linux/include/kvm, branch v4.15

KVM: arm/arm64: timer: Don't set irq as forwarded if no usable GIC

2017-12-18T09:53:23Z

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 Reviewed-by: Andre Przywara Tested-by: Andre Przywara Reviewed-by: Christoffer Dall Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall

KVM: arm/arm64: Don't enable/disable physical timer access on VHE

2017-11-29T15:46:09Z

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 Signed-off-by: Christoffer Dall

KVM: arm/arm64: GICv4: Use the doorbell interrupt as an unblocking source

2017-11-10T08:43:22Z

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 Reviewed-by: Eric Auger Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall

KVM: arm/arm64: GICv4: Wire mapping/unmapping of VLPIs in VFIO irq bypass

2017-11-10T08:28:52Z

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 Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall

KVM: arm/arm64: GICv4: Add init/teardown of the per-VM vPE irq domain

2017-11-10T08:06:56Z

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 Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall

KVM: arm/arm64: GICv4: Add property field and per-VM predicate

2017-11-10T08:06:45Z

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 Reviewed-by: Eric Auger Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall

KVM: arm/arm64: vgic: restructure kvm_vgic_(un)map_phys_irq

2017-11-06T16:20:19Z

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 Signed-off-by: Eric Auger Signed-off-by: Marc Zyngier Signed-off-by: Christoffer Dall

KVM: arm/arm64: Rework kvm_timer_should_fire

2017-11-06T15:23:17Z

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 Reviewed-by: Marc Zyngier

KVM: arm/arm64: Get rid of kvm_timer_flush_hwstate

2017-11-06T15:23:16Z

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 Acked-by: Marc Zyngier

KVM: arm/arm64: Avoid timer save/restore in vcpu entry/exit

2017-11-06T15:23:14Z

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 Signed-off-by: Christoffer Dall