25 Jul, 2017
1 commit
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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
Signed-off-by: Andrew Jones
Signed-off-by: Marc Zyngier
08 Jun, 2017
5 commits
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The PMU IRQ number is set through the VCPU device's KVM_SET_DEVICE_ATTR
ioctl handler for the KVM_ARM_VCPU_PMU_V3_IRQ attribute, but there is no
enforced or stated requirement that this must happen after initializing
the VGIC. As a result, calling vgic_valid_spi() which relies on the
nr_spis being set during the VGIC init can incorrectly fail.Introduce irq_is_spi, which determines if an IRQ number is within the
SPI range without verifying it against the actual VGIC properties.Signed-off-by: Christoffer Dall
Reviewed-by: Marc Zyngier -
When injecting an IRQ to the VGIC, you now have to present an owner
token for that IRQ line to show that you are the owner of that line.IRQ lines driven from userspace or via an irqfd do not have an owner and
will simply pass a NULL pointer.Also get rid of the unused kvm_vgic_inject_mapped_irq prototype.
Signed-off-by: Christoffer Dall
Acked-by: Marc Zyngier -
We check if other in-kernel devices have already been connected to the
GIC for a particular interrupt line when possible.For the PMU, we can do this whenever setting the PMU interrupt number
from userspace.For the timers, we have to wait until we try to enable the timer,
because we have a concept of default IRQ numbers that userspace
shouldn't have to work around in the initialization phase.Signed-off-by: Christoffer Dall
Reviewed-by: Marc Zyngier -
We are about to need this define in the arch timer code as well so move
it to a common location.Signed-off-by: Christoffer Dall
Acked-by: Marc Zyngier -
Since we got support for devices in userspace which allows reporting the
PMU overflow output status to userspace, we should actually allow
creating the PMU on systems without an in-kernel irqchip, which in turn
requires us to slightly clarify error codes for the ABI and move things
around for the initialization phase.Signed-off-by: Christoffer Dall
Reviewed-by: Marc Zyngier
04 Jun, 2017
1 commit
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Refactor PMU overflow handling in order to remove the request-less
vcpu kick. Now, since kvm_vgic_inject_irq() uses vcpu requests,
there should be no chance that a kick sent at just the wrong time
(between the VCPU's call to kvm_pmu_flush_hwstate() and before it
enters guest mode) results in a failure for the guest to see updated
GIC state until its next exit some time later for some other reason.Signed-off-by: Andrew Jones
Reviewed-by: Christoffer Dall
Signed-off-by: Christoffer Dall
09 Apr, 2017
1 commit
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When not using an in-kernel VGIC, but instead emulating an interrupt
controller in userspace, we should report the PMU overflow status to
that userspace interrupt controller using the KVM_CAP_ARM_USER_IRQ
feature.Reviewed-by: Alexander Graf
Reviewed-by: Marc Zyngier
Signed-off-by: Christoffer Dall
18 Nov, 2016
1 commit
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KVM calls kvm_pmu_set_counter_event_type() when PMCCFILTR is configured.
But this function can't deals with PMCCFILTR correctly because the evtCount
bits of PMCCFILTR, which is reserved 0, conflits with the SW_INCR event
type of other PMXEVTYPER registers. To fix it, when eventsel == 0, this
function shouldn't return immediately; instead it needs to check further
if select_idx is ARMV8_PMU_CYCLE_IDX.Another issue is that KVM shouldn't copy the eventsel bits of PMCCFILTER
blindly to attr.config. Instead it ought to convert the request to the
"cpu cycle" event type (i.e. 0x11).To support this patch and to prevent duplicated definitions, a limited
set of ARMv8 perf event types were relocated from perf_event.c to
asm/perf_event.h.Cc: stable@vger.kernel.org # 4.6+
Acked-by: Will Deacon
Signed-off-by: Wei Huang
Signed-off-by: Marc Zyngier
28 Sep, 2016
1 commit
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If userspace creates a PMU for the VCPU, but doesn't create an in-kernel
irqchip, then we end up in a nasty path where we try to take an
uninitialized spinlock, which can lead to all sorts of breakages.Luckily, QEMU always creates the VGIC before the PMU, so we can
establish this as ABI and check for the VGIC in the PMU init stage.
This can be relaxed at a later time if we want to support PMU with a
userspace irqchip.Cc: stable@vger.kernel.org
Cc: Shannon Zhao
Acked-by: Marc Zyngier
Signed-off-by: Christoffer Dall
20 May, 2016
1 commit
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Currently the PMU uses a member of the struct vgic_dist directly,
which not only breaks abstraction, but will fail with the new VGIC.
