| Age | Commit message (Collapse) | Author |
|---|
|
* kvm-arm64/pmu-fixes:
: vPMU fixes for 6.15 courtesy of Akihiko Odaki
:
: Various fixes to KVM's vPMU implementation, notably ensuring
: userspace-directed changes to the PMCs are reflected in the backing perf
: events.
KVM: arm64: PMU: Reload when resetting
KVM: arm64: PMU: Reload when user modifies registers
KVM: arm64: PMU: Fix SET_ONE_REG for vPMC regs
KVM: arm64: PMU: Assume PMU presence in pmu-emul.c
KVM: arm64: PMU: Set raw values from user to PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR}
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
Replace kvm_pmu_vcpu_reset() with the generic PMU reloading mechanism to
ensure the consistency with system registers and to reduce code size.
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250315-pmc-v5-5-ecee87dab216@daynix.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
Reload the perf event when setting the vPMU counter (vPMC) registers
(PMCCNTR_EL0 and PMEVCNTR<n>_EL0). This is a change corresponding to
commit 9228b26194d1 ("KVM: arm64: PMU: Fix GET_ONE_REG
for vPMC regs to return the current value") but for SET_ONE_REG.
Values of vPMC registers are saved in sysreg files on certain occasions.
These saved values don't represent the current values of the vPMC
registers if the perf events for the vPMCs count events after the save.
The current values of those registers are the sum of the sysreg file
value and the current perf event counter value. But, when userspace
writes those registers (using KVM_SET_ONE_REG), KVM only updates the
sysreg file value and leaves the current perf event counter value as is.
It is also important to keep the correct state even if userspace writes
them after first run, specifically when debugging Windows on QEMU with
GDB; QEMU tries to write back all visible registers when resuming the VM
execution with GDB, corrupting the PMU state. Windows always uses the
PMU so this can cause adverse effects on that particular OS.
Fix this by releasing the current perf event and trigger recreating one
with KVM_REQ_RELOAD_PMU.
Fixes: 051ff581ce70 ("arm64: KVM: Add access handler for event counter register")
Signed-off-by: Akihiko Odaki <akihiko.odaki@daynix.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250315-pmc-v5-3-ecee87dab216@daynix.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
With the PMUv3 cpucap, kvm_arm_pmu_available is no longer used in the
hot path of guest entry/exit. On top of that, guest support for PMUv3
may not correlate with host support for the feature, e.g. on IMPDEF
hardware.
Throw out the static key and just inspect the list of PMUs to determine
if PMUv3 is supported for KVM guests.
Tested-by: Janne Grunau <j@jannau.net>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250305202641.428114-7-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
KVM is about to learn some new tricks to virtualize PMUv3 on IMPDEF
hardware. As part of that, we now need to differentiate host support
from guest support for PMUv3.
Add a cpucap to determine if an architectural PMUv3 is present to guard
host usage of PMUv3 controls.
Tested-by: Janne Grunau <j@jannau.net>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250305202641.428114-6-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
Having separate helpers for enabling/disabling counters provides the
wrong abstraction, as the state of each counter needs to be evaluated
independently and, in some cases, use a different global enable bit.
Collapse the enable/disable accessors into a single, common helper that
reconfigures every counter set in @mask, leaving the complexity of
determining if an event is actually enabled in
kvm_pmu_counter_is_enabled().
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241217175513.3658056-1-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
Start reprogramming PMU events at nested boundaries now that everything
is in place to handle the EL2 event filter. Only repaint events where
the filter differs between EL1 and EL2 as a slight optimization.
PMU now 'works' for nested VMs, albeit slow.
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241025182559.3364829-1-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
The value of MDCR_EL2.HPMN controls the number of event counters made
visible to EL0 and EL1. This means it is possible for the guest
hypervisor to allow direct access to event counters to the L2.
Rework KVM's PMU register emulation to take the effects of HPMN into
account when handling a trap. For bitmask-style registers, writes only
affect accessible registers.
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241025182354.3364124-14-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
Nested PMU support requires dynamically changing the visible range of
PMU counters based on the exception level and value of MDCR_EL2.HPMN. At
the same time, the PMU emulation code needs to know the absolute number
of implemented counters, regardless of context.
Rename the existing helper to make it obvious that it returns the number
of implemented counters and not anything else.
