Kernel/Graphics: Introduce the DisplayConnector class

The DisplayConnector class is meant to replace the FramebufferDevice
class. The advantage of this class over the FramebufferDevice class is:
1. It removes the mmap interface entirely. This interface is unsafe, as
multiple processes could try to use it, and when switching to and from
text console mode, there's no "good" way to revoke a memory mapping from
this interface, let alone when there are multiple processes that call
this interface. Therefore, in the DisplayConnector class there's no
implementation for this method at all.
2. The class uses a new real-world structure called ModeSetting, which
takes into account the fact that real hardware requires more than width,
height and pitch settings to mode-set the display resolution.
3. The class assumes all instances should supply some sort of EDID,
so it facilitates such mechanism to do so. Even if a given driver does
not know what is the actual EDID, it will ask to create default-generic
EDID blob.
3. This class shifts the responsibilies of switching between console
mode and graphical mode from a GraphicsAdapter to the DisplayConnector
class, so when doing the switch, the GraphicsManagement code actually
asks each DisplayConnector object to do the switch and doesn't rely on
the GraphicsAdapter objects at all.

5 files changed, 503 insertions, 0 deletions

diff --git a/Kernel/CMakeLists.txt b/Kernel/CMakeLists.txt
index 6ef7641326..c95f5464e3 100644
--- a/Kernel/CMakeLists.txt
+++ b/Kernel/CMakeLists.txt
@@ -80,6 +80,7 @@ set(KERNEL_SOURCES
     Graphics/Console/ContiguousFramebufferConsole.cpp
     Graphics/Console/TextModeConsole.cpp
     Graphics/Console/VGAConsole.cpp
+    Graphics/DisplayConnector.cpp
     Graphics/FramebufferDevice.cpp
     Graphics/GraphicsManagement.cpp
     Graphics/Intel/NativeGraphicsAdapter.cpp
diff --git a/Kernel/Graphics/DisplayConnector.cpp b/Kernel/Graphics/DisplayConnector.cpp
new file mode 100644
index 0000000000..facf9b7ea9
--- /dev/null
+++ b/Kernel/Graphics/DisplayConnector.cpp
@@ -0,0 +1,333 @@
+/*
+ * Copyright (c) 2022, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#include <Kernel/Graphics/DisplayConnector.h>
+#include <Kernel/Graphics/GraphicsManagement.h>
+#include <LibC/sys/ioctl_numbers.h>
+
+namespace Kernel {
+
+DisplayConnector::DisplayConnector()
+    : CharacterDevice(226, GraphicsManagement::the().allocate_minor_device_number())
+{
+}
+
+ErrorOr<Memory::Region*> DisplayConnector::mmap(Process&, OpenFileDescription&, Memory::VirtualRange const&, u64, int, bool)
+{
+    return Error::from_errno(ENOTSUP);
+}
+
+ErrorOr<size_t> DisplayConnector::read(OpenFileDescription&, u64, UserOrKernelBuffer&, size_t)
+{
+    return Error::from_errno(ENOTIMPL);
+}
+ErrorOr<size_t> DisplayConnector::write(OpenFileDescription&, u64 offset, UserOrKernelBuffer const& framebuffer_data, size_t length)
+{
+    SpinlockLocker locker(m_control_lock);
+    // FIXME: We silently ignore the request if we are in console mode.
+    // WindowServer is not ready yet to handle errors such as EBUSY currently.
