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path: root/virt/kvm/arm/vgic/vgic.c
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2018-01-02KVM: arm/arm64: Support VGIC dist pend/active changes for mapped IRQsChristoffer Dall
For mapped IRQs (with the HW bit set in the LR) we have to follow some rules of the architecture. One of these rules is that VM must not be allowed to deactivate a virtual interrupt with the HW bit set unless the physical interrupt is also active. This works fine when injecting mapped interrupts, because we leave it up to the injector to either set EOImode==1 or manually set the active state of the physical interrupt. However, the guest can set virtual interrupt to be pending or active by writing to the virtual distributor, which could lead to deactivating a virtual interrupt with the HW bit set without the physical interrupt being active. We could set the physical interrupt to active whenever we are about to enter the VM with a HW interrupt either pending or active, but that would be really slow, especially on GICv2. So we take the long way around and do the hard work when needed, which is expected to be extremely rare. When the VM sets the pending state for a HW interrupt on the virtual distributor we set the active state on the physical distributor, because the virtual interrupt can become active and then the guest can deactivate it. When the VM clears the pending state we also clear it on the physical side, because the injector might otherwise raise the interrupt. We also clear the physical active state when the virtual interrupt is not active, since otherwise a SPEND/CPEND sequence from the guest would prevent signaling of future interrupts. Changing the state of mapped interrupts from userspace is not supported, and it's expected that userspace unmaps devices from VFIO before attempting to set the interrupt state, because the interrupt state is driven by hardware. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2018-01-02KVM: arm/arm64: Support a vgic interrupt line level sample functionChristoffer Dall
The GIC sometimes need to sample the physical line of a mapped interrupt. As we know this to be notoriously slow, provide a callback function for devices (such as the timer) which can do this much faster than talking to the distributor, for example by comparing a few in-memory values. Fall back to the good old method of poking the physical GIC if no callback is provided. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2018-01-02KVM: arm/arm64: vgic: Support level-triggered mapped interruptsChristoffer Dall
Level-triggered mapped IRQs are special because we only observe rising edges as input to the VGIC, and we don't set the EOI flag and therefore are not told when the level goes down, so that we can re-queue a new interrupt when the level goes up. One way to solve this problem is to side-step the logic of the VGIC and special case the validation in the injection path, but it has the unfortunate drawback of having to peak into the physical GIC state whenever we want to know if the interrupt is pending on the virtual distributor. Instead, we can maintain the current semantics of a level triggered interrupt by sort of treating it as an edge-triggered interrupt, following from the fact that we only observe an asserting edge. This requires us to be a bit careful when populating the LRs and when folding the state back in though: * We lower the line level when populating the LR, so that when subsequently observing an asserting edge, the VGIC will do the right thing. * If the guest never acked the interrupt while running (for example if it had masked interrupts at the CPU level while running), we have to preserve the pending state of the LR and move it back to the line_level field of the struct irq when folding LR state. If the guest never acked the interrupt while running, but changed the device state and lowered the line (again with interrupts masked) then we need to observe this change in the line_level. Both of the above situations are solved by sampling the physical line and set the line level when folding the LR back. * Finally, if the guest never acked the interrupt while running and sampling the line reveals that the device state has changed and the line has been lowered, we must clear the physical active state, since we will otherwise never be told when the interrupt becomes asserted again. This has the added benefit of making the timer optimization patches (https://lists.cs.columbia.edu/pipermail/kvmarm/2017-July/026343.html) a bit simpler, because the timer code doesn't have to clear the active state on the sync anymore. It also potentially improves the performance of the timer implementation because the GIC knows the state or the LR and only needs to clear the active state when the pending bit in the LR is still set, where the timer has to always clear it when returning from running the guest with an injected timer interrupt. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-12-01KVM: arm/arm64: Fix spinlock acquisition in vgic_set_ownerMarc Zyngier