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241025182354.3364124-13-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
MDCR_EL2.HPMN splits the PMU event counters into two ranges: the first
range is accessible from all ELs, and the second range is accessible
only to EL2/3. Supposing the guest hypervisor allows direct access to
the PMU counters from the L2, KVM needs to locally handle those
accesses.
Add a new complex trap configuration for HPMN that checks if the counter
index is accessible to the current context. As written, the architecture
suggests HPMN only causes PMEVCNTR<n>_EL0 to trap, though intuition (and
the pseudocode) suggest that the trap applies to PMEVTYPER<n>_EL0 as
well.
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20241025182354.3364124-11-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
There are 2 defines for the number of PMU counters:
ARMV8_PMU_MAX_COUNTERS and ARMPMU_MAX_HWEVENTS. Both are the same
currently, but Armv9.4/8.9 increases the number of possible counters
from 32 to 33. With this change, the maximum number of counters will
differ for KVM's PMU emulation which is PMUv3.4. Give KVM PMU emulation
its own define to decouple it from the rest of the kernel's number PMU
counters.
The VHE PMU code needs to match the PMU driver, so switch it to use
ARMPMU_MAX_HWEVENTS instead.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Tested-by: James Clark <james.clark@linaro.org>
Link: https://lore.kernel.org/r/20240731-arm-pmu-3-9-icntr-v3-6-280a8d7ff465@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
|
|
The PMUv3 and KVM code each have a define for the PMU cycle counter
index. Move KVM's define to a shared location and use it for PMUv3
driver.
Reviewed-by: Marc Zyngier <maz@kernel.org>
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Tested-by: James Clark <james.clark@linaro.org>
Link: https://lore.kernel.org/r/20240731-arm-pmu-3-9-icntr-v3-5-280a8d7ff465@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
|
|
Various PMUv3 registers which are a mask of counters are 64-bit
registers, but the accessor functions take a u32. This has been fine as
the upper 32-bits have been RES0 as there has been a maximum of 32
counters prior to Armv9.4/8.9. With Armv9.4/8.9, a 33rd counter is
added. Update the accessor functions to use a u64 instead.
Acked-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Rob Herring (Arm) <robh@kernel.org>
Tested-by: James Clark <james.clark@linaro.org>
Link: https://lore.kernel.org/r/20240731-arm-pmu-3-9-icntr-v3-2-280a8d7ff465@kernel.org
Signed-off-by: Will Deacon <will@kernel.org>
|
|
Programming PMU events in the host that count during guest execution is
a feature supported by perf, e.g.
perf stat -e cpu_cycles:G ./lkvm run
While this works for VHE, the guest/host event bitmaps are not carried
through to the hypervisor in the nVHE configuration. Make
kvm_pmu_update_vcpu_events() conditional on whether or not _hardware_
supports PMUv3 rather than if the vCPU as vPMU enabled.
Cc: stable@vger.kernel.org
Fixes: 84d751a019a9 ("KVM: arm64: Pass pmu events to hyp via vcpu")
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240305184840.636212-3-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
In order to make it easier to check whether a particular feature
is exposed to a guest, add a new set of helpers, with kvm_has_feat()
being the most useful.
Let's start making use of them in the PMU code (courtesy of Oliver).
Follow-up changes will introduce additional use patterns.
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Co-developed--by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-3-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
* kvm-arm64/pmu_pmcr_n:
: User-defined PMC limit, courtesy Raghavendra Rao Ananta
:
: Certain VMMs may want to reserve some PMCs for host use while running a
: KVM guest. This was a bit difficult before, as KVM advertised all
: supported counters to the guest. Userspace can now limit the number of
: advertised PMCs by writing to PMCR_EL0.N, as KVM's sysreg and PMU
: emulation enforce the specified limit for handling guest accesses.