+    if (console_mode()) {
+        return length;
+    }
+    return write_to_first_surface(offset, framebuffer_data, length);
+}
+
+void DisplayConnector::will_be_destroyed()
+{
+    GraphicsManagement::the().detach_display_connector({}, *this);
+    Device::will_be_destroyed();
+}
+
+void DisplayConnector::after_inserting()
+{
+    Device::after_inserting();
+    GraphicsManagement::the().attach_new_display_connector({}, *this);
+}
+
+bool DisplayConnector::console_mode() const
+{
+    VERIFY(m_control_lock.is_locked());
+    return m_console_mode;
+}
+
+void DisplayConnector::set_display_mode(Badge<GraphicsManagement>, DisplayMode mode)
+{
+    SpinlockLocker locker(m_control_lock);
+    m_console_mode = mode == DisplayMode::Console ? true : false;
+    if (m_console_mode)
+        enable_console();
+    else
+        disable_console();
+}
+
+ErrorOr<void> DisplayConnector::initialize_edid_for_generic_monitor()
+{
+    Array<u8, 128> virtual_monitor_edid = {
+        0x00, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x00, /* header */
+        0x0, 0x0,                                       /* manufacturer */
+        0x00, 0x00,                                     /* product code */
+        0x00, 0x00, 0x00, 0x00,                         /* serial number goes here */
+        0x01,                                           /* week of manufacture */
+        0x00,                                           /* year of manufacture */
+        0x01, 0x03,                                     /* EDID version */
+        0x80,                                           /* capabilities - digital */
+        0x00,                                           /* horiz. res in cm, zero for projectors */
+        0x00,                                           /* vert. res in cm */
+        0x78,                                           /* display gamma (120 == 2.2). */
+        0xEE,                                           /* features (standby, suspend, off, RGB, std */
+                                                        /* colour space, preferred timing mode) */
+        0xEE, 0x91, 0xA3, 0x54, 0x4C, 0x99, 0x26, 0x0F, 0x50, 0x54,
+        /* chromaticity for standard colour space. */
+        0x00, 0x00, 0x00, /* no default timings */
+        0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01, 0x01,
+        0x01, 0x01,
+        0x01, 0x01, 0x01, 0x01, /* no standard timings */
+        0x00, 0x00, 0x00, 0x06, 0x00, 0x00, 0x06, 0x00, 0x02, 0x02,
+        0x02, 0x02,
+        /* descriptor block 1 goes below */
+        0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        /* descriptor block 2, monitor ranges */
+        0x00, 0x00, 0x00, 0xFD, 0x00,
+        0x00, 0xC8, 0x00, 0xC8, 0x64, 0x00, 0x0A, 0x20, 0x20, 0x20,
+        0x20, 0x20,
+        /* 0-200Hz vertical, 0-200KHz horizontal, 1000MHz pixel clock */
+        0x20,
+        /* descriptor block 3, monitor name */
+        0x00, 0x00, 0x00, 0xFC, 0x00,
+        'G', 'e', 'n', 'e', 'r', 'i', 'c', 'S', 'c', 'r', 'e', 'e', 'n',
+        /* descriptor block 4: dummy data */
+        0x00, 0x00, 0x00, 0x10, 0x00,
+        0x0A, 0x20, 0x20, 0x20, 0x20, 0x20,
+        0x20, 0x20, 0x20, 0x20, 0x20, 0x20,
+        0x20,
+        0x00, /* number of extensions */
+        0x00  /* checksum goes here */
+    };
+    set_edid_bytes(virtual_monitor_edid);
+    return {};
+}
+
+void DisplayConnector::set_edid_bytes(Array<u8, 128> const& edid_bytes)
+{
+    memcpy((u8*)m_edid_bytes, edid_bytes.data(), sizeof(m_edid_bytes));
+    if (auto parsed_edid = EDID::Parser::from_bytes({ m_edid_bytes, sizeof(m_edid_bytes) }); !parsed_edid.is_error()) {
+        m_edid_parser = parsed_edid.release_value();
+        m_edid_valid = true;
+    } else {
+        dmesgln("DisplayConnector: Print offending EDID");
+        for (size_t x = 0; x < 128; x = x + 16) {
