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>
In order to start handling guest access to GICv3 system registers,
let's add a hook that will get called when we trap a system register
access. This is gated by a new static key (vgic_v3_cpuif_trap).
Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
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 <cdall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
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 <cdall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Having multiple devices being able to signal the same interrupt line is
very confusing and almost certainly guarantees a configuration error.
Therefore, introduce a very simple allocator which allows a device to
claim an interrupt line from the vgic for a given VM.
Signed-off-by: Christoffer Dall <cdall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
First we define an ABI using the vcpu devices that lets userspace set
the interrupt numbers for the various timers on both the 32-bit and
64-bit KVM/ARM implementations.
Second, we add the definitions for the groups and attributes introduced
by the above ABI. (We add the PMU define on the 32-bit side as well for
symmetry and it may get used some day.)
Third, we set up the arch-specific vcpu device operation handlers to
call into the timer code for anything related to the
KVM_ARM_VCPU_TIMER_CTRL group.
Fourth, we implement support for getting and setting the timer interrupt
numbers using the above defined ABI in the arch timer code.
Fifth, we introduce error checking upon enabling the arch timer (which
is called when first running a VCPU) to check that all VCPUs are
configured to use the same PPI for the timer (as mandated by the
architecture) and that the virtual and physical timers are not
configured to use the same IRQ number.
Signed-off-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
We currently initialize the arch timer IRQ numbers from the reset code,
presumably because we once intended to model multiple CPU or SoC types
from within the kernel and have hard-coded reset values in the reset
code.
As we are moving towards userspace being in charge of more fine-grained
CPU emulation and stitching together the pieces needed to emulate a
particular type of CPU, we should no longer have a tight coupling
between resetting a VCPU and setting IRQ numbers.
Therefore, move the logic to define and use the default IRQ numbers to
the timer code and set the IRQ number immediately when creating the
VCPU.
Signed-off-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
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 <cdall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
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 <cdall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
If userspace creates the VCPUs after initializing the VGIC, then we end
up in a situation where we trigger a bug in kvm_vcpu_get_idx(), because
it is called prior to adding the VCPU into the vcpus array on the VM.
There is no tight coupling between the VCPU index and the area of the
redistributor region used for the VCPU, so we can simply ensure that all
creations of redistributors are serialized per VM, and increment an
offset when we successfully add a redistributor.
The vgic_register_redist_iodev() function can be called from two paths:
vgic_redister_all_redist_iodev() which is called via the kvm_vgic_addr()
device attribute handler. This patch already holds the kvm->lock mutex.
The other path is via kvm_vgic_vcpu_init, which is called through a
longer chain from kvm_vm_ioctl_create_vcpu(), which releases the
kvm->lock mutex just before calling kvm_arch_vcpu_create(), so we can
simply take this mutex again later for our purposes.
Fixes: ab6f468c10 ("KVM: arm/arm64: Register iodevs when setting redist base and creating VCPUs")
Signed-off-by: Christoffer Dall <cdall@linaro.org>
Tested-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Second round of KVM/ARM Changes for v4.12.
Changes include:
- A fix related to the 32-bit idmap stub
- A fix to the bitmask used to deode the operands of an AArch32 CP
instruction
- We have moved the files shared between arch/arm/kvm and
arch/arm64/kvm to virt/kvm/arm
- We add support for saving/restoring the virtual ITS state to
userspace
The its->initialized doesn't bring much to the table, and creates
unnecessary ordering between setting the address and initializing it
(which amounts to exactly nothing).
Let's kill it altogether, making KVM_DEV_ARM_VGIC_CTRL_INIT the no-op
it deserves to be.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Instead of waiting with registering KVM iodevs until the first VCPU is
run, we can actually create the iodevs when the redist base address is
set. The only downside is that we must now also check if we need to do
this for VCPUs which are created after creating the VGIC, because there
is no enforced ordering between creating the VGIC (and setting its base
addresses) and creating the VCPUs.
