To date KVM has not trapped ID register accesses from AArch32, meaning
that guests get an unconstrained view of what hardware supports. This
can be a serious problem because we try to base the guest's feature
registers on values that are safe system-wide. Furthermore, KVM does not
implement the latest ISA in the PMU and Debug architecture, so we
constrain these fields to supported values.
Since KVM now correctly handles CP15 and CP10 register traps, we no
longer need to clear HCR_EL2.TID3 for 32 bit guests and will instead
emulate reads with their safe values.
Signed-off-by: Oliver Upton <oupton@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220503060205.2823727-6-oupton@google.com
(cherry picked from commit fd1264c4ca)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: Ib3e9b7446aee48495c19174b86fc9129dcd792db
In order to enable HCR_EL2.TID3 for AArch32 guests KVM needs to handle
traps where ESR_EL2.EC=0x8, which corresponds to an attempted VMRS
access from an ID group register. Specifically, the MVFR{0-2} registers
are accessed this way from AArch32. Conveniently, these registers are
architecturally mapped to MVFR{0-2}_EL1 in AArch64. Furthermore, KVM
already handles reads to these aliases in AArch64.
Plumb VMRS read traps through to the general AArch64 system register
handler.
Signed-off-by: Oliver Upton <oupton@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220503060205.2823727-5-oupton@google.com
(cherry picked from commit 9369bc5c5e)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I9cc5c2ff532454ea13bdb8b5ca6076133974284a
KVM currently does not trap ID register accesses from an AArch32 EL1.
This is painful for a couple of reasons. Certain unimplemented features
are visible to AArch32 EL1, as we limit PMU to version 3 and the debug
architecture to v8.0. Additionally, we attempt to paper over
heterogeneous systems by using register values that are safe
system-wide. All this hard work is completely sidestepped because KVM
does not set TID3 for AArch32 guests.
Fix up handling of CP15 feature registers by simply rerouting to their
AArch64 aliases. Punt setting HCR_EL2.TID3 to a later change, as we need
to fix up the oddball CP10 feature registers still.
Signed-off-by: Oliver Upton <oupton@google.com>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220503060205.2823727-4-oupton@google.com
(cherry picked from commit e651976667)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: Ifbf403ab93fa8307262720c5e881b70f9bb55492
emulate_sys_reg() returns 1 unconditionally, even though a a system
register access can fail. Furthermore, kvm_handle_sys_reg() writes to Rt
for every register read, regardless of if it actually succeeded.
Though this pattern is safe (as params.regval is initialized with the
current value of Rt) it is a bit ugly. Indicate failure if the register
access could not be emulated and only write to Rt on success.
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220503060205.2823727-3-oupton@google.com
(cherry picked from commit 28eda7b5e8)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I166bd129ea3a3f76f85126c7e5c386adf718bd4c
KVM indicates success/failure in several ways, but generally an integer
is used when conditionally bouncing to userspace is involved. That is
not the case from emulate_cp(); just use a bool instead.
No functional change intended.
Signed-off-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220503060205.2823727-2-oupton@google.com
(cherry picked from commit 001bb81999)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I803a4deacdb5234e3457b0186510b6b8ccfd66e5
Reintroduce the __kvm_nvhe_ symbols in kallsyms, ignoring the local
symbols in this namespace. The local symbols are not informative and
can cause aliasing issues when symbolizing the addresses.
With the necessary symbols now in kallsyms we can symbolize nVHE
addresses using the %p print format specifier:
[ 98.916444][ T426] kvm [426]: nVHE hyp panic at: [<ffffffc0096156fc>] __kvm_nvhe_overflow_stack+0x8/0x34!
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220420214317.3303360-7-kaleshsingh@google.com
(cherry picked from commit 6ccf9cb557)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: Iccb04ef986b7a68ad97bb0598c9a47fdcfe5ba64
The hypervisor stacks (for both nVHE Hyp mode and nVHE protected mode)
are aligned such that any valid stack address has PAGE_SHIFT bit as 1.
This allows us to conveniently check for overflow in the exception entry
without corrupting any GPRs. We won't recover from a stack overflow so
panic the hypervisor.
