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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [UNIKRAFT/BALLOON v2 3/7] plat/drivers/balloon: KVM Virtio balloon driver implementation
From: Cezar Craciunoiu <cezar.craciunoiu@xxxxxxxxx>
The implementation is based on different Virtio drivers in the project.
It follows a similar structure to 9p/blk/etc. After adding the device,
the driver uses virtqueues to send/take memory to/from KVM.
Other functions will interact with the driver through the inflate_balloon
and deflate_balloon calls.
Signed-off-by: Cezar Craciunoiu <cezar.craciunoiu@xxxxxxxxx>
---
plat/drivers/balloon/balloon_drv.c | 371 +++++++++++++++++++++++++++++
1 file changed, 371 insertions(+)
create mode 100644 plat/drivers/balloon/balloon_drv.c
diff --git a/plat/drivers/balloon/balloon_drv.c
b/plat/drivers/balloon/balloon_drv.c
new file mode 100644
index 0000000..832eff8
--- /dev/null
+++ b/plat/drivers/balloon/balloon_drv.c
@@ -0,0 +1,371 @@
+/* SPDX-License-Identifier: BSD-3-Clause */
+/*
+ * Authors: Cason Schindler & Jack Raney <cason.j.schindler@xxxxxxxxx>
+ * Cezar Craciunoiu <cezar.craciunoiu@xxxxxxxxx>
+ *
+ * Copyright (c) 2019, The University of Texas at Austin. All rights reserved.
+ * 2020, University Politehnica of Bucharest. All rights
reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ *
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ * 3. Neither the name of the copyright holder nor the names of its
+ * contributors may be used to endorse or promote products derived from
+ * this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+ * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
+ * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
+ * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
+ * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
+ * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
+ * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
+ * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+ * POSSIBILITY OF SUCH DAMAGE.
+ *
+ * THIS HEADER MAY NOT BE EXTRACTED OR MODIFIED IN ANY WAY.
+ */
+#include <uk/plat/common/sections.h>
+#include <sys/types.h>
+#include <uk/assert.h>
+#include <kvm/config.h>
+#include <inttypes.h>
+#include <uk/alloc.h>
+#include <uk/sglist.h>
+#include <uk/list.h>
+#include <uk/assert.h>
+#include <uk/mutex.h>
+#include <virtio/virtio_ids.h>
+#include <virtio/virtio_bus.h>
+#include <virtio/virtqueue.h>
+#include <balloon/balloon.h>
+
+#define DRIVER_NAME "virtio-balloon"
+#define VTBALLOON_PAGES_PER_REQUEST 8192
+
+static struct uk_alloc *a;
+
+static struct virtio_balloon_device *global_vb;
+
+/* pages given to hypervisor (in the balloon) */
+struct balloon_pages {
+
+ uint32_t num_pages;
+
+};
+
+/* temporary storage for pages with which we are either
+ * inflating or deflating the balloon
+ */
+struct transport_pages {
+
+ uint32_t num_pages;
+ uint32_t *pages;
+
+};
+
+/* wrapper for virtio device */
+struct virtio_balloon_device {
+
+ struct virtio_dev *vdev;
+
+ struct virtqueue *inflate_vq, *deflate_vq;
+
+ __u16 infvq_id;
+ __u16 defvq_id;
+
+ char *tag;
+
+ struct balloon_pages *balloon;
+
+ struct transport_pages *transport;
+
+ uint64_t features;
+ uint32_t flags;
+
+ struct uk_mutex lock;
+};
+
+static void clear_transport(struct virtio_balloon_device *vb)
+{
+ int num = vb->transport->num_pages;
+ int i;
+
+ for (i = 0; i < num; i++) {
+ (vb->transport->pages)[i] = 0;
+ vb->transport->num_pages -= 1;
+ }
+}
+
+/*-
+ * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
+ *
+ * Copyright (c) 2011, Bryan Venteicher <bryanv@xxxxxxxxxxx>
+ * All rights reserved.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
+ * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
+ * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
+ * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
+ * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
+ * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+ * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+ * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
+ * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+/* The above copyright notice applies only to the below function,
+ * vtballoon_send_page_frames, which is based on FreeBSD's function
+ * of the same name.
