs.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-20 11:05:12 +01:00
Marc Zyngier
0090c0a247 KVM: arm64: Add helper computing the state of 52bit PA support
Track whether the guest is using 52bit PAs, either LPA or LPA2.
This further simplifies the handling of LVA for 4k and 16k pages,
as LPA2 implies LVA in this case.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-09-20 11:05:12 +01:00
Marc Zyngier
ee372e6451 KVM: arm64: nv: Fix ATS12 handling of single-stage translation
Volodymyr reports that using a Xen DomU as a nested guest (where
HCR_EL2.E2H == 0), ATS12 results in a translation that stops at
the L2's S1, which isn't something you'd normally expects.

Comparing the code against the spec proves to be illuminating,
and suggests that the author of such code must have been tired,
cross-eyed, drunk, or maybe all of the above.

The gist of it is that, apart from HCR_EL2.VM or HCR_EL2.DC being
0, only the use of the EL2&0 translation regime limits the walk
to S1 only, and that we must finish the S2 walk in any other case.
Which solves the above issue, as E2H==0 indicates that ATS12 walks
the EL1&0 translation regime.

Explicitly checking for EL2&0 fixes this.

Reported-by: Volodymyr Babchuk <volodymyr_babchuk@epam.com>
Suggested-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Fixes: be04cebf3e ("KVM: arm64: nv: Add emulation of AT S12E{0,1}{R,W}")
Link: https://lore.kernel.org/r/20250806141707.3479194-2-volodymyr_babchuk@epam.com
Link: https://lore.kernel.org/r/20250809144811.2314038-2-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-08-28 12:44:42 -07:00
Marc Zyngier
5152977340 KVM: arm64: Follow specification when implementing WXN
The R_QXXPC and R_NPBXC rules have some interesting (and pretty
sharp) corners when defining the behaviour of of WXN at S1:

- when S1 overlay is enabled, WXN applies to the overlay and
  will remove W

- when S1 overlay is disabled, WXN applies to the base permissions
  and will remove X.

Today, we lumb the two together in a way that doesn't really match
the rules, making things awkward to follow what is happening, in
particular when overlays are enabled.

Split these two rules over two distinct paths, which makes things
a lot easier to read and validate against the architecture rules.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250701151648.754785-3-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-23 23:34:50 -07:00
Marc Zyngier
a508d5afb7 KVM: arm64: Remove the wi->{e0,}poe vs wr->{p,u}ov confusion
Some of the POE computation is a bit confused. Specifically, there
is an element of confusion between what wi->{e0,}poe an wr->{p,u}ov
actually represent.

- wi->{e0,}poe is an *input* to the walk, and indicates whether
  POE is enabled at EL0 or EL{1,2}

- wr->{p,u}ov is a *result* of the walk, and indicates whether
  overlays are enabled. Crutially, it is possible to have POE
  enabled, and yet overlays disabled, while the converse isn't
  true

What this all means is that once the base permissions have been
established, checking for wi->{e0,}poe makes little sense, because
the truth about overlays resides in wr->{p,u}ov. So constructs
checking for (wi->poe && wr->pov) only add perplexity.

Refactor compute_s1_overlay_permissions() and the way it is
called according to the above principles. Take the opportunity
to avoid reading registers that are not strictly required.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250701151648.754785-2-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2025-07-23 23:34:50 -07:00
Marc Zyngier
1b85d923ba Merge branch kvm-arm64/misc-6.16 into kvmarm-master/next
* kvm-arm64/misc-6.16:
  : .
  : Misc changes and improvements for 6.16:
  :
  : - Add a new selftest for the SVE host state being corrupted by a guest
  :
  : - Keep HCR_EL2.xMO set at all times for systems running with the kernel at EL2,
  :   ensuring that the window for interrupts is slightly bigger, and avoiding
  :   a pretty bad erratum on the AmpereOne HW
  :
  : - Replace a couple of open-coded on/off strings with str_on_off()
  :
  : - Get rid of the pKVM memblock sorting, which now appears to be superflous
  :
  : - Drop superflous clearing of ICH_LR_EOI in the LR when nesting
  :
  : - Add workaround for AmpereOne's erratum AC04_CPU_23, which suffers from
  :   a pretty bad case of TLB corruption unless accesses to HCR_EL2 are
  :   heavily synchronised
  :
  : - Add a per-VM, per-ITS debugfs entry to dump the state of the ITS tables
  :   in a human-friendly fashion
  : .
  KVM: arm64: Fix documentation for vgic_its_iter_next()
  KVM: arm64: vgic-its: Add debugfs interface to expose ITS tables
  arm64: errata: Work around AmpereOne's erratum AC04_CPU_23
  KVM: arm64: nv: Remove clearing of ICH_LR<n>.EOI if ICH_LR<n>.HW == 1
  KVM: arm64: Drop sort_memblock_regions()
  KVM: arm64: selftests: Add test for SVE host corruption
  KVM: arm64: Force HCR_EL2.xMO to 1 at all times in VHE mode
  KVM: arm64: Replace ternary flags with str_on_off() helper

Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-23 10:59:43 +01:00
D Scott Phillips
fed55f49fa arm64: errata: Work around AmpereOne's erratum AC04_CPU_23
On AmpereOne AC04, updates to HCR_EL2 can rarely corrupt simultaneous
translations for data addresses initiated by load/store instructions.
Only instruction initiated translations are vulnerable, not translations
from prefetches for example. A DSB before the store to HCR_EL2 is
sufficient to prevent older instructions from hitting the window for
corruption, and an ISB after is sufficient to prevent younger
instructions from hitting the window for corruption.

Signed-off-by: D Scott Phillips <scott@os.amperecomputing.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20250513184514.2678288-1-scott@os.amperecomputing.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-19 12:46:26 +01:00
Marc Zyngier
a0ec2b822c KVM: arm64: nv: Snapshot S1 ASID tagging information during walk
We currently completely ignore any sort of ASID tagging during a S1
walk, as AT doesn't care about it.

However, such information is required if we are going to create
anything that looks like a TLB from this walk.

Let's capture it both the nG and ASID information while walking
the page tables.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20250514103501.2225951-5-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-19 07:59:46 +01:00
Marc Zyngier
34fa9dece5 KVM: arm64: nv: Extract translation helper from the AT code
The address translation infrastructure is currently pretty tied to
the AT emulation.

However, we also need to features that require the use of VAs, such
as VNCR_EL2 (and maybe one of these days SPE), meaning that we need
a slightly more generic infrastructure.

Start this by introducing a new helper (__kvm_translate_va()) that
performs a S1 walk for a given translation regime, EL and PAN
settings.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20250514103501.2225951-4-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-19 07:59:46 +01:00
Marc Zyngier
3e4d597220 KVM: arm64: Don't feed uninitialised data to HCR_EL2
When the guest executes an AT S1E{0,1} from EL2, and that its
HCR_EL2.{E2H,TGE}=={1,1}, then this is a pure S1 translation
that doesn't involve a guest-supplied S2, and the full S1
context is already in place. This allows us to take a shortcut
and avoid save/restoring a bunch of registers.

However, we set HCR_EL2 to a value suitable for the use of AT
in guest context. And we do so by using the value that we saved.
Or not. In the case described above, we restore whatever junk
was on the stack, and carry on with it until the next entry.

Needless to say, this is completely broken.

But this also triggers the realisation that saving HCR_EL2 is
a bit pointless. We are always in host context at the point where
reach this code, and what we program to enter the guest is a known
value (vcpu->arch.hcr_el2).

Drop the pointless save/restore, and wrap the AT operations with
writes that switch between guest and host values for HCR_EL2.

Reported-by: D Scott Phillips <scott@os.amperecomputing.com>
Link: https://lore.kernel.org/r/20250422122612.2675672-4-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-14 10:43:50 +01:00
Marc Zyngier
ed648ab804 KVM: arm64: Teach address translation about access faults
It appears that our S1 PTW is completely oblivious of access faults.
Teach the S1 translation code about it.

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20250422122612.2675672-3-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-14 10:43:50 +01:00
Marc Zyngier
493b01de72 KVM: arm64: Fix PAR_EL1.{PTW,S} reporting on AT S1E*
When an AT S1E* operation fails, we need to report whether the
translation failed at S2, and whether this was during a S1 PTW.

But these two bits are not independent. PAR_EL1.PTW can only be
set of PAR_EL1.S is also set, and PAR_EL1.S can only be set on
its own when the full S1 PTW has succeeded, but that the access
itself is reporting a fault at S2.

