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2016-03-09arm64: KVM: vgic-v3: Avoid accessing ICH registersMarc Zyngier
Just like on GICv2, we're a bit hammer-happy with GICv3, and access them more often than we should. Adopt a policy similar to what we do for GICv2, only save/restoring the minimal set of registers. As we don't access the registers linearly anymore (we may skip some), the convoluted accessors become slightly simpler, and we can drop the ugly indexing macro that tended to confuse the reviewers. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-03-09KVM: arm/arm64: vgic-v2: Avoid accessing GICH registersMarc Zyngier
GICv2 registers are *slow*. As in "terrifyingly slow". Which is bad. But we're equaly bad, as we make a point in accessing them even if we don't have any interrupt in flight. A good solution is to first find out if we have anything useful to write into the GIC, and if we don't, to simply not do it. This involves tracking which LRs actually have something valid there. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29KVM: arm/arm64: timer: Add active state cachingMarc Zyngier
Programming the active state in the (re)distributor can be an expensive operation so it makes some sense to try and reduce the number of accesses as much as possible. So far, we program the active state on each VM entry, but there is some opportunity to do less. An obvious solution is to cache the active state in memory, and only program it in the HW when conditions change. But because the HW can also change things under our feet (the active state can transition from 1 to 0 when the guest does an EOI), some precautions have to be taken, which amount to only caching an "inactive" state, and always programing it otherwise. With this in place, we observe a reduction of around 700 cycles on a 2GHz GICv2 platform for a NULL hypercall. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29arm64: KVM: Add a new vcpu device control group for PMUv3Shannon Zhao
To configure the virtual PMUv3 overflow interrupt number, we use the vcpu kvm_device ioctl, encapsulating the KVM_ARM_VCPU_PMU_V3_IRQ attribute within the KVM_ARM_VCPU_PMU_V3_CTRL group. After configuring the PMUv3, call the vcpu ioctl with attribute KVM_ARM_VCPU_PMU_V3_INIT to initialize the PMUv3. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Acked-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29arm64: KVM: Add a new feature bit for PMUv3Shannon Zhao
To support guest PMUv3, use one bit of the VCPU INIT feature array. Initialize the PMU when initialzing the vcpu with that bit and PMU overflow interrupt set. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Acked-by: Peter Maydell <peter.maydell@linaro.org> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29arm64: KVM: Free perf event of PMU when destroying vcpuShannon Zhao
When KVM frees VCPU, it needs to free the perf_event of PMU. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29arm64: KVM: Reset PMU state when resetting vcpuShannon Zhao
When resetting vcpu, it needs to reset the PMU state to initial status. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29arm64: KVM: Add PMU overflow interrupt routingShannon Zhao
When calling perf_event_create_kernel_counter to create perf_event, assign a overflow handler. Then when the perf event overflows, set the corresponding bit of guest PMOVSSET register. If this counter is enabled and its interrupt is enabled as well, kick the vcpu to sync the interrupt. On VM entry, if there is counter overflowed and interrupt level is changed, inject the interrupt with corresponding level. On VM exit, sync the interrupt level as well if it has been changed. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29arm64: KVM: Add helper to handle PMCR register bitsShannon Zhao
According to ARMv8 spec, when writing 1 to PMCR.E, all counters are enabled by PMCNTENSET, while writing 0 to PMCR.E, all counters are disabled. When writing 1 to PMCR.P, reset all event counters, not including PMCCNTR, to zero. When writing 1 to PMCR.C, reset PMCCNTR to zero. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29arm64: KVM: Add access handler for PMSWINC registerShannon Zhao
Add access handler which emulates writing and reading PMSWINC register and add support for creating software increment event. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29arm64: KVM: Add access handler for PMOVSSET and PMOVSCLR registerShannon Zhao
Since the reset value of PMOVSSET and PMOVSCLR is UNKNOWN, use reset_unknown for its reset handler. Add a handler to emulate writing PMOVSSET or PMOVSCLR register. When writing non-zero value to PMOVSSET, the counter and its interrupt is enabled, kick this vcpu to sync PMU interrupt. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29arm64: KVM: PMU: Add perf event map and introduce perf event creating functionShannon Zhao