Abstract this access in the VGIC header file and refactor the validity
check in the PMU code.Signed-off-by: Andre Przywara
01 Apr, 2016
1 commit
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The kernel is written in C, not python, so we need braces around
multi-line if statements. GCC 6 actually warns about this, thanks to the
fantastic new "-Wmisleading-indentation" flag:| virt/kvm/arm/pmu.c: In function ‘kvm_pmu_overflow_status’:
| virt/kvm/arm/pmu.c:198:3: warning: statement is indented as if it were guarded by... [-Wmisleading-indentation]
| reg &= vcpu_sys_reg(vcpu, PMCNTENSET_EL0);
| ^~~
| arch/arm64/kvm/../../../virt/kvm/arm/pmu.c:196:2: note: ...this ‘if’ clause, but it is not
| if ((vcpu_sys_reg(vcpu, PMCR_EL0) & ARMV8_PMU_PMCR_E))
| ^~As it turns out, this particular case is harmless (we just do some &=
operations with 0), but worth fixing nonetheless.Signed-off-by: Will Deacon
Signed-off-by: Christoffer Dall
01 Mar, 2016
11 commits
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To configure the virtual PMUv3 overflow interrupt number, we use the
vcpu kvm_device ioctl, encapsulating the KVM_ARM_VCPU_PMU_V3_IRQ
attribute within the KVM_ARM_VCPU_PMU_V3_CTRL group.After configuring the PMUv3, call the vcpu ioctl with attribute
KVM_ARM_VCPU_PMU_V3_INIT to initialize the PMUv3.Signed-off-by: Shannon Zhao
Acked-by: Peter Maydell
Reviewed-by: Andrew Jones
Reviewed-by: Christoffer Dall
Signed-off-by: Marc Zyngier -
To support guest PMUv3, use one bit of the VCPU INIT feature array.
Initialize the PMU when initialzing the vcpu with that bit and PMU
overflow interrupt set.Signed-off-by: Shannon Zhao
Acked-by: Peter Maydell
Reviewed-by: Andrew Jones
Signed-off-by: Marc Zyngier -
When KVM frees VCPU, it needs to free the perf_event of PMU.
Signed-off-by: Shannon Zhao
Reviewed-by: Marc Zyngier
Reviewed-by: Andrew Jones
Signed-off-by: Marc Zyngier -
When resetting vcpu, it needs to reset the PMU state to initial status.
Signed-off-by: Shannon Zhao
Reviewed-by: Marc Zyngier
Reviewed-by: Andrew Jones
Signed-off-by: Marc Zyngier -
When calling perf_event_create_kernel_counter to create perf_event,
assign a overflow handler. Then when the perf event overflows, set the
corresponding bit of guest PMOVSSET register. If this counter is enabled
and its interrupt is enabled as well, kick the vcpu to sync the
interrupt.On VM entry, if there is counter overflowed and interrupt level is
changed, inject the interrupt with corresponding level. On VM exit, sync
the interrupt level as well if it has been changed.Signed-off-by: Shannon Zhao
Reviewed-by: Marc Zyngier
Reviewed-by: Andrew Jones
Reviewed-by: Christoffer Dall
Signed-off-by: Marc Zyngier -
According to ARMv8 spec, when writing 1 to PMCR.E, all counters are
enabled by PMCNTENSET, while writing 0 to PMCR.E, all counters are
disabled. When writing 1 to PMCR.P, reset all event counters, not
including PMCCNTR, to zero. When writing 1 to PMCR.C, reset PMCCNTR to
zero.Signed-off-by: Shannon Zhao
Reviewed-by: Marc Zyngier
Signed-off-by: Marc Zyngier -
Add access handler which emulates writing and reading PMSWINC
register and add support for creating software increment event.Signed-off-by: Shannon Zhao
Reviewed-by: Andrew Jones
Signed-off-by: Marc Zyngier -
Since the reset value of PMOVSSET and PMOVSCLR is UNKNOWN, use
reset_unknown for its reset handler. Add a handler to emulate writing
PMOVSSET or PMOVSCLR register.When writing non-zero value to PMOVSSET, the counter and its interrupt
is enabled, kick this vcpu to sync PMU interrupt.Signed-off-by: Shannon Zhao
Reviewed-by: Andrew Jones
Signed-off-by: Marc Zyngier -
When we use tools like perf on host, perf passes the event type and the
id of this event type category to kernel, then kernel will map them to
hardware event number and write this number to PMU PMEVTYPER_EL0
register. When getting the event number in KVM, directly use raw event
type to create a perf_event for it.Signed-off-by: Shannon Zhao
Reviewed-by: Marc Zyngier
Signed-off-by: Marc Zyngier -
Since the reset value of PMCNTENSET and PMCNTENCLR is UNKNOWN, use
reset_unknown for its reset handler. Add a handler to emulate writing
PMCNTENSET or PMCNTENCLR register.When writing to PMCNTENSET, call perf_event_enable to enable the perf
event. When writing to PMCNTENCLR, call perf_event_disable to disable
the perf event.Signed-off-by: Shannon Zhao
Signed-off-by: Marc Zyngier -
These kind of registers include PMEVCNTRn, PMCCNTR and PMXEVCNTR which
is mapped to PMEVCNTRn.The access handler translates all aarch32 register offsets to aarch64
ones and uses vcpu_sys_reg() to access their values to avoid taking care
of big endian.When reading these registers, return the sum of register value and the
value perf event counts.Signed-off-by: Shannon Zhao
Reviewed-by: Andrew Jones
Signed-off-by: Marc Zyngier
