The vgic_initialized() macro currently returns the state of the
vgic->ready flag, which indicates if the vgic is ready to be used when
running a VM, not specifically if its internal state has been
initialized.

Rename the macro accordingly in preparation for a more nuanced
initialization flow.
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Reviewed-by: NEric Auger <eric.auger@linaro.org>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

VGIC initialization currently happens in three phases:
 (1) kvm_vgic_create() (triggered by userspace GIC creation)
 (2) vgic_init_maps() (triggered by userspace GIC register read/write
     requests, or from kvm_vgic_init() if not already run)
 (3) kvm_vgic_init() (triggered by first VM run)

We were doing initialization of some state to correspond with the
state of a freshly-reset GIC in kvm_vgic_init(); this is too late,
since it will overwrite changes made by userspace using the
register access APIs before the VM is run. Move this initialization
earlier, into the vgic_init_maps() phase.

This fixes a bug where QEMU could successfully restore a saved
VM state snapshot into a VM that had already been run, but could
not restore it "from cold" using the -loadvm command line option
(the symptoms being that the restored VM would run but interrupts
were ignored).

Finally rename vgic_init_maps to vgic_init and renamed kvm_vgic_init to
kvm_vgic_map_resources.

  [ This patch is originally written by Peter Maydell, but I have
    modified it somewhat heavily, renaming various bits and moving code
    around.  If something is broken, I am to be blamed. - Christoffer ]
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Reviewed-by: NEric Auger <eric.auger@linaro.org>
Signed-off-by: NPeter Maydell <peter.maydell@linaro.org>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

When call kvm_vgic_inject_irq to inject interrupt, we can known which
vcpu the interrupt for by the irq_num and the cpuid. So we should just
kick this vcpu to avoid iterating through all.
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NShannon Zhao <zhaoshenglong@huawei.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

When 'injecting' an edge-triggered interrupt with a falling edge we
shouldn't clear the pending state on the distributor.  In fact, we
don't, because the check in vgic_validate_injection would prevent us
from ever reaching this bit of code.

Remove the unreachable snippet.
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

When vgic_update_irq_pending with level-sensitive false, it is need to
deactivates an interrupt, and, it can go to out directly.
Here return a false value, because it will be not need to kick.
Signed-off-by: Nwanghaibin <wanghaibin.wang@huawei.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

The EIRSR and ELRSR registers are 32-bit registers on GICv2, and we
store these as an array of two such registers on the vgic vcpu struct.
However, we access them as a single 64-bit value or as a bitmap pointer
in the generic vgic code, which breaks BE support.

Instead, store them as u64 values on the vgic structure and do the
word-swapping in the assembly code, which already handles the byte order
for BE systems.
Tested-by: NVictor Kamensky <victor.kamensky@linaro.org>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

Add support for read-only MMIO passthrough mappings by adding a
'writable' parameter to kvm_phys_addr_ioremap. For the moment,
mappings will be read-write even if 'writable' is false, but once
the definition of PAGE_S2_DEVICE gets changed, those mappings will
be created read-only.
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NArd Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

The sgi values calculated in read_set_clear_sgi_pend_reg() and
write_set_clear_sgi_pend_reg() were horribly incorrectly multiplied by 4
with catastrophic results in that subfunctions ended up overwriting
memory not allocated for the expected purpose.

This showed up as bugs in kfree() and the kernel complaining a lot of
you turn on memory debugging.

This addresses: http://marc.info/?l=kvm&m=141164910007868&w=2Reported-by: NShannon Zhao <zhaoshenglong@huawei.com>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

In order to make the number of interrupts configurable, use the new
fancy device management API to add KVM_DEV_ARM_VGIC_GRP_NR_IRQS as
a VGIC configurable attribute.

Userspace can now specify the exact size of the GIC (by increments
of 32 interrupts).
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

It is now quite easy to delay the allocation of the vgic tables
until we actually require it to be up and running (when the first
vcpu is kicking around, or someones tries to access the GIC registers).

This allow us to allocate memory for the exact number of CPUs we
have. As nobody configures the number of interrupts just yet,
use a fallback to VGIC_NR_IRQS_LEGACY.
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Nuke VGIC_NR_IRQS entierly, now that the distributor instance
contains the number of IRQ allocated to this GIC.

