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2018-08-12KVM: arm/arm64: vgic-v3: Add core support for Group0 SGIsMarc Zyngier1-1/+1
Although vgic-v3 now supports Group0 interrupts, it still doesn't deal with Group0 SGIs. As usually with the GIC, nothing is simple: - ICC_SGI1R can signal SGIs of both groups, since GICD_CTLR.DS==1 with KVM (as per 8.1.10, Non-secure EL1 access) - ICC_SGI0R can only generate Group0 SGIs - ICC_ASGI1R sees its scope refocussed to generate only Group0 SGIs (as per the note at the bottom of Table 8-14) We only support Group1 SGIs so far, so no material change. Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-07-21KVM: arm/arm64: vgic: Let userspace opt-in to writable v2 IGROUPRChristoffer Dall1-0/+3
Simply letting IGROUPR be writable from userspace would break migration from old kernels to newer kernels, because old kernels incorrectly report interrupt groups as group 1. This would not be a big problem if userspace wrote GICD_IIDR as read from the kernel, because we could detect the incompatibility and return an error to userspace. Unfortunately, this is not the case with current userspace implementations and simply letting IGROUPR be writable from userspace for an emulated GICv2 silently breaks migration and causes the destination VM to no longer run after migration. We now encourage userspace to write the read and expected value of GICD_IIDR as the first part of a GIC register restore, and if we observe a write to GICD_IIDR we know that userspace has been updated and has had a chance to cope with older kernels (VGICv2 IIDR.Revision == 0) incorrectly reporting interrupts as group 1, and therefore we now allow groups to be user writable. Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-07-21KVM: arm/arm64: vgic: Add group field to struct irqChristoffer Dall1-0/+1
In preparation for proper group 0 and group 1 support in the vgic, we add a field in the struct irq to store the group of all interrupts. We initialize the group to group 0 when emulating GICv2 and to group 1 when emulating GICv3, just like we treat them today. LPIs are always group 1. We also continue to ignore writes from the guest, preserving existing functionality, for now. Finally, we also add this field to the vgic debug logic to show the group for all interrupts. Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-07-21KVM: arm/arm64: vgic: Keep track of implementation revisionChristoffer Dall1-0/+3
As we are about to tweak implementation aspects of the VGIC emulation, while still preserving some level of backwards compatibility support, add a field to keep track of the implementation revision field which is reported to the VM and to userspace. Reviewed-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-25KVM: arm/arm64: Bump VGIC_V3_MAX_CPUS to 512Eric Auger1-1/+1
Let's raise the number of supported vcpus along with vgic v3 now that HW is looming with more physical CPUs. Signed-off-by: Eric Auger <eric.auger@redhat.com> Acked-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-25KVM: arm/arm64: Remove kvm_vgic_vcpu_early_initEric Auger1-1/+0
kvm_vgic_vcpu_early_init gets called after kvm_vgic_cpu_init which is confusing. The call path is as follows: kvm_vm_ioctl_create_vcpu |_ kvm_arch_cpu_create |_ kvm_vcpu_init |_ kvm_arch_vcpu_init |_ kvm_vgic_vcpu_init |_ kvm_arch_vcpu_postcreate |_ kvm_vgic_vcpu_early_init Static initialization currently done in kvm_vgic_vcpu_early_init() can be moved to kvm_vgic_vcpu_init(). So let's move the code and remove kvm_vgic_vcpu_early_init(). kvm_arch_vcpu_postcreate() does nothing. Signed-off-by: Eric Auger <eric.auger@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-05-25KVM: arm/arm64: Replace the single rdist region by a listEric Auger1-4/+10
At the moment KVM supports a single rdist region. We want to support several separate rdist regions so let's introduce a list of them. This patch currently only cares about a single entry in this list as the functionality to register several redist regions is not yet there. So this only translates the existing code into something functionally similar using that new data struct. The redistributor region handle is stored in the vgic_cpu structure to allow later computation of the TYPER last bit. Signed-off-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-04-27KVM: arm/arm64: vgic: Fix source vcpu issues for GICv2 SGIMarc Zyngier1-0/+1
