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 two patches, 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 third 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.
Jinhao Fan (4): hw/nvme: avoid unnecessary call to irq (de)assertion functions hw/nvme: add option to (de)assert irq with eventfd hw/nvme: use irqfd to send interrupts hw/nvme: add MSI-x mask handlers for irqfd hw/nvme/ctrl.c | 251 +++++++++++++++++++++++++++++++++++++++---- hw/nvme/nvme.h | 7 ++ hw/nvme/trace-events | 3 + 3 files changed, 243 insertions(+), 18 deletions(-) -- 2.25.1
