18 Commits

Author SHA1 Message Date
Vladimir Murzin
2988509dd8 ARM: KVM: Support vGICv3 ITS
This patch allows to build and use vGICv3 ITS in 32-bit mode.

Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-11-14 10:32:54 +00:00
Vladimir Murzin
d7d0a11e44 KVM: arm: vgic: Support 64-bit data manipulation on 32-bit host systems
We have couple of 64-bit registers defined in GICv3 architecture, so
unsigned long accesses to these registers will only access a single
32-bit part of that regitser. On the other hand these registers can't
be accessed as 64-bit with a single instruction like ldrd/strd or
ldmia/stmia if we run a 32-bit host because KVM does not support
access to MMIO space done by these instructions.

It means that a 32-bit guest accesses these registers in 32-bit
chunks, so the only thing we need to do is to ensure that
extract_bytes() always takes 64-bit data.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-22 13:21:59 +02:00
Vladimir Murzin
e533a37f7b KVM: arm: vgic: Fix compiler warnings when built for 32-bit
Well, this patch is looking ahead of time, but we'll get following
compiler warnings as soon as we introduce vgic-v3 to 32-bit world

  CC      arch/arm/kvm/../../../virt/kvm/arm/vgic/vgic-mmio-v3.o
arch/arm/kvm/../../../virt/kvm/arm/vgic/vgic-mmio-v3.c: In function 'vgic_mmio_read_v3r_typer':
arch/arm/kvm/../../../virt/kvm/arm/vgic/vgic-mmio-v3.c:184:35: warning: left shift count >= width of type [-Wshift-count-overflow]
  value = (mpidr & GENMASK(23, 0)) << 32;
                                   ^
In file included from ./include/linux/kernel.h:10:0,
                 from ./include/asm-generic/bug.h:13,
                 from ./arch/arm/include/asm/bug.h:59,
                 from ./include/linux/bug.h:4,
                 from ./include/linux/io.h:23,
                 from ./arch/arm/include/asm/arch_gicv3.h:23,
                 from ./include/linux/irqchip/arm-gic-v3.h:411,
                 from arch/arm/kvm/../../../virt/kvm/arm/vgic/vgic-mmio-v3.c:14:
arch/arm/kvm/../../../virt/kvm/arm/vgic/vgic-mmio-v3.c: In function 'vgic_v3_dispatch_sgi':
./include/linux/bitops.h:6:24: warning: left shift count >= width of type [-Wshift-count-overflow]
 #define BIT(nr)   (1UL << (nr))
                        ^
arch/arm/kvm/../../../virt/kvm/arm/vgic/vgic-mmio-v3.c:614:20: note: in expansion of macro 'BIT'
  broadcast = reg & BIT(ICC_SGI1R_IRQ_ROUTING_MODE_BIT);
                    ^
Let's fix them now.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-22 13:21:48 +02:00
Vladimir Murzin
7a1ff70828 KVM: arm64: vgic-its: Introduce config option to guard ITS specific code
By now ITS code guarded with KVM_ARM_VGIC_V3 config option which was
introduced to hide everything specific to vgic-v3 from 32-bit world.
We are going to support vgic-v3 in 32-bit world and KVM_ARM_VGIC_V3
will gone, but we don't have support for ITS there yet and we need to
continue keeping ITS away.
Introduce the new config option to prevent ITS code being build in
32-bit mode when support for vgic-v3 is done.

Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-22 13:21:47 +02:00
Christoffer Dall
d9ae449b3d KVM: arm64: vgic-its: Make updates to propbaser/pendbaser atomic
There are two problems with the current implementation of the MMIO
handlers for the propbaser and pendbaser:

First, the write to the value itself is not guaranteed to be an atomic
64-bit write so two concurrent writes to the structure field could be
intermixed.

Second, because we do a read-modify-update operation without any
synchronization, if we have two 32-bit accesses to separate parts of the
register, we can loose one of them.

