From: Jason Wang <jasowang@redhat.com>
To: Si-Wei Liu <si-wei.liu@oracle.com>,
mst@redhat.com, qemu-devel@nongnu.org
Cc: elic@nvidia.com
Subject: Re: [PATCH 2/2] vhost-vdpa: doorbell mapping support
Date: Thu, 6 May 2021 10:17:59 +0800 [thread overview]
Message-ID: <cb97a251-ed9e-4417-4aab-527a428c86d0@redhat.com> (raw)
In-Reply-To: <c2a0e640-4f76-c6a3-12a7-756204473030@oracle.com>
在 2021/5/1 上午6:32, Si-Wei Liu 写道:
>
>
> On 4/15/2021 1:04 AM, Jason Wang wrote:
>> This patch implements the doorbell mapping support for
>> vhost-vDPA. This is simply done by using mmap()/munmap() for the
>> vhost-vDPA fd during device start/stop. For the device without
>> doorbell support, we fall back to eventfd based notification
>> gracefully.
>>
>> Signed-off-by: Jason Wang <jasowang@redhat.com>
>> ---
>> hw/virtio/vhost-vdpa.c | 85 ++++++++++++++++++++++++++++++++++
>> include/hw/virtio/vhost-vdpa.h | 7 +++
>> 2 files changed, 92 insertions(+)
>>
>> diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
>> index dd4321bac2..c3a3b7566f 100644
>> --- a/hw/virtio/vhost-vdpa.c
>> +++ b/hw/virtio/vhost-vdpa.c
>> @@ -285,12 +285,95 @@ static int vhost_vdpa_init(struct vhost_dev
>> *dev, void *opaque)
>> return 0;
>> }
>> +static void vhost_vdpa_host_notifier_uninit(struct vhost_dev *dev,
>> + int queue_index)
>> +{
>> + size_t page_size = qemu_real_host_page_size;
>> + struct vhost_vdpa *v = dev->opaque;
>> + VirtIODevice *vdev = dev->vdev;
>> + VhostVDPAHostNotifier *n;
>> +
>> + n = &v->notifier[queue_index];
>> +
>> + if (n->addr) {
>> + virtio_queue_set_host_notifier_mr(vdev, queue_index, &n->mr,
>> false);
>> + object_unparent(OBJECT(&n->mr));
>> + munmap(n->addr, page_size);
>> + n->addr = NULL;
>> + }
>> +}
>> +
>> +static void vhost_vdpa_host_notifiers_uninit(struct vhost_dev *dev,
>> int n)
>> +{
>> + int i;
>> +
>> + for (i = 0; i < n; i++) {
>> + vhost_vdpa_host_notifier_uninit(dev, i);
>> + }
>> +}
>> +
>> +static int vhost_vdpa_host_notifier_init(struct vhost_dev *dev, int
>> queue_index)
>> +{
>> + size_t page_size = qemu_real_host_page_size;
>> + struct vhost_vdpa *v = dev->opaque;
>> + VirtIODevice *vdev = dev->vdev;
>> + VhostVDPAHostNotifier *n;
>> + int fd = v->device_fd;
>> + void *addr;
>> + char *name;
>> +
>> + vhost_vdpa_host_notifier_uninit(dev, queue_index);
>> +
>> + n = &v->notifier[queue_index];
>> +
>> + addr = mmap(NULL, page_size, PROT_WRITE, MAP_SHARED, fd,
>> + queue_index * page_size);
>> + if (addr == MAP_FAILED) {
>> + goto err;
>> + }
>> +
>> + name = g_strdup_printf("vhost-vdpa/host-notifier@%p mmaps[%d]",
>> + v, queue_index);
>> + memory_region_init_ram_device_ptr(&n->mr, OBJECT(vdev), name,
>> + page_size, addr);
>> + g_free(name);
>> +
>> + if (virtio_queue_set_host_notifier_mr(vdev, queue_index, &n->mr,
>> true)) {
>> + munmap(addr, page_size);
>> + goto err;
>> + }
>> + n->addr = addr;
>> +
>> + return 0;
>> +
>> +err:
>> + return -1;
>> +}
>> +
>> +static void vhost_vdpa_host_notifiers_init(struct vhost_dev *dev)
>> +{
>> + int i;
>> +
>> + for (i = 0; i < dev->nvqs; i++) {
>> + if (vhost_vdpa_host_notifier_init(dev, i)) {
> Shouldn't (hdev->vq_index + i) be used instead of i? or it's assumed
> to be single QP for vhost-vdpa for the moment?