KVM: selftests: aarch64: vPMU test for validating user accesses
KVM: selftests: aarch64: vPMU register test for unimplemented counters
KVM: selftests: aarch64: vPMU register test for implemented counters
KVM: selftests: aarch64: Introduce vpmu_counter_access test
tools: Import arm_pmuv3.h
KVM: arm64: PMU: Allow userspace to limit PMCR_EL0.N for the guest
KVM: arm64: Sanitize PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR} before first run
KVM: arm64: Add {get,set}_user for PM{C,I}NTEN{SET,CLR}, PMOVS{SET,CLR}
KVM: arm64: PMU: Set PMCR_EL0.N for vCPU based on the associated PMU
KVM: arm64: PMU: Add a helper to read a vCPU's PMCR_EL0
KVM: arm64: Select default PMU in KVM_ARM_VCPU_INIT handler
KVM: arm64: PMU: Introduce helpers to set the guest's PMU
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
* kvm-arm64/pmevtyper-filter:
: Fixes to KVM's handling of the PMUv3 exception level filtering bits
:
: - NSH (count at EL2) and M (count at EL3) should be stateful when the
: respective EL is advertised in the ID registers but have no effect on
: event counting.
:
: - NSU and NSK modify the event filtering of EL0 and EL1, respectively.
: Though the kernel may not use these bits, other KVM guests might.
: Implement these bits exactly as written in the pseudocode if EL3 is
: advertised.
KVM: arm64: Add PMU event filter bits required if EL3 is implemented
KVM: arm64: Make PMEVTYPER<n>_EL0.NSH RES0 if EL2 isn't advertised
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
For unimplemented counters, the registers PM{C,I}NTEN{SET,CLR}
and PMOVS{SET,CLR} are expected to have the corresponding bits RAZ.
Hence to ensure correct KVM's PMU emulation, mask out the RES0 bits.
Defer this work to the point that userspace can no longer change the
number of advertised PMCs.
Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20231020214053.2144305-7-rananta@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
The number of PMU event counters is indicated in PMCR_EL0.N.
For a vCPU with PMUv3 configured, the value is set to the same
value as the current PE on every vCPU reset. Unless the vCPU is
pinned to PEs that has the PMU associated to the guest from the
initial vCPU reset, the value might be different from the PMU's
PMCR_EL0.N on heterogeneous PMU systems.
Fix this by setting the vCPU's PMCR_EL0.N to the PMU's PMCR_EL0.N
value. Track the PMCR_EL0.N per guest, as only one PMU can be set
for the guest (PMCR_EL0.N must be the same for all vCPUs of the
guest), and it is convenient for updating the value.
To achieve this, the patch introduces a helper,
kvm_arm_pmu_get_max_counters(), that reads the maximum number of
counters from the arm_pmu associated to the VM. Make the function
global as upcoming patches will be interested to know the value
while setting the PMCR.N of the guest from userspace.
KVM does not yet support userspace modifying PMCR_EL0.N.
The following patch will add support for that.
Reviewed-by: Sebastian Ott <sebott@redhat.com>
Co-developed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Link: https://lore.kernel.org/r/20231020214053.2144305-5-rananta@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
Add a helper to read a vCPU's PMCR_EL0, and use it whenever KVM
reads a vCPU's PMCR_EL0.
Currently, the PMCR_EL0 value is tracked per vCPU. The following
patches will make (only) PMCR_EL0.N track per guest. Having the
new helper will be useful to combine the PMCR_EL0.N field
(tracked per guest) and the other fields (tracked per vCPU)
to provide the value of PMCR_EL0.
No functional change intended.
Reviewed-by: Sebastian Ott <sebott@redhat.com>
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20231020214053.2144305-4-rananta@google.com
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
Future changes to KVM's sysreg emulation will rely on having a valid PMU
instance to determine the number of implemented counters (PMCR_EL0.N).
This is earlier than when userspace is expected to modify the vPMU
device attributes, where the default is selected today.
Select the default PMU when handling KVM_ARM_VCPU_INIT such that it is
available in time for sysreg emulation.
Reviewed-by: Sebastian Ott <sebott@redhat.com>
Co-developed-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Signed-off-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Raghavendra Rao Ananta <rananta@google.com>
Link: https://lore.kernel.org/r/20231020214053.2144305-3-rananta@google.com
[Oliver: rewrite changelog]
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
The NSH bit, which filters event counting at EL2, is required by the
architecture if an implementation has EL2. Even though KVM doesn't
support nested virt yet, it makes no effort to hide the existence of EL2
from the ID registers. Userspace can, however, change the value of PFR0
to hide EL2. Align KVM's sysreg emulation with the architecture and make
NSH RES0 if EL2 isn't advertised. Keep in mind the bit is ignored when
constructing the backing perf event.