+ */
+
+static void vtballoon_send_page_frames(struct virtio_balloon_device *vb,
+ struct virtqueue *vq, int npages)
+{
+ struct uk_sglist sg;
+ struct uk_sglist_seg segs[1];
+ int c;
+ void *vq_cookie;
+ __u32 len = 0;
+
+ uk_sglist_init(&sg, 1, segs);
+
+ uk_sglist_append(&sg, vb->transport->pages, npages * sizeof(uint32_t));
+
+ virtqueue_buffer_enqueue(vq, &vq_cookie, &sg, 1, 0);
+
+ virtqueue_host_notify(vq);
+
+ /* wait on KVM to respond. Need a safer method for this */
+ while ((c = virtqueue_buffer_dequeue(vq, &vq_cookie, &len)) < 0)
+ ;
+
+}
+
+/**
+ * This is equivalent to leaking from the balloon and
+ * increasing memory reservation for guest.
+ */
+int deflate_balloon(uintptr_t *pages_to_guest, uint32_t num)
+{
+ struct virtio_balloon_device *vb = global_vb;
+ int num_pages_taken;
+ uint32_t i;
+
+ /* check if device is ready */
+ if (!global_vb)
+ return -ENXIO;
+
+ uk_mutex_lock(&vb->lock);
+
+ clear_transport(vb);
+
+ if (vb->balloon->num_pages < num)
+ num = vb->balloon->num_pages;
+
+ for (i = 0; i < num; i++) {
+ vb->transport->pages[i] = pages_to_guest[i];
+ vb->balloon->num_pages -= 1;
+ vb->transport->num_pages += 1;
+ }
+
+ num_pages_taken = vb->transport->num_pages;
+
+ if (vb->transport->num_pages != 0) {
+ vtballoon_send_page_frames(vb, vb->deflate_vq,
+ vb->transport->num_pages);
+ }
+
+ uk_mutex_unlock(&vb->lock);
+
+ return num_pages_taken;
+}
+
+/**
+ * This is equivalent to filling the balloon and
+ * decreasing memory reservation for guest.
+ */
+int inflate_balloon(uintptr_t *pages_to_host, uint32_t num)
+{
+ struct virtio_balloon_device *vb = global_vb;
+ int num_pages_given;
+ uint32_t i;
+
+ /* check if device is ready */
+ if (!global_vb)
+ return -ENXIO;
+
+ uk_mutex_lock(&vb->lock);
+
+ clear_transport(vb);
+
+ for (i = 0; i < num; i++) {
+ vb->transport->pages[i] = pages_to_host[i] / __PAGE_SIZE;
+ vb->balloon->num_pages += 1;
+ vb->transport->num_pages += 1;
+ }
+
+ num_pages_given = vb->transport->num_pages;
+
+ if (vb->transport->num_pages != 0) {
+ vtballoon_send_page_frames(vb, vb->inflate_vq,
+ vb->transport->num_pages);
+ }
+
+ uk_mutex_unlock(&vb->lock);
+
+ return num_pages_given;
+}
+
+
+static inline void virtio_balloon_feature_set(struct virtio_balloon_device *vb)
+{
+ vb->features = 0;
+ vb->flags = 0;
+ vb->vdev->features = 0;
+}
+
+static int virtio_balloon_vq_alloc(struct virtio_balloon_device *vb)
+{
+ int vq_avail = 0;
+ int rc = 0;
+ __u16 qdesc_size[2];
+
+ vq_avail = virtio_find_vqs(vb->vdev, 2, &(qdesc_size[0]));
+ if (unlikely(vq_avail != 2)) {
+ uk_pr_err(DRIVER_NAME": Expected: %d queues, found %d\n",
+ 2, vq_avail);
+ rc = -ENOMEM;
+ goto exit;
+ }
+
+ vb->infvq_id = 0;
+ vb->defvq_id = 1;
+