Now that we make sure we don't inject multiple instances of the same GICv2 SGI at the same time, we've made another bug more obvious: If we exit with an active SGI, we completely lose track of which vcpu it came from. On the next entry, we restore it with 0 as a source, and if that wasn't the right one, too bad. While this doesn't seem to trouble GIC-400, the architectural model gets offended and doesn't deactivate the interrupt on EOI. Another connected issue is that we will happilly make pending an interrupt from another vcpu, overriding the above zero with something that is just as inconsistent. Don't do that. The final issue is that we signal a maintenance interrupt when no pending interrupts are present in the LR. Assuming we've fixed the two issues above, we end-up in a situation where we keep exiting as soon as we've reached the active state, and not be able to inject the following pending. The fix comes in 3 parts: - GICv2 SGIs have their source vcpu saved if they are active on exit, and restored on entry - Multi-SGIs cannot go via the Pending+Active state, as this would corrupt the source field - Multi-SGIs are converted to using MI on EOI instead of NPIE Fixes: 16ca6a607d84bef0 ("KVM: arm/arm64: vgic: Don't populate multiple LRs with the same vintid") Reported-by: Mark Rutland <mark.rutland@arm.com> Tested-by: Mark Rutland <mark.rutland@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@arm.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-04-20arm/arm64: KVM: Add PSCI version selection APIMarc Zyngier1-2/+14
Although we've implemented PSCI 0.1, 0.2 and 1.0, we expose either 0.1 or 1.0 to a guest, defaulting to the latest version of the PSCI implementation that is compatible with the requested version. This is no different from doing a firmware upgrade on KVM. But in order to give a chance to hypothetical badly implemented guests that would have a fit by discovering something other than PSCI 0.2, let's provide a new API that allows userspace to pick one particular version of the API. This is implemented as a new class of "firmware" registers, where we expose the PSCI version. This allows the PSCI version to be save/restored as part of a guest migration, and also set to any supported version if the guest requires it. Cc: stable@vger.kernel.org #4.16 Reviewed-by: Christoffer Dall <cdall@kernel.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19Merge tag 'kvm-arm-fixes-for-v4.16-2' into HEADMarc Zyngier1-0/+1
Resolve conflicts with current mainline
2018-03-19KVM: arm/arm64: Keep GICv2 HYP VAs in kvm_vgic_global_stateMarc Zyngier1-6/+6
As we're about to change the way we map devices at HYP, we need to move away from kern_hyp_va on an IO address. One way of achieving this is to store the VAs in kvm_vgic_global_state, and use that directly from the HYP code. This requires a small change to create_hyp_io_mappings so that it can also return a HYP VA. We take this opportunity to nuke the vctrl_base field in the emulated distributor, as it is not used anymore. Acked-by: Catalin Marinas <catalin.marinas@arm.com> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19KVM: arm/arm64: Get rid of vgic_elrsrChristoffer Dall1-2/+0
There is really no need to store the vgic_elrsr on the VGIC data structures as the only need we have for the elrsr is to figure out if an LR is inactive when we save the VGIC state upon returning from the guest. We can might as well store this in a temporary local variable. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-14KVM: arm/arm64: Reset mapped IRQs on VM resetChristoffer Dall1-0/+1
We currently don't allow resetting mapped IRQs from userspace, because their state is controlled by the hardware. But we do need to reset the state when the VM is reset, so we provide a function for the 'owner' of the mapped interrupt to reset the interrupt state. Currently only the timer uses mapped interrupts, so we call this function from the timer reset logic. Cc: stable@vger.kernel.org Fixes: 4c60e360d6df ("KVM: arm/arm64: Provide a get_input_level for the arch timer") Signed-off-by: Christoffer Dall <cdall@kernel.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-02-11Merge tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvmLinus Torvalds2-1/+14