While at it, build the event type mask using explicit field definitions
instead of relying on ARMV8_PMU_EVTYPE_MASK. KVM probably should've been
doing this in the first place, as it avoids changes to the
aforementioned mask affecting sysreg emulation.
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Link: https://lore.kernel.org/r/20231019185618.3442949-2-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
The vCPU-scoped feature bitmap was left in place a couple of releases
ago in case the change to VM-scoped vCPU features broke anyone. Nobody
has complained and the interop between VM and vCPU bitmaps is pretty
gross. Throw it out.
Link: https://lore.kernel.org/r/20230920195036.1169791-9-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
Most of the internal definitions for PMU emulation are guarded with
CONFIG_HW_PERF_EVENTS. However, this isn't enough, and leads to
these definitions leaking if CONFIG_KVM isn't enabled.
This leads to some compilation breakage in this exact configuration.
Fix it by falling back to the dummy stubs if either perf or KVM
isn't selected.
Reported-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Tested-by: Alexander Stein <alexander.stein@ew.tq-group.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
|
|
Huang Shijie reports that, when profiling a guest from the host
with a number of events that exceeds the number of available
counters, the reported counts are wildly inaccurate. Without
the counter oversubscription, the reported counts are correct.
Their investigation indicates that upon counter rotation (which
takes place on the back of a timer interrupt), we fail to
re-apply the guest EL0 enabling, leading to the counting of host
events instead of guest events.
In order to solve this, add yet another hook between the host PMU
driver and KVM, re-applying the guest EL0 configuration if the
right conditions apply (the host is VHE, we are in interrupt
context, and we interrupted a running vcpu). This triggers a new
vcpu request which will apply the correct configuration on guest
reentry.
With this, we have the correct counts, even when the counters are
oversubscribed.
Reported-by: Huang Shijie <shijie@os.amperecomputing.com>
Suggested-by: Oliver Upton <oliver.upton@linux.dev>
Tested_by: Huang Shijie <shijie@os.amperecomputing.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Cc: Leo Yan <leo.yan@linaro.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20230809013953.7692-1-shijie@os.amperecomputing.com
Acked-by: Mark Rutland <mark.rutland@arm.com>
Link: https://lore.kernel.org/r/20230820090108.177817-1-maz@kernel.org
|
|
There's no longer a need for the baggage of the old scheme for handling
configurable ID register fields. Rip it all out in favor of the
generalized infrastructure.
Link: https://lore.kernel.org/r/20230609190054.1542113-12-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
KVM allows userspace to write an IMPDEF PMU version to the corresponding
32bit and 64bit ID register fields for the sake of backwards
compatibility with kernels that lacked commit 3d0dba5764b9 ("KVM: arm64:
PMU: Move the ID_AA64DFR0_EL1.PMUver limit to VM creation"). Plumbing
that IMPDEF PMU version through to the gues is getting in the way of
progress, and really doesn't any sense in the first place.
Bite the bullet and reinterpret the IMPDEF PMU version as NI (0) for
userspace writes. Additionally, spill the dirty details into a comment.
Link: https://lore.kernel.org/r/20230609190054.1542113-5-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
|
|
Having the ARM PMUv3 driver sitting in arch/arm64/kernel is getting
in the way of being able to use perf on ARMv8 cores running a 32bit
kernel, such as 32bit KVM guests.
This patch moves it into drivers/perf/arm_pmuv3.c, with an include
file in include/linux/perf/arm_pmuv3.h. The only thing left in
arch/arm64 is some mundane perf stuff.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Zaid Al-Bassam <zalbassam@google.com>
Tested-by: Florian Fainelli <f.fainelli@gmail.com>
Link: https://lore.kernel.org/r/20230317195027.3746949-2-zalbassam@google.com
Signed-off-by: Will Deacon <will@kernel.org>
|
|
PMUv3p5 (which is mandatory with ARMv8.5) comes with some extra
features:
- All counters are 64bit
- The overflow point is controlled by the PMCR_EL0.LP bit
Add the required checks in the helpers that control counter
width and overflow, as well as the sysreg handling for the LP
bit. A new kvm_pmu_is_3p5() helper makes it easy to spot the
PMUv3p5 specific handling.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221113163832.3154370-14-maz@kernel.org
|
|
As further patches will enable the selection of a PMU revision
from userspace, sample the supported PMU revision at VM creation
time, rather than building each time the ID_AA64DFR0_EL1 register
is accessed.
