Marc Zyngier [Wed, 14 Apr 2021 13:44:05 +0000 (14:44 +0100)]
KVM: arm64: Divorce the perf code from oprofile helpers
KVM/arm64 is the sole user of perf_num_counters(), and really
could do without it. Stop using the obsolete API by relying on
the existing probing code.
KVM: arm64: Fix Function ID typo for PTP_KVM service
Per include/linux/arm-smccc.h, the Function ID of PTP_KVM service is
defined as ARM_SMCCC_VENDOR_HYP_KVM_PTP_FUNC_ID. Fix the typo in
documentation to keep the git grep consistent.
Jon Hunter [Tue, 20 Apr 2021 13:24:19 +0000 (14:24 +0100)]
ptp: Don't print an error if ptp_kvm is not supported
Commit 300bb1fe7671 ("ptp: arm/arm64: Enable ptp_kvm for arm/arm64")
enable ptp_kvm support for ARM platforms and for any ARM platform that
does not support this, the following error message is displayed ...
ERR KERN fail to initialize ptp_kvm
For platforms that do not support ptp_kvm this error is a bit misleading
and so fix this by only printing this message if the error returned by
kvm_arch_ptp_init() is not -EOPNOTSUPP. Note that -EOPNOTSUPP is only
returned by ARM platforms today if ptp_kvm is not supported.
Fixes: 300bb1fe7671 ("ptp: arm/arm64: Enable ptp_kvm for arm/arm64") Signed-off-by: Jon Hunter <jonathanh@nvidia.com> Acked-by: Richard Cochran <richardcochran@gmail.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210420132419.1318148-1-jonathanh@nvidia.com
Marc Zyngier [Wed, 14 Apr 2021 16:41:14 +0000 (17:41 +0100)]
bug: Provide dummy version of bug_get_file_line() when !GENERIC_BUG
Provide the missing dummy bug_get_file_line() implementation when
GENENERIC_BUG isn't selected.
Reported-by: kernel test robot <lkp@intel.com> Fixes: 26dbc7e299c7 ("bug: Factor out a getter for a bug's file line") Cc: Andrew Scull <ascull@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
coresight: trbe: Fix return value check in arm_trbe_register_coresight_cpu()
In case of error, the function devm_kasprintf() returns NULL
pointer not ERR_PTR(). The IS_ERR() test in the return value
check should be replaced with NULL test.
drivers/hwtracing/coresight/coresight-core.c:26:1: warning:
symbol '__pcpu_scope_csdev_sink' was not declared. Should it be static?
As csdev_sink is not used outside of coresight-core.c after the
introduction of coresight_[set|get]_percpu_sink() helpers, this
change marks it static.
When reading the base address of the a REDIST region
through KVM_VGIC_V3_ADDR_TYPE_REDIST we expect the
redistributor region list to be populated with a single
element.
However list_first_entry() expects the list to be non empty.
Instead we should use list_first_entry_or_null which effectively
returns NULL if the list is empty.
Fixes: dbd9733ab674 ("KVM: arm/arm64: Replace the single rdist region by a list") Cc: <Stable@vger.kernel.org> # v4.18+ Signed-off-by: Eric Auger <eric.auger@redhat.com> Reported-by: Gavin Shan <gshan@redhat.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210412150034.29185-1-eric.auger@redhat.com
Ard Biesheuvel [Tue, 2 Mar 2021 09:01:12 +0000 (10:01 +0100)]
arm64: fpsimd: run kernel mode NEON with softirqs disabled
Kernel mode NEON can be used in task or softirq context, but only in
a non-nesting manner, i.e., softirq context is only permitted if the
interrupt was not taken at a point where the kernel was using the NEON
in task context.
This means all users of kernel mode NEON have to be aware of this
limitation, and either need to provide scalar fallbacks that may be much
slower (up to 20x for AES instructions) and potentially less safe, or
use an asynchronous interface that defers processing to a later time
when the NEON is guaranteed to be available.
Given that grabbing and releasing the NEON is cheap, we can relax this
restriction, by increasing the granularity of kernel mode NEON code, and
always disabling softirq processing while the NEON is being used in task
context.
Ard Biesheuvel [Tue, 2 Mar 2021 09:01:11 +0000 (10:01 +0100)]
arm64: assembler: introduce wxN aliases for wN registers
The AArch64 asm syntax has this slightly tedious property that the names
used in mnemonics to refer to registers depend on whether the opcode in
question targets the entire 64-bits (xN), or only the least significant
8, 16 or 32 bits (wN). When writing parameterized code such as macros,
this can be annoying, as macro arguments don't lend themselves to
indexed lookups, and so generating a reference to wN in a macro that
receives xN as an argument is problematic.
For instance, an upcoming patch that modifies the implementation of the
cond_yield macro to be able to refer to 32-bit registers would need to
modify invocations such as
cond_yield 3f, x8
to
cond_yield 3f, 8
so that the second argument can be token pasted after x or w to emit the
correct register reference. Unfortunately, this interferes with the self
documenting nature of the first example, where the second argument is
obviously a register, whereas in the second example, one would need to
go and look at the code to find out what '8' means.
