From b600b5f6ce62d6e2e862eeb1d360595b571b21d5 Mon Sep 17 00:00:00 2001 From: Sasha Levin Date: Fri, 27 May 2011 19:18:40 +0300 Subject: [PATCH] kvm tools: Use ioeventfd in virtio-rng Use ioeventfds to receive notifications of IO events in virtio-rng. Doing so prevents an exit every time we need to supply randomness to the guest. Signed-off-by: Sasha Levin [ penberg@kernel.org: kill debugging printf ] Signed-off-by: Pekka Enberg --- tools/kvm/virtio/rng.c | 26 +++++++++++++++++++++++++- 1 file changed, 25 insertions(+), 1 deletion(-) diff --git a/tools/kvm/virtio/rng.c b/tools/kvm/virtio/rng.c index 1a3bda3b0040..ede0e2b85cff 100644 --- a/tools/kvm/virtio/rng.c +++ b/tools/kvm/virtio/rng.c @@ -10,6 +10,7 @@ #include "kvm/pci.h" #include "kvm/threadpool.h" #include "kvm/irq.h" +#include "kvm/ioeventfd.h" #include #include @@ -177,11 +178,19 @@ static struct ioport_operations virtio_rng_io_ops = { .io_out = virtio_rng_pci_io_out, }; +static void ioevent_callback(struct kvm *kvm, void *param) +{ + struct rng_dev_job *job = param; + + thread_pool__do_job(job->job_id); +} + void virtio_rng__init(struct kvm *kvm) { - u8 pin, line, dev; + u8 pin, line, dev, i; u16 rdev_base_addr; struct rng_dev *rdev; + struct ioevent ioevent; rdev = malloc(sizeof(*rdev)); if (rdev == NULL) @@ -213,6 +222,20 @@ void virtio_rng__init(struct kvm *kvm) pci__register(&rdev->pci_hdr, dev); list_add_tail(&rdev->list, &rdevs); + + for (i = 0; i < NUM_VIRT_QUEUES; i++) { + ioevent = (struct ioevent) { + .io_addr = rdev_base_addr + VIRTIO_PCI_QUEUE_NOTIFY, + .io_len = sizeof(u16), + .fn = ioevent_callback, + .fn_ptr = &rdev->jobs[i], + .datamatch = i, + .fn_kvm = kvm, + .fd = eventfd(0, 0), + }; + + ioeventfd__add_event(&ioevent); + } } void virtio_rng__delete_all(struct kvm *kvm) @@ -222,6 +245,7 @@ void virtio_rng__delete_all(struct kvm *kvm) rdev = list_first_entry(&rdevs, struct rng_dev, list); list_del(&rdev->list); + ioeventfd__del_event(rdev->base_addr + VIRTIO_PCI_QUEUE_NOTIFY, 0); free(rdev); } } -- 2.39.5