On 20/08/2017 22:56, Paul E. McKenney wrote: >> KVM: async_pf: avoid async pf injection when in guest mode >> KVM: cpuid: Fix read/write out-of-bounds vulnerability in cpuid emulation >> arm: KVM: Allow unaligned accesses at HYP >> arm64: KVM: Allow unaligned accesses at EL2 >> arm64: KVM: Preserve RES1 bits in SCTLR_EL2 >> KVM: arm/arm64: Handle possible NULL stage2 pud when ageing pages >> KVM: nVMX: Fix exception injection >> kvm: async_pf: fix rcu_irq_enter() with irqs enabled >> KVM: arm/arm64: vgic-v3: Fix nr_pre_bits bitfield extraction >> KVM: s390: fix ais handling vs cpu model >> KVM: arm/arm64: Fix isues with GICv2 on GICv3 migration >> >> Nothing really stands out to me which would "fix" the issue. > > My guess would be an undo of the change that provoked the problem > in the first place. Did you try bisecting within the above group > of commits? > > Either way, CCing Paolo for his thoughts? There is "kvm: async_pf: fix rcu_irq_enter() with irqs enabled", but it would have caused splats, not deadlocks. If you are using nested virtualization, "KVM: async_pf: avoid async pf injection when in guest mode" can be a wildcard, but only if you have memory pressure. My bet is still on the former changing the timing just a little bit. Paolo
