When reading back from the list registers, we need to perform
two actions for level interrupts:
1) clear the soft-pending bit if the interrupt is not pending
anymore *in the list register*
2) resample the line level and propagate it to the pending state
But these two actions shouldn't be linked, and we should *always*
resample the line level, no matter what state is in the list
register. Otherwise, we may end-up injecting spurious interrupts
that have been already retired.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
When modifying the active state of an interrupt via the MMIO interface,
we should ensure that the write has the intended effect.
If a guest sets an interrupt to active, but that interrupt is already
flushed into a list register on a running VCPU, then that VCPU will
write the active state back into the struct vgic_irq upon returning from
the guest and syncing its state. This is a non-benign race, because the
guest can observe that an interrupt is not active, and it can have a
reasonable expectations that other VCPUs will not ack any IRQs, and then
set the state to active, and expect it to stay that way. Currently we
are not honoring this case.
Thefore, change both the SACTIVE and CACTIVE mmio handlers to stop the
world, change the irq state, potentially queue the irq if we're setting
it to active, and then continue.
We take this chance to slightly optimize these functions by not stopping
the world when touching private interrupts where there is inherently no
possible race.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
We now store the mapped hardware IRQ number in our struct, so we
don't need the irq_phys_map for the new VGIC.
Implement the hardware IRQ mapping on top of the reworked arch
timer interface.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Connect to the new VGIC to the irqfd framework, so that we can
inject IRQs.
GSI routing and MSI routing is not yet implemented.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Enable the VGIC operation by properly initialising the registers
in the hypervisor GIC interface.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
map_resources is the last initialization step. It is executed on
first VCPU run. At that stage the code checks that userspace has provided
the base addresses for the relevant VGIC regions, which depend on the
type of VGIC that is exposed to the guest. Also we check if the two
regions overlap.
If the checks succeeded, we register the respective register frames with
the kvm_io_bus framework.
If we emulate a GICv2, the function also forces vgic_init execution if
it has not been executed yet. Also we map the virtual GIC CPU interface
onto the guest's CPU interface.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
This patch allocates and initializes the data structures used
to model the vgic distributor and virtual cpu interfaces. At that
stage the number of IRQs and number of virtual CPUs is frozen.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
This patch implements the vgic_creation function which is
called on CREATE_IRQCHIP VM IOCTL (v2 only) or KVM_CREATE_DEVICE
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Implements kvm_vgic_hyp_init and vgic_probe function.
This uses the new firmware independent VGIC probing to support both ACPI
and DT based systems (code from Marc Zyngier).
The vgic_global struct is enriched with new fields populated
by those functions.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Using the VMCR accessors we provide access to GIC CPU interface state
to userland by wiring it up to the existing userland interface.
[Marc: move and make VMCR accessors static, streamline MMIO handlers]
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Since the GIC CPU interface is always virtualized by the hardware,
we don't have CPU interface state information readily available in our
emulation if userland wants to save or restore it.
Fortunately the GIC hypervisor interface provides the VMCR register to
access the required virtual CPU interface bits.
Provide wrappers for GICv2 and GICv3 hosts to have access to this
register.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Userland may want to save and restore the state of the in-kernel VGIC,
so we provide the code which takes a userland request and translate
that into calls to our MMIO framework.
From Christoffer:
When accessing the VGIC state from userspace we really don't want a VCPU
to be messing with the state at the same time, and the API specifies
that we should return -EBUSY if any VCPUs are running.
Check and prevent VCPUs from running by grabbing their mutexes, one by
one, and error out if we fail.
(Note: This could potentially be simplified to just do a simple check
and see if any VCPUs are running, and return -EBUSY then, without
enforcing the locking throughout the duration of the uaccess, if we
think that taking/releasing all these mutexes for every single GIC
register access is too heavyweight.)
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Userland can access the emulated GIC to save and restore its state
for initialization or migration purposes.
The kvm_io_bus API requires an absolute gpa, which does not fit the
KVM_DEV_ARM_VGIC_GRP_DIST_REGS user API, that only provides relative
offsets. So we provide a wrapper to plug into our MMIO framework and
find the respective register handler.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
This patch implements the switches for KVM_DEV_ARM_VGIC_GRP_DIST_REGS
and KVM_DEV_ARM_VGIC_GRP_CPU_REGS API which allows the userspace to
access VGIC registers.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
This patch implements the KVM_DEV_ARM_VGIC_GRP_ADDR group which
enables to set the base address of GIC regions as seen by the guest.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
kvm_vgic_addr is used by the userspace to set the base address of
the following register regions, as seen by the guest:
- distributor(v2 and v3),
- re-distributors (v3),
- CPU interface (v2).
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
This patch implements the KVM_DEV_ARM_VGIC_GRP_CTRL group API
featuring KVM_DEV_ARM_VGIC_CTRL_INIT attribute. The vgic_init
function is not yet implemented though.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
This patch implements the KVM_DEV_ARM_VGIC_GRP_NR_IRQS group. This
modality is supported by both VGIC V2 and V3 KVM device as will be
other groups, hence the introduction of common helpers.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
This patch introduces the skeleton for the KVM device operations
associated to KVM_DEV_TYPE_ARM_VGIC_V2 and KVM_DEV_TYPE_ARM_VGIC_V3.
At that stage kvm_vgic_create is stubbed.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
In contrast to GICv2 SGIs in a GICv3 implementation are not triggered
by a MMIO write, but with a system register write. KVM knows about
that register already, we just need to implement the handler and wire
it up to the core KVM/ARM code.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Since GICv3 supports much more than the 8 CPUs the GICv2 ITARGETSR
register can handle, the new IROUTER register covers the whole range
of possible target (V)CPUs by using the same MPIDR that the cores
report themselves.