+            dmesgln("{:02x} {:02x} {:02x} {:02x} {:02x} {:02x} {:02x} {:02x} {:02x} {:02x} {:02x} {:02x} {:02x} {:02x} {:02x} {:02x}",
+                m_edid_bytes[x], m_edid_bytes[x + 1], m_edid_bytes[x + 2], m_edid_bytes[x + 3],
+                m_edid_bytes[x + 4], m_edid_bytes[x + 5], m_edid_bytes[x + 6], m_edid_bytes[x + 7],
+                m_edid_bytes[x + 8], m_edid_bytes[x + 9], m_edid_bytes[x + 10], m_edid_bytes[x + 11],
+                m_edid_bytes[x + 12], m_edid_bytes[x + 13], m_edid_bytes[x + 14], m_edid_bytes[x + 15]);
+        }
+        dmesgln("DisplayConnector: Parsing EDID failed: {}", parsed_edid.error());
+    }
+}
+
+ErrorOr<void> DisplayConnector::flush_rectangle(size_t, FBRect const&)
+{
+    return Error::from_errno(ENOTSUP);
+}
+
+DisplayConnector::ModeSetting DisplayConnector::current_mode_setting() const
+{
+    SpinlockLocker locker(m_modeset_lock);
+    return m_current_mode_setting;
+}
+
+ErrorOr<ByteBuffer> DisplayConnector::get_edid() const
+{
+    if (!m_edid_valid)
+        return Error::from_errno(ENOTIMPL);
+    return ByteBuffer::copy(m_edid_bytes, sizeof(m_edid_bytes));
+}
+
+ErrorOr<void> DisplayConnector::ioctl(OpenFileDescription&, unsigned request, Userspace<void*> arg)
+{
+    if (request != FB_IOCTL_GET_HEAD_EDID) {
+        // Allow anyone to query the EDID. Eventually we'll publish the current EDID on /sys
+        // so it doesn't really make sense to require the video pledge to query it.
+        TRY(Process::current().require_promise(Pledge::video));
+    }
+
+    // TODO: We really should have ioctls for destroying resources as well
+    switch (request) {
+    case FB_IOCTL_GET_PROPERTIES: {
+        auto user_properties = static_ptr_cast<FBProperties*>(arg);
+        FBProperties properties {};
+        properties.flushing_support = flush_support();
+        properties.doublebuffer_support = double_framebuffering_capable();
+        properties.partial_flushing_support = partial_flush_support();
+        properties.refresh_rate_support = refresh_rate_support();
+
+        return copy_to_user(user_properties, &properties);
+    }
+    case FB_IOCTL_GET_HEAD_MODE_SETTING: {
+        auto user_head_mode_setting = static_ptr_cast<FBHeadModeSetting*>(arg);
+        FBHeadModeSetting head_mode_setting {};
+        TRY(copy_from_user(&head_mode_setting, user_head_mode_setting));
+        {
+            SpinlockLocker control_locker(m_control_lock);
+            head_mode_setting.horizontal_stride = m_current_mode_setting.horizontal_stride;
+            head_mode_setting.pixel_clock_in_khz = m_current_mode_setting.pixel_clock_in_khz;
+            head_mode_setting.horizontal_active = m_current_mode_setting.horizontal_active;
+            head_mode_setting.horizontal_front_porch_pixels = m_current_mode_setting.horizontal_front_porch_pixels;
+            head_mode_setting.horizontal_sync_time_pixels = m_current_mode_setting.horizontal_sync_time_pixels;
+            head_mode_setting.horizontal_blank_pixels = m_current_mode_setting.horizontal_blank_pixels;
+            head_mode_setting.vertical_active = m_current_mode_setting.vertical_active;
+            head_mode_setting.vertical_front_porch_lines = m_current_mode_setting.vertical_front_porch_lines;
+            head_mode_setting.vertical_sync_time_lines = m_current_mode_setting.vertical_sync_time_lines;
+            head_mode_setting.vertical_blank_lines = m_current_mode_setting.vertical_blank_lines;
+            head_mode_setting.horizontal_offset = m_current_mode_setting.horizontal_offset;
+            head_mode_setting.vertical_offset = m_current_mode_setting.vertical_offset;
+        }
+        return copy_to_user(user_head_mode_setting, &head_mode_setting);
+    }
+    case FB_IOCTL_GET_HEAD_EDID: {
+        auto user_head_edid = static_ptr_cast<FBHeadEDID*>(arg);
+        FBHeadEDID head_edid {};
+        TRY(copy_from_user(&head_edid, user_head_edid));
+
+        auto edid_bytes = TRY(get_edid());