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220420214317.3303360-6-kaleshsingh@google.com
(cherry picked from commit 66de19fad9)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: Ic0f68bc0fac9e14818907347569e4b821fa1c117
Map the stack pages in the flexible private VA range and allocate
guard pages below the stack as unbacked VA space. The stack is aligned
so that any valid stack address has PAGE_SHIFT bit as 1 - this is used
for overflow detection (implemented in a subsequent patch in the series)
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220420214317.3303360-5-kaleshsingh@google.com
(cherry picked from commit 1a919b17ef)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I27367ca9ab78bfcc2711f6525b066436bfb5b264
Map the stack pages in the flexible private VA range and allocate
guard pages below the stack as unbacked VA space. The stack is aligned
so that any valid stack address has PAGE_SHIFT bit as 1 - this is used
for overflow detection (implemented in a subsequent patch in the series).
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220420214317.3303360-4-kaleshsingh@google.com
(cherry picked from commit ce3354318a)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I1ad6534d695c095dbd2cee7c49b983838b5ebcd2
pkvm_hyp_alloc_private_va_range() can be used to reserve private VA ranges
in the pKVM nVHE hypervisor. Allocations are aligned based on the order of
the requested size.
This will be used to implement stack guard pages for pKVM nVHE hypervisor
(in a subsequent patch in the series).
Credits to Quentin Perret <qperret@google.com> for the idea of moving
private VA allocation out of __pkvm_create_private_mapping()
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220420214317.3303360-3-kaleshsingh@google.com
(cherry picked from commit f922c13e77)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I093a2e775da0a204f06b0cdc7132db95cf2dedf9
hyp_alloc_private_va_range() can be used to reserve private VA ranges
in the nVHE hypervisor. Allocations are aligned based on the order of
the requested size.
This will be used to implement stack guard pages for KVM nVHE hypervisor
(nVHE Hyp mode / not pKVM), in a subsequent patch in the series.
Signed-off-by: Kalesh Singh <kaleshsingh@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220420214317.3303360-2-kaleshsingh@google.com
(cherry picked from commit 92abe0f81e)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: Ib3890641a63649d8ab356a488dd5c68c1ecb54b7
Now that basline support for the Scalable Matrix Extension (SME) is present
introduce the Kconfig option allowing it to be built. While the feature
registers don't impose a strong requirement for a system with SME to
support SVE at runtime the support for streaming mode SVE is mostly
shared with normal SVE so depend on SVE.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-28-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit a1f4ccd25c)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I9b3f9152ff1960c29959c6fecc00f7ee3048fe67
While we don't currently support SME in guests we do currently support it
for the host system so we need to take care of SME's impact, including
the floating point register state, when running guests. Simiarly to SVE
we need to manage the traps in CPACR_RL1, what is new is the handling of
streaming mode and ZA.
Normally we defer any handling of the floating point register state until
the guest first uses it however if the system is in streaming mode FPSIMD
and SVE operations may generate SME traps which we would need to distinguish
from actual attempts by the guest to use SME. Rather than do this for the
time being if we are in streaming mode when entering the guest we force
the floating point state to be saved immediately and exit streaming mode,
meaning that the guest won't generate SME traps for supported operations.
We could handle ZA in the access trap similarly to the FPSIMD/SVE state
without the disruption caused by streaming mode but for simplicity
handle it the same way as streaming mode for now.
This will be revisited when we support SME for guests (hopefully before SME
hardware becomes available), for now it will only incur additional cost on
systems with SME and even there only if streaming mode or ZA are enabled.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220419112247.711548-27-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 861262ab86)
[willdeacon@: Resolved WFxT conflicts per upstream merge commit b2c4caf331
("Merge branch kvm-arm64/wfxt into kvmarm-master/next")]
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I5eec3de9abb6635e513f74499b83eeec3067e37f
SME defines two new traps which need to be enabled for guests to ensure
that they can't use SME, one for the main SME operations which mirrors the
traps for SVE and another for access to TPIDR2 in SCTLR_EL2.
For VHE manage SMEN along with ZEN in activate_traps() and the FP state
management callbacks, along with SCTLR_EL2.EnTPIDR2. There is no
existing dynamic management of SCTLR_EL2.
For nVHE manage TSM in activate_traps() along with the fine grained
traps for TPIDR2 and SMPRI. There is no existing dynamic management of
fine grained traps.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220419112247.711548-26-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 51729fb1d0)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I65db29259147f02629b2298437ae958f39c9617f
For the time being we do not support use of SME by KVM guests, support for
this will be enabled in future. In order to prevent any side effects or
side channels via the new system registers, including the EL0 read/write
register TPIDR2, explicitly undefine all the system registers added by
SME and mask out the SME bitfield in SYS_ID_AA64PFR1.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220419112247.711548-25-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 90807748ca)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I37c99cc7d83402aacc876eab9079e1df9223c3c1
When saving and restoring the floating point state over an EFI runtime
call ensure that we handle streaming mode, only handling FFR if we are not
in streaming mode and ensuring that we are in normal mode over the call
into runtime services.