Pull KVM updates from Radim Krčmář: "ARM: - icache invalidation optimizations, improving VM startup time - support for forwarded level-triggered interrupts, improving performance for timers and passthrough platform devices - a small fix for power-management notifiers, and some cosmetic changes PPC: - add MMIO emulation for vector loads and stores - allow HPT guests to run on a radix host on POWER9 v2.2 CPUs without requiring the complex thread synchronization of older CPU versions - improve the handling of escalation interrupts with the XIVE interrupt controller - support decrement register migration - various cleanups and bugfixes. s390: - Cornelia Huck passed maintainership to Janosch Frank - exitless interrupts for emulated devices - cleanup of cpuflag handling - kvm_stat counter improvements - VSIE improvements - mm cleanup x86: - hypervisor part of SEV - UMIP, RDPID, and MSR_SMI_COUNT emulation - paravirtualized TLB shootdown using the new KVM_VCPU_PREEMPTED bit - allow guests to see TOPOEXT, GFNI, VAES, VPCLMULQDQ, and more AVX512 features - show vcpu id in its anonymous inode name - many fixes and cleanups - per-VCPU MSR bitmaps (already merged through x86/pti branch) - stable KVM clock when nesting on Hyper-V (merged through x86/hyperv)" * tag 'kvm-4.16-1' of git://git.kernel.org/pub/scm/virt/kvm/kvm: (197 commits) KVM: PPC: Book3S: Add MMIO emulation for VMX instructions KVM: PPC: Book3S HV: Branch inside feature section KVM: PPC: Book3S HV: Make HPT resizing work on POWER9 KVM: PPC: Book3S HV: Fix handling of secondary HPTEG in HPT resizing code KVM: PPC: Book3S PR: Fix broken select due to misspelling KVM: x86: don't forget vcpu_put() in kvm_arch_vcpu_ioctl_set_sregs() KVM: PPC: Book3S PR: Fix svcpu copying with preemption enabled KVM: PPC: Book3S HV: Drop locks before reading guest memory kvm: x86: remove efer_reload entry in kvm_vcpu_stat KVM: x86: AMD Processor Topology Information x86/kvm/vmx: do not use vm-exit instruction length for fast MMIO when running nested kvm: embed vcpu id to dentry of vcpu anon inode kvm: Map PFN-type memory regions as writable (if possible) x86/kvm: Make it compile on 32bit and with HYPYERVISOR_GUEST=n KVM: arm/arm64: Fixup userspace irqchip static key optimization KVM: arm/arm64: Fix userspace_irqchip_in_use counting KVM: arm/arm64: Fix incorrect timer_is_pending logic MAINTAINERS: update KVM/s390 maintainers MAINTAINERS: add Halil as additional vfio-ccw maintainer MAINTAINERS: add David as a reviewer for KVM/s390 ...
2018-02-08Merge tag 'arm64-upstream' of ↵Linus Torvalds1-0/+51
git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux Pull more arm64 updates from Catalin Marinas: "As I mentioned in the last pull request, there's a second batch of security updates for arm64 with mitigations for Spectre/v1 and an improved one for Spectre/v2 (via a newly defined firmware interface API). Spectre v1 mitigation: - back-end version of array_index_mask_nospec() - masking of the syscall number to restrict speculation through the syscall table - masking of __user pointers prior to deference in uaccess routines Spectre v2 mitigation update: - using the new firmware SMC calling convention specification update - removing the current PSCI GET_VERSION firmware call mitigation as vendors are deploying new SMCCC-capable firmware - additional branch predictor hardening for synchronous exceptions and interrupts while in user mode Meltdown v3 mitigation update: - Cavium Thunder X is unaffected but a hardware erratum gets in the way. The kernel now starts with the page tables mapped as global and switches to non-global if kpti needs to be enabled. Other: - Theoretical trylock bug fixed" * tag 'arm64-upstream' of git://git.kernel.org/pub/scm/linux/kernel/git/arm64/linux: (38 commits) arm64: Kill PSCI_GET_VERSION as a variant-2 workaround arm64: Add ARM_SMCCC_ARCH_WORKAROUND_1 BP hardening support arm/arm64: smccc: Implement SMCCC v1.1 inline primitive arm/arm64: smccc: Make function identifiers an unsigned quantity firmware/psci: Expose SMCCC version through psci_ops firmware/psci: Expose PSCI conduit arm64: KVM: Add SMCCC_ARCH_WORKAROUND_1 fast handling arm64: KVM: Report SMCCC_ARCH_WORKAROUND_1 BP hardening support arm/arm64: KVM: Turn kvm_psci_version into a static inline arm/arm64: KVM: Advertise SMCCC v1.1 arm/arm64: KVM: Implement PSCI 1.0 support arm/arm64: KVM: Add smccc accessors to PSCI code arm/arm64: KVM: Add PSCI_VERSION helper arm/arm64: KVM: Consolidate the PSCI include files arm64: KVM: Increment PC after handling an SMC trap arm: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls arm64: KVM: Fix SMCCC handling of unimplemented SMC/HVC calls arm64: entry: Apply BP hardening for suspicious interrupts from EL0 arm64: entry: Apply BP hardening for high-priority synchronous exceptions arm64: futex: Mask __user pointers prior to dereference ...