So let's fix this by defining wxN aliases for all xN registers, which
resolve to the 32-bit alias of each respective 64-bit register. This
allows the macro implementation to paste the xN reference after a w to
obtain the correct register name.
The users of the conditional NEON yield macros have all been switched to
the simplified cond_yield macro, and so the NEON specific ones can be
removed.
Alexandru Elisei [Fri, 9 Apr 2021 15:21:54 +0000 (16:21 +0100)]
KVM: arm64: Don't advertise FEAT_SPE to guests
Even though KVM sets up MDCR_EL2 to trap accesses to the SPE buffer and
sampling control registers and to inject an undefined exception, the
presence of FEAT_SPE is still advertised in the ID_AA64DFR0_EL1 register,
if the hardware supports it. Getting an undefined exception when accessing
a register usually happens for a hardware feature which is not implemented,
and indeed this is how PMU emulation is handled when the virtual machine
has been created without the KVM_ARM_VCPU_PMU_V3 feature. Let's be
consistent and never advertise FEAT_SPE, because KVM doesn't have support
for emulating it yet.
Alexandru Elisei [Fri, 9 Apr 2021 15:21:53 +0000 (16:21 +0100)]
KVM: arm64: Don't print warning when trapping SPE registers
KVM sets up MDCR_EL2 to trap accesses to the SPE buffer and sampling
control registers and it relies on the fact that KVM injects an undefined
exception for unknown registers. This mechanism of injecting undefined
exceptions also prints a warning message for the host kernel; for example,
when a guest tries to access PMSIDR_EL1:
This is unnecessary, because KVM has explicitly configured trapping of
those registers and is well aware of their existence. Prevent the warning
by adding the SPE registers to the list of registers that KVM emulates.
The access function will inject the undefined exception.
Marc Zyngier [Tue, 6 Apr 2021 12:46:42 +0000 (13:46 +0100)]
KVM: arm64: Clarify vcpu reset behaviour
Although the KVM_ARM_VCPU_INIT documentation mention that the
registers are reset to their "initial values", it doesn't
describe what these values are.
Describe this state explicitly.
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org>
Marc Zyngier [Thu, 8 Apr 2021 13:10:10 +0000 (14:10 +0100)]
arm64: Get rid of CONFIG_ARM64_VHE
CONFIG_ARM64_VHE was introduced with ARMv8.1 (some 7 years ago),
and has been enabled by default for almost all that time.
Given that newer systems that are VHE capable are finally becoming
available, and that some systems are even incapable of not running VHE,
drop the configuration altogether.
Anyone willing to stick to non-VHE on VHE hardware for obscure
reasons should use the 'kvm-arm.mode=nvhe' command-line option.
Marc Zyngier [Thu, 8 Apr 2021 13:10:09 +0000 (14:10 +0100)]
arm64: Cope with CPUs stuck in VHE mode
It seems that the CPUs part of the SoC known as Apple M1 have the
terrible habit of being stuck with HCR_EL2.E2H==1, in violation
of the architecture.
Try and work around this deplorable state of affairs by detecting
the stuck bit early and short-circuit the nVHE dance. Additional
filtering code ensures that attempts at switching to nVHE from
the command-line are also ignored.
It is still unknown whether there are many more such nuggets
to be found...
Marc Zyngier [Thu, 8 Apr 2021 13:10:08 +0000 (14:10 +0100)]
arm64: cpufeature: Allow early filtering of feature override
Some CPUs are broken enough that some overrides need to be rejected
at the earliest opportunity. In some cases, that's right at cpu
feature override time.
Provide the necessary infrastructure to filter out overrides,
and to report such filtered out overrides to the core cpufeature code.
Marc Zyngier [Tue, 6 Apr 2021 13:10:33 +0000 (14:10 +0100)]
KVM: arm64: Mark the kvmarm ML as moderated for non-subscribers
The kvmarm mailing list is moderated for non-subscriber, but that
was never advertised. Fix this with the hope that people will
eventually subscribe before posting, saving me the hassle of
letting their post through eventually.
Alexandru Elisei [Wed, 7 Apr 2021 14:48:57 +0000 (15:48 +0100)]
KVM: arm64: Initialize VCPU mdcr_el2 before loading it
When a VCPU is created, the kvm_vcpu struct is initialized to zero in
kvm_vm_ioctl_create_vcpu(). On VHE systems, the first time
vcpu.arch.mdcr_el2 is loaded on hardware is in vcpu_load(), before it is
set to a sensible value in kvm_arm_setup_debug() later in the run loop. The
result is that KVM executes for a short time with MDCR_EL2 set to zero.