In addition to translating this MPIDR into a vcpu pointer we store
the originally written value as well. The architecture allows to
write any values into the register, which must be read back as written.
Since we don't support affinity level 3, we don't need to take care
about the upper word of this 64-bit register, which simplifies the
handling a bit.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
We implement the only one ID register that is required by the
architecture, also this is the one that Linux actually checks.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
The redistributor TYPER tells the OS about the associated MPIDR,
also the LAST bit is crucial to determine the number of redistributors.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
As in the GICv2 emulation we handle those three registers in one
function.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Create a new file called vgic-mmio-v3.c and describe the GICv3
distributor and redistributor registers there.
This adds a special macro to deal with the split of SGI/PPI in the
redistributor and SPIs in the distributor, which allows us to reuse
the existing GICv2 handlers for those registers which are compatible.
Also we provide a function to deal with the registration of the two
separate redistributor frames per VCPU.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
As this register is v2 specific, its implementation lives entirely
in vgic-mmio-v2.c.
This register allows setting the source mask of an IPI.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Triggering an IPI via this register is v2 specific, so the
implementation lives entirely in vgic-mmio-v2.c.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
The target register handlers are v2 emulation specific, so their
implementation lives entirely in vgic-mmio-v2.c.
We copy the old VGIC behaviour of assigning an IRQ to the first VCPU
set in the target mask instead of making it possibly pending on
multiple VCPUs.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
The config register handlers are shared between the v2 and v3
emulation, so their implementation goes into vgic-mmio.c, to be
easily referenced from the v3 emulation as well later.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
The priority register handlers are shared between the v2 and v3
emulation, so their implementation goes into vgic-mmio.c, to be
easily referenced from the v3 emulation as well later.
There is a corner case when we change the priority of a pending
interrupt which we don't handle at the moment.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
The active register handlers are shared between the v2 and v3
emulation, so their implementation goes into vgic-mmio.c, to be
easily referenced from the v3 emulation as well later.
Since activation/deactivation of an interrupt may happen entirely
in the guest without it ever exiting, we need some extra logic to
properly track the active state.
For clearing the active state, we basically have to halt the guest to
make sure this is properly propagated into the respective VCPUs.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
The pending register handlers are shared between the v2 and v3
emulation, so their implementation goes into vgic-mmio.c, to be easily
referenced from the v3 emulation as well later.
For level triggered interrupts the real line level is unaffected by
this write, so we keep this state separate and combine it with the
device's level to get the actual pending state.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
As the enable register handlers are shared between the v2 and v3
emulation, their implementation goes into vgic-mmio.c, to be easily
referenced from the v3 emulation as well later.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Those three registers are v2 emulation specific, so their implementation
lives entirely in vgic-mmio-v2.c. Also they are handled in one function,
as their implementation is pretty simple.
When the guest enables the distributor, we kick all VCPUs to get
potentially pending interrupts serviced.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Create vgic-mmio-v2.c to describe GICv2 emulation specific handlers
using the initializer macros provided by the VGIC MMIO framework.
Provide a function to register the GICv2 distributor registers to
the kvm_io_bus framework.
The actual handler functions are still stubs in this patch.
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Add an MMIO handling framework to the VGIC emulation:
Each register is described by its offset, size (or number of bits per
IRQ, if applicable) and the read/write handler functions. We provide
initialization macros to describe each GIC register later easily.
Separate dispatch functions for read and write accesses are connected
to the kvm_io_bus framework and binary-search for the responsible
register handler based on the offset address within the region.
We convert the incoming data (referenced by a pointer) to the host's
endianess and use pass-by-value to hand the data over to the actual
handler functions.
The register handler prototype and the endianess conversion are
courtesy of Christoffer Dall.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Tell KVM whether a particular VCPU has an IRQ that needs handling
in the guest. This is used to decide whether a VCPU is runnable.
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
As the GICv3 virtual interface registers differ from their GICv2
siblings, we need different handlers for processing maintenance
interrupts and reading/writing to the LRs.
Implement the respective handler functions and connect them to
existing code to be called if the host is using a GICv3.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Processing maintenance interrupts and accessing the list registers
are dependent on the host's GIC version.
Introduce vgic-v2.c to contain GICv2 specific functions.
Implement the GICv2 specific code for syncing the emulation state
into the VGIC registers.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Implement the framework for syncing IRQs between our emulation and
the list registers, which represent the guest's view of IRQs.
This is done in kvm_vgic_flush_hwstate and kvm_vgic_sync_hwstate,
which gets called on guest entry and exit.
The code talking to the actual GICv2/v3 hardware is added in the
following patches.
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Eric Auger <eric.auger@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Adds the sorting function to cover the case where you have more IRQs
to consider than you have LRs. We now consider priorities.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Provide a vgic_queue_irq_unlock() function which decides whether a
given IRQ needs to be queued to a VCPU's ap_list.
This should be called whenever an IRQ becomes pending or enabled,
either as a result of userspace injection, from in-kernel emulated
devices like the architected timer or from MMIO accesses to the
distributor emulation.
Also provides the necessary functions to allow userland to inject an
IRQ to a guest.
Since this is the first code that starts using our locking mechanism, we
add some (hopefully) clear documentation of our locking strategy and
requirements along with this patch.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
The new VGIC implementation centers around a struct vgic_irq instance
per virtual IRQ.
Provide a function to retrieve the right instance for a given IRQ
number and (in case of private interrupts) the right VCPU.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Auger <eric.auger@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