When we use tools like perf on host, perf passes the event type and the id of this event type category to kernel, then kernel will map them to hardware event number and write this number to PMU PMEVTYPER<n>_EL0 register. When getting the event number in KVM, directly use raw event type to create a perf_event for it. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29arm64: KVM: Add access handler for PMCNTENSET and PMCNTENCLR registerShannon Zhao
Since the reset value of PMCNTENSET and PMCNTENCLR is UNKNOWN, use reset_unknown for its reset handler. Add a handler to emulate writing PMCNTENSET or PMCNTENCLR register. When writing to PMCNTENSET, call perf_event_enable to enable the perf event. When writing to PMCNTENCLR, call perf_event_disable to disable the perf event. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29arm64: KVM: Add access handler for event counter registerShannon Zhao
These kind of registers include PMEVCNTRn, PMCCNTR and PMXEVCNTR which is mapped to PMEVCNTRn. The access handler translates all aarch32 register offsets to aarch64 ones and uses vcpu_sys_reg() to access their values to avoid taking care of big endian. When reading these registers, return the sum of register value and the value perf event counts. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29arm64: KVM: Add access handler for PMCR registerShannon Zhao
Add reset handler which gets host value of PMCR_EL0 and make writable bits architecturally UNKNOWN except PMCR.E which is zero. Add an access handler for PMCR. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2016-02-29arm64: KVM: Define PMU data structure for each vcpuShannon Zhao
Here we plan to support virtual PMU for guest by full software emulation, so define some basic structs and functions preparing for futher steps. Define struct kvm_pmc for performance monitor counter and struct kvm_pmu for performance monitor unit for each vcpu. According to ARMv8 spec, the PMU contains at most 32(ARMV8_PMU_MAX_COUNTERS) counters. Since this only supports ARM64 (or PMUv3), add a separate config symbol for it. Signed-off-by: Shannon Zhao <shannon.zhao@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-12-14KVM: arm/arm64: vgic-v3: Make the LR indexing macro publicMarc Zyngier
We store GICv3 LRs in reverse order so that the CPU can save/restore them in rever order as well (don't ask why, the design is crazy), and yet generate memory traffic that doesn't completely suck. We need this macro to be available to the C version of save/restore. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-11-24KVM: arm/arm64: arch_timer: Preserve physical dist. active state on LR.activeChristoffer Dall
We were incorrectly removing the active state from the physical distributor on the timer interrupt when the timer output level was deasserted. We shouldn't be doing this without considering the virtual interrupt's active state, because the architecture requires that when an LR has the HW bit set and the pending or active bits set, then the physical interrupt must also have the corresponding bits set. This addresses an issue where we have been observing an inconsistency between the LR state and the physical distributor state where the LR state was active and the physical distributor was not active, which shouldn't happen. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-06Merge tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds
Pull KVM updates from Paolo Bonzini: "First batch of KVM changes for 4.4. s390: A bunch of fixes and optimizations for interrupt and time handling. PPC: Mostly bug fixes. ARM: No big features, but many small fixes and prerequisites including: - a number of fixes for the arch-timer - introducing proper level-triggered semantics for the arch-timers - a series of patches to synchronously halt a guest (prerequisite for IRQ forwarding) - some tracepoint improvements - a tweak for the EL2 panic handlers - some more VGIC cleanups getting rid of redundant state x86: Quite a few changes: - support for VT-d posted interrupts (i.e. PCI devices can inject interrupts directly into vCPUs). This introduces a new component (in virt/lib/) that connects VFIO and KVM together. The same infrastructure will be used for ARM interrupt forwarding as well. - more Hyper-V features, though the main one Hyper-V synthetic interrupt controller will have to wait for 4.5. These will let KVM expose Hyper-V devices. - nested virtualization now supports VPID (same as PCID