2018-02-07arm/arm64: KVM: Turn kvm_psci_version into a static inlineMarc Zyngier1-1/+20
We're about to need kvm_psci_version in HYP too. So let's turn it into a static inline, and pass the kvm structure as a second parameter (so that HYP can do a kern_hyp_va on it). Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-07arm/arm64: KVM: Advertise SMCCC v1.1Marc Zyngier1-1/+1
The new SMC Calling Convention (v1.1) allows for a reduced overhead when calling into the firmware, and provides a new feature discovery mechanism. Make it visible to KVM guests. Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-07arm/arm64: KVM: Implement PSCI 1.0 supportMarc Zyngier1-0/+3
PSCI 1.0 can be trivially implemented by providing the FEATURES call on top of PSCI 0.2 and returning 1.0 as the PSCI version. We happily ignore everything else, as they are either optional or are clarifications that do not require any additional change. PSCI 1.0 is now the default until we decide to add a userspace selection API. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-07arm/arm64: KVM: Add PSCI_VERSION helperMarc Zyngier1-2/+4
As we're about to trigger a PSCI version explosion, it doesn't hurt to introduce a PSCI_VERSION helper that is going to be used everywhere. Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-07arm/arm64: KVM: Consolidate the PSCI include filesMarc Zyngier1-0/+27
As we're about to update the PSCI support, and because I'm lazy, let's move the PSCI include file to include/kvm so that both ARM architectures can find it. Acked-by: Christoffer Dall <christoffer.dall@linaro.org> Tested-by: Ard Biesheuvel <ard.biesheuvel@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
2018-02-01Merge branch 'x86/hyperv' of ↵Radim Krčmář1-1/+1
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Topic branch for stable KVM clockource under Hyper-V. Thanks to Christoffer Dall for resolving the ARM conflict.
2018-01-02KVM: arm/arm64: Provide a get_input_level for the arch timerChristoffer Dall1-0/+2
The VGIC can now support the life-cycle of mapped level-triggered interrupts, and we no longer have to read back the timer state on every exit from the VM if we had an asserted timer interrupt signal, because the VGIC already knows if we hit the unlikely case where the guest disables the timer without ACKing the virtual timer interrupt. This means we rework a bit of the code to factor out the functionality to snapshot the timer state from vtimer_save_state(), and we can reuse this functionality in the sync path when we have an irqchip in userspace, and also to support our implementation of the get_input_level() function for the timer. This change also means that we can no longer rely on the timer's view of the interrupt line to set the active state, because we no longer maintain this state for mapped interrupts when exiting from the guest. Instead, we only set the active state if the virtual interrupt is active, and otherwise we simply let the timer fire again and raise the virtual interrupt from the ISR. Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2018-01-02KVM: arm/arm64: Support a vgic interrupt line level sample functionChristoffer Dall1-1/+12
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>
2017-12-18KVM: arm/arm64: timer: Don't set irq as forwarded if no usable GICMarc Zyngier1-1/+1
If we don't have a usable GIC, do not try to set the vcpu affinity as this is guaranteed to fail. Reported-by: Andre Przywara <andre.przywara@arm.com> Reviewed-by: Andre Przywara <andre.przywara@arm.com> Tested-by: Andre Przywara <andre.przywara@arm.com> 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>
2017-11-29KVM: arm/arm64: Don't enable/disable physical timer access on VHEChristoffer Dall1-3/+0
After the timer optimization rework we accidentally end up calling physical timer enable/disable functions on VHE systems, which is neither needed nor correct, since the CNTHCTL_EL2 register format is different when HCR_EL2.E2H is set. The CNTHCTL_EL2 is initialized when CPUs become online in kvm_timer_init_vhe() and we don't have to call these functions on VHE systems, which also allows us to inline the non-VHE functionality. Reported-by: Jintack Lim <jintack@cs.columbia.edu> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-11-10KVM: arm/arm64: GICv4: Use the doorbell interrupt as an unblocking sourceMarc Zyngier1-0/+3
The doorbell interrupt is only useful if the vcpu is blocked on WFI. In all other cases, recieving a doorbell interrupt is just a waste of cycles. So let's only enable the doorbell if a vcpu is getting blocked, and disable it when it is unblocked. This is very similar to what we're doing for the background timer. Reviewed-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>
2017-11-10KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypassMarc Zyngier1-0/+8