vgic_set_owner acquires the irq lock without disabling interrupts, resulting in a lockdep splat (an interrupt could fire and result in the same lock being taken if the same virtual irq is to be injected). In practice, it is almost impossible to trigger this bug, but better safe than sorry. Convert the lock acquisition to a spin_lock_irqsave() and keep lockdep happy. Reported-by: James Morse <james.morse@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-11-29KVM: arm/arm64: VGIC: extend !vgic_is_initialized guardAndre Przywara
Commit f39d16cbabf9 ("KVM: arm/arm64: Guard kvm_vgic_map_is_active against !vgic_initialized") introduced a check whether the VGIC has been initialized before accessing the spinlock and the VGIC data structure. However the vgic_get_irq() call in the variable declaration sneaked through the net, so lets make sure that this also gets called only after we actually allocated the arrays this function accesses. Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-11-10KVM: arm/arm64: GICv4: Hook vPE scheduling into vgic flush/syncMarc Zyngier
The redistributor needs to be told which vPE is about to be run, and tells us whether there is any pending VLPI on exit. Let's add the scheduling calls to the vgic flush/sync functions, allowing the VLPIs to be delivered to the guest. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-11-10KVM: arm/arm64: GICv4: Use pending_last as a scheduling hintMarc Zyngier
When a vPE exits, the pending_last flag is set when there are pending VLPIs stored in the pending table. Similarily, this flag will be set when a doorbell interrupt fires, as it indicates the same condition. Let's update kvm_vgic_vcpu_pending_irq() to account for that flag as well, making a vcpu runnable when set. Acked-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-11-06KVM: arm/arm64: vgic: restructure kvm_vgic_(un)map_phys_irqEric Auger
We want to reuse the core of the map/unmap functions for IRQ forwarding. Let's move the computation of the hwirq in kvm_vgic_map_phys_irq and pass the linux IRQ as parameter. the host_irq is added to struct vgic_irq. We introduce kvm_vgic_map/unmap_irq which take a struct vgic_irq handle as a parameter. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-11-06KVM: arm/arm64: Support calling vgic_update_irq_pending from irq contextChristoffer Dall
We are about to optimize our timer handling logic which involves injecting irqs to the vgic directly from the irq handler. Unfortunately, the injection path can take any AP list lock and irq lock and we must therefore make sure to use spin_lock_irqsave where ever interrupts are enabled and we are taking any of those locks, to avoid deadlocking between process context and the ISR. This changes a lot of the VGIC code, but the good news are that the changes are mostly mechanical. Acked-by: Marc Zyngier <marc,zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-11-06KVM: arm/arm64: Guard kvm_vgic_map_is_active against !vgic_initializedChristoffer Dall
If the vgic is not initialized, don't try to grab its spinlocks or traverse its data structures. This is important because we soon have to start considering the active state of a virtual interrupts when doing vcpu_load, which may happen early on before the vgic is initialized. Signed-off-by: Christoffer Dall <cdall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-08KVM: arm/arm64: Disallow userspace control of in-kernel IRQ linesChristoffer Dall
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>
2017-06-08KVM: arm/arm64: Introduce an allocator for in-kernel irq linesChristoffer Dall
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>
2017-06-04KVM: arm/arm64: use vcpu requests for irq injectionAndrew Jones
Don't use request-less VCPU kicks when injecting IRQs, as a VCPU kick meant to trigger the interrupt injection could be sent while the VCPU is outside guest mode, which means no IPI is sent, and after it has called kvm_vgic_flush_hwstate(), meaning it won't see the updated GIC state until its next exit some time later for some other reason. The receiving VCPU only needs to check this request in VCPU RUN to handle it. By checking it, if it's pending, a memory barrier will be issued that ensures all state is visible. See "Ensuring Requests Are Seen" of Documentation/virtual/kvm/vcpu-requests.rst Signed-off-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-05-23KVM: arm/arm64: Simplify active_change_prepare and plug raceChristoffer Dall
We don't need to stop a specific VCPU when changing the active state, because private IRQs can only be modified by a running VCPU for the VCPU itself and it is therefore already stopped. However, it is also possible for two VCPUs to be modifying the active state of SPIs at the same time, which can cause the thread being stuck in the loop that checks other VCPU threads for a potentially very long time, or to modify the active state of a running VCPU. Fix this by serializing all accesses to setting and clearing the active state of interrupts using the KVM mutex. Reported-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-05-09Merge tag 'kvm-arm-for-v4.12-round2' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD 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
2017-05-08Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
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 ...
