RGBCube/serenity
1
Fork 0
mirror of https://github.com/RGBCube/serenity synced 2025-05-31 22:48:11 +00:00
Code Issues Activity Actions

Kernel/Graphics: Bring back the mmap interface for DisplayConnectors

Browse source 
The mmap interface was removed when we introduced the DisplayConnector
class, as it was quite unsafe to use and didn't handle switching between
graphical and text modes safely. By using the SharedFramebufferVMObject,
we are able to elegantly coordinate the switch by remapping the attached
mmap'ed-Memory::Region(s) with different mappings, therefore, keeping
WindowServer to think that the mappings it has are still valid, while
they are going to a different physical range until we are back to the
graphical mode (after a switch from text mode).

Most drivers take advantage of the fact that we know where is the actual
framebuffer in physical memory space, the SharedFramebufferVMObject is
created with that information. However, the VirtIO driver is different
in that aspect, because it relies on DMA transactions to show graphics
on the framebuffer, so the SharedFramebufferVMObject is created with
that mindset to support the arbitrary framebuffer location in physical
memory space.
This commit is contained in:
Liav A 2022-05-13 03:23:13 +03:00 • committed by Linus Groh
parent 3d22917548
commit e2ed6ef741
19 changed files with 309 additions and 341 deletions
Download patch file Download diff file Expand all files Collapse all files