Let's use the irq bypass mechanism also used for x86 posted interrupts to intercept the virtual PCIe endpoint configuration and establish our LPI->VLPI mapping. 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: Add init/teardown of the per-VM vPE irq domainMarc Zyngier1-0/+19
In order to control the GICv4 view of virtual CPUs, we rely on an irqdomain allocated for that purpose. Let's add a couple of helpers to that effect. At the same time, the vgic data structures gain new fields to track all this... erm... wonderful stuff. The way we hook into the vgic init is slightly convoluted. We need the vgic to be initialized (in order to guarantee that the number of vcpus is now fixed), and we must have a vITS (otherwise this is all very pointless). So we end-up calling the init from both vgic_init and vgic_its_create. 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: Add property field and per-VM predicateMarc Zyngier1-0/+3
Add a new has_gicv4 field in the global VGIC state that indicates whether the HW is GICv4 capable, as a per-VM predicate indicating if there is a possibility for a VM to support direct injection (the above being true and the VM having an ITS). 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> Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-11-06KVM: arm/arm64: vgic: restructure kvm_vgic_(un)map_phys_irqEric Auger1-3/+5
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: Rework kvm_timer_should_fireChristoffer Dall1-1/+2
kvm_timer_should_fire() can be called in two different situations from the kvm_vcpu_block(). The first case is before calling kvm_timer_schedule(), used for wait polling, and in this case the VCPU thread is running and the timer state is loaded onto the hardware so all we have to do is check if the virtual interrupt lines are asserted, becasue the timer interrupt handler functions will raise those lines as appropriate. The second case is inside the wait loop of kvm_vcpu_block(), where we have already called kvm_timer_schedule() and therefore the hardware will be disabled and the software view of the timer state is up to date (timer->loaded is false), and so we can simply check if the timer should fire by looking at the software state. Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-11-06KVM: arm/arm64: Get rid of kvm_timer_flush_hwstateChristoffer Dall1-1/+0
Now when both the vtimer and the ptimer when using both the in-kernel vgic emulation and a userspace IRQ chip are driven by the timer signals and at the vcpu load/put boundaries, instead of recomputing the timer state at every entry/exit to/from the guest, we can get entirely rid of the flush hwstate function. Signed-off-by: Christoffer Dall <cdall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
2017-11-06KVM: arm/arm64: Avoid timer save/restore in vcpu entry/exitChristoffer Dall1-2/+14
We don't need to save and restore the hardware timer state and examine if it generates interrupts on on every entry/exit to the guest. The timer hardware is perfectly capable of telling us when it has expired by signaling interrupts. When taking a vtimer interrupt in the host, we don't want to mess with the timer configuration, we just want to forward the physical interrupt to the guest as a virtual interrupt. We can use the split priority drop and deactivate feature of the GIC to do this, which leaves an EOI'ed interrupt active on the physical distributor, making sure we don't keep taking timer interrupts which would prevent the guest from running. We can then forward the physical interrupt to the VM using the HW bit in the LR of the GIC, like we do already, which lets the guest directly deactivate both the physical and virtual timer simultaneously, allowing the timer hardware to exit the VM and generate a new physical interrupt when the timer output is again asserted later on. We do need to capture this state when migrating VCPUs between physical CPUs, however, which we use the vcpu put/load functions for, which are called through preempt notifiers whenever the thread is scheduled away from the CPU or called directly if we return from the ioctl to userspace. One caveat is that we have to save and restore the timer state in both kvm_timer_vcpu_[put/load] and kvm_timer_[schedule/unschedule], because we can have the following flows: 1. kvm_vcpu_block 2. kvm_timer_schedule 3. schedule 4. kvm_timer_vcpu_put (preempt notifier) 5. schedule (vcpu thread gets scheduled back) 6. kvm_timer_vcpu_load (preempt notifier) 7. kvm_timer_unschedule And a version where we don't actually call schedule: 1. kvm_vcpu_block 2. kvm_timer_schedule 7. kvm_timer_unschedule Since kvm_timer_[schedule/unschedule] may not be followed by put/load, but put/load also may be called independently, we call the timer save/restore functions from both paths. Since they rely on the loaded flag to never save/restore when unnecessary, this doesn't cause any harm, and we ensure that all invokations of either set of functions work as intended. An added benefit beyond not having to read and write the timer sysregs on every entry and exit is that we no longer have to actively write the active state to the physical distributor, because we configured the irq for the vtimer to only get a priority drop when handling the interrupt in the GIC driver (we called irq_set_vcpu_affinity()), and the interrupt stays active after firing on the host. Reviewed-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-11-06KVM: arm/arm64: Use separate timer for phys timer emulationChristoffer Dall1-0/+3