2017-05-04KVM: arm/arm64: Move shared files to virt/kvm/armChristoffer Dall
For some time now we have been having a lot of shared functionality between the arm and arm64 KVM support in arch/arm, which not only required a horrible inter-arch reference from the Makefile in arch/arm64/kvm, but also created confusion for newcomers to the code base, as was recently seen on the mailing list. Further, it causes confusion for things like cscope, which needs special attention to index specific shared files for arm64 from the arm tree. Move the shared files into virt/kvm/arm and move the trace points along with it. When moving the tracepoints we have to modify the way the vgic creates definitions of the trace points, so we take the chance to include the VGIC tracepoints in its very own special vgic trace.h file. Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09KVM: arm/arm64: vgic: Improve sync_hwstate performanceChristoffer Dall
There is no need to call any functions to fold LRs when we don't use any LRs and we don't need to mess with overflow flags, take spinlocks, or prune the AP list if the AP list is empty. Note: list_empty is a single atomic read (uses READ_ONCE) and can therefore check if a list is empty or not without the need to take the spinlock protecting the list. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09KVM: arm/arm64: vgic: Don't check vgic_initialized in sync/flushChristoffer Dall
Now when we do an early init of the static parts of the VGIC data structures, we can do things like checking if the AP lists are empty directly without having to explicitly check if the vgic is initialized and reduce a bit of work in our critical path. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09KVM: arm/arm64: vgic: Get rid of unnecessary process_maintenance operationChristoffer Dall
Since we always read back the LRs that we wrote to the guest and the MISR and EISR registers simply provide a summary of the configuration of the bits in the LRs, there is really no need to read back those status registers and process them. We might as well just signal the notifyfd when folding the LR state and save some cycles in the process. We now clear the underflow bit in the fold_lr_state functions as we only need to clear this bit if we had used all the LRs, so this is as good a place as any to do that work. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-04-09KVM: arm/arm64: vgic: Only set underflow when actually out of LRsChristoffer Dall
We currently assume that all the interrupts in our AP list will be queued to LRs, but that's not necessarily the case, because some of them could have been migrated away to different VCPUs and only the VCPU thread itself can remove interrupts from its AP list. Therefore, slightly change the logic to only setting the underflow interrupt when we actually run out of LRs. As it turns out, this allows us to further simplify the handling in vgic_sync_hwstate in later patches. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09KVM: arm/arm64: vgic: Avoid flushing vgic state when there's no pending IRQShih-Wei Li
We do not need to flush vgic states in each world switch unless there is pending IRQ queued to the vgic's ap list. We can thus reduce the overhead by not grabbing the spinlock and not making the extra function call to vgic_flush_lr_state. Note: list_empty is a single atomic read (uses READ_ONCE) and can therefore check if a list is empty or not without the need to take the spinlock protecting the list. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Shih-Wei Li <shihwei@cs.columbia.edu> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09KVM: arm/arm64: vgic: Defer touching GICH_VMCR to vcpu_load/putChristoffer Dall
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>
2017-03-23arm: kvm: move kvm_vgic_global_state out of .text sectionArd Biesheuvel
The kvm_vgic_global_state struct contains a static key which is written to by jump_label_init() at boot time. So in preparation of making .text regions truly (well, almost truly) read-only, mark kvm_vgic_global_state __ro_after_init so it moves to the .rodata section instead. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Laura Abbott <labbott@redhat.com> Reviewed-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Signed-off-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2017-02-01KVM: arm/arm64: Remove kvm_vgic_inject_mapped_irqChristoffer Dall
The only benefit of having kvm_vgic_inject_mapped_irq separate from kvm_vgic_inject_irq is that we pass a boolean that we use for error checking on the injection path. While this could potentially help in some aspect of robustness, it's also a little bit of a defensive move, and arguably callers into the vgic should have make sure they have marked their virtual IRQs as mapped if required. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-01-25KVM: arm/arm64: Remove struct vgic_irq pending fieldChristoffer Dall
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: Kick VCPUs when queueing already pending IRQsShih-Wei Li
In cases like IPI, we could be queueing an interrupt for a VCPU that is already running and is not about to exit, because the VCPU has entered the VM with the interrupt pending and would not trap on EOI'ing that interrupt. This could result to delays in interrupt deliveries or even loss of interrupts. To guarantee prompt interrupt injection, here we have to try to kick the VCPU. Signed-off-by: Shih-Wei Li <shihwei@cs.columbia.edu> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-09-27KVM: arm/arm64: vgic: Don't flush/sync without a working vgicChristoffer Dall
