virt: vbox: Add support for the new VBG_IOCTL_ACQUIRE_GUEST_CAPABILITIES ioctl (631beddc) · Commits · EulixOS / Software / Kernel

drivers/virt/vboxguest/vboxguest_core.c

+162 −1

Original line number	Diff line number	Diff line
		@@ -679,7 +679,7 @@ static int vbg_set_host_capabilities(struct vbg_dev *gdev,

		WARN_ON(!mutex_is_locked(&gdev->session_mutex));

		caps = gdev->set_guest_caps_tracker.mask;
		caps = gdev->acquired_guest_caps \| gdev->set_guest_caps_tracker.mask;

		if (gdev->guest_caps_host == caps)
		return 0;
		@@ -703,6 +703,113 @@ static int vbg_set_host_capabilities(struct vbg_dev *gdev,
		return vbg_status_code_to_errno(rc);
		}

		/**
		* Acquire (get exclusive access) guest capabilities for a session.
		* Takes the session mutex.
		* Return: 0 or negative errno value.
		* @gdev: The Guest extension device.
		* @session: The session.
		* @flags: Flags (VBGL_IOC_AGC_FLAGS_XXX).
		* @or_mask: The capabilities to add.
		* @not_mask: The capabilities to remove.
		* @session_termination: Set if we're called by the session cleanup code.
		* This tweaks the error handling so we perform
		* proper session cleanup even if the host
		* misbehaves.
		*/
		static int vbg_acquire_session_capabilities(struct vbg_dev *gdev,
		struct vbg_session *session,
		u32 or_mask, u32 not_mask,
		u32 flags, bool session_termination)
		{
		unsigned long irqflags;
		bool wakeup = false;
		int ret = 0;

		mutex_lock(&gdev->session_mutex);

		if (gdev->set_guest_caps_tracker.mask & or_mask) {
		vbg_err("%s error: cannot acquire caps which are currently set\n",
		__func__);
		ret = -EINVAL;
		goto out;
		}

		/*
		* Mark any caps in the or_mask as now being in acquire-mode. Note
		* once caps are in acquire_mode they always stay in this mode.
		* This impacts event handling, so we take the event-lock.
		*/
		spin_lock_irqsave(&gdev->event_spinlock, irqflags);
		gdev->acquire_mode_guest_caps \|= or_mask;
		spin_unlock_irqrestore(&gdev->event_spinlock, irqflags);

		/* If we only have to switch the caps to acquire mode, we're done. */
		if (flags & VBGL_IOC_AGC_FLAGS_CONFIG_ACQUIRE_MODE)
		goto out;

		not_mask &= ~or_mask; /* or_mask takes priority over not_mask */
		not_mask &= session->acquired_guest_caps;
		or_mask &= ~session->acquired_guest_caps;

		if (or_mask == 0 && not_mask == 0)
		goto out;

		if (gdev->acquired_guest_caps & or_mask) {
		ret = -EBUSY;
		goto out;
		}

		gdev->acquired_guest_caps \|= or_mask;
		gdev->acquired_guest_caps &= ~not_mask;
		/* session->acquired_guest_caps impacts event handling, take the lock */
		spin_lock_irqsave(&gdev->event_spinlock, irqflags);
		session->acquired_guest_caps \|= or_mask;
		session->acquired_guest_caps &= ~not_mask;
		spin_unlock_irqrestore(&gdev->event_spinlock, irqflags);

		ret = vbg_set_host_capabilities(gdev, session, session_termination);
		/* Roll back on failure, unless it's session termination time. */
		if (ret < 0 && !session_termination) {
		gdev->acquired_guest_caps &= ~or_mask;
		gdev->acquired_guest_caps \|= not_mask;
		spin_lock_irqsave(&gdev->event_spinlock, irqflags);
		session->acquired_guest_caps &= ~or_mask;
		session->acquired_guest_caps \|= not_mask;
		spin_unlock_irqrestore(&gdev->event_spinlock, irqflags);
		}

