cfn/computing-offload
Code Issues Proposed changes
computing-offload/generic_vdpa/qemu/vhost-Add-Shadow-VirtQueue-kick-forwarding-capabilit.patch
jiangdongxu 79c4324644 add generic_vdpa basecode 
Change-Id: I2d302dda68298877c65c99147f5bf22186a59aac
2024-09-19 17:19:46 +08:00

396 lines
12 KiB
Diff
Raw Blame History

From 41585669f68a3896d6d8a5bea868f192b30fad76 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= <eperezma@redhat.com>
Date: Mon, 14 Mar 2022 18:34:42 +0100
Subject: [PATCH] vhost: Add Shadow VirtQueue kick forwarding capabilities
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit
At this mode no buffer forwarding will be performed in SVQ mode: Qemu
will just forward the guest's kicks to the device.
Host memory notifiers regions are left out for simplicity, and they will
not be addressed in this series.
Signed-off-by: Eugenio Pérez <eperezma@redhat.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Jason Wang <jasowang@redhat.com>
Signed-off-by: fangyi <eric.fangyi@huawei.com>
---
hw/virtio/vhost-shadow-virtqueue.c | 55 +++++++++++
hw/virtio/vhost-shadow-virtqueue.h | 14 +++
hw/virtio/vhost-vdpa.c | 144 ++++++++++++++++++++++++++++-
include/hw/virtio/vhost-vdpa.h | 4 +
4 files changed, 215 insertions(+), 2 deletions(-)
diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c
index c1db02c53e..e5da907b8e 100644
--- a/hw/virtio/vhost-shadow-virtqueue.c
+++ b/hw/virtio/vhost-shadow-virtqueue.c
@@ -11,6 +11,59 @@
#include "hw/virtio/vhost-shadow-virtqueue.h"
#include "qemu/error-report.h"
+#include "qemu/main-loop.h"
+#include "linux-headers/linux/vhost.h"
+
+/**
+ * Forward guest notifications.
+ *
+ * @n: guest kick event notifier, the one that guest set to notify svq.
+ */
+static void vhost_handle_guest_kick(EventNotifier *n)
+{
+ VhostShadowVirtqueue *svq = container_of(n, VhostShadowVirtqueue, svq_kick);
+ event_notifier_test_and_clear(n);
+ event_notifier_set(&svq->hdev_kick);
+}
+
+/**
+ * Set a new file descriptor for the guest to kick the SVQ and notify for avail
+ *
+ * @svq: The svq
+ * @svq_kick_fd: The svq kick fd
+ *
+ * Note that the SVQ will never close the old file descriptor.
+ */
+void vhost_svq_set_svq_kick_fd(VhostShadowVirtqueue *svq, int svq_kick_fd)
+{
+ EventNotifier *svq_kick = &svq->svq_kick;
+ bool poll_stop = VHOST_FILE_UNBIND != event_notifier_get_fd(svq_kick);
+ bool poll_start = svq_kick_fd != VHOST_FILE_UNBIND;
+
+ if (poll_stop) {
+ event_notifier_set_handler(svq_kick, NULL);
+ }
+
+ /*
+ * event_notifier_set_handler already checks for guest's notifications if
+ * they arrive at the new file descriptor in the switch, so there is no
+ * need to explicitly check for them.
+ */
+ if (poll_start) {
+ event_notifier_init_fd(svq_kick, svq_kick_fd);
+ event_notifier_set(svq_kick);
+ event_notifier_set_handler(svq_kick, vhost_handle_guest_kick);
+ }
+}
+
+/**
+ * Stop the shadow virtqueue operation.
