This patch series changes qemu-nvme's interrupt emulation to use event notifiers, which can ensure thread-safe interrupt delivery when iothread is used. In the first patche, I convert qemu-nvme's IO emulation logic to send irq via eventfd, so that the actual assertion and deassertion is always done in the main loop thread with BQL held. In the second patch, support is added to send irq via KVM irqfd, bypassing qemu's MSI-x emulation. In the last patch, I add MSI-x mask handlers when irqfd is enabled so that qemu-nvme knows which vector is masked even when qemu's MSI-x emulation is bypassed.
Changes since v1: - Made nvme_irq_(de)assert wrappers around eventfd call and actual irq assertion - Dropped the previous first patch to avoid duplicate checks for irq_enabled and msix_enabled Jinhao Fan (3): hw/nvme: support irq(de)assertion with eventfd hw/nvme: use KVM irqfd when available hw/nvme: add MSI-x mask handlers for irqfd hw/nvme/ctrl.c | 264 ++++++++++++++++++++++++++++++++++++++++--- hw/nvme/nvme.h | 7 ++ hw/nvme/trace-events | 3 + 3 files changed, 257 insertions(+), 17 deletions(-) -- 2.25.1
