1 files changed, 221 insertions, 45 deletions

diff --git a/drivers/virt/vboxguest/vboxguest_core.c b/drivers/virt/vboxguest/vboxguest_core.c
index 18ebd7a6af98..0b43efddea22 100644
--- a/drivers/virt/vboxguest/vboxguest_core.c
+++ b/drivers/virt/vboxguest/vboxguest_core.c
@@ -559,7 +559,7 @@ static int vbg_reset_host_event_filter(struct vbg_dev *gdev,
  * Changes the event filter mask for the given session.
  *
  * This is called in response to VBG_IOCTL_CHANGE_FILTER_MASK as well as to
- * do session cleanup. Takes the session spinlock.
+ * do session cleanup. Takes the session mutex.
  *
  * Return: 0 or negative errno value.
  * @gdev:			The Guest extension device.
@@ -662,7 +662,156 @@ static int vbg_reset_host_capabilities(struct vbg_dev *gdev)
 }
 
 /**
- * Sets the guest capabilities for a session. Takes the session spinlock.
+ * Set guest capabilities on the host.
+ * Must be called with gdev->session_mutex hold.
+ * Return: 0 or negative errno value.
+ * @gdev:			The Guest extension device.
+ * @session:			The session.
+ * @session_termination:	Set if we're called by the session cleanup code.
+ */
+static int vbg_set_host_capabilities(struct vbg_dev *gdev,
+				     struct vbg_session *session,
+				     bool session_termination)
+{
+	struct vmmdev_mask *req;
+	u32 caps;
+	int rc;
+
+	WARN_ON(!mutex_is_locked(&gdev->session_mutex));
+
+	caps = gdev->acquired_guest_caps | gdev->set_guest_caps_tracker.mask;
+
+	if (gdev->guest_caps_host == caps)
+		return 0;
+
+	/* On termination the requestor is the kernel, as we're cleaning up. */
+	req = vbg_req_alloc(sizeof(*req), VMMDEVREQ_SET_GUEST_CAPABILITIES,
+			    session_termination ? VBG_KERNEL_REQUEST :
+						  session->requestor);
+	if (!req) {
+		gdev->guest_caps_host = U32_MAX;
+		return -ENOMEM;
+	}
+
+	req->or_mask = caps;
+	req->not_mask = ~caps;
+	rc = vbg_req_perform(gdev, req);
+	vbg_req_free(req, sizeof(*req));
+
+	gdev->guest_caps_host = (rc >= 0) ? caps : U32_MAX;
+
+	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 mutex.
  * Return: 0 or negative errno value.
  * @gdev:			The Guest extension device.
  * @session:			The session.
@@ -678,62 +827,40 @@ static int vbg_set_session_capabilities(struct vbg_dev *gdev,
 					u32 or_mask, u32 not_mask,
 					bool session_termination)
 {
-	struct vmmdev_mask *req;
 	u32 changed, previous;
-	int rc, ret = 0;
-
-	/*
-	 * Allocate a request buffer before taking the spinlock, when
-	 * the session is being terminated the requestor is the kernel,
-	 * as we're cleaning up.
-	 */
-	req = vbg_req_alloc(sizeof(*req), VMMDEVREQ_SET_GUEST_CAPABILITIES,
-			    session_termination ? VBG_KERNEL_REQUEST :
-						  session->requestor);
-	if (!req) {
-		if (!session_termination)
-			return -ENOMEM;
-		/* Ignore allocation failure, we must do session cleanup. */
-	}
+	int ret = 0;
 
 	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->guest_caps;
-	session->guest_caps |= or_mask;
-	session->guest_caps &= ~not_mask;
+	previous = session->set_guest_caps;
+	session->set_guest_caps |= or_mask;
+	session->set_guest_caps &= ~not_mask;
 
 	/* If anything actually changed, update the global usage counters. */
-	changed = previous ^ session->guest_caps;
+	changed = previous ^ session->set_guest_caps;
 	if (!changed)
 		goto out;
 
-	vbg_track_bit_usage(&gdev->guest_caps_tracker, changed, previous);
-	or_mask = gdev->guest_caps_tracker.mask;
-
-	if (gdev->guest_caps_host == or_mask || !req)
-		goto out;
+	vbg_track_bit_usage(&gdev->set_guest_caps_tracker, changed, previous);
 
-	gdev->guest_caps_host = or_mask;
-	req->or_mask = or_mask;
-	req->not_mask = ~or_mask;
-	rc = vbg_req_perform(gdev, req);
-	if (rc < 0) {
-		ret = vbg_status_code_to_errno(rc);
-
-		/* Failed, roll back (unless it's session termination time). */
-		gdev->guest_caps_host = U32_MAX;
-		if (session_termination)
-			goto out;
-
-		vbg_track_bit_usage(&gdev->guest_caps_tracker, changed,
-				    session->guest_caps);
-		session->guest_caps = previous;
+	ret = vbg_set_host_capabilities(gdev, session, session_termination);
+	/* Roll back on failure, unless it's session termination time. */
+	if (ret < 0 && !session_termination) {
+		vbg_track_bit_usage(&gdev->set_guest_caps_tracker, changed,
+				    session->set_guest_caps);
+		session->set_guest_caps = previous;
 	}
 
 out:
 	mutex_unlock(&gdev->session_mutex);
-	vbg_req_free(req, sizeof(*req));
 
 	return ret;
 }
@@ -949,6 +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);
 
@@ -1006,6 +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)
@@ -1017,6 +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);
@@ -1031,6 +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;
 }
@@ -1150,7 +1299,9 @@ static int vbg_req_allowed(struct vbg_dev *gdev, struct vbg_session *session,
 	case VMMDEVREQ_VIDEO_ACCEL_ENABLE:
 	case VMMDEVREQ_VIDEO_ACCEL_FLUSH:
 	case VMMDEVREQ_VIDEO_SET_VISIBLE_REGION:
+	case VMMDEVREQ_VIDEO_UPDATE_MONITOR_POSITIONS:
 	case VMMDEVREQ_GET_DISPLAY_CHANGE_REQEX:
+	case VMMDEVREQ_GET_DISPLAY_CHANGE_REQ_MULTI:
 	case VMMDEVREQ_GET_SEAMLESS_CHANGE_REQ:
 	case VMMDEVREQ_GET_VRDPCHANGE_REQ:
 	case VMMDEVREQ_LOG_STRING:
@@ -1432,6 +1583,29 @@ 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)
 {
@@ -1452,7 +1626,7 @@ static int vbg_ioctl_change_guest_capabilities(struct vbg_dev *gdev,
 	if (ret)
 		return ret;
 
-	caps->u.out.session_caps = session->guest_caps;
+	caps->u.out.session_caps = session->set_guest_caps;
 	caps->u.out.global_caps = gdev->guest_caps_host;
 
 	return 0;
@@ -1541,6 +1715,8 @@ 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:
@@ -1563,7 +1739,7 @@ int vbg_core_ioctl(struct vbg_session *session, unsigned int req, void *data)
 		return vbg_ioctl_log(data);
 	}
 
-	vbg_debug("VGDrvCommonIoCtl: Unknown req %#08x\n", req);
+	vbg_err_ratelimited("Userspace made an unknown ioctl req %#08x\n", req);
 	return -ENOTTY;
 }