+ * @svq: Shadow Virtqueue
+ */
+void vhost_svq_stop(VhostShadowVirtqueue *svq)
+{
+ event_notifier_set_handler(&svq->svq_kick, NULL);
+}
/**
* Creates vhost shadow virtqueue, and instructs the vhost device to use the
@@ -39,6 +92,7 @@ VhostShadowVirtqueue *vhost_svq_new(void)
goto err_init_hdev_call;
}
+ event_notifier_init_fd(&svq->svq_kick, VHOST_FILE_UNBIND);
return g_steal_pointer(&svq);
err_init_hdev_call:
@@ -56,6 +110,7 @@ err_init_hdev_kick:
void vhost_svq_free(gpointer pvq)
{
VhostShadowVirtqueue *vq = pvq;
+ vhost_svq_stop(vq);
event_notifier_cleanup(&vq->hdev_kick);
event_notifier_cleanup(&vq->hdev_call);
g_free(vq);
diff --git a/hw/virtio/vhost-shadow-virtqueue.h b/hw/virtio/vhost-shadow-virtqueue.h
index f1519e3c7b..1cbc87d5d8 100644
--- a/hw/virtio/vhost-shadow-virtqueue.h
+++ b/hw/virtio/vhost-shadow-virtqueue.h
@@ -18,8 +18,22 @@ typedef struct VhostShadowVirtqueue {
EventNotifier hdev_kick;
/* Shadow call notifier, sent to vhost */
EventNotifier hdev_call;
+
+ /*
+ * Borrowed virtqueue's guest to host notifier. To borrow it in this event
+ * notifier allows to recover the VhostShadowVirtqueue from the event loop
+ * easily. If we use the VirtQueue's one, we don't have an easy way to
+ * retrieve VhostShadowVirtqueue.
+ *
+ * So shadow virtqueue must not clean it, or we would lose VirtQueue one.
+ */
+ EventNotifier svq_kick;
} VhostShadowVirtqueue;
+void vhost_svq_set_svq_kick_fd(VhostShadowVirtqueue *svq, int svq_kick_fd);
+
+void vhost_svq_stop(VhostShadowVirtqueue *svq);
+
VhostShadowVirtqueue *vhost_svq_new(void);
void vhost_svq_free(gpointer vq);
diff --git a/hw/virtio/vhost-vdpa.c b/hw/virtio/vhost-vdpa.c
index 25a2f570a2..7331c8ee04 100644
--- a/hw/virtio/vhost-vdpa.c
+++ b/hw/virtio/vhost-vdpa.c
@@ -17,12 +17,14 @@
#include "hw/virtio/vhost.h"
#include "hw/virtio/vhost-backend.h"
#include "hw/virtio/virtio-net.h"
+#include "hw/virtio/vhost-shadow-virtqueue.h"
#include "hw/virtio/vhost-vdpa.h"
#include "exec/address-spaces.h"
#include "qemu/main-loop.h"
#include "cpu.h"
#include "trace.h"
#include "qemu-common.h"
+#include "qapi/error.h"
static unsigned int vhost_vdpa_used_memslots;
@@ -344,6 +346,30 @@ static bool vhost_vdpa_one_time_request(struct vhost_dev *dev)
return v->index != 0;
}
+static int vhost_vdpa_init_svq(struct vhost_dev *hdev, struct vhost_vdpa *v,
+ Error **errp)
+{
+ g_autoptr(GPtrArray) shadow_vqs = NULL;
+
+ if (!v->shadow_vqs_enabled) {
+ return 0;
+ }
+
+ shadow_vqs = g_ptr_array_new_full(hdev->nvqs, vhost_svq_free);
+ for (unsigned n = 0; n < hdev->nvqs; ++n) {
+ g_autoptr(VhostShadowVirtqueue) svq = vhost_svq_new();
+
+ if (unlikely(!svq)) {
+ error_setg(errp, "Cannot create svq %u", n);
+ return -1;
+ }
+ g_ptr_array_add(shadow_vqs, g_steal_pointer(&svq));
+ }
+
+ v->shadow_vqs = g_steal_pointer(&shadow_vqs);
+ return 0;
+}