We were using the same hrtimer for emulating the physical timer and for making sure a blocking VCPU thread would be eventually woken up. That worked fine in the previous arch timer design, but as we are about to actually use the soft timer expire function for the physical timer emulation, change the logic to use a dedicated hrtimer. This has the added benefit of not having to cancel any work in the sync path, which in turn allows us to run the flush and sync with IRQs disabled. Note that the hrtimer used to program the host kernel's timer to generate an exit from the guest when the emulated physical timer fires never has to inject any work, and to share the soft_timer_cancel() function with the bg_timer, we change the function to only cancel any pending work if the pointer to the work struct is not null. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-11-06KVM: arm/arm64: Rename soft timer to bg_timerChristoffer Dall1-1/+1
As we are about to introduce a separate hrtimer for the physical timer, call this timer bg_timer, because we refer to this timer as the background timer in the code and comments elsewhere. Signed-off-by: Christoffer Dall <cdall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
2017-11-06KVM: arm/arm64: Make timer_arm and timer_disarm helpers more genericChristoffer Dall1-3/+0
We are about to add an additional soft timer to the arch timer state for a VCPU and would like to be able to reuse the functions to program and cancel a timer, so we make them slightly more generic and rename to make it more clear that these functions work on soft timers and not the hardware resource that this code is managing. The armed flag on the timer state is only used to assert a condition, and we don't rely on this assertion in any meaningful way, so we can simply get rid of this flack and slightly reduce complexity. Acked-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-07-25KVM: arm/arm64: PMU: Fix overflow interrupt injectionAndrew Jones1-2/+0
kvm_pmu_overflow_set() is called from perf's interrupt handler, making the call of kvm_vgic_inject_irq() from it introduced with "KVM: arm/arm64: PMU: remove request-less vcpu kick" a really bad idea, as it's quite easy to try and retake a lock that the interrupted context is already holding. The fix is to use a vcpu kick, leaving the interrupt injection to kvm_pmu_sync_hwstate(), like it was doing before the refactoring. We don't just revert, though, because before the kick was request-less, leaving the vcpu exposed to the request-less vcpu kick race, and also because the kick was used unnecessarily from register access handlers. Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Andrew Jones <drjones@redhat.com> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-15KVM: arm64: vgic-v3: Add hook to handle guest GICv3 sysreg accesses at EL2Marc Zyngier1-0/+1
In order to start handling guest access to GICv3 system registers, let's add a hook that will get called when we trap a system register access. This is gated by a new static key (vgic_v3_cpuif_trap). Tested-by: Alexander Graf <agraf@suse.de> Acked-by: David Daney <david.daney@cavium.com> Reviewed-by: Eric Auger <eric.auger@redhat.com> Reviewed-by: Christoffer Dall <cdall@linaro.org> Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15Merge branch 'kvmarm-master/master' into HEADMarc Zyngier1-1/+4
2017-06-08KVM: arm/arm64: Don't assume initialized vgic when setting PMU IRQChristoffer Dall1-0/+2
The PMU IRQ number is set through the VCPU device's KVM_SET_DEVICE_ATTR ioctl handler for the KVM_ARM_VCPU_PMU_V3_IRQ attribute, but there is no enforced or stated requirement that this must happen after initializing the VGIC. As a result, calling vgic_valid_spi() which relies on the nr_spis being set during the VGIC init can incorrectly fail. Introduce irq_is_spi, which determines if an IRQ number is within the SPI range without verifying it against the actual VGIC properties. Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-08KVM: arm/arm64: Disallow userspace control of in-kernel IRQ linesChristoffer Dall1-3/+1
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 Dall1-0/+5
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>
2017-06-08KVM: arm/arm64: Allow setting the timer IRQ numbers from userspaceChristoffer Dall1-0/+4