By using the atomic cmpxchg64 we should cover both issues above.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-08-15 23:00:20 +02:00
Andre Przywara
0e4e82f154 KVM: arm64: vgic-its: Enable ITS emulation as a virtual MSI controller
Now that all ITS emulation functionality is in place, we advertise
MSI functionality to userland and also the ITS device to the guest - if
userland has configured that.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18 18:14:38 +01:00
Andre Przywara
424c33830f KVM: arm64: vgic-its: Implement basic ITS register handlers
Add emulation for some basic MMIO registers used in the ITS emulation.
This includes:
- GITS_{CTLR,TYPER,IIDR}
- ID registers
- GITS_{CBASER,CREADR,CWRITER}
  (which implement the ITS command buffer handling)
- GITS_BASER<n>

Most of the handlers are pretty straight forward, only the CWRITER
handler is a bit more involved by taking the new its_cmd mutex and
then iterating over the command buffer.
The registers holding base addresses and attributes are sanitised before
storing them.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18 18:14:36 +01:00
Andre Przywara
1085fdc68c KVM: arm64: vgic-its: Introduce new KVM ITS device
Introduce a new KVM device that represents an ARM Interrupt Translation
Service (ITS) controller. Since there can be multiple of this per guest,
we can't piggy back on the existing GICv3 distributor device, but create
a new type of KVM device.
On the KVM_CREATE_DEVICE ioctl we allocate and initialize the ITS data
structure and store the pointer in the kvm_device data.
Upon an explicit init ioctl from userland (after having setup the MMIO
address) we register the handlers with the kvm_io_bus framework.
Any reference to an ITS thus has to go via this interface.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18 18:14:35 +01:00
Andre Przywara
59c5ab4098 KVM: arm64: vgic-its: Introduce ITS emulation file with MMIO framework
The ARM GICv3 ITS emulation code goes into a separate file, but needs
to be connected to the GICv3 emulation, of which it is an option.
The ITS MMIO handlers require the respective ITS pointer to be passed in,
so we amend the existing VGIC MMIO framework to let it cope with that.
Also we introduce the basic ITS data structure and initialize it, but
don't return any success yet, as we are not yet ready for the show.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18 18:14:35 +01:00
Andre Przywara
0aa1de5731 KVM: arm64: vgic: Handle ITS related GICv3 redistributor registers
In the GICv3 redistributor there are the PENDBASER and PROPBASER
registers which we did not emulate so far, as they only make sense
when having an ITS. In preparation for that emulate those MMIO
accesses by storing the 64-bit data written into it into a variable
which we later read in the ITS emulation.
We also sanitise the registers, making sure RES0 regions are respected
and checking for valid memory attributes.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18 18:14:35 +01:00
Andre Przywara
5dd4b924e3 KVM: arm/arm64: vgic: Add refcounting for IRQs
In the moment our struct vgic_irq's are statically allocated at guest
creation time. So getting a pointer to an IRQ structure is trivial and
safe. LPIs are more dynamic, they can be mapped and unmapped at any time
during the guest's _runtime_.
In preparation for supporting LPIs we introduce reference counting for
those structures using the kernel's kref infrastructure.
Since private IRQs and SPIs are statically allocated, we avoid actually
refcounting them, since they would never be released anyway.
But we take provisions to increase the refcount when an IRQ gets onto a
VCPU list and decrease it when it gets removed. Also this introduces
vgic_put_irq(), which wraps kref_put and hides the release function from
the callers.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18 18:10:48 +01:00
Andre Przywara
8f6cdc1c2e KVM: arm/arm64: vgic: Move redistributor kvm_io_devices
Logically a GICv3 redistributor is assigned to a (v)CPU, so we should
aim to keep redistributor related variables out of our struct vgic_dist.

Let's start by replacing the redistributor related kvm_io_device array
with two members in our existing struct vgic_cpu, which are naturally
per-VCPU and thus don't require any allocation / freeing.
So apart from the better fit with the redistributor design this saves
some code as well.

Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Tested-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18 18:09:40 +01:00
Andre Przywara
621ecd8d21 KVM: arm/arm64: vgic-new: Add GICv3 SGI system register trap handler
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>
2016-05-20 15:39:59 +02:00
Andre Przywara
78a714aba0 KVM: arm/arm64: vgic-new: Add GICv3 IROUTER register handlers
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>
2016-05-20 15:39:58 +02:00
Andre Przywara
54f59d2b3a KVM: arm/arm64: vgic-new: Add GICv3 IDREGS register handler
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>
2016-05-20 15:39:57 +02:00
Andre Przywara
741972d8a6 KVM: arm/arm64: vgic-new: Add GICv3 redistributor IIDR and TYPER handler
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>
2016-05-20 15:39:57 +02:00
Andre Przywara
fd59ed3be1 KVM: arm/arm64: vgic-new: Add GICv3 CTLR, IIDR, TYPER handlers
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>
2016-05-20 15:39:56 +02:00
Andre Przywara
ed9b8cefa9 KVM: arm/arm64: vgic-new: Add GICv3 MMIO handling framework
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>
2016-05-20 15:39:56 +02:00