As a result, it makes no sense to carry both ptw and s2 as parameters
to fail_s1_walk(), and they should be unified.

This fixes a number of cases where we were reporting PTW=1 *and*
S=0, which makes no sense.

Link: https://lore.kernel.org/r/20250422122612.2675672-2-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2025-05-14 10:43:50 +01:00
Kevin Brodsky
83d78bbfd2 arm64/sysreg: Rename POE_RXW to POE_RWX
It is customary to list R, W, X permissions in that order. In fact
this is already the case for PIE constants (PIE_RWX). Rename POE_RXW
accordingly, as well as POE_XW (currently unused).

While at it also swap the W/X lines in
compute_s1_overlay_permissions() to follow the R, W, X order.

Signed-off-by: Kevin Brodsky <kevin.brodsky@arm.com>
Link: https://lore.kernel.org/r/20250219164029.2309119-3-kevin.brodsky@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2025-03-10 18:10:40 +00:00
Linus Torvalds
9ad09c4f28 arm64 updates for 6.14
Confidential Computing:
 * Register a platform device when running in CCA realm mode to enable
   automatic loading of dependent modules.
 
 CPU Features:
 * Update a bunch of system register definitions to pick up new field
   encodings from the architectural documentation.
 
 * Add hwcaps and selftests for the new (2024) dpISA extensions.
 
 Documentation:
 * Update EL3 (firmware) requirements for booting Linux on modern arm64
   designs.
 
 * Remove stale information about the kernel virtual memory map.
 
 Miscellaneous:
 * Minor cleanups and typo fixes.
 
 Memory management:
 * Fix vmemmap_check_pmd() to look at the PMD type bits
 
 * LPA2 (52-bit physical addressing) cleanups and minor fixes.
 
 * Adjust physical address space depending upon whether or not LPA2 is
   enabled.
 
 Perf and PMUs:
 * Add port filtering support for NVIDIA's NVLINK-C2C Coresight PMU
 
 * Extend AXI filtering support for the DDR PMU on NXP IMX SoCs
 
 * Fix Designware PCIe PMU event numbering.
 
 * Add generic branch events for the Apple M1 CPU PMU.
 
 * Add support for Marvell Odyssey DDR and LLC-TAD PMUs.
 
 * Cleanups to the Hisilicon DDRC and Uncore PMU code.
 
 * Advertise discard mode for the SPE PMU.
 
 * Add the perf users mailing list to our MAINTAINERS entry.
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Merge tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux

Pull arm64 updates from Will Deacon:
 "We've got a little less than normal thanks to the holidays in
  December, but there's the usual summary below. The highlight is
  probably the 52-bit physical addressing (LPA2) clean-up from Ard.

  Confidential Computing:

   - Register a platform device when running in CCA realm mode to enable
     automatic loading of dependent modules

  CPU Features:

   - Update a bunch of system register definitions to pick up new field
     encodings from the architectural documentation

   - Add hwcaps and selftests for the new (2024) dpISA extensions

  Documentation:

   - Update EL3 (firmware) requirements for booting Linux on modern
     arm64 designs

   - Remove stale information about the kernel virtual memory map

  Miscellaneous:

   - Minor cleanups and typo fixes

  Memory management:

   - Fix vmemmap_check_pmd() to look at the PMD type bits

   - LPA2 (52-bit physical addressing) cleanups and minor fixes

   - Adjust physical address space depending upon whether or not LPA2 is
     enabled

  Perf and PMUs:

   - Add port filtering support for NVIDIA's NVLINK-C2C Coresight PMU

   - Extend AXI filtering support for the DDR PMU on NXP IMX SoCs

   - Fix Designware PCIe PMU event numbering

   - Add generic branch events for the Apple M1 CPU PMU

   - Add support for Marvell Odyssey DDR and LLC-TAD PMUs

   - Cleanups to the Hisilicon DDRC and Uncore PMU code

   - Advertise discard mode for the SPE PMU

   - Add the perf users mailing list to our MAINTAINERS entry"

* tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (64 commits)
  Documentation: arm64: Remove stale and redundant virtual memory diagrams
  perf docs: arm_spe: Document new discard mode
  perf: arm_spe: Add format option for discard mode
  MAINTAINERS: Add perf list for drivers/perf/
  arm64: Remove duplicate included header
  drivers/perf: apple_m1: Map generic branch events
  arm64: rsi: Add automatic arm-cca-guest module loading
  kselftest/arm64: Add 2024 dpISA extensions to hwcap test
  KVM: arm64: Allow control of dpISA extensions in ID_AA64ISAR3_EL1
  arm64/hwcap: Describe 2024 dpISA extensions to userspace
  arm64/sysreg: Update ID_AA64SMFR0_EL1 to DDI0601 2024-12
  arm64: Filter out SVE hwcaps when FEAT_SVE isn't implemented
  drivers/perf: hisi: Set correct IRQ affinity for PMUs with no association
  arm64/sme: Move storage of reg_smidr to __cpuinfo_store_cpu()
  arm64: mm: Test for pmd_sect() in vmemmap_check_pmd()
  arm64/mm: Replace open encodings with PXD_TABLE_BIT
  arm64/mm: Rename pte_mkpresent() as pte_mkvalid()
  arm64/sysreg: Update ID_AA64ISAR2_EL1 to DDI0601 2024-09
  arm64/sysreg: Update ID_AA64ZFR0_EL1 to DDI0601 2024-09
  arm64/sysreg: Update ID_AA64FPFR0_EL1 to DDI0601 2024-09
  ...
2025-01-20 21:21:49 -08:00
Marc Zyngier
7052e808c4 arm64/sysreg: Get rid of the TCR2_EL1x SysregFields
TCR2_EL1x is a pretty bizarre construct, as it is shared between
TCR2_EL1 and TCR2_EL12. But the latter is obviously only an
accessor to the former.

In order to make things more consistent, upgrade TCR2_EL1x to
a full-blown sysreg definition for TCR2_EL1, and describe TCR2_EL12
as a mapping to TCR2_EL1.

This results in a couple of minor changes to the actual code.

Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241219173351.1123087-3-maz@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
2024-12-19 18:00:58 +00:00
Marc Zyngier
6fc3a49f23 KVM: arm64: Fix S1/S2 combination when FWB==1 and S2 has Device memory type
The G.a revision of the ARM ARM had it pretty clear that HCR_EL2.FWB
had no influence on "The way that stage 1 memory types and attributes
are combined with stage 2 Device type and attributes." (D5.5.5).

However, this wording was lost in further revisions of the architecture.

Restore the intended behaviour, which is to take the strongest memory
type of S1 and S2 in this case, as if FWB was 0. The specification is
being fixed accordingly.

Fixes: be04cebf3e ("KVM: arm64: nv: Add emulation of AT S12E{0,1}{R,W}")
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241125094756.609590-1-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-11-26 07:32:27 -08:00
Marc Zyngier
1c6801d565 KVM: arm64: Handle WXN attribute
Until now, we didn't really care about WXN as it didn't have an
effect on the R/W permissions (only the execution could be droppped),
and therefore not of interest for AT.

However, with S1POE, WXN can revoke the Write permission if an
overlay is active and that execution is allowed. This *is* relevant
to AT.

Add full handling of WXN so that we correctly handle this case.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241023145345.1613824-38-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-10-31 02:44:23 +00:00
Marc Zyngier
e39ce7033c KVM: arm64: Handle stage-1 permission overlays
We now have the intrastructure in place to emulate S1POE:

- direct permissions are always overlay-capable
- indirect permissions are overlay-capable if the permissions are
  in the 0b0xxx range
- the overlays are strictly substractive

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241023145345.1613824-37-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-10-31 02:44:23 +00:00
Marc Zyngier
7cd5c2796c KVM: arm64: Make PAN conditions part of the S1 walk context
Move the conditions describing PAN as part of the s1_walk_info
structure, in an effort to declutter the permission processing.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241023145345.1613824-36-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-10-31 02:44:22 +00:00
Marc Zyngier
8a9b304d7e KVM: arm64: Disable hierarchical permissions when POE is enabled
The hierarchical permissions must be disabled when POE is enabled
in the translation regime used for a given table walk.

We store the two enable bits in the s1_walk_info structure so that
they can be retrieved down the line, as they will be useful.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20241023145345.1613824-35-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-10-31 02:44:22 +00:00