		/*
		* If we added a capability, check if that means some other thread in
		* our session should be unblocked because there are events pending
		* (the result of vbg_get_allowed_event_mask_for_session() may change).
		*
		* HACK ALERT! When the seamless support capability is added we generate
		* a seamless change event so that the ring-3 client can sync with
		* the seamless state.
		*/
		if (ret == 0 && or_mask != 0) {
		spin_lock_irqsave(&gdev->event_spinlock, irqflags);

		if (or_mask & VMMDEV_GUEST_SUPPORTS_SEAMLESS)
		gdev->pending_events \|=
		VMMDEV_EVENT_SEAMLESS_MODE_CHANGE_REQUEST;

		if (gdev->pending_events)
		wakeup = true;

		spin_unlock_irqrestore(&gdev->event_spinlock, irqflags);

		if (wakeup)
		wake_up(&gdev->event_wq);
		}

		out:
		mutex_unlock(&gdev->session_mutex);

		return ret;
		}

		/**
		* Sets the guest capabilities for a session. Takes the session spinlock.
		* Return: 0 or negative errno value.
		@@ -725,6 +832,13 @@ static int vbg_set_session_capabilities(struct vbg_dev *gdev,

		mutex_lock(&gdev->session_mutex);

		if (gdev->acquire_mode_guest_caps & or_mask) {
		vbg_err("%s error: cannot set caps which are in acquire_mode\n",
		__func__);
		ret = -EBUSY;
		goto out;
		}

		/* Apply the changes to the session mask. */
		previous = session->set_guest_caps;
		session->set_guest_caps \|= or_mask;
		@@ -962,6 +1076,7 @@ void vbg_core_close_session(struct vbg_session *session)
		struct vbg_dev *gdev = session->gdev;
		int i, rc;

		vbg_acquire_session_capabilities(gdev, session, 0, U32_MAX, 0, true);
		vbg_set_session_capabilities(gdev, session, 0, U32_MAX, true);
		vbg_set_session_event_filter(gdev, session, 0, U32_MAX, true);

		@@ -1019,6 +1134,25 @@ static int vbg_ioctl_driver_version_info(
		return 0;
		}

		/* Must be called with the event_lock held */
		static u32 vbg_get_allowed_event_mask_for_session(struct vbg_dev *gdev,
		struct vbg_session *session)
		{
		u32 acquire_mode_caps = gdev->acquire_mode_guest_caps;
		u32 session_acquired_caps = session->acquired_guest_caps;
		u32 allowed_events = VMMDEV_EVENT_VALID_EVENT_MASK;

		if ((acquire_mode_caps & VMMDEV_GUEST_SUPPORTS_GRAPHICS) &&
		!(session_acquired_caps & VMMDEV_GUEST_SUPPORTS_GRAPHICS))
		allowed_events &= ~VMMDEV_EVENT_DISPLAY_CHANGE_REQUEST;

		if ((acquire_mode_caps & VMMDEV_GUEST_SUPPORTS_SEAMLESS) &&
		!(session_acquired_caps & VMMDEV_GUEST_SUPPORTS_SEAMLESS))
		allowed_events &= ~VMMDEV_EVENT_SEAMLESS_MODE_CHANGE_REQUEST;

		return allowed_events;
		}

		static bool vbg_wait_event_cond(struct vbg_dev *gdev,
		struct vbg_session *session,
		u32 event_mask)
		@@ -1030,6 +1164,7 @@ static bool vbg_wait_event_cond(struct vbg_dev *gdev,
		spin_lock_irqsave(&gdev->event_spinlock, flags);

		events = gdev->pending_events & event_mask;
		events &= vbg_get_allowed_event_mask_for_session(gdev, session);
		wakeup = events \|\| session->cancel_waiters;

		spin_unlock_irqrestore(&gdev->event_spinlock, flags);
		@@ -1044,6 +1179,7 @@ static u32 vbg_consume_events_locked(struct vbg_dev *gdev,
		{
		u32 events = gdev->pending_events & event_mask;

		events &= vbg_get_allowed_event_mask_for_session(gdev, session);
		gdev->pending_events &= ~events;
		return events;
		}
		@@ -1445,6 +1581,29 @@ static int vbg_ioctl_change_filter_mask(struct vbg_dev *gdev,
		false);
		}

		static int vbg_ioctl_acquire_guest_capabilities(struct vbg_dev *gdev,
		struct vbg_session *session,
		struct vbg_ioctl_acquire_guest_caps *caps)
		{
		u32 flags, or_mask, not_mask;