This has several unintended consequences:
* Setting MDCR_EL2.HPMN to 0 is constrained unpredictable according to ARM
DDI 0487G.a, page D13-3820. The behavior specified by the architecture
in this case is for the PE to behave as if MDCR_EL2.HPMN is set to a
value less than or equal to PMCR_EL0.N, which means that an unknown
number of counters are now disabled by MDCR_EL2.HPME, which is zero.
* The host configuration for the other debug features controlled by
MDCR_EL2 is temporarily lost. This has been harmless so far, as Linux
doesn't use the other fields, but that might change in the future.
Let's avoid both issues by initializing the VCPU's mdcr_el2 field in
kvm_vcpu_vcpu_first_run_init(), thus making sure that the MDCR_EL2 register
has a consistent value after each vcpu_load().
Alexandru Elisei [Wed, 7 Apr 2021 14:48:56 +0000 (15:48 +0100)]
Documentation: KVM: Document KVM_GUESTDBG_USE_HW control flag for arm64
Commit 21b6f32f9471 ("KVM: arm64: guest debug, define API headers") added
the arm64 KVM_GUESTDBG_USE_HW flag for the KVM_SET_GUEST_DEBUG ioctl and
commit 834bf88726f0 ("KVM: arm64: enable KVM_CAP_SET_GUEST_DEBUG")
documented and implemented the flag functionality. Since its introduction,
at no point was the flag known by any name other than KVM_GUESTDBG_USE_HW
for the arm64 architecture, so refer to it as such in the documentation.
Jianyong Wu [Wed, 9 Dec 2020 06:09:30 +0000 (14:09 +0800)]
ptp: arm/arm64: Enable ptp_kvm for arm/arm64
Currently, there is no mechanism to keep time sync between guest and host
in arm/arm64 virtualization environment. Time in guest will drift compared
with host after boot up as they may both use third party time sources
to correct their time respectively. The time deviation will be in order
of milliseconds. But in some scenarios,like in cloud environment, we ask
for higher time precision.
kvm ptp clock, which chooses the host clock source as a reference
clock to sync time between guest and host, has been adopted by x86
which takes the time sync order from milliseconds to nanoseconds.
This patch enables kvm ptp clock for arm/arm64 and improves clock sync precision
significantly.
Test result comparisons between with kvm ptp clock and without it in arm/arm64
are as follows. This test derived from the result of command 'chronyc
sources'. we should take more care of the last sample column which shows
the offset between the local clock and the source at the last measurement.
The dns1.synet.edu.cn is the network reference clock for guest and
120.25.115.20 is the network reference clock for host. we can't get the
clock error between guest and host directly, but a roughly estimated value
will be in order of hundreds of us to ms.
with kvm ptp in guest:
chrony has been disabled in host to remove the disturb by network clock.
The PHC0 is the ptp clock which choose the host clock as its source
clock. So we can see that the clock difference between host and guest
is in order of ns.
Jianyong Wu [Wed, 9 Dec 2020 06:09:29 +0000 (14:09 +0800)]
KVM: arm64: Add support for the KVM PTP service
Implement the hypervisor side of the KVM PTP interface.
The service offers wall time and cycle count from host to guest.
The caller must specify whether they want the host's view of
either the virtual or physical counter.
Thomas Gleixner [Wed, 9 Dec 2020 06:09:27 +0000 (14:09 +0800)]
time: Add mechanism to recognize clocksource in time_get_snapshot
System time snapshots are not conveying information about the current
clocksource which was used, but callers like the PTP KVM guest
implementation have the requirement to evaluate the clocksource type to
select the appropriate mechanism.
Introduce a clocksource id field in struct clocksource which is by default
set to CSID_GENERIC (0). Clocksource implementations can set that field to
a value which allows to identify the clocksource.
Store the clocksource id of the current clocksource in the
system_time_snapshot so callers can evaluate which clocksource was used to
take the snapshot and act accordingly.
Jianyong Wu [Wed, 9 Dec 2020 06:09:26 +0000 (14:09 +0800)]
ptp: Reorganize ptp_kvm.c to make it arch-independent
Currently, the ptp_kvm module contains a lot of x86-specific code.
Let's move this code into a new arch-specific file in the same directory,
and rename the arch-independent file to ptp_kvm_common.c.
Eric Auger [Wed, 7 Apr 2021 13:59:37 +0000 (15:59 +0200)]
KVM: selftests: vgic_init kvm selftests fixup
Bring some improvements/rationalization over the first version
of the vgic_init selftests:
- ucall_init is moved in run_cpu()
- vcpu_args_set is not called as not needed
- whenever a helper is supposed to succeed, call the non "_" version
- helpers do not return -errno, instead errno is checked by the caller
- vm_gic struct is used whenever possible, as well as vm_gic_destroy
- _kvm_create_device takes an addition fd parameter
Gavin Shan [Tue, 16 Mar 2021 04:11:26 +0000 (12:11 +0800)]
KVM: arm64: Don't retrieve memory slot again in page fault handler
We needn't retrieve the memory slot again in user_mem_abort() because
the corresponding memory slot has been passed from the caller. This
would save some CPU cycles. For example, the time used to write 1GB
memory, which is backed by 2MB hugetlb pages and write-protected, is
dropped by 6.8% from 928ms to 864ms.