Signed-off-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Pull KVM updates from Paolo Bonzini:
"ARM:
- HYP mode stub supports kexec/kdump on 32-bit
- improved PMU support
- virtual interrupt controller performance improvements
- support for userspace virtual interrupt controller (slower, but
necessary for KVM on the weird Broadcom SoCs used by the Raspberry
Pi 3)
MIPS:
- basic support for hardware virtualization (ImgTec P5600/P6600/I6400
and Cavium Octeon III)
PPC:
- in-kernel acceleration for VFIO
s390:
- support for guests without storage keys
- adapter interruption suppression
x86:
- usual range of nVMX improvements, notably nested EPT support for
accessed and dirty bits
- emulation of CPL3 CPUID faulting
generic:
- first part of VCPU thread request API
- kvm_stat improvements"
* tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (227 commits)
kvm: nVMX: Don't validate disabled secondary controls
KVM: put back #ifndef CONFIG_S390 around kvm_vcpu_kick
Revert "KVM: Support vCPU-based gfn->hva cache"
tools/kvm: fix top level makefile
KVM: x86: don't hold kvm->lock in KVM_SET_GSI_ROUTING
KVM: Documentation: remove VM mmap documentation
kvm: nVMX: Remove superfluous VMX instruction fault checks
KVM: x86: fix emulation of RSM and IRET instructions
KVM: mark requests that need synchronization
KVM: return if kvm_vcpu_wake_up() did wake up the VCPU
KVM: add explicit barrier to kvm_vcpu_kick
KVM: perform a wake_up in kvm_make_all_cpus_request
KVM: mark requests that do not need a wakeup
KVM: remove #ifndef CONFIG_S390 around kvm_vcpu_wake_up
KVM: x86: always use kvm_make_request instead of set_bit
KVM: add kvm_{test,clear}_request to replace {test,clear}_bit
s390: kvm: Cpu model support for msa6, msa7 and msa8
KVM: x86: remove irq disablement around KVM_SET_CLOCK/KVM_GET_CLOCK
kvm: better MWAIT emulation for guests
KVM: x86: virtualize cpuid faulting
...
We plan to support different migration ABIs, ie. characterizing
the ITS table layout format in guest RAM. For example, a new ABI
will be needed if vLPIs get supported for nested use case.
So let's introduce an array of supported ABIs (at the moment a single
ABI is supported though). The following characteristics are foreseen
to vary with the ABI: size of table entries, save/restore operation,
the way abi settings are applied.
By default the MAX_ABI_REV is applied on its creation. In subsequent
patches we will introduce a way for the userspace to change the ABI
in use.
The entry sizes now are set according to the ABI version and not
hardcoded anymore.
Signed-off-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
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 <agraf@suse.de>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
If you're running with a userspace gic or other interrupt controller
(that is no vgic in the kernel), then you have so far not been able to
use the architected timers, because the output of the architected
timers, which are driven inside the kernel, was a kernel-only construct
between the arch timer code and the vgic.
This patch implements the new KVM_CAP_ARM_USER_IRQ feature, where we use a
side channel on the kvm_run structure, run->s.regs.device_irq_level, to
always notify userspace of the timer output levels when using a userspace
irqchip.
This works by ensuring that before we enter the guest, if the timer
output level has changed compared to what we last told userspace, we
don't enter the guest, but instead return to userspace to notify it of
the new level. If we are exiting, because of an MMIO for example, and
the level changed at the same time, the value is also updated and
userspace can sample the line as it needs. This is nicely achieved
simply always updating the timer_irq_level field after the main run
loop.
Note that the kvm_timer_update_irq trace event is changed to show the
host IRQ number for the timer instead of the guest IRQ number, because
the kernel no longer know which IRQ userspace wires up the timer signal
to.
Also note that this patch implements all required functionality but does
not yet advertise the capability.
Reviewed-by: Alexander Graf <agraf@suse.de>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
There is no need to calculate and maintain live_lrs when we always
populate the lowest numbered LRs first on every entry and clear all LRs
on every exit.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
We don't have to save/restore the VMCR on every entry to/from the guest,
since on GICv2 we can access the control interface from EL1 and on VHE
systems with GICv3 we can access the control interface from KVM running
in EL2.
GICv3 systems without VHE becomes the rare case, which has to
save/restore the register on each round trip.
Note that userspace accesses may see out-of-date values if the VCPU is
running while accessing the VGIC state via the KVM device API, but this
is already the case and it is up to userspace to quiesce the CPUs before
reading the CPU registers from the GIC for an up-to-date view.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
We currently have some code to clear the list registers on GICv3, but we
never call this code, because the caller got nuked when removing the old
vgic. We also used to have a similar GICv2 part, but that got lost in
the process too.
Let's reintroduce the logic for GICv2 and call the logic when we
initialize the use of hypervisors on the CPU, for example when first
loading KVM or when exiting a low power state.
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Emulate read and write operations to CNTP_TVAL, CNTP_CVAL and CNTP_CTL.
Now VMs are able to use the EL1 physical timer.
Signed-off-by: Jintack Lim <jintack@cs.columbia.edu>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