+        if (head_edid.bytes != nullptr) {
+            // Only return the EDID if a buffer was provided. Either way,
+            // we'll write back the bytes_size with the actual size
+            if (head_edid.bytes_size < edid_bytes.size()) {
+                head_edid.bytes_size = edid_bytes.size();
+                TRY(copy_to_user(user_head_edid, &head_edid));
+                return Error::from_errno(EOVERFLOW);
+            }
+            TRY(copy_to_user(head_edid.bytes, (void const*)edid_bytes.data(), edid_bytes.size()));
+        }
+        head_edid.bytes_size = edid_bytes.size();
+        return copy_to_user(user_head_edid, &head_edid);
+    }
+    case FB_IOCTL_SET_HEAD_MODE_SETTING: {
+        auto user_mode_setting = static_ptr_cast<FBHeadModeSetting const*>(arg);
+        auto head_mode_setting = TRY(copy_typed_from_user(user_mode_setting));
+
+        if (head_mode_setting.horizontal_stride < 0)
+            return Error::from_errno(EINVAL);
+        if (head_mode_setting.pixel_clock_in_khz < 0)
+            return Error::from_errno(EINVAL);
+        if (head_mode_setting.horizontal_active < 0)
+            return Error::from_errno(EINVAL);
+        if (head_mode_setting.horizontal_front_porch_pixels < 0)
+            return Error::from_errno(EINVAL);
+        if (head_mode_setting.horizontal_sync_time_pixels < 0)
+            return Error::from_errno(EINVAL);
+        if (head_mode_setting.horizontal_blank_pixels < 0)
+            return Error::from_errno(EINVAL);
+        if (head_mode_setting.vertical_active < 0)
+            return Error::from_errno(EINVAL);
+        if (head_mode_setting.vertical_front_porch_lines < 0)
+            return Error::from_errno(EINVAL);
+        if (head_mode_setting.vertical_sync_time_lines < 0)
+            return Error::from_errno(EINVAL);
+        if (head_mode_setting.vertical_blank_lines < 0)
+            return Error::from_errno(EINVAL);
+        if (head_mode_setting.horizontal_offset < 0)
+            return Error::from_errno(EINVAL);
+        if (head_mode_setting.vertical_offset < 0)
+            return Error::from_errno(EINVAL);
+        {
+            SpinlockLocker control_locker(m_control_lock);
+            ModeSetting requested_mode_setting;
+            requested_mode_setting.horizontal_stride = 0;
+            requested_mode_setting.pixel_clock_in_khz = head_mode_setting.pixel_clock_in_khz;
+            requested_mode_setting.horizontal_active = head_mode_setting.horizontal_active;
+            requested_mode_setting.horizontal_front_porch_pixels = head_mode_setting.horizontal_front_porch_pixels;
+            requested_mode_setting.horizontal_sync_time_pixels = head_mode_setting.horizontal_sync_time_pixels;
+            requested_mode_setting.horizontal_blank_pixels = head_mode_setting.horizontal_blank_pixels;
+            requested_mode_setting.vertical_active = head_mode_setting.vertical_active;
+            requested_mode_setting.vertical_front_porch_lines = head_mode_setting.vertical_front_porch_lines;
+            requested_mode_setting.vertical_sync_time_lines = head_mode_setting.vertical_sync_time_lines;
+            requested_mode_setting.vertical_blank_lines = head_mode_setting.vertical_blank_lines;
+            requested_mode_setting.horizontal_offset = head_mode_setting.horizontal_offset;
+            requested_mode_setting.vertical_offset = head_mode_setting.vertical_offset;
+
+            TRY(set_mode_setting(requested_mode_setting));
+        }
+        return {};
+    }
+
+    case FB_IOCTL_SET_SAFE_HEAD_MODE_SETTING: {
+        SpinlockLocker control_locker(m_control_lock);
+        TRY(set_safe_mode_setting());
+        return {};
+    }
+
+    case FB_IOCTL_SET_HEAD_VERTICAL_OFFSET_BUFFER: {
+        // FIXME: We silently ignore the request if we are in console mode.
+        // WindowServer is not ready yet to handle errors such as EBUSY currently.