Gavin Shan [Tue, 16 Mar 2021 04:11:24 +0000 (12:11 +0800)]
KVM: arm64: Hide kvm_mmu_wp_memory_region()
We needn't expose the function as it's only used by mmu.c since it
was introduced by commit c64735554c0a ("KVM: arm: Add initial dirty
page locking support").
Trace Buffer Extension (TRBE) implements a trace buffer per CPU which is
accessible via the system registers. The TRBE supports different addressing
modes including CPU virtual address and buffer modes including the circular
buffer mode. The TRBE buffer is addressed by a base pointer (TRBBASER_EL1),
an write pointer (TRBPTR_EL1) and a limit pointer (TRBLIMITR_EL1). But the
access to the trace buffer could be prohibited by a higher exception level
(EL3 or EL2), indicated by TRBIDR_EL1.P. The TRBE can also generate a CPU
private interrupt (PPI) on address translation errors and when the buffer
is full. Overall implementation here is inspired from the Arm SPE driver.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Leach <mike.leach@linaro.org> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
[ Mark the buffer truncated on WRAP event, error code cleanup ] Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Link: https://lore.kernel.org/r/20210405164307.1720226-18-suzuki.poulose@arm.com Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
coresight: core: Add support for dedicated percpu sinks
Add support for dedicated sinks that are bound to individual CPUs. (e.g,
TRBE). To allow quicker access to the sink for a given CPU bound source,
keep a percpu array of the sink devices. Also, add support for building
a path to the CPU local sink from the ETM.
This adds a new percpu sink type CORESIGHT_DEV_SUBTYPE_SINK_PERCPU_SYSMEM.
This new sink type is exclusively available and can only work with percpu
source type device CORESIGHT_DEV_SUBTYPE_SOURCE_PROC.
This defines a percpu structure that accommodates a single coresight_device
which can be used to store an initialized instance from a sink driver. As
these sinks are exclusively linked and dependent on corresponding percpu
sources devices, they should also be the default sink device during a perf
session.
Outwards device connections are scanned while establishing paths between a
source and a sink device. But such connections are not present for certain
percpu source and sink devices which are exclusively linked and dependent.
Build the path directly and skip connection scanning for such devices.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Leach <mike.leach@linaro.org> Cc: Suzuki K Poulose <suzuki.poulose@arm.com> Tested-by: Suzuki K Poulose <suzuki.poulose@arm.com> Reviewed-by: Mike Leach <mike.leach@linaro.org> Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
[Moved the set/get percpu sink APIs from TRBE patch to here
Fixed build break on arm32] Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Link: https://lore.kernel.org/r/20210405164307.1720226-17-suzuki.poulose@arm.com Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
The context associated with an ETM for a given perf event
includes :
- handle -> the perf output handle for the AUX buffer.
- the path for the trace components
- the buffer config for the sink.
The path and the buffer config are part of the "aux_priv" data
(etm_event_data) setup by the setup_aux() callback, and made available
via perf_get_aux(handle).
Now with a sink supporting IRQ, the sink could "end" an output
handle when the buffer reaches the programmed limit and would try
to restart a handle. This could fail if there is not enough
space left the AUX buffer (e.g, the userspace has not consumed
the data). This leaves the "handle" disconnected from the "event"
and also the "perf_get_aux()" cleared. This all happens within
the sink driver, without the etm_perf driver being aware.
Now when the event is actually stopped, etm_event_stop()
will need to access the "event_data". But since the handle
is not valid anymore, we loose the information to stop the
"trace" path. So, we need a reliable way to access the etm_event_data
even when the handle may not be active.
This patch replaces the per_cpu handle array with a per_cpu context
for the ETM, which tracks the "handle" as well as the "etm_event_data".
The context notes the etm_event_data at etm_event_start() and clears
it at etm_event_stop(). This makes sure that we don't access a
stale "etm_event_data" as we are guaranteed that it is not
freed by free_aux() as long as the event is active and tracing,
also provides us with access to the critical information
needed to wind up a session even in the absence of an active
output_handle.
This is not an issue for the legacy sinks as none of them supports
an IRQ and is centrally handled by the etm-perf.
Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Cc: Leo Yan <leo.yan@linaro.org> Cc: Mike Leach <mike.leach@linaro.org> Reviewed-by: Mike Leach <mike.leach@linaro.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Link: https://lore.kernel.org/r/20210405164307.1720226-16-suzuki.poulose@arm.com Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
dts: bindings: Document device tree bindings for ETE
Document the device tree bindings for Embedded Trace Extensions.
ETE can be connected to legacy coresight components and thus
could optionally contain a connection graph as described by
the CoreSight bindings.