This shouldn't result in any change in behaviour.
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20221113163832.3154370-11-maz@kernel.org
|
|
pseudocode
Ricardo recently pointed out that the PMU chained counter emulation
in KVM wasn't quite behaving like the one on actual hardware, in
the sense that a chained counter would expose an overflow on
both halves of a chained counter, while KVM would only expose the
overflow on the top half.
The difference is subtle, but significant. What does the architecture
say (DDI0087 H.a):
- Up to PMUv3p4, all counters but the cycle counter are 32bit
- A 32bit counter that overflows generates a CHAIN event on the
adjacent counter after exposing its own overflow status
- The CHAIN event is accounted if the counter is correctly
configured (CHAIN event selected and counter enabled)
This all means that our current implementation (which uses 64bit
perf events) prevents us from emulating this overflow on the lower half.
How to fix this? By implementing the above, to the letter.
This largely results in code deletion, removing the notions of
"counter pair", "chained counters", and "canonical counter".
The code is further restructured to make the CHAIN handling similar
to SWINC, as the two are now extremely similar in behaviour.
Reported-by: Ricardo Koller <ricarkol@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Link: https://lore.kernel.org/r/20221113163832.3154370-3-maz@kernel.org
|
|
Moving kvm_pmu_events into the vcpu (and refering to it) broke the
somewhat unusual case where the kernel has no support for a PMU
at all.
In order to solve this, move things around a bit so that we can
easily avoid refering to the pmu structure outside of PMU-aware
code. As a bonus, pmu.c isn't compiled in when HW_PERF_EVENTS
isn't selected.
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/202205161814.KQHpOzsJ-lkp@intel.com
|
|
Instead of the host accessing hyp data directly, pass the pmu
events of the current cpu to hyp via the vcpu.
This adds 64 bits (in two fields) to the vcpu that need to be
synced before every vcpu run in nvhe and protected modes.
However, it isolates the hypervisor from the host, which allows
us to use pmu in protected mode in a subsequent patch.
No visible side effects in behavior intended.
Signed-off-by: Fuad Tabba <tabba@google.com>
Reviewed-by: Oliver Upton <oupton@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220510095710.148178-4-tabba@google.com
|
|
struct kvm_pmu has 2 holes using 10 bytes. This is instantiated
in all vcpus, so it adds up. Repack the structures to remove the
holes.
No functional change intended.
Reviewed-by: Oliver Upton <oupton@google.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220510095710.148178-3-tabba@google.com
|
|
The ARM PMU driver calls kvm_host_pmu_init() after probing to tell KVM that
a hardware PMU is available for guest emulation. Heterogeneous systems can
have more than one PMU present, and the callback gets called multiple
times, once for each of them. Keep track of all the PMUs available to KVM,
as they're going to be needed later.
Reviewed-by: Reiji Watanabe <reijiw@google.com>
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20220127161759.53553-5-alexandru.elisei@arm.com
|
|
Move the definition of kvm_arm_pmu_available to pmu-emul.c and, out of
"necessity", hide it behind CONFIG_HW_PERF_EVENTS. Provide a stub for
the key's wrapper, kvm_arm_support_pmu_v3(). Moving the key's definition
out of perf.c will allow a future commit to delete perf.c entirely.
Signed-off-by: Sean Christopherson <seanjc@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20211111020738.2512932-16-seanjc@google.com
|
|
Russell reported that since 5.13, KVM's probing of the PMU has
started to fail on his HW. As it turns out, there is an implicit
ordering dependency between the architectural PMU probing code and
and KVM's own probing. If, due to probe ordering reasons, KVM probes
before the PMU driver, it will fail to detect the PMU and prevent it
from being advertised to guests as well as the VMM.
Obviously, this is one probing too many, and we should be able to
deal with any ordering.
Add a callback from the PMU code into KVM to advertise the registration
of a host CPU PMU, allowing for any probing order.
