On Thu, Sep 24, 2020 at 12:07:04PM +0100, Alexandru Elisei wrote: > From: Julien Thierry <julien.thierry@xxxxxxx> > > kvm_vcpu_kick() is not NMI safe. When the overflow handler is called from > NMI context, defer waking the vcpu to an irq_work queue. > > A vcpu can be freed while it's not running by kvm_destroy_vm(). Prevent > running the irq_work for a non-existent vcpu by calling irq_work_sync() on > the PMU destroy path. > > Cc: Julien Thierry <julien.thierry.kdev@xxxxxxxxx> > Cc: Marc Zyngier <marc.zyngier@xxxxxxx> > Cc: Will Deacon <will.deacon@xxxxxxx> > Cc: Mark Rutland <mark.rutland@xxxxxxx> > Cc: Catalin Marinas <catalin.marinas@xxxxxxx> > Cc: James Morse <james.morse@xxxxxxx> > Cc: Suzuki K Pouloze <suzuki.poulose@xxxxxxx> > Cc: kvm@xxxxxxxxxxxxxxx > Cc: kvmarm@xxxxxxxxxxxxxxxxxxxxx > Signed-off-by: Julien Thierry <julien.thierry@xxxxxxx> > Tested-by: Sumit Garg <sumit.garg@xxxxxxxxxx> (Developerbox) > [Alexandru E.: Added irq_work_sync()] > Signed-off-by: Alexandru Elisei <alexandru.elisei@xxxxxxx> > --- > I suggested in v6 that I will add an irq_work_sync() to > kvm_pmu_vcpu_reset(). It turns out it's not necessary: a vcpu reset is done > by the vcpu being reset with interrupts enabled, which means all the work > has had a chance to run before the reset takes place. I don't understand this ^^ But the patch itself looks good, so I'm going to queue this lot anyway! Will