Cc: devicetree@vger.kernel.org Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Mike Leach <mike.leach@linaro.org> Reviewed-by: Rob Herring <robh@kernel.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Link: https://lore.kernel.org/r/20210405164307.1720226-15-suzuki.poulose@arm.com Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Add ETE as one of the supported device types we support
with ETM4x driver. The devices are named following the
existing convention as ete<N>.
ETE mandates that the trace resource status register is programmed
before the tracing is turned on. For the moment simply write to
it indicating TraceActive.
Add support for handling the system registers for Embedded Trace
Extensions (ETE). ETE shares most of the registers with ETMv4 except
for some and also adds some new registers. Re-arrange the ETMv4x list
to share the common definitions and add the ETE sysreg support.
ETE may not implement the OS lock and instead could rely on
the PE OS Lock for the trace unit access. This is indicated
by the TRCOLSR.OSM == 0b100. Add support for handling the
PE OS lock
coresight: Do not scan for graph if none is present
If a graph node is not found for a given node, of_get_next_endpoint()
will emit the following error message :
OF: graph: no port node found in /<node_name>
If the given component doesn't have any explicit connections (e.g,
ETE) we could simply ignore the graph parsing. As for any legacy
component where this is mandatory, the device will not be usable
as before this patch. Updating the DT bindings to Yaml and enabling
the schema checks can detect such issues with the DT.
coresight: etm-perf: Allow an event to use different sinks
When a sink is not specified by the user, the etm perf driver
finds a suitable sink automatically, based on the first ETM
where this event could be scheduled. Then we allocate the
sink buffer based on the selected sink. This is fine for a
CPU bound event as the "sink" is always guaranteed to be
reachable from the ETM (as this is the only ETM where the
event is going to be scheduled). However, if we have a thread
bound event, the event could be scheduled on any of the ETMs
on the system. In this case, currently we automatically select
a sink and exclude any ETMs that cannot reach the selected
sink. This is problematic especially for 1x1 configurations.
We end up in tracing the event only on the "first" ETM,
as the default sink is local to the first ETM and unreachable
from the rest. However, we could allow the other ETMs to
trace if they all have a sink that is compatible with the
"selected" sink and can use the sink buffer. This can be
easily done by verifying that they are all driven by the
same driver and matches the same subtype. Please note
that at anytime there can be only one ETM tracing the event.
Adding support for different types of sinks for a single
event is complex and is not something that we expect
on a sane configuration.
arm64: KVM: Enable access to TRBE support for host
For a nvhe host, the EL2 must allow the EL1&0 translation
regime for TraceBuffer (MDCR_EL2.E2TB == 0b11). This must
be saved/restored over a trip to the guest. Also, before
entering the guest, we must flush any trace data if the
TRBE was enabled. And we must prohibit the generation
of trace while we are in EL1 by clearing the TRFCR_EL1.
For vhe, the EL2 must prevent the EL1 access to the Trace
Buffer.
The MDCR_EL2 bit definitions for TRBE are available here :
KVM: arm64: Move SPE availability check to VCPU load
At the moment, we check the availability of SPE on the given
CPU (i.e, SPE is implemented and is allowed at the host) during
every guest entry. This can be optimized a bit by moving the
check to vcpu_load time and recording the availability of the
feature on the current CPU via a new flag. This will also be useful
for adding the TRBE support.
Cc: Marc Zyngier <maz@kernel.org> Cc: Will Deacon <will@kernel.org> Cc: Alexandru Elisei <Alexandru.Elisei@arm.com> Cc: James Morse <james.morse@arm.com> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Acked-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210405164307.1720226-7-suzuki.poulose@arm.com Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Some other tests dedicate to KVM_DEV_ARM_VGIC_GRP_REDIST_REGS group
and especially the GICR_TYPER read. The goal was to test the case
recently fixed by commit 23bde34771f1
("KVM: arm64: vgic-v3: Drop the reporting of GICR_TYPER.Last for userspace").
The API under test can be found at
Documentation/virt/kvm/devices/arm-vgic-v3.rst
Eric Auger [Mon, 5 Apr 2021 16:39:40 +0000 (18:39 +0200)]
KVM: arm64: vgic-v3: Expose GICR_TYPER.Last for userspace
Commit 23bde34771f1 ("KVM: arm64: vgic-v3: Drop the
reporting of GICR_TYPER.Last for userspace") temporarily fixed
a bug identified when attempting to access the GICR_TYPER
register before the redistributor region setting, but dropped
the support of the LAST bit.
Emulating the GICR_TYPER.Last bit still makes sense for
architecture compliance though. This patch restores its support
(if the redistributor region was set) while keeping the code safe.
We introduce a new helper, vgic_mmio_vcpu_rdist_is_last() which
computes whether a redistributor is the highest one of a series
of redistributor contributor pages.
With this new implementation we do not need to have a uaccess
read accessor anymore.