77
Kernel/Graphics/VirtIOGPU/GraphicsAdapter.cpp
View file

@ -48,6 +48,83 @@ ErrorOr<void> VirtIOGraphicsAdapter::initialize_adapter()
return {};
}
ErrorOr<void> VirtIOGraphicsAdapter::mode_set_resolution(Badge<VirtIODisplayConnector>, VirtIODisplayConnector& connector, size_t width, size_t height)
{
SpinlockLocker locker(m_operation_lock);
VERIFY(connector.scanout_id() < VIRTIO_GPU_MAX_SCANOUTS);
auto rounded_buffer_size = TRY(calculate_framebuffer_size(width, height));
TRY(attach_physical_range_to_framebuffer(connector, true, 0, rounded_buffer_size));
TRY(attach_physical_range_to_framebuffer(connector, false, rounded_buffer_size, rounded_buffer_size));
return {};
}
void VirtIOGraphicsAdapter::set_dirty_displayed_rect(Badge<VirtIODisplayConnector>, VirtIODisplayConnector& connector, Graphics::VirtIOGPU::Protocol::Rect const& dirty_rect, bool main_buffer)
{
VERIFY(m_operation_lock.is_locked());
VERIFY(connector.scanout_id() < VIRTIO_GPU_MAX_SCANOUTS);
Scanout::PhysicalBuffer& buffer = main_buffer ? m_scanouts[connector.scanout_id().value()].main_buffer : m_scanouts[connector.scanout_id().value()].back_buffer;
if (buffer.dirty_rect.width == 0 || buffer.dirty_rect.height == 0) {
buffer.dirty_rect = dirty_rect;
} else {
auto current_dirty_right = buffer.dirty_rect.x + buffer.dirty_rect.width;
auto current_dirty_bottom = buffer.dirty_rect.y + buffer.dirty_rect.height;
buffer.dirty_rect.x = min(buffer.dirty_rect.x, dirty_rect.x);
buffer.dirty_rect.y = min(buffer.dirty_rect.y, dirty_rect.y);
buffer.dirty_rect.width = max(current_dirty_right, dirty_rect.x + dirty_rect.width) - buffer.dirty_rect.x;
buffer.dirty_rect.height = max(current_dirty_bottom, dirty_rect.y + dirty_rect.height) - buffer.dirty_rect.y;
}
}
void VirtIOGraphicsAdapter::flush_displayed_image(Badge<VirtIODisplayConnector>, VirtIODisplayConnector& connector, Graphics::VirtIOGPU::Protocol::Rect const& dirty_rect, bool main_buffer)
{
VERIFY(m_operation_lock.is_locked());
VERIFY(connector.scanout_id() < VIRTIO_GPU_MAX_SCANOUTS);
Scanout::PhysicalBuffer& buffer = main_buffer ? m_scanouts[connector.scanout_id().value()].main_buffer : m_scanouts[connector.scanout_id().value()].back_buffer;
flush_displayed_image(buffer.resource_id, dirty_rect);
buffer.dirty_rect = {};
}
void VirtIOGraphicsAdapter::transfer_framebuffer_data_to_host(Badge<VirtIODisplayConnector>, VirtIODisplayConnector& connector, Graphics::VirtIOGPU::Protocol::Rect const& rect, bool main_buffer)
{
VERIFY(m_operation_lock.is_locked());
VERIFY(connector.scanout_id() < VIRTIO_GPU_MAX_SCANOUTS);
Scanout::PhysicalBuffer& buffer = main_buffer ? m_scanouts[connector.scanout_id().value()].main_buffer : m_scanouts[connector.scanout_id().value()].back_buffer;
transfer_framebuffer_data_to_host(connector.scanout_id(), buffer.resource_id, rect);
}
ErrorOr<void> VirtIOGraphicsAdapter::attach_physical_range_to_framebuffer(VirtIODisplayConnector& connector, bool main_buffer, size_t framebuffer_offset, size_t framebuffer_size)
{
VERIFY(m_operation_lock.is_locked());
Scanout::PhysicalBuffer& buffer = main_buffer ? m_scanouts[connector.scanout_id().value()].main_buffer : m_scanouts[connector.scanout_id().value()].back_buffer;
buffer.framebuffer_offset = framebuffer_offset;
// 1. Create BUFFER using VIRTIO_GPU_CMD_RESOURCE_CREATE_2D
if (buffer.resource_id.value() != 0)
delete_resource(buffer.resource_id);
auto display_info = connector.display_information({});
buffer.resource_id = create_2d_resource(display_info.rect);
// 2. Attach backing storage using VIRTIO_GPU_CMD_RESOURCE_ATTACH_BACKING
ensure_backing_storage(buffer.resource_id, connector.framebuffer_region(), buffer.framebuffer_offset, framebuffer_size);
// 3. Use VIRTIO_GPU_CMD_SET_SCANOUT to link the framebuffer to a display scanout.
set_scanout_resource(connector.scanout_id(), buffer.resource_id, display_info.rect);
// 4. Render our test pattern
connector.draw_ntsc_test_pattern({});
// 5. Use VIRTIO_GPU_CMD_TRANSFER_TO_HOST_2D to update the host resource from guest memory.
transfer_framebuffer_data_to_host(connector.scanout_id(), buffer.resource_id, display_info.rect);
// 6. Use VIRTIO_GPU_CMD_RESOURCE_FLUSH to flush the updated resource to the display.
flush_displayed_image(buffer.resource_id, display_info.rect);
// Make sure we constrain the existing dirty rect (if any)
if (buffer.dirty_rect.width != 0 || buffer.dirty_rect.height != 0) {
auto dirty_right = buffer.dirty_rect.x + buffer.dirty_rect.width;
auto dirty_bottom = buffer.dirty_rect.y + buffer.dirty_rect.height;
buffer.dirty_rect.width = min(dirty_right, display_info.rect.x + display_info.rect.width) - buffer.dirty_rect.x;
buffer.dirty_rect.height = min(dirty_bottom, display_info.rect.y + display_info.rect.height) - buffer.dirty_rect.y;
}
return {};
}
VirtIOGraphicsAdapter::VirtIOGraphicsAdapter(PCI::DeviceIdentifier const& device_identifier, NonnullOwnPtr<Memory::Region> scratch_space_region)
: VirtIO::Device(device_identifier)
, m_scratch_space(move(scratch_space_region))