From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001

From: Hans de Goede <hdegoede@redhat.com>

Date: Tue, 19 May 2020 15:30:29 +0200

Subject: [PATCH] virt: vbox: Add vbg_set_host_capabilities() helper function

Add vbg_set_host_capabilities() helper function,  this is a preparation

patch for adding support for the VBGL_IOCTL_GUEST_CAPS_ACQUIRE ioctl.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>

Upstream Status: https://lore.kernel.org/lkml/20200520195440.38759-1-hdegoede@redhat.com/

---

 drivers/virt/vboxguest/vboxguest_core.c | 79 ++++++++++++++-----------

 1 file changed, 46 insertions(+), 33 deletions(-)

diff --git a/drivers/virt/vboxguest/vboxguest_core.c b/drivers/virt/vboxguest/vboxguest_core.c

index aee5eff229f2..15b3cb618c6e 100644

--- a/drivers/virt/vboxguest/vboxguest_core.c

+++ b/drivers/virt/vboxguest/vboxguest_core.c

@@ -661,6 +661,48 @@ static int vbg_reset_host_capabilities(struct vbg_dev *gdev)

 	return vbg_status_code_to_errno(rc);

 }

+/**

+ * 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->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);

+}

+

 /**

  * Sets the guest capabilities for a session. Takes the session spinlock.

  * Return: 0 or negative errno value.

@@ -678,23 +720,8 @@ 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);

@@ -709,23 +736,10 @@ static int vbg_set_session_capabilities(struct vbg_dev *gdev,

 		goto out;

 	vbg_track_bit_usage(&gdev->set_guest_caps_tracker, changed, previous);

-	or_mask = gdev->set_guest_caps_tracker.mask;

-

-	if (gdev->guest_caps_host == or_mask || !req)

-		goto out;

-

-	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;

+	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;

@@ -733,7 +747,6 @@ static int vbg_set_session_capabilities(struct vbg_dev *gdev,

 out:

 	mutex_unlock(&gdev->session_mutex);

-	vbg_req_free(req, sizeof(*req));

 	return ret;

 }

-- 

2.26.2