First we define an ABI using the vcpu devices that lets userspace set the interrupt numbers for the various timers on both the 32-bit and 64-bit KVM/ARM implementations. Second, we add the definitions for the groups and attributes introduced by the above ABI. (We add the PMU define on the 32-bit side as well for symmetry and it may get used some day.) Third, we set up the arch-specific vcpu device operation handlers to call into the timer code for anything related to the KVM_ARM_VCPU_TIMER_CTRL group. Fourth, we implement support for getting and setting the timer interrupt numbers using the above defined ABI in the arch timer code. Fifth, we introduce error checking upon enabling the arch timer (which is called when first running a VCPU) to check that all VCPUs are configured to use the same PPI for the timer (as mandated by the architecture) and that the virtual and physical timers are not configured to use the same IRQ number. Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-08KVM: arm/arm64: Move timer IRQ default init to arch_timer.cChristoffer Dall1-3/+1
We currently initialize the arch timer IRQ numbers from the reset code, presumably because we once intended to model multiple CPU or SoC types from within the kernel and have hard-coded reset values in the reset code. As we are moving towards userspace being in charge of more fine-grained CPU emulation and stitching together the pieces needed to emulate a particular type of CPU, we should no longer have a tight coupling between resetting a VCPU and setting IRQ numbers. Therefore, move the logic to define and use the default IRQ numbers to the timer code and set the IRQ number immediately when creating the VCPU. Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-08KVM: arm/arm64: Move irq_is_ppi() to header fileChristoffer Dall1-0/+2
We are about to need this define in the arch timer code as well so move it to a common location. Signed-off-by: Christoffer Dall <cdall@linaro.org> Acked-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-08KVM: arm64: Allow creating the PMU without the in-kernel GICChristoffer Dall1-0/+6
Since we got support for devices in userspace which allows reporting the PMU overflow output status to userspace, we should actually allow creating the PMU on systems without an in-kernel irqchip, which in turn requires us to slightly clarify error codes for the ABI and move things around for the initialization phase. Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-05-18KVM: arm/arm64: Fix bug when registering redist iodevsChristoffer Dall1-1/+4
If userspace creates the VCPUs after initializing the VGIC, then we end up in a situation where we trigger a bug in kvm_vcpu_get_idx(), because it is called prior to adding the VCPU into the vcpus array on the VM. There is no tight coupling between the VCPU index and the area of the redistributor region used for the VCPU, so we can simply ensure that all creations of redistributors are serialized per VM, and increment an offset when we successfully add a redistributor. The vgic_register_redist_iodev() function can be called from two paths: vgic_redister_all_redist_iodev() which is called via the kvm_vgic_addr() device attribute handler. This patch already holds the kvm->lock mutex. The other path is via kvm_vgic_vcpu_init, which is called through a longer chain from kvm_vm_ioctl_create_vcpu(), which releases the kvm->lock mutex just before calling kvm_arch_vcpu_create(), so we can simply take this mutex again later for our purposes. Fixes: ab6f468c10 ("KVM: arm/arm64: Register iodevs when setting redist base and creating VCPUs") Signed-off-by: Christoffer Dall <cdall@linaro.org> Tested-by: Jean-Philippe Brucker <jean-philippe.brucker@arm.com> Reviewed-by: Eric Auger <eric.auger@redhat.com>
2017-05-09Merge tag 'kvm-arm-for-v4.12-round2' of ↵Paolo Bonzini1-1/+4
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
2017-05-09KVM: arm/arm64: Get rid of its->initialized fieldMarc Zyngier1-1/+0
The its->initialized doesn't bring much to the table, and creates unnecessary ordering between setting the address and initializing it (which amounts to exactly nothing). Let's kill it altogether, making KVM_DEV_ARM_VGIC_CTRL_INIT the no-op it deserves to be. Signed-off-by: Marc Zyngier <marc.zyngier@arm.com> Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com>
2017-05-09KVM: arm/arm64: Register iodevs when setting redist base and creating VCPUsChristoffer Dall1-0/+1
Instead of waiting with registering KVM iodevs until the first VCPU is run, we can actually create the iodevs when the redist base address is set. The only downside is that we must now also check if we need to do this for VCPUs which are created after creating the VGIC, because there is no enforced ordering between creating the VGIC (and setting its base addresses) and creating the VCPUs. Signed-off-by: Christoffer Dall <cdall@linaro.org> Reviewed-by: Eric Auger <eric.auger@redhat.com>