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Kernel/Graphics: Bring back the mmap interface for DisplayConnectors

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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
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22
Kernel/Graphics/VirtIOGPU/GraphicsAdapter.h
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@ -50,10 +50,25 @@ public:
Graphics::VirtIOGPU::ResourceID allocate_resource_id(Badge<VirtIODisplayConnector>);
Graphics::VirtIOGPU::ContextID allocate_context_id(Badge<VirtIODisplayConnector>);
ErrorOr<void> mode_set_resolution(Badge<VirtIODisplayConnector>, VirtIODisplayConnector&, size_t width, size_t height);
void set_dirty_displayed_rect(Badge<VirtIODisplayConnector>, VirtIODisplayConnector&, Graphics::VirtIOGPU::Protocol::Rect const& dirty_rect, bool main_buffer);
void flush_displayed_image(Badge<VirtIODisplayConnector>, VirtIODisplayConnector&, Graphics::VirtIOGPU::Protocol::Rect const& dirty_rect, bool main_buffer);
void transfer_framebuffer_data_to_host(Badge<VirtIODisplayConnector>, VirtIODisplayConnector&, Graphics::VirtIOGPU::Protocol::Rect const& rect, bool main_buffer);
private:
ErrorOr<void> attach_physical_range_to_framebuffer(VirtIODisplayConnector& connector, bool main_buffer, size_t framebuffer_offset, size_t framebuffer_size);
void flush_dirty_rectangle(Graphics::VirtIOGPU::ScanoutID, Graphics::VirtIOGPU::ResourceID, Graphics::VirtIOGPU::Protocol::Rect const& dirty_rect);
struct Scanout {
struct PhysicalBuffer {
size_t framebuffer_offset { 0 };
Graphics::VirtIOGPU::Protocol::Rect dirty_rect {};
Graphics::VirtIOGPU::ResourceID resource_id { 0 };
};
RefPtr<VirtIODisplayConnector> display_connector;
PhysicalBuffer main_buffer;
PhysicalBuffer back_buffer;
};
VirtIOGraphicsAdapter(PCI::DeviceIdentifier const&, NonnullOwnPtr<Memory::Region> scratch_space_region);
@ -65,6 +80,13 @@ private:
u32 get_pending_events();
void clear_pending_events(u32 event_bitmask);
// 2D framebuffer stuff
static ErrorOr<FlatPtr> calculate_framebuffer_size(size_t width, size_t height)
{
// VirtIO resources can only map on page boundaries!
return Memory::page_round_up(sizeof(u32) * width * height);
}
// 3D Command stuff
Graphics::VirtIOGPU::ContextID create_context();
void attach_resource_to_context(Graphics::VirtIOGPU::ResourceID resource_id, Graphics::VirtIOGPU::ContextID context_id);