but for vCPUs) which makes it quite a bit faster - for future hardware that supports NVDIMM, there is support for clflushopt, clwb, pcommit - support for "split irqchip", i.e. LAPIC in kernel + IOAPIC/PIC/PIT in userspace, which reduces the attack surface of the hypervisor - obligatory smattering of SMM fixes - on the guest side, stable scheduler clock support was rewritten to not require help from the hypervisor" * tag 'for-linus' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (123 commits) KVM: VMX: Fix commit which broke PML KVM: x86: obey KVM_X86_QUIRK_CD_NW_CLEARED in kvm_set_cr0() KVM: x86: allow RSM from 64-bit mode KVM: VMX: fix SMEP and SMAP without EPT KVM: x86: move kvm_set_irq_inatomic to legacy device assignment KVM: device assignment: remove pointless #ifdefs KVM: x86: merge kvm_arch_set_irq with kvm_set_msi_inatomic KVM: x86: zero apic_arb_prio on reset drivers/hv: share Hyper-V SynIC constants with userspace KVM: x86: handle SMBASE as physical address in RSM KVM: x86: add read_phys to x86_emulate_ops KVM: x86: removing unused variable KVM: don't pointlessly leave KVM_COMPAT=y in non-KVM configs KVM: arm/arm64: Merge vgic_set_lr() and vgic_sync_lr_elrsr() KVM: arm/arm64: Clean up vgic_retire_lr() and surroundings KVM: arm/arm64: Optimize away redundant LR tracking KVM: s390: use simple switch statement as multiplexer KVM: s390: drop useless newline in debugging data KVM: s390: SCA must not cross page boundaries KVM: arm: Do not indent the arguments of DECLARE_BITMAP ...
2015-11-04KVM: arm/arm64: Merge vgic_set_lr() and vgic_sync_lr_elrsr()Pavel Fedin
Now we see that vgic_set_lr() and vgic_sync_lr_elrsr() are always used together. Merge them into one function, saving from second vgic_ops dereferencing every time. Signed-off-by: Pavel Fedin <p.fedin@samsung.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-11-04KVM: arm/arm64: Optimize away redundant LR trackingPavel Fedin
Currently we use vgic_irq_lr_map in order to track which LRs hold which IRQs, and lr_used bitmap in order to track which LRs are used or free. vgic_irq_lr_map is actually used only for piggy-back optimization, and can be easily replaced by iteration over lr_used. This is good because in future, when LPI support is introduced, number of IRQs will grow up to at least 16384, while numbers from 1024 to 8192 are never going to be used. This would be a huge memory waste. In its turn, lr_used is also completely redundant since ae705930fca6322600690df9dc1c7d0516145a93 ("arm/arm64: KVM: Keep elrsr/aisr in sync with software model"), because together with lr_used we also update elrsr. This allows to easily replace lr_used with elrsr, inverting all conditions (because in elrsr '1' means 'free'). Signed-off-by: Pavel Fedin <p.fedin@samsung.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-22KVM: arm: Do not indent the arguments of DECLARE_BITMAPMichal Marek
Besides being a coding style issue, it confuses make tags: ctags: Warning: include/kvm/arm_vgic.h:307: null expansion of name pattern "\1" ctags: Warning: include/kvm/arm_vgic.h:308: null expansion of name pattern "\1" ctags: Warning: include/kvm/arm_vgic.h:309: null expansion of name pattern "\1" ctags: Warning: include/kvm/arm_vgic.h:317: null expansion of name pattern "\1" Cc: kvmarm@lists.cs.columbia.edu Signed-off-by: Michal Marek <mmarek@suse.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-22arm/arm64: KVM: Rework the arch timer to use level-triggered semanticsChristoffer Dall
The arch timer currently uses edge-triggered semantics in the sense that the line is never sampled by the vgic and lowering the line from the timer to the vgic doesn't have any effect on the pending state of virtual interrupts in the vgic. This means that we do not support a guest with the otherwise valid behavior of (1) disable interrupts (2) enable the timer (3) disable the timer (4) enable interrupts. Such a guest would validly not expect to see any interrupts on real hardware, but will see interrupts on KVM. This patch fixes this shortcoming through the following series of changes. First, we change the flow of the timer/vgic sync/flush operations. Now the timer is always flushed/synced before the vgic, because the vgic samples the state of the timer output. This has the implication that we move the timer operations in to non-preempible sections, but that is fine after the previous commit getting rid of hrtimer schedules on every entry/exit. Second, we change the internal behavior of the timer, letting the timer keep track of its previous output state, and only lower/raise the line to the vgic when the state changes. Note that in theory this could have been accomplished more simply by signalling the vgic every time the state *potentially* changed, but we don't want to be hitting the vgic more often than necessary. Third, we get rid of the use of the map->active field in the vgic and instead simply set the interrupt as active on the physical distributor whenever the input to the GIC is asserted and conversely clear the physical active state when the input to the GIC is deasserted. Fourth, and finally, we now initialize the timer PPIs (and all the other unused PPIs for now), to be level-triggered, and modify the sync code to sample the line state on HW sync and re-inject a new interrupt if it is still pending at that time. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-22arm/arm64: KVM: arch_timer: Only schedule soft timer on vcpu_blockChristoffer Dall
We currently schedule a soft timer every time we exit the guest if the timer did not expire while running the guest. This is really not necessary, because the only work we do in the timer work function is to kick the vcpu. Kicking the vcpu does two things: (1) If the vpcu thread is on a waitqueue, make it runnable and remove it from the waitqueue. (2) If the vcpu is running on a different physical CPU from the one doing the kick, it sends a reschedule IPI. The second case cannot happen, because the soft timer is only ever scheduled when the vcpu is not running. The first case is only relevant when the vcpu thread is on a waitqueue, which is only the case when the vcpu thread has called kvm_vcpu_block(). Therefore, we only need to make sure a timer is scheduled for kvm_vcpu_block(), which we do by encapsulating all calls to kvm_vcpu_block() with kvm_timer_{un}schedule calls. Additionally, we only schedule a soft timer if the timer is enabled and unmasked, since it is useless otherwise. Note that theoretically userspace can use the SET_ONE_REG interface to change registers that should cause the timer to fire, even if the vcpu is blocked without a scheduled timer, but this case was not supported before this patch and we leave it for future work for now. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-10-09arm/arm64: KVM: Only allow 64bit hosts to build VGICv3Jean-Philippe Brucker
Hardware virtualisation of GICv3 is only supported by 64bit hosts for the moment. Some VGICv3 bits are missing from the 32bit side, and this patch allows to still be able to build 32bit hosts when CONFIG_ARM_GIC_V3 is selected. To this end, we introduce a new option, CONFIG_KVM_ARM_VGIC_V3, that is only enabled on the 64bit side. The selection is done unconditionally because CONFIG_ARM_GIC_V3 is always enabled on arm64. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-09-17arm/arm64: KVM: Remove 'config KVM_ARM_MAX_VCPUS'Ming Lei
This patch removes config option of KVM_ARM_MAX_VCPUS, and like other ARCHs, just choose the maximum allowed value from hardware, and follows the reasons: 1) from distribution view, the option has to be defined as the max allowed value because it need to meet all kinds of virtulization applications and need to support most of SoCs; 2) using a bigger value doesn't introduce extra memory consumption, and the help text in Kconfig isn't accurate because kvm_vpu structure isn't allocated until request of creating VCPU is sent from QEMU; 3) the main effect is that the field of vcpus[] in 'struct kvm' becomes a bit bigger(sizeof(void *) per vcpu) and need more cache lines to hold the structure, but 'struct kvm' is one generic struct, and it has worked well on other ARCHs already in this way. Also, the world switch frequecy is often low, for example, it is ~2000 when running kernel building load in VM from APM xgene KVM host, so the effect is very small, and the difference can't be observed in my test at all. Cc: Dann Frazier <dann.frazier@canonical.com> Signed-off-by: Ming Lei <ming.lei@canonical.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-08-12KVM: arm/arm64: timer: Allow the timer to control the active stateMarc Zyngier
In order to remove the crude hack where we sneak the masked bit into the timer's control register, make use of the phys_irq_map API control the active state of the interrupt. This causes some limited changes to allow for potential error propagation. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-08-12KVM: arm/arm64: vgic: Prevent userspace injection of a mapped interruptMarc Zyngier
Virtual interrupts mapped to a HW interrupt should only be triggered from inside the kernel. Otherwise, you could end up confusing the kernel (and the GIC's) state machine. Rearrange the injection path so that kvm_vgic_inject_irq is used for non-mapped interrupts, and kvm_vgic_inject_mapped_irq is used for mapped interrupts. The latter should only be called from inside the kernel (timer, irqfd). Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-08-12KVM: arm/arm64: vgic: Add vgic_{get,set}_phys_irq_activeMarc Zyngier
