While testing KVM running on PREEMPT_RT, starting guest could simply freeze the machine. This is because we are using spinlocks for VGIC locks, which is invalid in the VGIC case since the locks must be take with interrupts disabled.
The solution is to use raw_spinlock instead of spinlocks. Replacing those locks also highlighted an issue where we attempt to cond_resched with interrupts disabled. Patch 1 fixes the cond_resched issue. Patch 2-4 replace the VGIC spinlocks with raw_spinlocks Cheers, Julien --> Julien Thierry (4): KVM: arm/arm64: vgic: Do not cond_resched_lock() with IRQs disabled KVM: arm/arm64: vgic: Make vgic_irq->irq_lock a raw_spinlock KVM: arm/arm64: vgic: Make vgic_dist->lpi_list_lock a raw_spinlock KVM: arm/arm64: vgic: Make vgic_cpu->ap_list_lock a raw_spinlock include/kvm/arm_vgic.h | 6 +- virt/kvm/arm/vgic/vgic-debug.c | 4 +- virt/kvm/arm/vgic/vgic-init.c | 8 +-- virt/kvm/arm/vgic/vgic-its.c | 22 +++---- virt/kvm/arm/vgic/vgic-mmio-v2.c | 14 ++--- virt/kvm/arm/vgic/vgic-mmio-v3.c | 12 ++-- virt/kvm/arm/vgic/vgic-mmio.c | 67 +++++++++----------- virt/kvm/arm/vgic/vgic-v2.c | 4 +- virt/kvm/arm/vgic/vgic-v3.c | 8 +-- virt/kvm/arm/vgic/vgic.c | 130 +++++++++++++++++++-------------------- 10 files changed, 132 insertions(+), 143 deletions(-) -- 1.9.1 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