+ vb->inflate_vq = virtio_vqueue_setup(vb->vdev, vb->infvq_id,
+ qdesc_size[0], NULL, a);
+ vb->inflate_vq->priv = vb;
+
+ if (unlikely(PTRISERR(vb->inflate_vq))) {
+ uk_pr_err(DRIVER_NAME": Failed to set up virtqueue %"PRIu16"\n",
+ vb->infvq_id);
+ rc = PTR2ERR(vb->inflate_vq);
+ }
+
+ vb->deflate_vq = virtio_vqueue_setup(vb->vdev, vb->defvq_id,
+ qdesc_size[1], NULL, a);
+ vb->deflate_vq->priv = vb;
+
+ if (unlikely(PTRISERR(vb->deflate_vq))) {
+ uk_pr_err(DRIVER_NAME": Failed to set up virtqueue %"PRIu16"\n",
+ vb->defvq_id);
+ rc = PTR2ERR(vb->deflate_vq);
+ }
+
+exit:
+ return rc;
+}
+
+static int virtio_balloon_start(struct virtio_balloon_device *vb)
+{
+ /* Disable interrupts for queues to suppress error messages */
+ virtqueue_intr_disable(vb->inflate_vq);
+ virtqueue_intr_disable(vb->deflate_vq);
+ virtio_dev_drv_up(vb->vdev);
+ uk_pr_info(DRIVER_NAME": %s started\n", vb->tag);
+
+ return 0;
+}
+
+static int virtio_balloon_add_dev(struct virtio_dev *vdev)
+{
+
+ struct virtio_balloon_device *vbdev;
+ int rc = 0;
+ void *alc;
+
+ UK_ASSERT(vdev != NULL);
+
+ vbdev = uk_calloc(a, 1, sizeof(*vbdev));
+
+ if (!vbdev) {
+ rc = -ENOMEM;
+ goto err_out;
+ }
+
+ vbdev->tag = "VIRTIO_BALLOON_DRV_DEV";
+
+ uk_mutex_init(&vbdev->lock);
+
+ vbdev->vdev = vdev;
+ virtio_balloon_feature_set(vbdev);
+ rc = virtio_balloon_vq_alloc(vbdev);
+ if (rc)
+ goto err_out;
+
+ vbdev->transport = uk_calloc(a, 1, sizeof(struct transport_pages));
+ if (!(vbdev->transport)) {
+ rc = -ENOMEM;
+ goto err_out;
+ }
+ vbdev->transport->pages = uk_calloc(a, 1,
+ VTBALLOON_PAGES_PER_REQUEST * sizeof(uint32_t));
+ if (!(vbdev->transport->pages)) {
+ rc = -ENOMEM;
+ goto err_out;
+ }
+ vbdev->balloon = uk_calloc(a, 1, sizeof(struct balloon_pages));
+ if (!(vbdev->balloon)) {
+ rc = -ENOMEM;
+ goto err_out;
+ }
+
+ rc = virtio_balloon_start(vbdev);
+ if (rc)
+ goto err_out;
+
+exit:
+ global_vb = vbdev;
+ /* initial alloc and free to trigger ballon init */
+ alc = uk_palloc(a, 1);
+ uk_pfree(a, alc, 1);
+ return rc;
+err_out:
+ uk_free(a, vbdev->transport->pages);
+ uk_free(a, vbdev->transport);
+ uk_free(a, vbdev->balloon);
+ uk_free(a, vbdev);
+ goto exit;
+
+}
+
+static int virtio_balloon_drv_init(struct uk_alloc *drv_allocator)
+{
+ if (!drv_allocator)
+ return -EINVAL;
+
+ a = drv_allocator;
+ return 0;
+
+}
+
+static const struct virtio_dev_id vballoon_dev_id[] = {
+ {VIRTIO_ID_BALLOON},
+ {VIRTIO_ID_INVALID} /* List Terminator */
+};
+
+static struct virtio_driver virtio_balloon_driver = {
+ .dev_ids = vballoon_dev_id,
+ .init = virtio_balloon_drv_init,
+ .add_dev = virtio_balloon_add_dev
+};
+VIRTIO_BUS_REGISTER_DRIVER(&virtio_balloon_driver);
--
2.20.1
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