Fixes: 5421db1be3b1 ("KVM: arm64: Divorce the perf code from oprofile helpers")
Reported-by: "Russell King (Oracle)" <linux@armlinux.org.uk>
Tested-by: Russell King (Oracle) <rmk+kernel@armlinux.org.uk>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/YUYRKVflRtUytzy5@shell.armlinux.org.uk
Cc: stable@vger.kernel.org
|
|
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.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Acked-by: Will Deacon <will@kernel.org>
Link: https://lore.kernel.org/r/20210414134409.1266357-2-maz@kernel.org
|
|
We currently find out about the presence of a HW PMU (or the handling
of that PMU by perf, which amounts to the same thing) in a fairly
roundabout way, by checking the number of counters available to perf.
That's good enough for now, but we will soon need to find about about
that on paths where perf is out of reach (in the world switch).
Instead, let's turn kvm_arm_support_pmu_v3() into a static key.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Link: https://lore.kernel.org/r/20210209114844.3278746-2-maz@kernel.org
Message-Id: <20210305185254.3730990-5-maz@kernel.org>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
|
|
KVM_ARM_PMU only existed for the benefit of 32bit ARM hosts,
and makes no sense now that we are 64bit only. Get rid of it.
Signed-off-by: Marc Zyngier <maz@kernel.org>
|
|
The PMU ready state has no user left. Goodbye.
Reviewed-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
|
|
Pull KVM updates from Paolo Bonzini:
"For x86, there is a new alternative and (in the future) more scalable
implementation of extended page tables that does not need a reverse
map from guest physical addresses to host physical addresses.
For now it is disabled by default because it is still lacking a few of
the existing MMU's bells and whistles. However it is a very solid
piece of work and it is already available for people to hammer on it.
Other updates:
ARM:
- New page table code for both hypervisor and guest stage-2
- Introduction of a new EL2-private host context
- Allow EL2 to have its own private per-CPU variables
- Support of PMU event filtering
- Complete rework of the Spectre mitigation
PPC:
- Fix for running nested guests with in-kernel IRQ chip
- Fix race condition causing occasional host hard lockup
- Minor cleanups and bugfixes
x86:
- allow trapping unknown MSRs to userspace
- allow userspace to force #GP on specific MSRs
- INVPCID support on AMD
- nested AMD cleanup, on demand allocation of nested SVM state
- hide PV MSRs and hypercalls for features not enabled in CPUID
- new test for MSR_IA32_TSC writes from host and guest
- cleanups: MMU, CPUID, shared MSRs
- LAPIC latency optimizations ad bugfixes"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (232 commits)
kvm: x86/mmu: NX largepage recovery for TDP MMU
kvm: x86/mmu: Don't clear write flooding count for direct roots
kvm: x86/mmu: Support MMIO in the TDP MMU
kvm: x86/mmu: Support write protection for nesting in tdp MMU
kvm: x86/mmu: Support disabling dirty logging for the tdp MMU
kvm: x86/mmu: Support dirty logging for the TDP MMU
kvm: x86/mmu: Support changed pte notifier in tdp MMU
kvm: x86/mmu: Add access tracking for tdp_mmu
kvm: x86/mmu: Support invalidate range MMU notifier for TDP MMU
kvm: x86/mmu: Allocate struct kvm_mmu_pages for all pages in TDP MMU
kvm: x86/mmu: Add TDP MMU PF handler
kvm: x86/mmu: Remove disallowed_hugepage_adjust shadow_walk_iterator arg
kvm: x86/mmu: Support zapping SPTEs in the TDP MMU
KVM: Cache as_id in kvm_memory_slot
kvm: x86/mmu: Add functions to handle changed TDP SPTEs
kvm: x86/mmu: Allocate and free TDP MMU roots
kvm: x86/mmu: Init / Uninit the TDP MMU
kvm: x86/mmu: Introduce tdp_iter
KVM: mmu: extract spte.h and spte.c
KVM: mmu: Separate updating a PTE from kvm_set_pte_rmapp
...
|
|
As we can now hide events from the guest, let's also adjust its view of
PCMEID{0,1}_EL1 so that it can figure out why some common events are not
counting as they should.
The astute user can still look into the TRM for their CPU and find out
they've been cheated, though. Nobody's perfect.
Signed-off-by: Marc Zyngier <maz@kernel.org>
|
|
kvm_vcpu_kick() is not NMI safe. When the overflow handler is called from
NMI context, defer waking the vcpu to an irq_work queue.
A vcpu can be freed while it's not running by kvm_destroy_vm(). Prevent
running the irq_work for a non-existent vcpu by calling irq_work_sync() on
the PMU destroy path.