Also add VGIC_NR_IRQS_LEGACY to preserve the current API.
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Now that we can (almost) dynamically size the number of interrupts,
we're facing an interesting issue:

We have to evaluate at runtime whether or not an access hits a valid
register, based on the sizing of this particular instance of the
distributor. Furthermore, the GIC spec says that accessing a reserved
register is RAZ/WI.

For this, add a new field to our range structure, indicating the number
of bits a single interrupts uses. That allows us to find out whether or
not the access is in range.
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

We now have the information about the number of CPU interfaces in
the distributor itself. Let's get rid of VGIC_MAX_CPUS, and just
rely on KVM_MAX_VCPUS where we don't have the choice. Yet.
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Having a dynamic number of supported interrupts means that we
cannot relly on VGIC_NR_SHARED_IRQS being fixed anymore.

Instead, make it take the distributor structure as a parameter,
so it can return the right value.
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

So far, all the VGIC data structures are statically defined by the
*maximum* number of vcpus and interrupts it supports. It means that
we always have to oversize it to cater for the worse case.

Start by changing the data structures to be dynamically sizeable,
and allocate them at runtime.

The sizes are still very static though.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

As it stands, nothing prevents userspace from injecting an interrupt
before the guest's GIC is actually initialized.

This goes unnoticed so far (as everything is pretty much statically
allocated), but ends up exploding in a spectacular way once we switch
to a more dynamic allocation (the GIC data structure isn't there yet).

The fix is to test for the "ready" flag in the VGIC distributor before
trying to inject the interrupt. Note that in order to avoid breaking
userspace, we have to ignore what is essentially an error.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>
Acked-by: NChristoffer Dall <christoffer.dall@linaro.org>

The VGIC virtual distributor implementation documentation was written a
very long time ago, before the true nature of the beast had been
partially absorbed into my bloodstream.  Clarify the docs.

Plus, it fixes an actual bug.  ICFRn, pfff.
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

Writes to GICD_ISPENDR0 and GICD_ICPENDR0 ignore all settings of the
pending state for SGIs.  Make sure the implementation handles this
correctly.
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

Writes to GICD_ISPENDRn and GICD_ICPENDRn are currently not handled
correctly for level-triggered interrupts.  The spec states that for
level-triggered interrupts, writes to the GICD_ISPENDRn activate the
output of a flip-flop which is in turn or'ed with the actual input
interrupt signal.  Correspondingly, writes to GICD_ICPENDRn simply
deactivates the output of that flip-flop, but does not (of course) affect
the external input signal.  Reads from GICC_IAR will also deactivate the
flip-flop output.

This requires us to track the state of the level-input separately from
the state in the flip-flop.  We therefore introduce two new variables on
the distributor struct to track these two states.  Astute readers may
notice that this is introducing more state than required (because an OR
of the two states gives you the pending state), but the remaining vgic
code uses the pending bitmap for optimized operations to figure out, at
the end of the day, if an interrupt is pending or not on the distributor
side.  Refactoring the code to consider the two state variables all the
places where we currently access the precomputed pending value, did not
look pretty.
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

If we unqueue a level-triggered interrupt completely, and the LR does
not stick around in the active state (and will therefore no longer
generate a maintenance interrupt), then we should clear the queued flag
so that the vgic can actually queue this level-triggered interrupt at a
later time and deal with its pending state then.

Note: This should actually be properly fixed to handle the active state
on the distributor.
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

We have a special bitmap on the distributor struct to keep track of when
level-triggered interrupts are queued on the list registers.  This was
named irq_active, which is confusing, because the active state of an
interrupt as per the GIC spec is a different thing, not specifically
related to edge-triggered/level-triggered configurations but rather
indicates an interrupt which has been ack'ed but not yet eoi'ed.

Rename the bitmap and the corresponding accessor functions to irq_queued
to clarify what this is actually used for.
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

The irq_state field on the distributor struct is ambiguous in its
meaning; the comment says it's the level of the input put, but that
doesn't make much sense for edge-triggered interrupts.  The code
actually uses this state variable to check if the interrupt is in the
pending state on the distributor so clarify the comment and rename the
actual variable and accessor methods.
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

Now that we have a dynamic means to register kvm_device_ops, use that
for the ARM VGIC, instead of relying on the static table.

Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NPaolo Bonzini <pbonzini@redhat.com>

We extract the vgic probe function from the of_device_id data pointer,
which is const. Kill the sparse warning by ensuring that the local
function pointer is also marked as const.

Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

vgic_ioaddr_overlap claims to return a bool, but in reality it returns
an int. Shut sparse up by fixing the type signature.

Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

If the physical address of GICV isn't page-aligned, then we end up
creating a stage-2 mapping of the page containing it, which causes us to
map neighbouring memory locations directly into the guest.

As an example, consider a platform with GICV at physical 0x2c02f000
running a 64k-page host kernel. If qemu maps this into the guest at
0x80010000, then guest physical addresses 0x80010000 - 0x8001efff will
map host physical region 0x2c020000 - 0x2c02efff. Accesses to these
physical regions may cause UNPREDICTABLE behaviour, for example, on the
Juno platform this will cause an SError exception to EL3, which brings
down the entire physical CPU resulting in RCU stalls / HYP panics / host
crashing / wasted weeks of debugging.

SBSA recommends that systems alias the 4k GICV across the bounding 64k
region, in which case GICV physical could be described as 0x2c020000 in
the above scenario.

This patch fixes the problem by failing the vgic probe if the physical
base address or the size of GICV aren't page-aligned. Note that this
generated a warning in dmesg about freeing enabled IRQs, so I had to
move the IRQ enabling later in the probe.

Cc: Christoffer Dall <christoffer.dall@linaro.org>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Gleb Natapov <gleb@kernel.org>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Joel Schopp <joel.schopp@amd.com>
Cc: Don Dutile <ddutile@redhat.com>
Acked-by: NPeter Maydell <peter.maydell@linaro.org>
Acked-by: NJoel Schopp <joel.schopp@amd.com>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NWill Deacon <will.deacon@arm.com>
Signed-off-by: NChristoffer Dall <christoffer.dall@linaro.org>

Fix vgic_bitmap_get_reg function to return 'right' word address of
'unsigned long' bitmap value in case of BE 64bit image.
Signed-off-by: NVictor Kamensky <victor.kamensky@linaro.org>
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

According to recent clarifications of mmio.data array meaning -
the mmio.data array should hold bytes as they would appear in
memory. Vgic is little endian device. And in case of BE image
kernel side that emulates vgic, holds data in BE form. So we
need to byteswap cpu<->le32 vgic registers when we read/write them
from mmio.data[].

Change has no effect in LE case because cpu already runs in le32.
Signed-off-by: NVictor Kamensky <victor.kamensky@linaro.org>
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Acked-by: NMarc Zyngier <marc.zyngier@arm.com>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Add the last missing bits that enable GICv2 emulation on top of
GICv3 hardware.
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Move the GICv2 world switch code into its own file, and add the
necessary indirection to the arm64 switch code.

Also introduce a new type field to the vgic_params structure.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

So far, irqchip_in_kernel() was implemented by testing the value of
vctrl_base, which worked fine with GICv2.

With GICv3, this field is useless, as we're using system registers
instead of a emmory mapped interface. To solve this, add a boolean
flag indicating if the we're using a vgic or not.
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Brutally hack the innocent vgic code, and move the GICv2 specific code
to its own file, using vgic_ops and vgic_params as a way to pass
information between the two blocks.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Move all the data specific to a given GIC implementation into its own
little structure.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Move the code dealing with enabling the VGIC on to vgic_ops.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Instead of directly messing with with the GICH_VMCR bits for the CPU
interface save/restore code, add accessors that encode/decode the
entire set of registers exposed by VMCR.

Not the most efficient thing, but given that this code is only used
by the save/restore code, performance is far from being critical.
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Move the code dealing with LR underflow handling to its own functions,
and make them accessible through vgic_ops.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Instead of directly dealing with the GICH_MISR bits, move the code to
its own function and use a couple of public flags to represent the
actual state.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Move the GICH_EISR access to its own function.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

Move the GICH_ELRSR access to its own functions, and add them to
the vgic_ops structure.
Acked-by: NCatalin Marinas <catalin.marinas@arm.com>
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>

In order to split the various register manipulation from the main vgic
code, introduce a vgic_ops structure, and start by abstracting the
LR manipulation code with a couple of accessors.
Reviewed-by: NChristoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: NMarc Zyngier <marc.zyngier@arm.com>