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 <levinsasha...@gmail.com>
---
tools/kvm/virtio/rng.c | 27 ++++++++++++++++++++++++++-
1 files changed, 26 insertions(+), 1 deletions(-)
diff --git a/tools/kvm/virtio/rng.c b/tools/kvm/virtio/rng.c
index 1a3bda3..d5d7795c 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 <linux/virtio_ring.h>
#include <linux/virtio_rng.h>
@@ -154,6 +155,7 @@ static bool virtio_rng_pci_io_out(struct ioport *ioport,
struct kvm *kvm, u16 po
break;
case VIRTIO_PCI_QUEUE_NOTIFY: {
u16 queue_index;
+ printf("regular exit");
queue_index = ioport__read16(data);
thread_pool__do_job(rdev->jobs[queue_index].job_id);
break;
@@ -177,11 +179,19 @@ 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 +223,20 @@ 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 +246,7 @@ 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);
}
}
--
1.7.5.rc3
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