From: Hans de Goede <hdegoede@xxxxxxxxxx> Add support for the new VBG_IOCTL_ACQUIRE_GUEST_CAPABILITIES ioctl, this is necessary for automatic resizing of the guest resolution to match the VM-window size to work with the new VMSVGA virtual GPU which is now the new default in VirtualBox. BugLink: https://bugzilla.redhat.com/show_bug.cgi?id=1789545 Signed-off-by: Hans de Goede <hdegoede@xxxxxxxxxx> Upstream Status: https://lore.kernel.org/lkml/20200520195440.38759-1-hdegoede@xxxxxxxxxx/ --- drivers/virt/vboxguest/vboxguest_core.c | 163 +++++++++++++++++++++++- drivers/virt/vboxguest/vboxguest_core.h | 14 ++ include/uapi/linux/vboxguest.h | 24 ++++ 3 files changed, 200 insertions(+), 1 deletion(-) diff --git a/drivers/virt/vboxguest/vboxguest_core.c b/drivers/virt/vboxguest/vboxguest_core.c index 15b3cb618c6e..4f1addaa3f6f 100644 --- a/drivers/virt/vboxguest/vboxguest_core.c +++ b/drivers/virt/vboxguest/vboxguest_core.c @@ -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: diff --git a/drivers/virt/vboxguest/vboxguest_core.h b/drivers/virt/vboxguest/vboxguest_core.h index dc745a033164..ab4bf64e2cec 100644 --- a/drivers/virt/vboxguest/vboxguest_core.h +++ b/drivers/virt/vboxguest/vboxguest_core.h @@ -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 diff --git a/include/uapi/linux/vboxguest.h b/include/uapi/linux/vboxguest.h index f79d7abe27db..15125f6ec60d 100644 --- a/include/uapi/linux/vboxguest.h +++ b/include/uapi/linux/vboxguest.h @@ -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. */ -- 2.26.2 _______________________________________________ kernel mailing list -- kernel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to kernel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/kernel@xxxxxxxxxxxxxxxxxxxxxxx
