From 10857ec0ad5d201d524d20b477da1cf3f7f4a3b0 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Eugenio=20P=C3=A9rez?= Date: Mon, 14 Mar 2022 18:34:41 +0100 Subject: vhost: Add VhostShadowVirtqueue MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Vhost shadow virtqueue (SVQ) is an intermediate jump for virtqueue notifications and buffers, allowing qemu to track them. While qemu is forwarding the buffers and virtqueue changes, it is able to commit the memory it's being dirtied, the same way regular qemu's VirtIO devices do. This commit only exposes basic SVQ allocation and free. Next patches of the series add functionality like notifications and buffers forwarding. Signed-off-by: Eugenio Pérez Acked-by: Michael S. Tsirkin Signed-off-by: Jason Wang --- hw/virtio/vhost-shadow-virtqueue.c | 62 ++++++++++++++++++++++++++++++++++++++ 1 file changed, 62 insertions(+) create mode 100644 hw/virtio/vhost-shadow-virtqueue.c (limited to 'hw/virtio/vhost-shadow-virtqueue.c') diff --git a/hw/virtio/vhost-shadow-virtqueue.c b/hw/virtio/vhost-shadow-virtqueue.c new file mode 100644 index 0000000000..c1db02c53e --- /dev/null +++ b/hw/virtio/vhost-shadow-virtqueue.c @@ -0,0 +1,62 @@ +/* + * vhost shadow virtqueue + * + * SPDX-FileCopyrightText: Red Hat, Inc. 2021 + * SPDX-FileContributor: Author: Eugenio Pérez + * + * SPDX-License-Identifier: GPL-2.0-or-later + */ + +#include "qemu/osdep.h" +#include "hw/virtio/vhost-shadow-virtqueue.h" + +#include "qemu/error-report.h" + +/** + * Creates vhost shadow virtqueue, and instructs the vhost device to use the + * shadow methods and file descriptors. + * + * Returns the new virtqueue or NULL. + * + * In case of error, reason is reported through error_report. + */ +VhostShadowVirtqueue *vhost_svq_new(void) +{ + g_autofree VhostShadowVirtqueue *svq = g_new0(VhostShadowVirtqueue, 1); + int r; + + r = event_notifier_init(&svq->hdev_kick, 0); + if (r != 0) { + error_report("Couldn't create kick event notifier: %s (%d)", + g_strerror(errno), errno); + goto err_init_hdev_kick; + } + + r = event_notifier_init(&svq->hdev_call, 0); + if (r != 0) { + error_report("Couldn't create call event notifier: %s (%d)", + g_strerror(errno), errno); + goto err_init_hdev_call; + } + + return g_steal_pointer(&svq); + +err_init_hdev_call: + event_notifier_cleanup(&svq->hdev_kick); + +err_init_hdev_kick: + return NULL; +} + +/** + * Free the resources of the shadow virtqueue. + * + * @pvq: gpointer to SVQ so it can be used by autofree functions. + */ +void vhost_svq_free(gpointer pvq) +{ + VhostShadowVirtqueue *vq = pvq; + event_notifier_cleanup(&vq->hdev_kick); + event_notifier_cleanup(&vq->hdev_call); + g_free(vq); +} -- cgit v1.2.3