+        SpinlockLocker control_locker(m_control_lock);
+        if (console_mode()) {
+            return {};
+        }
+
+        auto user_head_vertical_buffer_offset = static_ptr_cast<FBHeadVerticalOffset const*>(arg);
+        auto head_vertical_buffer_offset = TRY(copy_typed_from_user(user_head_vertical_buffer_offset));
+
+        SpinlockLocker locker(m_modeset_lock);
+
+        if (head_vertical_buffer_offset.offsetted < 0 || head_vertical_buffer_offset.offsetted > 1)
+            return Error::from_errno(EINVAL);
+        TRY(set_y_offset(head_vertical_buffer_offset.offsetted == 0 ? 0 : m_current_mode_setting.vertical_active));
+        if (head_vertical_buffer_offset.offsetted == 0)
+            m_vertical_offsetted = false;
+        else
+            m_vertical_offsetted = true;
+        return {};
+    }
+    case FB_IOCTL_GET_HEAD_VERTICAL_OFFSET_BUFFER: {
+        auto user_head_vertical_buffer_offset = static_ptr_cast<FBHeadVerticalOffset*>(arg);
+        FBHeadVerticalOffset head_vertical_buffer_offset {};
+        TRY(copy_from_user(&head_vertical_buffer_offset, user_head_vertical_buffer_offset));
+
+        head_vertical_buffer_offset.offsetted = m_vertical_offsetted;
+        return copy_to_user(user_head_vertical_buffer_offset, &head_vertical_buffer_offset);
+    }
+    case FB_IOCTL_FLUSH_HEAD_BUFFERS: {
+        if (!partial_flush_support())
+            return Error::from_errno(ENOTSUP);
+        MutexLocker locker(m_flushing_lock);
+        auto user_flush_rects = static_ptr_cast<FBFlushRects const*>(arg);
+        auto flush_rects = TRY(copy_typed_from_user(user_flush_rects));
+        if (Checked<unsigned>::multiplication_would_overflow(flush_rects.count, sizeof(FBRect)))
+            return Error::from_errno(EFAULT);
+        if (flush_rects.count > 0) {
+            for (unsigned i = 0; i < flush_rects.count; i++) {
+                FBRect user_dirty_rect;
+                TRY(copy_from_user(&user_dirty_rect, &flush_rects.rects[i]));
+                {
+                    SpinlockLocker control_locker(m_control_lock);
+                    if (console_mode())
+                        return {};
+                    TRY(flush_rectangle(flush_rects.buffer_index, user_dirty_rect));
+                }
+            }
+        }
+        return {};
+    };
+    case FB_IOCTL_FLUSH_HEAD: {
+        // FIXME: We silently ignore the request if we are in console mode.
+        // WindowServer is not ready yet to handle errors such as EBUSY currently.
+        MutexLocker locker(m_flushing_lock);
+        SpinlockLocker control_locker(m_control_lock);
+        if (console_mode())
+            return {};
+        if (!flush_support())
+            return Error::from_errno(ENOTSUP);
+        TRY(flush_first_surface());
+        return {};
+    }
+    }
+    return EINVAL;
+}
+
+}
diff --git a/Kernel/Graphics/DisplayConnector.h b/Kernel/Graphics/DisplayConnector.h
new file mode 100644
index 0000000000..ee01d7cdf4
--- /dev/null
+++ b/Kernel/Graphics/DisplayConnector.h
@@ -0,0 +1,144 @@
+/*
+ * Copyright (c) 2022, Liav A. <liavalb@hotmail.co.il>
+ *
+ * SPDX-License-Identifier: BSD-2-Clause
+ */
+
+#pragma once
+
+#include <AK/Types.h>
+#include <Kernel/Devices/CharacterDevice.h>
+#include <LibC/sys/ioctl_numbers.h>
+#include <LibEDID/EDID.h>
+
+namespace Kernel {
+
+class GraphicsManagement;
+class DisplayConnector : public CharacterDevice {
+    friend class GraphicsManagement;
+    friend class DeviceManagement;
+
+public:
+    struct ModeSetting {
+        size_t horizontal_blanking_start() const
+        {
+            return horizontal_active;
+        }
+        size_t horizontal_sync_start() const