+
static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp)
{
struct vhost_vdpa *v;
@@ -366,6 +392,10 @@ static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp)
dev->opaque = opaque ;
v->listener = vhost_vdpa_memory_listener;
v->msg_type = VHOST_IOTLB_MSG_V2;
+ ret = vhost_vdpa_init_svq(dev, v, errp);
+ if (ret) {
+ goto err;
+ }
vhost_vdpa_get_iova_range(v);
@@ -377,6 +407,10 @@ static int vhost_vdpa_init(struct vhost_dev *dev, void *opaque, Error **errp)
VIRTIO_CONFIG_S_DRIVER);
return 0;
+
+err:
+ ram_block_discard_disable(false);
+ return ret;
}
static void vhost_vdpa_host_notifier_uninit(struct vhost_dev *dev,
@@ -447,8 +481,14 @@ static void vhost_vdpa_host_notifiers_uninit(struct vhost_dev *dev, int n)
static void vhost_vdpa_host_notifiers_init(struct vhost_dev *dev)
{
+ struct vhost_vdpa *v = dev->opaque;
int i;
+ if (v->shadow_vqs_enabled) {
+ /* FIXME SVQ is not compatible with host notifiers mr */
+ return;
+ }
+
for (i = dev->vq_index; i < dev->vq_index + dev->nvqs; i++) {
if (vhost_vdpa_host_notifier_init(dev, i)) {
goto err;
@@ -462,6 +502,21 @@ err:
return;
}
+static void vhost_vdpa_svq_cleanup(struct vhost_dev *dev)
+{
+ struct vhost_vdpa *v = dev->opaque;
+ size_t idx;
+
+ if (!v->shadow_vqs) {
+ return;
+ }
+
+ for (idx = 0; idx < v->shadow_vqs->len; ++idx) {
+ vhost_svq_stop(g_ptr_array_index(v->shadow_vqs, idx));
+ }
+ g_ptr_array_free(v->shadow_vqs, true);
+}
+
static int vhost_vdpa_cleanup(struct vhost_dev *dev)
{
struct vhost_vdpa *v;
@@ -470,6 +525,7 @@ static int vhost_vdpa_cleanup(struct vhost_dev *dev)
trace_vhost_vdpa_cleanup(dev, v);
vhost_vdpa_host_notifiers_uninit(dev, dev->nvqs);
memory_listener_unregister(&v->listener);
+ vhost_vdpa_svq_cleanup(dev);
dev->opaque = NULL;
ram_block_discard_disable(false);
@@ -561,11 +617,26 @@ static int vhost_vdpa_get_device_id(struct vhost_dev *dev,
return ret;
}
+static void vhost_vdpa_reset_svq(struct vhost_vdpa *v)
+{
+ if (!v->shadow_vqs_enabled) {
+ return;
+ }
+
+ for (unsigned i = 0; i < v->shadow_vqs->len; ++i) {
+ VhostShadowVirtqueue *svq = g_ptr_array_index(v->shadow_vqs, i);
+ vhost_svq_stop(svq);
+ }
+}
+
static int vhost_vdpa_reset_device(struct vhost_dev *dev)
{
+ struct vhost_vdpa *v = dev->opaque;
int ret;
uint8_t status = 0;
+ vhost_vdpa_reset_svq(v);
+
ret = vhost_vdpa_call(dev, VHOST_VDPA_SET_STATUS, &status);
trace_vhost_vdpa_reset_device(dev, status);
return ret;
@@ -649,13 +720,74 @@ static int vhost_vdpa_get_config(struct vhost_dev *dev, uint8_t *config,
return ret;
}
+static int vhost_vdpa_set_vring_dev_kick(struct vhost_dev *dev,
+ struct vhost_vring_file *file)
+{
+ trace_vhost_vdpa_set_vring_kick(dev, file->index, file->fd);
+ return vhost_vdpa_call(dev, VHOST_SET_VRING_KICK, file);
+}
+
+/**
+ * Set the shadow virtqueue descriptors to the device
+ *
+ * @dev: The vhost device model