In order to control the active state of an interrupt, introduce a pair of accessors allowing the state to be set/queried. This only affects the logical state, and the HW state will only be applied at world-switch time. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-08-12KVM: arm/arm64: vgic: Allow dynamic mapping of physical/virtual interruptsMarc Zyngier
In order to be able to feed physical interrupts to a guest, we need to be able to establish the virtual-physical mapping between the two worlds. The mappings are kept in a set of RCU lists, indexed by virtual interrupts. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-08-12KVM: arm/arm64: vgic: Convert struct vgic_lr to use bitfieldsMarc Zyngier
As we're about to cram more information in the vgic_lr structure (HW interrupt number and additional state information), we switch to a layout similar to the HW's: - use bitfields to save space (we don't need more than 10 bits to represent the irq numbers) - source CPU and HW interrupt can share the same field, as a SGI doesn't have a physical line. Reviewed-by: Alex Bennée <alex.bennee@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-04-07Merge tag 'kvm-arm-for-4.1' of ↵Paolo Bonzini
git://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into 'kvm-next' KVM/ARM changes for v4.1: - fixes for live migration - irqfd support - kvm-io-bus & vgic rework to enable ioeventfd - page ageing for stage-2 translation - various cleanups
2015-03-30KVM: arm/arm64: rework MMIO abort handling to use KVM MMIO busAndre Przywara
Currently we have struct kvm_exit_mmio for encapsulating MMIO abort data to be passed on from syndrome decoding all the way down to the VGIC register handlers. Now as we switch the MMIO handling to be routed through the KVM MMIO bus, it does not make sense anymore to use that structure already from the beginning. So we keep the data in local variables until we put them into the kvm_io_bus framework. Then we fill kvm_exit_mmio in the VGIC only, making it a VGIC private structure. On that way we replace the data buffer in that structure with a pointer pointing to a single location in a local variable, so we get rid of some copying on the way. With all of the virtual GIC emulation code now being registered with the kvm_io_bus, we can remove all of the old MMIO handling code and its dispatching functionality. I didn't bother to rename kvm_exit_mmio (to vgic_mmio or something), because that touches a lot of code lines without any good reason. This is based on an original patch by Nikolay. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Cc: Nikolay Nikolaev <n.nikolaev@virtualopensystems.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-03-30KVM: arm/arm64: prepare GICv3 emulation to use kvm_io_bus MMIO handlingAndre Przywara
Using the framework provided by the recent vgic.c changes, we register a kvm_io_bus device on mapping the virtual GICv3 resources. The distributor mapping is pretty straight forward, but the redistributors need some more love, since they need to be tagged with the respective redistributor (read: VCPU) they are connected with. We use the kvm_io_bus framework to register one devices per VCPU. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-03-26KVM: arm/arm64: prepare GICv2 emulation to be handled by kvm_io_busAndre Przywara
Using the framework provided by the recent vgic.c changes we register a kvm_io_bus device when initializing the virtual GICv2. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-03-26KVM: arm/arm64: implement kvm_io_bus MMIO handling for the VGICAndre Przywara
Currently we use a lot of VGIC specific code to do the MMIO dispatching. Use the previous reworks to add kvm_io_bus style MMIO handlers. Those are not yet called by the MMIO abort handler, also the actual VGIC emulator function do not make use of it yet, but will be enabled with the following patches. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-03-26KVM: move iodev.h from virt/kvm/ to include/kvmAndre Przywara
iodev.h contains definitions for the kvm_io_bus framework. This is needed both by the generic KVM code in virt/kvm as well as by architecture specific code under arch/. Putting the header file in virt/kvm and using local includes in the architecture part seems at least dodgy to me, so let's move the file into include/kvm, so that a more natural "#include <kvm/iodev.h>" can be used by all of the code. This also solves a problem later when using struct kvm_io_device in arm_vgic.h. Fixing up the FSF address in the GPL header and a wrong include path on the way. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2015-03-14arm/arm64: KVM: Fix migration race in the arch timerChristoffer Dall