+        {
+            return horizontal_active + horizontal_front_porch_pixels;
+        }
+        size_t horizontal_sync_end() const
+        {
+            return horizontal_active + horizontal_front_porch_pixels + horizontal_sync_time_pixels;
+        }
+        size_t horizontal_total() const
+        {
+            return horizontal_active + horizontal_blank_pixels;
+        }
+
+        size_t vertical_blanking_start() const
+        {
+            return vertical_active;
+        }
+        size_t vertical_sync_start() const
+        {
+            return vertical_active + vertical_front_porch_lines;
+        }
+        size_t vertical_sync_end() const
+        {
+            return vertical_active + vertical_front_porch_lines + vertical_sync_time_lines;
+        }
+        size_t vertical_total() const
+        {
+            return vertical_active + vertical_blank_lines;
+        }
+
+        size_t horizontal_stride; // Note: This is commonly known as "pitch"
+        size_t pixel_clock_in_khz;
+
+        size_t horizontal_active;
+        size_t horizontal_front_porch_pixels;
+        size_t horizontal_sync_time_pixels;
+        size_t horizontal_blank_pixels;
+
+        size_t vertical_active;
+        size_t vertical_front_porch_lines;
+        size_t vertical_sync_time_lines;
+        size_t vertical_blank_lines;
+
+        size_t horizontal_offset; // Note: This is commonly known as "x offset"
+        size_t vertical_offset;   // Note: This is commonly known as "y offset"
+    };
+
+public:
+    enum class DisplayMode {
+        Graphical,
+        Console,
+    };
+
+public:
+    virtual ~DisplayConnector() = default;
+
+    virtual bool mutable_mode_setting_capable() const = 0;
+    virtual bool double_framebuffering_capable() const = 0;
+    virtual bool flush_support() const = 0;
+    virtual bool partial_flush_support() const = 0;
+    // Note: This can indicate to userland if the underlying hardware requires
+    // a defined refresh rate being supplied when modesetting the screen resolution.
+    // Paravirtualized hardware don't need such setting and can safely ignore this.
+    virtual bool refresh_rate_support() const = 0;
+
+    bool console_mode() const;
+    ErrorOr<ByteBuffer> get_edid() const;
+    virtual ErrorOr<void> set_mode_setting(ModeSetting const&) = 0;
+    virtual ErrorOr<void> set_safe_mode_setting() = 0;
+    ModeSetting current_mode_setting() const;
+    virtual ErrorOr<void> set_y_offset(size_t y) = 0;
+    virtual ErrorOr<void> unblank() = 0;
+
+    void set_display_mode(Badge<GraphicsManagement>, DisplayMode);
+
+protected:
+    void set_edid_bytes(Array<u8, 128> const& edid_bytes);
+
+    // ^File
+    virtual bool is_seekable() const override { return true; }
+    virtual bool can_read(OpenFileDescription const&, u64) const final override { return true; }
+    virtual bool can_write(OpenFileDescription const&, u64) const final override { return true; }
+    virtual ErrorOr<size_t> read(OpenFileDescription&, u64, UserOrKernelBuffer&, size_t) override final;
+    virtual ErrorOr<size_t> write(OpenFileDescription&, u64, UserOrKernelBuffer const&, size_t) override final;
+    virtual ErrorOr<Memory::Region*> mmap(Process&, OpenFileDescription&, Memory::VirtualRange const&, u64, int, bool) override final;
+    virtual ErrorOr<void> ioctl(OpenFileDescription&, unsigned request, Userspace<void*> arg) override final;
+    virtual StringView class_name() const override final { return "DisplayConnector"sv; }
+
+    DisplayConnector();
+    virtual ErrorOr<size_t> write_to_first_surface(u64 offset, UserOrKernelBuffer const&, size_t length) = 0;