[Alexandru E.: Added irq_work_sync()]
Signed-off-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Alexandru Elisei <alexandru.elisei@arm.com>
Tested-by: Sumit Garg <sumit.garg@linaro.org> (Developerbox)
Cc: Julien Thierry <julien.thierry.kdev@gmail.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Will Deacon <will.deacon@arm.com>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Suzuki K Pouloze <suzuki.poulose@arm.com>
Cc: kvm@vger.kernel.org
Cc: kvmarm@lists.cs.columbia.edu
Link: https://lore.kernel.org/r/20200924110706.254996-6-alexandru.elisei@arm.com
Signed-off-by: Will Deacon <will@kernel.org>
|
|
We use "pmc->idx" and the "chained" bitmap to determine if the pmc is
chained, in kvm_pmu_pmc_is_chained(). But idx might be uninitialized
(and random) when we doing this decision, through a KVM_ARM_VCPU_INIT
ioctl -> kvm_pmu_vcpu_reset(). And the test_bit() against this random
idx will potentially hit a KASAN BUG [1].
In general, idx is the static property of a PMU counter that is not
expected to be modified across resets, as suggested by Julien. It
looks more reasonable if we can setup the PMU counter idx for a vcpu
in its creation time. Introduce a new function - kvm_pmu_vcpu_init()
for this basic setup. Oh, and the KASAN BUG will get fixed this way.
[1] https://www.spinics.net/lists/kvm-arm/msg36700.html
Fixes: 80f393a23be6 ("KVM: arm/arm64: Support chained PMU counters")
Suggested-by: Andrew Murray <andrew.murray@arm.com>
Suggested-by: Julien Thierry <julien.thierry@arm.com>
Acked-by: Julien Thierry <julien.thierry@arm.com>
Signed-off-by: Zenghui Yu <yuzenghui@huawei.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
|
|
ARMv8 provides support for chained PMU counters, where an event type
of 0x001E is set for odd-numbered counters, the event counter will
increment by one for each overflow of the preceding even-numbered
counter. Let's emulate this in KVM by creating a 64 bit perf counter
when a user chains two emulated counters together.
For chained events we only support generating an overflow interrupt
on the high counter. We use the attributes of the low counter to
determine the attributes of the perf event.
Suggested-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
|
|
We currently use pmc->bitmask to determine the width of the pmc - however
it's superfluous as the pmc index already describes if the pmc is a cycle
counter or event counter. The architecture clearly describes the widths of
these counters.
Let's remove the bitmask to simplify the code.
Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
|
|
The kvm_pmu_{enable/disable}_counter functions can enable/disable
multiple counters at once as they operate on a bitmask. Let's
make this clearer by renaming the function.
Suggested-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Andrew Murray <andrew.murray@arm.com>
Reviewed-by: Julien Thierry <julien.thierry@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
|
|
Based on 1 normalized pattern(s):
this program is free software you can redistribute it and or modify
it under the terms of the gnu general public license version 2 as
published by the free software foundation this program is
distributed in the hope that it will be useful but without any
warranty without even the implied warranty of merchantability or
fitness for a particular purpose see the gnu general public license
for more details you should have received a copy of the gnu general
public license along with this program if not see http www gnu org
licenses
extracted by the scancode license scanner the SPDX license identifier
GPL-2.0-only
has been chosen to replace the boilerplate/reference in 503 file(s).
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Alexios Zavras <alexios.zavras@intel.com>
Reviewed-by: Allison Randal <allison@lohutok.net>
Reviewed-by: Enrico Weigelt <info@metux.net>
Cc: linux-spdx@vger.kernel.org
Link: https://lkml.kernel.org/r/20190602204653.811534538@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
|
|
kvm_pmu_overflow_set() is called from perf's interrupt handler,
making the call of kvm_vgic_inject_irq() from it introduced with
"KVM: arm/arm64: PMU: remove request-less vcpu kick" a really bad
idea, as it's quite easy to try and retake a lock that the
interrupted context is already holding. The fix is to use a vcpu
kick, leaving the interrupt injection to kvm_pmu_sync_hwstate(),
like it was doing before the refactoring. We don't just revert,
though, because before the kick was request-less, leaving the vcpu
exposed to the request-less vcpu kick race, and also because the
kick was used unnecessarily from register access handlers.
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
|