If the vgic hasn't been created and initialized, we shouldn't attempt to look at its data structures or flush/sync anything to the GIC hardware. This fixes an issue reported by Alexander Graf when using a userspace irqchip. Fixes: 0919e84c0fc1 ("KVM: arm/arm64: vgic-new: Add IRQ sync/flush framework") Cc: stable@vger.kernel.org Reported-by: Alexander Graf <agraf@suse.de> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-22arm64: KVM: Use static keys for selecting the GIC backendVladimir Murzin
Currently GIC backend is selected via alternative framework and this is fine. We are going to introduce vgic-v3 to 32-bit world and there we don't have patching framework in hand, so we can either check support for GICv3 every time we need to choose which backend to use or try to optimise it by using static keys. The later looks quite promising because we can share logic involved in selecting GIC backend between architectures if both uses static keys. This patch moves arm64 from alternative to static keys framework for selecting GIC backend. For that we embed static key into vgic_global and enable the key during vgic initialisation based on what has already been exposed by the host GIC driver. 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>
2016-08-10KVM: arm64: vgic-its: Plug race in vgic_put_irqChristoffer Dall
Right now the following sequence of events can happen: 1. Thread X calls vgic_put_irq 2. Thread Y calls vgic_add_lpi 3. Thread Y gets lpi_list_lock 4. Thread X drops the ref count to 0 and blocks on lpi_list_lock 5. Thread Y finds the irq via the lpi_list_lock, raises the ref count to 1, and release the lpi_list_lock. 6. Thread X proceeds and frees the irq. Avoid this by holding the spinlock around the kref_put. Reviewed-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-07-22KVM: arm/arm64: Enable irqchip routingEric Auger
This patch adds compilation and link against irqchip. Main motivation behind using irqchip code is to enable MSI routing code. In the future irqchip routing may also be useful when targeting multiple irqchips. Routing standard callbacks now are implemented in vgic-irqfd: - kvm_set_routing_entry - kvm_set_irq - kvm_set_msi They only are supported with new_vgic code. Both HAVE_KVM_IRQCHIP and HAVE_KVM_IRQ_ROUTING are defined. KVM_CAP_IRQ_ROUTING is advertised and KVM_SET_GSI_ROUTING is allowed. So from now on IRQCHIP routing is enabled and a routing table entry must exist for irqfd injection to succeed for a given SPI. This patch builds a default flat irqchip routing table (gsi=irqchip.pin) covering all the VGIC SPI indexes. This routing table is overwritten by the first first user-space call to KVM_SET_GSI_ROUTING ioctl. MSI routing setup is not yet allowed. Signed-off-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Generalize use of vgic_get_irq_krefMarc Zyngier
Instead of sprinkling raw kref_get() calls everytime we cannot do a normal vgic_get_irq(), use the existing vgic_get_irq_kref(), which does the same thing and is paired with a vgic_put_irq(). vgic_get_irq_kref is moved to vgic.h in order to be easily shared. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-07-18KVM: arm64: vgic-its: Enable ITS emulation as a virtual MSI controllerAndre Przywara
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>
2016-07-18KVM: arm64: vgic-its: Connect LPIs to the VGIC emulationAndre Przywara
LPIs are dynamically created (mapped) at guest runtime and their actual number can be quite high, but is mostly assigned using a very sparse allocation scheme. So arrays are not an ideal data structure to hold the information. We use a spin-lock protected linked list to hold all mapped LPIs, represented by their struct vgic_irq. This lock is grouped between the ap_list_lock and the vgic_irq lock in our locking order. Also we store a pointer to that struct vgic_irq in our struct its_itte, so we can easily access it. Eventually we call our new vgic_get_lpi() from vgic_get_irq(), so the VGIC code gets transparently access to LPIs. 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: arm64: vgic-its: Implement basic ITS register handlersAndre Przywara
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>
2016-07-18KVM: arm/arm64: vgic: Add refcounting for IRQsAndre Przywara
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>
2016-05-20KVM: arm/arm64: vgic-new: implement mapped IRQ handlingAndre Przywara
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>
2016-05-20KVM: arm/arm64: vgic-new: vgic_init: implement vgic_initEric Auger
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>
2016-05-20KVM: arm/arm64: vgic-new: Add CTLR, TYPER and IIDR handlersMarc Zyngier
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>
2016-05-20KVM: arm/arm64: vgic-new: Implement kvm_vgic_vcpu_pending_irqEric Auger
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>
2016-05-20KVM: arm/arm64: vgic-new: Add GICv3 world switch backendMarc Zyngier
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>
2016-05-20KVM: arm/arm64: vgic-new: Add GICv2 world switch backendMarc Zyngier
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>
2016-05-20KVM: arm/arm64: vgic-new: Add IRQ sync/flush frameworkMarc Zyngier
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>
2016-05-20KVM: arm/arm64: vgic-new: Add IRQ sortingChristoffer Dall
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>
2016-05-20KVM: arm/arm64: vgic-new: Implement virtual IRQ injectionChristoffer Dall
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>
2016-05-20KVM: arm/arm64: vgic-new: Add acccessor to new struct vgic_irq instanceChristoffer Dall
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>