Only single queue pair is supported, I'm working on the multiqueue support.
> If the latter, would be good to add some comment.
I agree, and I think it's better to use vq_index + i to avoid future
changes.
>> + goto err;
>> + }
>> + }
>> +
>> + return;
>> +
>> +err:
>> + vhost_vdpa_host_notifiers_uninit(dev, i);
> I'm not sure if it is really the intent to leave other vqs behind - I
> presume that either none of them is mapped, or all mappable should be
> mapped. Why here just uninit the first unmappable vq?
I'm not sure I get here, there's a loop in
vhost_vdpa_host_notifiers_uninit(), so we either:
1) map all doorbells
or
2) no doorell is mapped
>
>> + return;
>> +}
>> +
>> static int vhost_vdpa_cleanup(struct vhost_dev *dev)
>> {
>> struct vhost_vdpa *v;
>> assert(dev->vhost_ops->backend_type == VHOST_BACKEND_TYPE_VDPA);
>> v = dev->opaque;
>> trace_vhost_vdpa_cleanup(dev, v);
>> + vhost_vdpa_host_notifiers_uninit(dev, dev->nvqs);
>> memory_listener_unregister(&v->listener);
>> dev->opaque = NULL;
>> @@ -467,6 +550,7 @@ static int vhost_vdpa_dev_start(struct vhost_dev
>> *dev, bool started)
>> if (started) {
>> uint8_t status = 0;
>> memory_listener_register(&v->listener, &address_space_memory);
>> + vhost_vdpa_host_notifiers_init(dev);
>> vhost_vdpa_set_vring_ready(dev);
>> vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_DRIVER_OK);
>> vhost_vdpa_call(dev, VHOST_VDPA_GET_STATUS, &status);
>> @@ -476,6 +560,7 @@ static int vhost_vdpa_dev_start(struct vhost_dev
>> *dev, bool started)
>> vhost_vdpa_reset_device(dev);
>> vhost_vdpa_add_status(dev, VIRTIO_CONFIG_S_ACKNOWLEDGE |
>> VIRTIO_CONFIG_S_DRIVER);
>> + vhost_vdpa_host_notifiers_uninit(dev, dev->nvqs);
>> memory_listener_unregister(&v->listener);
>> return 0;
>> diff --git a/include/hw/virtio/vhost-vdpa.h
>> b/include/hw/virtio/vhost-vdpa.h
>> index 9b81a409da..0f11ecff34 100644
>> --- a/include/hw/virtio/vhost-vdpa.h
>> +++ b/include/hw/virtio/vhost-vdpa.h
>> @@ -14,11 +14,18 @@
>> #include "hw/virtio/virtio.h"
>> +typedef struct VhostVDPAHostNotifier {
>> + MemoryRegion mr;
>> + void *addr;
>> +} VhostVDPAHostNotifier;
>> +
>> typedef struct vhost_vdpa {
>> int device_fd;
>> uint32_t msg_type;
>> MemoryListener listener;
>> struct vhost_dev *dev;
>> + VhostVDPAHostNotifier notifier[VIRTIO_QUEUE_MAX];
>> + bool host_notifier_set;
> What this host_notifier_set is used for? Doesn't seem it's ever set or
> referenced?
Right, will remove it.
Thanks
>
>> } VhostVDPA;
>> extern AddressSpace address_space_memory;
> Thanks,
> -Siwei
>
next prev parent reply other threads:[~2021-05-06 2:19 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-15 8:04 [PATCH 0/2] vhost-vDPA: doorbell mapping support Jason Wang
2021-04-15 8:04 ` [PATCH 1/2] vhost-vdpa: skip ram device from the IOTLB mapping Jason Wang
2021-04-15 8:04 ` [PATCH 2/2] vhost-vdpa: doorbell mapping support Jason Wang
2021-04-30 22:32 ` Si-Wei Liu
2021-05-06 2:17 ` Jason Wang [this message]
2021-05-06 21:15 ` Si-Wei Liu
2021-05-04 8:38 ` [PATCH 0/2] vhost-vDPA: " Michael S. Tsirkin
2021-05-06 7:20 ` Jason Wang
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=cb97a251-ed9e-4417-4aab-527a428c86d0@redhat.com \
--to=jasowang@redhat.com \
--cc=elic@nvidia.com \
--cc=mst@redhat.com \
--cc=qemu-devel@nongnu.org \
--cc=si-wei.liu@oracle.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).