+    virtual void enable_console() = 0;
+    virtual void disable_console() = 0;
+    virtual ErrorOr<void> flush_first_surface() = 0;
+    virtual ErrorOr<void> flush_rectangle(size_t buffer_index, FBRect const& rect);
+
+    ErrorOr<void> initialize_edid_for_generic_monitor();
+
+    mutable Spinlock m_control_lock;
+    mutable Mutex m_flushing_lock;
+
+    bool m_console_mode { false };
+
+    bool m_vertical_offsetted { false };
+
+    mutable Spinlock m_modeset_lock;
+    ModeSetting m_current_mode_setting {};
+
+    Optional<EDID::Parser> m_edid_parser;
+    EDID::Parser::RawBytes m_edid_bytes {};
+    bool m_edid_valid { false };
+
+private:
+    virtual void will_be_destroyed() override;
+    virtual void after_inserting() override;
+
+    IntrusiveListNode<DisplayConnector, RefPtr<DisplayConnector>> m_list_node;
+};
+}
diff --git a/Kernel/Graphics/GraphicsManagement.cpp b/Kernel/Graphics/GraphicsManagement.cpp
index 48536992dc..d5fb78d185 100644
--- a/Kernel/Graphics/GraphicsManagement.cpp
+++ b/Kernel/Graphics/GraphicsManagement.cpp
@@ -95,15 +95,34 @@ void GraphicsManagement::set_vga_text_mode_cursor(size_t console_width, size_t x
 
 void GraphicsManagement::deactivate_graphical_mode()
 {
+    // FIXME: Remove this once we don't support Framebuffer devices anymore.
     for (auto& graphics_device : m_graphics_devices) {
         graphics_device.enable_consoles();
     }
+
+    for (auto& connector : m_display_connector_nodes) {
+        connector.set_display_mode({}, DisplayConnector::DisplayMode::Console);
+    }
 }
 void GraphicsManagement::activate_graphical_mode()
 {
+    // FIXME: Remove this once we don't support Framebuffer devices anymore.
     for (auto& graphics_device : m_graphics_devices) {
         graphics_device.disable_consoles();
     }
+
+    for (auto& connector : m_display_connector_nodes) {
+        connector.set_display_mode({}, DisplayConnector::DisplayMode::Graphical);
+    }
+}
+
+void GraphicsManagement::attach_new_display_connector(Badge<DisplayConnector>, DisplayConnector& connector)
+{
+    m_display_connector_nodes.append(connector);
+}
+void GraphicsManagement::detach_display_connector(Badge<DisplayConnector>, DisplayConnector& connector)
+{
+    m_display_connector_nodes.remove(connector);
 }
 
 static inline bool is_vga_compatible_pci_device(PCI::DeviceIdentifier const& device_identifier)
diff --git a/Kernel/Graphics/GraphicsManagement.h b/Kernel/Graphics/GraphicsManagement.h
index 428ac52b0d..b730d4012a 100644
--- a/Kernel/Graphics/GraphicsManagement.h
+++ b/Kernel/Graphics/GraphicsManagement.h
@@ -12,6 +12,7 @@
 #include <AK/Types.h>
 #include <Kernel/Bus/PCI/Definitions.h>
 #include <Kernel/Graphics/Console/Console.h>
+#include <Kernel/Graphics/DisplayConnector.h>
 #include <Kernel/Graphics/GenericGraphicsAdapter.h>
 #include <Kernel/Graphics/VGACompatibleAdapter.h>
 #include <Kernel/Graphics/VirtIOGPU/GraphicsAdapter.h>
@@ -29,6 +30,9 @@ public:
     unsigned allocate_minor_device_number() { return m_current_minor_number++; };
     GraphicsManagement();
 
+    void attach_new_display_connector(Badge<DisplayConnector>, DisplayConnector&);
+    void detach_display_connector(Badge<DisplayConnector>, DisplayConnector&);
+
     bool framebuffer_devices_console_only() const;
     bool framebuffer_devices_use_bootloader_framebuffer() const;
     bool framebuffer_devices_exist() const;
@@ -55,6 +59,8 @@ private:
     RefPtr<VGACompatibleAdapter> m_vga_adapter;
     unsigned m_current_minor_number { 0 };
 
+    IntrusiveList<&DisplayConnector::m_list_node> m_display_connector_nodes;
+
     RecursiveSpinlock m_main_vga_lock;
     bool m_vga_access_is_disabled { false };
 };