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path: root/virt/kvm/arm/vgic/vgic-mmio.c
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2017-03-07KVM: arm/arm64: Let vcpu thread modify its own active stateJintack Lim1-8/+24
Currently, if a vcpu thread tries to change the active state of an interrupt which is already on the same vcpu's AP list, it will loop forever. Since the VGIC mmio handler is called after a vcpu has already synced back the LR state to the struct vgic_irq, we can just let it proceed safely. Cc: stable@vger.kernel.org Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Jintack Lim <jintack@cs.columbia.edu> Signed-off-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-01-30KVM: arm/arm64: vgic: Implement KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO ioctlVijaya Kumar K1-0/+54
Userspace requires to store and restore of line_level for level triggered interrupts using ioctl KVM_DEV_ARM_VGIC_GRP_LEVEL_INFO. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@cavium.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-01-30KVM: arm/arm64: vgic: Introduce VENG0 and VENG1 fields to vmcr structVijaya Kumar K1-0/+16
ICC_VMCR_EL2 supports virtual access to ICC_IGRPEN1_EL1.Enable and ICC_IGRPEN0_EL1.Enable fields. Add grpen0 and grpen1 member variables to struct vmcr to support read and write of these fields. Also refactor vgic_set_vmcr and vgic_get_vmcr() code. Drop ICH_VMCR_CTLR_SHIFT and ICH_VMCR_CTLR_MASK macros and instead use ICH_VMCR_EOI* and ICH_VMCR_CBPR* macros. Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@cavium.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-01-30KVM: arm/arm64: vgic: Add distributor and redistributor accessVijaya Kumar K1-1/+1
VGICv3 Distributor and Redistributor registers are accessed using KVM_DEV_ARM_VGIC_GRP_DIST_REGS and KVM_DEV_ARM_VGIC_GRP_REDIST_REGS with KVM_SET_DEVICE_ATTR and KVM_GET_DEVICE_ATTR ioctls. These registers are accessed as 32-bit and cpu mpidr value passed along with register offset is used to identify the cpu for redistributor registers access. The version of VGIC v3 specification is defined here Documentation/virtual/kvm/devices/arm-vgic-v3.txt Also update arch/arm/include/uapi/asm/kvm.h to compile for AArch32 mode. Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@cavium.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-01-30KVM: arm/arm64: vgic: Implement support for userspace accessVijaya Kumar K1-6/+72
Read and write of some registers like ISPENDR and ICPENDR from userspace requires special handling when compared to guest access for these registers. Refer to Documentation/virtual/kvm/devices/arm-vgic-v3.txt for handling of ISPENDR, ICPENDR registers handling. Add infrastructure to support guest and userspace read and write for the required registers Also moved vgic_uaccess from vgic-mmio-v2.c to vgic-mmio.c Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@cavium.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-01-25KVM: arm/arm64: Remove struct vgic_irq pending fieldChristoffer Dall1-14/+5
One of the goals behind the VGIC redesign was to get rid of cached or intermediate state in the data structures, but we decided to allow ourselves to precompute the pending value of an IRQ based on the line level and pending latch state. However, this has now become difficult to base proper GICv3 save/restore on, because there is a potential to modify the pending state without knowing if an interrupt is edge or level configured. See the following post and related message for more background: https://lists.cs.columbia.edu/pipermail/kvmarm/2017-January/023195.html This commit gets rid of the precomputed pending field in favor of a function that calculates the value when needed, irq_is_pending(). The soft_pending field is renamed to pending_latch to represent that this latch is the equivalent hardware latch which gets manipulated by the input signal for edge-triggered interrupts and when writing to the SPENDR/CPENDR registers. After this commit save/restore code should be able to simply restore the pending_latch state, line_level state, and config state in any order and get the desired result. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Tested-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-11-04KVM: arm/arm64: vgic: Prevent access to invalid SPIsAndre Przywara1-14/+27
In our VGIC implementation we limit the number of SPIs to a number that the userland application told us. Accordingly we limit the allocation of memory for virtual IRQs to that number. However in our MMIO dispatcher we didn't check if we ever access an IRQ beyond that limit, leading to out-of-bound accesses. Add a test against the number of allocated SPIs in check_region(). Adjust the VGIC_ADDR_TO_INT macro to avoid an actual division, which is not implemented on ARM(32). [maz: cleaned-up original patch] Cc: stable@vger.kernel.org Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-09-22ARM: KVM: Support vgic-v3Vladimir Murzin1-2/+0
This patch allows to build and use vgic-v3 in 32-bit mode. Unfortunately, it can not be split in several steps without extra stubs to keep patches independent and bisectable. For instance, virt/kvm/arm/vgic/vgic-v3.c uses function from vgic-v3-sr.c, handling access to GICv3 cpu interface from the guest requires vgic_v3.vgic_sre to be already defined. It is how support has been done: * handle SGI requests from the guest * report configured SRE on access to GICv3 cpu interface from the guest * required vgic-v3 macros are provided via uapi.h * static keys are used to select GIC backend * to make vgic-v3 build KVM_ARM_VGIC_V3 guard is removed along with the static inlines Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-07-18KVM: arm/arm64: Fix vGICv2 KVM_DEV_ARM_VGIC_GRP_CPU/DIST_REGSEric Auger1-1/+3
For VGICv2 save and restore the CPU interface registers are accessed. Restore the modality which has been altered. Also explicitly set the iodev_type for both the DIST and CPU interface. Signed-off-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Introduce ITS emulation file with MMIO frameworkAndre Przywara1-7/+30
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>
2016-07-18KVM: arm/arm64: vgic: Add refcounting for IRQsAndre Przywara1-1/+24
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>
2016-06-02KVM: arm/arm64: vgic-new: Removel harmful BUG_ONMarc Zyngier1-3/+1
When changing the active bit from an MMIO trap, we decide to explode if the intid is that of a private interrupt. This flawed logic comes from the fact that we were assuming that kvm_vcpu_kick() as called by kvm_arm_halt_vcpu() would not return before the called vcpu responded, but this is not the case, so we need to perform this wait even for private interrupts. Dropping the BUG_ON seems like the right thing to do. [ Commit message tweaked by Christoffer ] Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-05-20KVM: arm/arm64: vgic-new: Synchronize changes to active stateChristoffer Dall1-39/+66
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>
2016-05-20KVM: arm/arm64: vgic-new: Add GICv3 MMIO handling frameworkAndre Przywara1-0/+5
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>
2016-05-20KVM: arm/arm64: vgic-new: Add CONFIG registers handlersAndre Przywara1-0/+47
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>
2016-05-20KVM: arm/arm64: vgic-new: Add PRIORITY registers handlersAndre Przywara1-0/+40
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>
2016-05-20KVM: arm/arm64: vgic-new: Add ACTIVE registers handlersAndre Przywara1-0/+81
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>
2016-05-20KVM: arm/arm64: vgic-new: Add PENDING registers handlersAndre Przywara1-0/+60
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>
2016-05-20KVM: arm/arm64: vgic-new: Add ENABLE registers handlersAndre Przywara1-0/+56
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>
2016-05-20KVM: arm/arm64: vgic-new: Add GICv2 MMIO handling frameworkAndre Przywara1-0/+26
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>
2016-05-20KVM: arm/arm64: vgic-new: Add MMIO handling frameworkMarc Zyngier1-0/+184
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>