We currently assume that ZA will not be modified by runtime services, the
specification is not yet finalised so this may need updating if that
changes.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-24-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit e0838f6373)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I9d4d05592424936cbad874b1d243f5b7b06904fb
Both streaming mode and ZA may increase power consumption when they are
enabled and streaming mode makes many FPSIMD and SVE instructions undefined
which will cause problems for any kernel mode floating point so disable
both when we flush the CPU state. This covers both kernel_neon_begin() and
idle and after flushing the state a reload is always required anyway.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-23-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit d45d7ff704)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: Id0e7342d5ea9b7e5f58dadc605115a3c4f8beb10
The ZA array can be read and written with the NT_ARM_ZA. Similarly to
our interface for the SVE vector registers the regset consists of a
header with information on the current vector length followed by an
optional register data payload, represented as for signals as a series
of horizontal vectors from 0 to VL/8 in the endianness independent
format used for vectors.
On get if ZA is enabled then register data will be provided, otherwise
it will be omitted. On set if register data is provided then ZA is
enabled and initialized using the provided data, otherwise it is
disabled.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-22-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 776b4a1cf3)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: Ibdf9669b3aafe579850e200d19bc013b66d0d96e
The streaming mode SVE registers are represented using the same data
structures as for SVE but since the vector lengths supported and in use
may not be the same as SVE we represent them with a new type NT_ARM_SSVE.
Unfortunately we only have a single 16 bit reserved field available in
the header so there is no space to fit the current and maximum vector
length for both standard and streaming SVE mode without redefining the
structure in a way the creates a complicatd and fragile ABI. Since FFR
is not present in streaming mode it is read and written as zero.
Setting NT_ARM_SSVE registers will put the task into streaming mode,
similarly setting NT_ARM_SVE registers will exit it. Reads that do not
correspond to the current mode of the task will return the header with
no register data. For compatibility reasons on write setting no flag for
the register type will be interpreted as setting SVE registers, though
users can provide no register data as an alternative mechanism for doing
so.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-21-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit e12310a0d3)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I3174e91e2ad91fb8c7dbb1d00bdf6b5994a94744
Implement support for ZA in signal handling in a very similar way to how
we implement support for SVE registers, using a signal context structure
with optional register state after it. Where present this register state
stores the ZA matrix as a series of horizontal vectors numbered from 0 to
VL/8 in the endinanness independent format used for vectors.
As with SVE we do not allow changes in the vector length during signal
return but we do allow ZA to be enabled or disabled.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-20-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 39782210eb)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I170423659e6070c1437404f5154d24943d99fbc1
When in streaming mode we have the same set of SVE registers as we do in
regular SVE mode with the exception of FFR and the use of the SME vector
length. Provide signal handling for these registers by taking one of the
reserved words in the SVE signal context as a flags field and defining a
flag which is set for streaming mode. When the flag is set the vector
length is set to the streaming mode vector length and we save and
restore streaming mode data. We support entering or leaving streaming
mode based on the value of the flag but do not support changing the
vector length, this is not currently supported SVE signal handling.
We could instead allocate a separate record in the signal frame for the
streaming mode SVE context but this inflates the size of the maximal signal
frame required and adds complication when validating signal frames from
userspace, especially given the current structure of the code.
Any implementation of support for streaming mode vectors in signals will
have some potential for causing issues for applications that attempt to
handle SVE vectors in signals, use streaming mode but do not understand
streaming mode in their signal handling code, it is hard to identify a
case that is clearly better than any other - they all have cases where
they could cause unexpected register corruption or faults.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-19-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 85ed24dad2)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: Ibd4b809a104a52497eafcb71ed3f83bfc84c8072
By default all SME operations in userspace will trap. When this happens
we allocate storage space for the SME register state, set up the SVE
registers and disable traps. We do not need to initialize ZA since the
architecture guarantees that it will be zeroed when enabled and when we
trap ZA is disabled.
On syscall we exit streaming mode if we were previously in it and ensure
that all but the lower 128 bits of the registers are zeroed while
preserving the state of ZA. This follows the aarch64 PCS for SME, ZA
state is preserved over a function call and streaming mode is exited.