+ * @svq: The shadow virtqueue
+ * @idx: The index of the virtqueue in the vhost device
+ * @errp: Error
+ */
+static bool vhost_vdpa_svq_setup(struct vhost_dev *dev,
+ VhostShadowVirtqueue *svq, unsigned idx,
+ Error **errp)
+{
+ struct vhost_vring_file file = {
+ .index = dev->vq_index + idx,
+ };
+ const EventNotifier *event_notifier = &svq->hdev_kick;
+ int r;
+
+ file.fd = event_notifier_get_fd(event_notifier);
+ r = vhost_vdpa_set_vring_dev_kick(dev, &file);
+ if (unlikely(r != 0)) {
+ error_setg_errno(errp, -r, "Can't set device kick fd");
+ }
+
+ return r == 0;
+}
+
+static bool vhost_vdpa_svqs_start(struct vhost_dev *dev)
+{
+ struct vhost_vdpa *v = dev->opaque;
+ Error *err = NULL;
+ unsigned i;
+
+ if (!v->shadow_vqs) {
+ return true;
+ }
+
+ for (i = 0; i < v->shadow_vqs->len; ++i) {
+ VhostShadowVirtqueue *svq = g_ptr_array_index(v->shadow_vqs, i);
+ bool ok = vhost_vdpa_svq_setup(dev, svq, i, &err);
+ if (unlikely(!ok)) {
+ error_reportf_err(err, "Cannot setup SVQ %u: ", i);
+ return false;
+ }
+ }
+
+ return true;
+}
+
static int vhost_vdpa_dev_start(struct vhost_dev *dev, bool started)
{
struct vhost_vdpa *v = dev->opaque;
+ bool ok;
trace_vhost_vdpa_dev_start(dev, started);
if (started) {
vhost_vdpa_host_notifiers_init(dev);
+ ok = vhost_vdpa_svqs_start(dev);
+ if (unlikely(!ok)) {
+ return -1;
+ }
vhost_vdpa_set_vring_ready(dev);
} else {
vhost_vdpa_host_notifiers_uninit(dev, dev->nvqs);
@@ -727,8 +859,16 @@ static int vhost_vdpa_get_vring_base(struct vhost_dev *dev,
static int vhost_vdpa_set_vring_kick(struct vhost_dev *dev,
struct vhost_vring_file *file)
{
- trace_vhost_vdpa_set_vring_kick(dev, file->index, file->fd);
- return vhost_vdpa_call(dev, VHOST_SET_VRING_KICK, file);
+ struct vhost_vdpa *v = dev->opaque;
+ int vdpa_idx = file->index - dev->vq_index;
+
+ if (v->shadow_vqs_enabled) {
+ VhostShadowVirtqueue *svq = g_ptr_array_index(v->shadow_vqs, vdpa_idx);
+ vhost_svq_set_svq_kick_fd(svq, file->fd);
+ return 0;
+ } else {
+ return vhost_vdpa_set_vring_dev_kick(dev, file);
+ }
}
static int vhost_vdpa_set_vring_call(struct vhost_dev *dev,
diff --git a/include/hw/virtio/vhost-vdpa.h b/include/hw/virtio/vhost-vdpa.h
index 3ce79a646d..009a9f3b6b 100644
--- a/include/hw/virtio/vhost-vdpa.h
+++ b/include/hw/virtio/vhost-vdpa.h
@@ -12,6 +12,8 @@
#ifndef HW_VIRTIO_VHOST_VDPA_H
#define HW_VIRTIO_VHOST_VDPA_H
+#include <gmodule.h>
+
#include "hw/virtio/virtio.h"
#include "standard-headers/linux/vhost_types.h"
@@ -27,6 +29,8 @@ typedef struct vhost_vdpa {
bool iotlb_batch_begin_sent;
MemoryListener listener;
struct vhost_vdpa_iova_range iova_range;
+ bool shadow_vqs_enabled;
+ GPtrArray *shadow_vqs;
struct vhost_dev *dev;
VhostVDPAHostNotifier notifier[VIRTIO_QUEUE_MAX];
} VhostVDPA;
--
2.27.0
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