To improve the readability, we introduce the new
vgic_v3_free_redist_region helper and also rename
vgic_v3_insert_redist_region into vgic_v3_alloc_redist_region
Eric Auger [Mon, 5 Apr 2021 16:39:38 +0000 (18:39 +0200)]
KVM: arm64: Simplify argument passing to vgic_uaccess_[read|write]
vgic_uaccess() takes a struct vgic_io_device argument, converts it
to a struct kvm_io_device and passes it to the read/write accessor
functions, which convert it back to a struct vgic_io_device.
Avoid the indirection by passing the struct vgic_io_device argument
directly to vgic_uaccess_{read,write}.
kvm_arch_vcpu_precreate() returns -EBUSY if the vgic is
already initialized. So let's document that KVM_DEV_ARM_VGIC_CTRL_INIT
must be called after all vcpu creations.
Eric Auger [Mon, 5 Apr 2021 16:39:36 +0000 (18:39 +0200)]
KVM: arm/arm64: vgic: Reset base address on kvm_vgic_dist_destroy()
On vgic_dist_destroy(), the addresses are not reset. However for
kvm selftest purpose this would allow to continue the test execution
even after a failure when running KVM_RUN. So let's reset the
base addresses.
Eric Auger [Mon, 5 Apr 2021 16:39:35 +0000 (18:39 +0200)]
KVM: arm64: vgic-v3: Fix error handling in vgic_v3_set_redist_base()
vgic_v3_insert_redist_region() may succeed while
vgic_register_all_redist_iodevs fails. For example this happens
while adding a redistributor region overlapping a dist region. The
failure only is detected on vgic_register_all_redist_iodevs when
vgic_v3_check_base() gets called in vgic_register_redist_iodev().
In such a case, remove the newly added redistributor region and free
it.
The doc says:
"The characteristics of a specific redistributor region can
be read by presetting the index field in the attr data.
Only valid for KVM_DEV_TYPE_ARM_VGIC_V3"
Unfortunately the existing code fails to read the input attr data.
Fixes: 04c110932225 ("KVM: arm/arm64: Implement KVM_VGIC_V3_ADDR_TYPE_REDIST_REGION") Cc: stable@vger.kernel.org#v4.17+ Signed-off-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210405163941.510258-3-eric.auger@redhat.com
Eric Auger [Mon, 5 Apr 2021 16:39:33 +0000 (18:39 +0200)]
KVM: arm64: vgic-v3: Fix some error codes when setting RDIST base
KVM_DEV_ARM_VGIC_GRP_ADDR group doc says we should return
-EEXIST in case the base address of the redist is already set.
We currently return -EINVAL.
However we need to return -EINVAL in case a legacy REDIST address
is attempted to be set while REDIST_REGIONS were set. This case
is discriminated by looking at the count field.
CoreSight PMU supports aux-buffer for the ETM tracing. The trace
generated by the ETM (associated with individual CPUs, like Intel PT)
is captured by a separate IP (CoreSight TMC-ETR/ETF until now).
The TMC-ETR applies formatting of the raw ETM trace data, as it
can collect traces from multiple ETMs, with the TraceID to indicate
the source of a given trace packet.
Arm Trace Buffer Extension is new "sink" IP, attached to individual
CPUs and thus do not provide additional formatting, like TMC-ETR.
Additionally, a system could have both TRBE *and* TMC-ETR for
the trace collection. e.g, TMC-ETR could be used as a single
trace buffer to collect data from multiple ETMs to correlate
the traces from different CPUs. It is possible to have a
perf session where some events end up collecting the trace
in TMC-ETR while the others in TRBE. Thus we need a way
to identify the type of the trace for each AUX record.
Define the trace formats exported by the CoreSight PMU.
We don't define the flags following the "ETM" as this
information is available to the user when issuing
the session. What is missing is the additional
formatting applied by the "sink" which is decided
at the runtime and the user may not have a control on.
So we define :
- CORESIGHT format (indicates the Frame format)
- RAW format (indicates the format of the source)
The default value is CORESIGHT format for all the records
(i,e == 0). Add the RAW format for others that use
raw format.
Cc: Peter Zijlstra <peterz@infradead.org> Cc: Mike Leach <mike.leach@linaro.org> Cc: Mathieu Poirier <mathieu.poirier@linaro.org> Cc: Leo Yan <leo.yan@linaro.org> Cc: Anshuman Khandual <anshuman.khandual@arm.com> Reviewed-by: Mike Leach <mike.leach@linaro.org> Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com> Link: https://lore.kernel.org/r/20210405164307.1720226-3-suzuki.poulose@arm.com Signed-off-by: Mathieu Poirier <mathieu.poirier@linaro.org>
Allocate a byte for advertising the PMU specific format type
of the given AUX record. A PMU could end up providing hardware
trace data in multiple format in a single session.
e.g, The format of hardware buffer produced by CoreSight ETM
PMU depends on the type of the "sink" device used for collection
for an event (Traditional TMC-ETR/Bs with formatting or
TRBEs without any formatting).