When a VCPU is no longer running, we currently check to see if it has a timer scheduled in the future, and if it does, we schedule a host hrtimer to notify is in case the timer expires while the VCPU is still not running. When the hrtimer fires, we mask the guest's timer and inject the timer IRQ (still relying on the guest unmasking the time when it receives the IRQ). This is all good and fine, but when migration a VM (checkpoint/restore) this introduces a race. It is unlikely, but possible, for the following sequence of events to happen: 1. Userspace stops the VM 2. Hrtimer for VCPU is scheduled 3. Userspace checkpoints the VGIC state (no pending timer interrupts) 4. The hrtimer fires, schedules work in a workqueue 5. Workqueue function runs, masks the timer and injects timer interrupt 6. Userspace checkpoints the timer state (timer masked) At restore time, you end up with a masked timer without any timer interrupts and your guest halts never receiving timer interrupts. Fix this by only kicking the VCPU in the workqueue function, and sample the expired state of the timer when entering the guest again and inject the interrupt and mask the timer only then. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-03-14arm/arm64: KVM: support for un-queuing active IRQsChristoffer Dall
Migrating active interrupts causes the active state to be lost completely. This implements some additional bitmaps to track the active state on the distributor and export this to user space. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-03-14arm/arm64: KVM: Keep elrsr/aisr in sync with software modelChristoffer Dall
There is an interesting bug in the vgic code, which manifests itself when the KVM run loop has a signal pending or needs a vmid generation rollover after having disabled interrupts but before actually switching to the guest. In this case, we flush the vgic as usual, but we sync back the vgic state and exit to userspace before entering the guest. The consequence is that we will be syncing the list registers back to the software model using the GICH_ELRSR and GICH_EISR from the last execution of the guest, potentially overwriting a list register containing an interrupt. This showed up during migration testing where we would capture a state where the VM has masked the arch timer but there were no interrupts, resulting in a hung test. Cc: Marc Zyngier <marc.zyngier@arm.com> Reported-by: Alex Bennee <alex.bennee@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Alex Bennée <alex.bennee@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-03-12arm/arm64: KVM: Kill CONFIG_KVM_ARM_{VGIC,TIMER}Christoffer Dall
We can definitely decide at run-time whether to use the GIC and timers or not, and the extra code and data structures that we allocate space for is really negligable with this config option, so I don't think it's worth the extra complexity of always having to define stub static inlines. The !CONFIG_KVM_ARM_VGIC/TIMER case is pretty much an untested code path anyway, so we're better off just getting rid of it. Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
2015-01-20arm/arm64: KVM: allow userland to request a virtual GICv3Andre Przywara
With all of the GICv3 code in place now we allow userland to ask the kernel for using a virtual GICv3 in the guest. Also we provide the necessary support for guests setting the memory addresses for the virtual distributor and redistributors. This requires some userland code to make use of that feature and explicitly ask for a virtual GICv3. Document that KVM_CREATE_IRQCHIP only works for GICv2, but is considered legacy and using KVM_CREATE_DEVICE is preferred. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-01-20arm/arm64: KVM: enable kernel side of GICv3 emulationAndre Przywara
With all the necessary GICv3 emulation code in place, we can now connect the code to the GICv3 backend in the kernel. The LR register handling is different depending on the emulated GIC model, so provide different implementations for each. Also allow non-v2-compatible GICv3 implementations (which don't provide MMIO regions for the virtual CPU interface in the DT), but restrict those hosts to support GICv3 guests only. If the device tree provides a GICv2 compatible GICV resource entry, but that one is faulty, just disable the GICv2 emulation and let the user use at least the GICv3 emulation for guests. To provide proper support for the legacy KVM_CREATE_IRQCHIP ioctl, note virtual GICv2 compatibility in struct vgic_params and use it on creating a VGICv2. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-01-20arm64: KVM: add SGI generation register emulationAndre Przywara