Since the traps for SME do not distinguish between streaming mode SVE
and ZA usage if ZA is in use rather than reenabling traps we instead
zero the parts of the SVE registers not shared with FPSIMD and leave SME
enabled, this simplifies handling SME traps. If ZA is not in use then we
reenable SME traps and fall through to normal handling of SVE.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-17-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 8bd7f91c03)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I98fc449f3310a91bb42e5c1b44f6ff5929d61e4a
Allocate space for storing ZA on first access to SME and use that to save
and restore ZA state when context switching. We do this by using the vector
form of the LDR and STR ZA instructions, these do not require streaming
mode and have implementation recommendations that they avoid contention
issues in shared SMCU implementations.
Since ZA is architecturally guaranteed to be zeroed when enabled we do not
need to explicitly zero ZA, either we will be restoring from a saved copy
or trapping on first use of SME so we know that ZA must be disabled.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-16-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit 0033cd9339)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I95f189d064fb54f6d7d632e3b6c07d11aef9c6f0
When in streaming mode we need to save and restore the streaming mode
SVE register state rather than the regular SVE register state. This uses
the streaming mode vector length and omits FFR but is otherwise identical,
if TIF_SVE is enabled when we are in streaming mode then streaming mode
takes precedence.
This does not handle use of streaming SVE state with KVM, ptrace or
signals. This will be updated in further patches.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-15-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit af7167d6d2)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I3070deb80c9ca0a387ea1da8235e459cdb58ecf0
In SME the use of both streaming SVE mode and ZA are tracked through
PSTATE.SM and PSTATE.ZA, visible through the system register SVCR. In
order to context switch the floating point state for SME we need to
context switch the contents of this register as part of context
switching the floating point state.
Since changing the vector length exits streaming SVE mode and disables
ZA we also make sure we update SVCR appropriately when setting vector
length, and similarly ensure that new threads have streaming SVE mode
and ZA disabled.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-14-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit b40c559b45)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: If9fae0de37b347114fc7f0450120bc5bbf0a6757
The Scalable Matrix Extension introduces support for a new thread specific
data register TPIDR2 intended for use by libc. The kernel must save the
value of TPIDR2 on context switch and should ensure that all new threads
start off with a default value of 0. Add a field to the thread_struct to
store TPIDR2 and context switch it with the other thread specific data.
In case there are future extensions which also use TPIDR2 we introduce
system_supports_tpidr2() and use that rather than system_supports_sme()
for TPIDR2 handling.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-13-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit a9d6915859)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: Ib5944d3519b12a2898cd32e2af4863f9062b9bee
The vector lengths used for SME are controlled through a similar set of
registers to those for SVE and enumerated using a similar algorithm with
some slight differences due to the fact that unlike SVE there are no
restrictions on which combinations of vector lengths can be supported
nor any mandatory vector lengths which must be implemented. Add a new
vector type and implement support for enumerating it.
One slightly awkward feature is that we need to read the current vector
length using a different instruction (or enter streaming mode which
would have the same issue and be higher cost). Rather than add an ops
structure we add special cases directly in the otherwise generic
vec_probe_vqs() function, this is a bit inelegant but it's the only
place where this is an issue.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-10-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit b42990d3bf)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I7970dc4fa69b88c4db262abc55552b3a82072cd4
SME requires similar setup to that for SVE: disable traps to EL2 and
make sure that the maximum vector length is available to EL1, for SME we
have two traps - one for SME itself and one for TPIDR2.
In addition since we currently make no active use of priority control
for SCMUs we map all SME priorities lower ELs may configure to 0, the
architecture specified minimum priority, to ensure that nothing we
manage is able to configure itself to consume excessive resources. This
will need to be revisited should there be a need to manage SME
priorities at runtime.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-8-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit b2cf6a2328)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I320fddaaaa1e267d4f4f5e7b14d9e91de5b5998f
As with SVE rather than impose ambitious toolchain requirements for SME
we manually encode the few instructions which we require in order to
perform the work the kernel needs to do. The instructions used to save
and restore context are provided as assembler macros while those for
entering and leaving streaming mode are done in asm volatile blocks
since they are expected to be used from C.
We could do the SMSTART and SMSTOP operations with read/modify/write
cycles on SVCR but using the aliases provided for individual field
accesses should be slightly faster. These instructions are aliases for
MSR but since our minimum toolchain requirements are old enough to mean
that we can't use the sX_X_cX_cX_X form and they always use xzr rather
than taking a value like write_sysreg_s() wants we just use .inst.