# Boring story of why this is needed. Goto The_End_of_Story for skipping.
CoreSight ETM trace allows instruction level tracing of Arm CPUs.
The ETM generates the CPU excecution trace and pumps it into CoreSight
AMBA Trace Bus and is collected by a different CoreSight component
(traditionally CoreSight TMC-ETR /ETB/ETF), called "sink".
Important to note that there is no guarantee that every CPU has
a dedicated sink. Thus multiple ETMs could pump the trace data
into the same "sink" and thus they apply additional formatting
of the trace data for the user to decode it properly and attribute
the trace data to the corresponding ETM.
However, with the introduction of Arm Trace buffer Extensions (TRBE),
we now have a dedicated per-CPU architected sink for collecting the
trace. Since the TRBE is always per-CPU, it doesn't apply any formatting
of the trace. The support for this driver is under review [1].
Now a system could have a per-cpu TRBE and one or more shared
TMC-ETRs on the system. A user could choose a "specific" sink
for a perf session (e.g, a TMC-ETR) or the driver could automatically
select the nearest sink for a given ETM. It is possible that
some ETMs could end up using TMC-ETR (e.g, if the TRBE is not
usable on the CPU) while the others using TRBE in a single
perf session. Thus we now have "formatted" trace collected
from TMC-ETR and "unformatted" trace collected from TRBE.
However, we don't get into a situation where a single event
could end up using TMC-ETR & TRBE. i.e, any AUX buffer is
guaranteed to be either RAW or FORMATTED, but not a mix
of both.
As for perf decoding, we need to know the type of the data
in the individual AUX buffers, so that it can set up the
"OpenCSD" (library for decoding CoreSight trace) decoder
instance appropriately. Thus the perf.data file must conatin
the hints for the tool to decode the data correctly.
Since this is a runtime variable, and perf tool doesn't have
a control on what sink gets used (in case of automatic sink
selection), we need this information made available from
the PMU driver for each AUX record.
Andrew Scull [Thu, 18 Mar 2021 14:33:11 +0000 (14:33 +0000)]
KVM: arm64: Log source when panicking from nVHE hyp
To aid with debugging, add details of the source of a panic from nVHE
hyp. This is done by having nVHE hyp exit to nvhe_hyp_panic_handler()
rather than directly to panic(). The handler will then add the extra
details for debugging before panicking the kernel.
If the panic was due to a BUG(), look up the metadata to log the file
and line, if available, otherwise log an address that can be looked up
in vmlinux. The hyp offset is also logged to allow other hyp VAs to be
converted, similar to how the kernel offset is logged during a panic.
__hyp_panic_string is now inlined since it no longer needs to be
referenced as a symbol and the message is free to diverge between VHE
and nVHE.
The following is an example of the logs generated by a BUG in nVHE hyp.
Andrew Scull [Thu, 18 Mar 2021 14:33:10 +0000 (14:33 +0000)]
KVM: arm64: Use BUG and BUG_ON in nVHE hyp
hyp_panic() reports the address of the panic by using ELR_EL2, but this
isn't a useful address when hyp_panic() is called directly. Replace such
direct calls with BUG() and BUG_ON() which use BRK to trigger an
exception that then goes to hyp_panic() with the correct address. Also
remove the hyp_panic() declaration from the header file to avoid
accidental misuse.
Andrew Scull [Thu, 18 Mar 2021 14:33:08 +0000 (14:33 +0000)]
bug: Factor out a getter for a bug's file line
There is some non-trivial config-based logic to get the file name and
line number associated with a bug. Factor this out to a getter that can
be resused.
Signed-off-by: Andrew Scull <ascull@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210318143311.839894-3-ascull@google.com
Andrew Scull [Thu, 18 Mar 2021 14:33:07 +0000 (14:33 +0000)]
bug: Remove redundant condition check in report_bug
report_bug() will return early if it cannot find a bug corresponding to
the provided address. The subsequent test for the bug will always be
true so remove it.
Fixes: 1b4cfe3c0a30d ("lib/bug.c: exclude non-BUG/WARN exceptions from report_bug()") Signed-off-by: Andrew Scull <ascull@google.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: "Steven Rostedt (VMware)" <rostedt@goodmis.org> Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org> Acked-by: Will Deacon <will@kernel.org> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210318143311.839894-2-ascull@google.com
David Brazdil [Wed, 31 Mar 2021 13:30:48 +0000 (13:30 +0000)]
KVM: arm64: Support PREL/PLT relocs in EL2 code
gen-hyprel tool parses object files of the EL2 portion of KVM
and generates runtime relocation data. While only filtering for
R_AARCH64_ABS64 relocations in the input object files, it has an
allow-list of relocation types that are used for relative
addressing. Other, unexpected, relocation types are rejected and
cause the build to fail.
This allow-list did not include the position-relative relocation
types R_AARCH64_PREL64/32/16 and the recently introduced _PLT32.