While the generation of a (virtual) inter-processor interrupt (SGI) on a GICv2 works by writing to a MMIO register, GICv3 uses the system register ICC_SGI1R_EL1 to trigger them. Add a trap handler function that calls the new SGI register handler in the GICv3 code. As ICC_SRE_EL1.SRE at this point is still always 0, this will not trap yet, but will only be used later when all the data structures have been initialized properly. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-01-20arm/arm64: KVM: add virtual GICv3 distributor emulationAndre Przywara
With everything separated and prepared, we implement a model of a GICv3 distributor and redistributors by using the existing framework to provide handler functions for each register group. Currently we limit the emulation to a model enforcing a single security state, with SRE==1 (forcing system register access) and ARE==1 (allowing more than 8 VCPUs). We share some of the functions provided for GICv2 emulation, but take the different ways of addressing (v)CPUs into account. Save and restore is currently not implemented. Similar to the split-off of the GICv2 specific code, the new emulation code goes into a new file (vgic-v3-emul.c). Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-01-20arm/arm64: KVM: make the value of ICC_SRE_EL1 a per-VM variableAndre Przywara
ICC_SRE_EL1 is a system register allowing msr/mrs accesses to the GIC CPU interface for EL1 (guests). Currently we force it to 0, but for proper GICv3 support we have to allow guests to use it (depending on their selected virtual GIC model). So add ICC_SRE_EL1 to the list of saved/restored registers on a world switch, but actually disallow a guest to change it by only restoring a fixed, once-initialized value. This value depends on the GIC model userland has chosen for a guest. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-01-20arm/arm64: KVM: make the maximum number of vCPUs a per-VM valueAndre Przywara
Currently the maximum number of vCPUs supported is a global value limited by the used GIC model. GICv3 will lift this limit, but we still need to observe it for guests using GICv2. So the maximum number of vCPUs is per-VM value, depending on the GIC model the guest uses. Store and check the value in struct kvm_arch, but keep it down to 8 for now. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-01-20arm/arm64: KVM: introduce per-VM opsAndre Przywara
Currently we only have one virtual GIC model supported, so all guests use the same emulation code. With the addition of another model we end up with different guests using potentially different vGIC models, so we have to split up some functions to be per VM. Introduce a vgic_vm_ops struct to hold function pointers for those functions that are different and provide the necessary code to initialize them. Also split up the vgic_init() function to separate out VGIC model specific functionality into a separate function, which will later be different for a GICv3 model. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2015-01-20arm/arm64: KVM: pass down user space provided GIC type into vGIC codeAndre Przywara
With the introduction of a second emulated GIC model we need to let userspace specify the GIC model to use for each VM. Pass the userspace provided value down into the vGIC code and store it there to differentiate later. Signed-off-by: Andre Przywara <andre.przywara@arm.com> Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2014-12-15arm/arm64: KVM: Require in-kernel vgic for the arch timersChristoffer Dall
It is curently possible to run a VM with architected timers support without creating an in-kernel VGIC, which will result in interrupts from the virtual timer going nowhere. To address this issue, move the architected timers initialization to the time when we run a VCPU for the first time, and then only initialize (and enable) the architected timers if we have a properly created and initialized in-kernel VGIC. When injecting interrupts from the virtual timer to the vgic, the current setup should ensure that this never calls an on-demand init of the VGIC, which is the only call path that could return an error from kvm_vgic_inject_irq(), so capture the return value and raise a warning if there's an error there. We also change the kvm_timer_init() function from returning an int to be a void function, since the function always succeeds. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>