		if (vbg_ioctl_chk(&caps->hdr, sizeof(caps->u.in), 0))
		return -EINVAL;

		flags = caps->u.in.flags;
		or_mask = caps->u.in.or_mask;
		not_mask = caps->u.in.not_mask;

		if (flags & ~VBGL_IOC_AGC_FLAGS_VALID_MASK)
		return -EINVAL;

		if ((or_mask \| not_mask) & ~VMMDEV_GUEST_CAPABILITIES_MASK)
		return -EINVAL;

		return vbg_acquire_session_capabilities(gdev, session, or_mask,
		not_mask, flags, false);
		}

		static int vbg_ioctl_change_guest_capabilities(struct vbg_dev *gdev,
		struct vbg_session session, struct vbg_ioctl_set_guest_caps caps)
		{
		@@ -1554,6 +1713,8 @@ int vbg_core_ioctl(struct vbg_session session, unsigned int req, void data)
		return vbg_ioctl_interrupt_all_wait_events(gdev, session, data);
		case VBG_IOCTL_CHANGE_FILTER_MASK:
		return vbg_ioctl_change_filter_mask(gdev, session, data);
		case VBG_IOCTL_ACQUIRE_GUEST_CAPABILITIES:
		return vbg_ioctl_acquire_guest_capabilities(gdev, session, data);
		case VBG_IOCTL_CHANGE_GUEST_CAPABILITIES:
		return vbg_ioctl_change_guest_capabilities(gdev, session, data);
		case VBG_IOCTL_CHECK_BALLOON:

drivers/virt/vboxguest/vboxguest_core.h

+14 −0

Original line number	Diff line number	Diff line
		@@ -117,6 +117,15 @@ struct vbg_dev {
		*/
		u32 event_filter_host;

		/**
		* Guest capabilities which have been switched to acquire_mode.
		*/
		u32 acquire_mode_guest_caps;
		/**
		* Guest capabilities acquired by vbg_acquire_session_capabilities().
		* Only one session can acquire a capability at a time.
		*/
		u32 acquired_guest_caps;
		/**
		* Usage counters for guest capabilities requested through
		* vbg_set_session_capabilities(). Indexed by capability bit
		@@ -164,6 +173,11 @@ struct vbg_session {
		* host filter. Protected by vbg_gdev.session_mutex.
		*/
		u32 event_filter;
		/**
		* Guest capabilities acquired by vbg_acquire_session_capabilities().
		* Only one session can acquire a capability at a time.
		*/
		u32 acquired_guest_caps;
		/**
		* Guest capabilities set through vbg_set_session_capabilities().
		* A capability claimed by any guest session will be reported to the

include/uapi/linux/vboxguest.h

+24 −0

Original line number	Diff line number	Diff line
		@@ -257,6 +257,30 @@ VMMDEV_ASSERT_SIZE(vbg_ioctl_change_filter, 24 + 8);
		_IOWR('V', 12, struct vbg_ioctl_change_filter)


		/** VBG_IOCTL_ACQUIRE_GUEST_CAPABILITIES data structure. */
		struct vbg_ioctl_acquire_guest_caps {
		/** The header. */
		struct vbg_ioctl_hdr hdr;
		union {
		struct {
		/** Flags (VBGL_IOC_AGC_FLAGS_XXX). */
		__u32 flags;
		/** Capabilities to set (VMMDEV_GUEST_SUPPORTS_XXX). */
		__u32 or_mask;
		/** Capabilities to drop (VMMDEV_GUEST_SUPPORTS_XXX). */
		__u32 not_mask;
		} in;
		} u;
		};
		VMMDEV_ASSERT_SIZE(vbg_ioctl_acquire_guest_caps, 24 + 12);

		#define VBGL_IOC_AGC_FLAGS_CONFIG_ACQUIRE_MODE 0x00000001
		#define VBGL_IOC_AGC_FLAGS_VALID_MASK 0x00000001

		#define VBG_IOCTL_ACQUIRE_GUEST_CAPABILITIES \
		_IOWR('V', 13, struct vbg_ioctl_acquire_guest_caps)


		/** VBG_IOCTL_CHANGE_GUEST_CAPABILITIES data structure. */
		struct vbg_ioctl_set_guest_caps {
		/** The header. */