On 13/04/21 13:03, Lai Jiangshan wrote:
This patch claims that it has a place to stash the IRQ when EFLAGS.IF=0, but inject_pending_event() seams to ignore EFLAGS.IF and queues the IRQ to the guest directly in the first branch of using "kvm_x86_ops.set_irq(vcpu)".
This is only true for pure-userspace irqchip. For split-irqchip, in which case the "place to stash" the interrupt is vcpu->arch.pending_external_vector.
For pure-userspace irqchip, KVM_INTERRUPT only cares about being able to stash the interrupt in vcpu->arch.interrupt.injected. It is indeed wrong for userspace to call KVM_INTERRUPT if the vCPU is not ready for interrupt injection, but KVM_INTERRUPT does not return an error.
Ignoring the fact that this would be incorrect use of the API, are you saying that the incorrect injection was not possible before this patch?
Paolo
