On Tue, Jun 27, 2017 at 03:00:10PM +0200, Alexander Graf wrote: > > > + /* XXX PMU IRQ is missing */ > > > > So I was wondering why you chose not to wire up the PMU in order to finish > > Because the PMU IRQ is only available from the machine file, so it'll need > some more plumbing to get the qemu_irq object available from kvm.c. OK, I just wrote a patch based on this patch for the PMU and will post it in a second. > > > this off, since I knew KVM has commit 3dbbdf78636e "KVM: arm/arm64: Report > > PMU overflow interrupts to userspace irqchip", which I presume should > > allow the PMU to work too. However, attempting to start a guest with > > -machine virt,accel=kvm,kernel-irqchip=off -cpu host,pmu=on doesn't provide > > it a PMU. AFAICT, that's only because KVM still has > > > > /* > > * We currently require an in-kernel VGIC to use the PMU emulation, > > * because we do not support forwarding PMU overflow interrupts to > > * userspace yet. > > */ > > if (!irqchip_in_kernel(vcpu->kvm) || !vgic_initialized(vcpu->kvm)) > > return -ENODEV; > > > > in kvm_arm_pmu_v3_init(). Anyone know why that wasn't removed with > > 3dbbdf78636e? > > I guess it should get removed when the PMU sync works? OK, I'll post the KVM patch at the same time. I noticed another thing while testing with a virtio-scsi disk; I get this on output when booting with userspace irqchip virtio-scsi: Failed to set guest notifiers (-11), ensure -enable-kvm is set qemu-system-aarch64: virtio_bus_start_ioeventfd: failed. Fallback to userspace (slower). Just a warning, but I guess it should be removed, at least when the user has explicitly asked for a userspace irqchip with kernel-irqchip=no. Thanks, drew