Signed-off-by: Mark Brown <broonie@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-7-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit ca8a4ebcff)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: Iefe76395cf940518d7ef245c2c0c434f8ea28d51
The arm64 Scalable Matrix Extension (SME) adds some new system registers,
fields in existing system registers and exception syndromes. This patch
adds definitions for these for use in future patches implementing support
for this extension.
Since SME will be the first user of FEAT_HCX in the kernel also include
the definitions for enumerating it and the HCRX system register it adds.
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419112247.711548-6-broonie@kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
(cherry picked from commit b4adc83b07)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: Ic1698ac8d3b7935d95a52d439c4e3bccde09b91b
For WFxT instructions used with very small delays, it is not
unlikely that the deadline is already expired by the time we
reach the WFx handling code.
Check for this condition as soon as possible, and return to the
guest immediately if we can.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220419182755.601427-7-maz@kernel.org
(cherry picked from commit a3fb596514)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I03090182ab73793c54601d8beb09be3ec090a053
When trapping a blocking WFIT instruction, take it into account when
computing the deadline of the background timer.
The state is tracked with a new vcpu flag, and is gated by a new
CPU capability, which isn't currently enabled.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220419182755.601427-6-maz@kernel.org
(cherry picked from commit 89f5074c50)
[willdeacon@: Use kvm_vcpu_block() instead of kvm_vcpu_halt() in context]
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I9819233e1cb0df8a4bfb5018a47249b16fecae49
Refactor kvm_timer_compute_delta() and extract a helper that
compute the delta (in ns) between a given timer and an arbitrary
value.
No functional change expected.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220419182755.601427-5-maz@kernel.org
(cherry picked from commit daf85a5f6b)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I5082092730945b808bd0bfb051c071340beb0266
kvm_cpu_has_pending_timer() ends up checking all the possible
timers for a wake-up cause. However, we already check for
pending interrupts whenever we try to wake-up a vcpu, including
the timer interrupts.
Obviously, doing the same work twice is once too many. Reduce
this helper to almost nothing, but keep it around, as we are
going to make use of it soon.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220419182755.601427-4-maz@kernel.org
(cherry picked from commit b57de4ffd7)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I051492d81a822d21c9434d5a09e8f670fe1d788d
The ISS field exposed by ESR_ELx contain two additional subfields
with FEAT_WFxT:
- RN, the register number containing the timeout
- RV, indicating if the register number is valid
Describe these two fields according to the arch spec.
No functional change.
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419182755.601427-3-maz@kernel.org
(cherry picked from commit bdcc2f2803)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: Ia52d9e0985e113afb1eaa75d7b51047e80348477
Starting with FEAT_WFXT in ARMv8.7, the TI field in the ISS
that is reported on a WFx trap is expanded by one bit to
allow the description of WFET and WFIT.
Special care is taken to exclude the WFxT bit from the mask
used to match WFI so that it also matches WFIT when trapped from
EL0.
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220419182755.601427-2-maz@kernel.org
(cherry picked from commit 6a437208cb)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I000829397e606b68f067e5433efd339a1b4d15db
Since all the fields in the main ID registers are 4 bits wide we have up
until now not bothered specifying the width in the code. Since we now
wish to use this mechanism to enumerate features from the floating point
feature registers which do not follow this pattern add a width to the
table. This means updating all the existing table entries but makes it
less likely that we run into issues in future due to implicitly assuming
a 4 bit width.
Signed-off-by: Mark Brown <broonie@kernel.org>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220207152109.197566-4-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
(cherry picked from commit 0a2eec83c2)
[willdeacon@: Add missing .field_width initialisers per upstream merge commit
8d93b7a242 ("Merge branch 'for-next/fpsimd' into for-next/core")]
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: Ic2bd609d701fbdcc53b9d60cb402b4a6a102bfe7
CPACR_EL1 has several bitfields for controlling traps for floating point
features to EL1, each of which has a separate bits for EL0 and EL1. Marc
Zyngier noted that we are not consistent in our use of defines to
manipulate these, sometimes using a define covering the whole field and
sometimes using defines for the individual bits. Make this consistent by
expanding the whole field defines where they are used (currently only in
the KVM code) and deleting them so that no further uses can be
introduced.
Suggested-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20220207152109.197566-3-broonie@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
(cherry picked from commit 3bb72d86d8)
Signed-off-by: Will Deacon <willdeacon@google.com>
Bug: 233587962
Bug: 233588291
Change-Id: I2e42e5c18bfdcbeac99eec5121b1ef5117c05ec8