While not seen used by toolchains in the wild, add them to the
allow-list for completeness.
Fixes: 8c49b5d43d4c ("KVM: arm64: Generate hyp relocation data") Cc: <stable@vger.kernel.org> Reported-by: Will Deacon <will@kernel.org> Signed-off-by: David Brazdil <dbrazdil@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20210331133048.63311-1-dbrazdil@google.com
Xiaofei Tan [Wed, 31 Mar 2021 09:44:39 +0000 (17:44 +0800)]
arm64: sve: Provide sve_cond_update_zcr_vq fallback when !ARM64_SVE
Compilation fails when KVM is selected and ARM64_SVE isn't.
The root cause is that sve_cond_update_zcr_vq is not defined when
ARM64_SVE is not selected. Fix it by adding an empty definition
when CONFIG_ARM64_SVE=n.
Will Deacon [Wed, 9 Dec 2020 06:09:24 +0000 (14:09 +0800)]
arm/arm64: Probe for the presence of KVM hypervisor
Although the SMCCC specification provides some limited functionality for
describing the presence of hypervisor and firmware services, this is
generally applicable only to functions designated as "Arm Architecture
Service Functions" and no portable discovery mechanism is provided for
standard hypervisor services, despite having a designated range of
function identifiers reserved by the specification.
In an attempt to avoid the need for additional firmware changes every
time a new function is added, introduce a UID to identify the service
provider as being compatible with KVM. Once this has been established,
additional services can be discovered via a feature bitmap.
Reviewed-by: Steven Price <steven.price@arm.com> Signed-off-by: Will Deacon <will@kernel.org> Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
[maz: move code to its own file, plug it into PSCI] Signed-off-by: Marc Zyngier <maz@kernel.org> Link: https://lore.kernel.org/r/20201209060932.212364-2-jianyong.wu@arm.com
Marc Zyngier [Mon, 22 Mar 2021 12:09:51 +0000 (12:09 +0000)]
KVM: arm64: Generate final CTR_EL0 value when running in Protected mode
In protected mode, late CPUs are not allowed to boot (enforced by
the PSCI relay). We can thus specialise the read_ctr macro to
always return a pre-computed, sanitised value. Special care is
taken to prevent the use of this custome version outside of
the protected mode.
Reviewed-by: Quentin Perret <qperret@google.com> Signed-off-by: Marc Zyngier <maz@kernel.org>
Shenming Lu [Mon, 22 Mar 2021 06:01:58 +0000 (14:01 +0800)]
KVM: arm64: GICv4.1: Give a chance to save VLPI state
Before GICv4.1, we don't have direct access to the VLPI state. So
we simply let it fail early when encountering any VLPI in saving.
But now we don't have to return -EACCES directly if on GICv4.1. Let’s
change the hard code and give a chance to save the VLPI state (and
preserve the UAPI).
Zenghui Yu [Mon, 22 Mar 2021 06:01:57 +0000 (14:01 +0800)]
KVM: arm64: GICv4.1: Restore VLPI pending state to physical side
When setting the forwarding path of a VLPI (switch to the HW mode),
we can also transfer the pending state from irq->pending_latch to
VPT (especially in migration, the pending states of VLPIs are restored
into kvm’s vgic first). And we currently send "INT+VSYNC" to trigger
a VLPI to pending.
Shenming Lu [Mon, 22 Mar 2021 06:01:56 +0000 (14:01 +0800)]
KVM: arm64: GICv4.1: Try to save VLPI state in save_pending_tables
After pausing all vCPUs and devices capable of interrupting, in order
to save the states of all interrupts, besides flushing the states in
kvm’s vgic, we also try to flush the states of VLPIs in the virtual
pending tables into guest RAM, but we need to have GICv4.1 and safely
unmap the vPEs first.
As for the saving of VSGIs, which needs the vPEs to be mapped and might
conflict with the saving of VLPIs, but since we will map the vPEs back
at the end of save_pending_tables and both savings require the kvm->lock
to be held (thus only happen serially), it will work fine.
Shenming Lu [Mon, 22 Mar 2021 06:01:55 +0000 (14:01 +0800)]
KVM: arm64: GICv4.1: Add function to get VLPI state
With GICv4.1 and the vPE unmapped, which indicates the invalidation
of any VPT caches associated with the vPE, we can get the VLPI state
by peeking at the VPT. So we add a function for this.
Shenming Lu [Mon, 22 Mar 2021 06:01:54 +0000 (14:01 +0800)]
irqchip/gic-v3-its: Drop the setting of PTZ altogether
GICv4.1 gives a way to get the VLPI state, which needs to map the
vPE first, and after the state read, we may remap the vPE back while
the VPT is not empty. So we can't assume that the VPT is empty at
the first map. Besides, the optimization of PTZ is probably limited
since the HW should be fairly efficient to parse the empty VPT. Let's
drop the setting of PTZ altogether.
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