x86: 64, generic: replace fbdev with simpledrm

efifb, the simple-framebuffer fbdev driver, hyperv_fb and xen-fbfront
carry the display on these two subtargets, with fbcon and DRM fbdev
emulation on top. A DRM driver can claim the firmware framebuffer on its
own, so the legacy hardware drivers only add size to every image.

Mark the firmware framebuffer as a generic system framebuffer so sysfb
registers it as simple-framebuffer for simpledrm, and enable hyperv_drm
for Hyper-V guests as its help text asks. DRM fbdev emulation and fbcon
stay, so the boot log and the console prompt still reach the screen; the
emulation serves fbcon, as generic leaves FB_DEVICE off and no /dev/fb
node appears. VGA_CONSOLE and VT stay as well: a BIOS boot through GRUB
pc leaves the machine in VGA text mode, where the firmware offers no
framebuffer for simpledrm to drive, so vgacon is the only console there.
A Xen PV or PVH guest has neither, and keeps its console on hvc0. The
shared x86 config and the legacy and geode subtargets are untouched.

Signed-off-by: Daniel Golle <daniel@makrotopia.org>

target/linux/x86/64/config-6.18

@@ -132,14 +132,20 @@ CONFIG_DRM=y
 CONFIG_DRM_ACCEL=y
 CONFIG_DRM_BOCHS=y
 CONFIG_DRM_BRIDGE=y
+CONFIG_DRM_CLIENT=y
+CONFIG_DRM_CLIENT_LIB=y
+CONFIG_DRM_CLIENT_SELECTION=y
+CONFIG_DRM_CLIENT_SETUP=y
 CONFIG_DRM_FBDEV_EMULATION=y
 CONFIG_DRM_FBDEV_OVERALLOC=100
 CONFIG_DRM_GEM_SHMEM_HELPER=y
-# CONFIG_DRM_HYPERV is not set
+CONFIG_DRM_HYPERV=y
 CONFIG_DRM_KMS_HELPER=y
 CONFIG_DRM_PANEL=y
 CONFIG_DRM_PANEL_BRIDGE=y
 CONFIG_DRM_PANEL_ORIENTATION_QUIRKS=y
+CONFIG_DRM_SIMPLEDRM=y
+CONFIG_DRM_SYSFB_HELPER=y
 CONFIG_DRM_TTM=y
 CONFIG_DRM_TTM_HELPER=y
 CONFIG_DRM_VIRTIO_GPU=y
@@ -168,28 +174,14 @@ CONFIG_EFI_RUNTIME_WRAPPERS=y
 CONFIG_EFI_STUB=y
 # CONFIG_EFI_TEST is not set
 CONFIG_FAILOVER=y
-CONFIG_FB=y
-CONFIG_FB_CFB_COPYAREA=y
-CONFIG_FB_CFB_FILLRECT=y
-CONFIG_FB_CFB_IMAGEBLIT=y
 CONFIG_FB_CORE=y
 CONFIG_FB_DEFERRED_IO=y
-CONFIG_FB_DEVICE=y
-CONFIG_FB_EFI=y
-CONFIG_FB_HYPERV=y
-CONFIG_FB_IOMEM_FOPS=y
-CONFIG_FB_IOMEM_HELPERS=y
-CONFIG_FB_IOMEM_HELPERS_DEFERRED=y
-CONFIG_FB_MODE_HELPERS=y
-CONFIG_FB_SIMPLE=y
 CONFIG_FB_SYSMEM_FOPS=y
 CONFIG_FB_SYSMEM_HELPERS=y
 CONFIG_FB_SYSMEM_HELPERS_DEFERRED=y
 CONFIG_FB_SYS_COPYAREA=y
 CONFIG_FB_SYS_FILLRECT=y
 CONFIG_FB_SYS_IMAGEBLIT=y
-CONFIG_FB_TILEBLITTING=y
-# CONFIG_FB_VESA is not set
 CONFIG_FIRMWARE_TABLE=y
 CONFIG_FONT_8x16=y
 CONFIG_FONT_8x8=y
@@ -483,6 +475,7 @@ CONFIG_SWIOTLB=y
 CONFIG_SWIOTLB_XEN=y
 CONFIG_SYNC_FILE=y
 CONFIG_SYSFB=y
+CONFIG_SYSFB_SIMPLEFB=y
 # CONFIG_SYSTEM76_ACPI is not set
 CONFIG_SYS_HYPERVISOR=y
 # CONFIG_TDX_GUEST_DRIVER is not set
@@ -584,7 +577,6 @@ CONFIG_XEN_DEBUG_FS=y
 CONFIG_XEN_DEV_EVTCHN=y
 CONFIG_XEN_DOM0=y
 CONFIG_XEN_EFI=y
-CONFIG_XEN_FBDEV_FRONTEND=y
 CONFIG_XEN_GNTDEV=y
 CONFIG_XEN_GRANT_DEV_ALLOC=y
 CONFIG_XEN_GRANT_DMA_OPS=y

target/linux/x86/generic/config-6.18

@@ -73,14 +73,20 @@ CONFIG_DMA_SHARED_BUFFER=y
 CONFIG_DRM=y
 CONFIG_DRM_BOCHS=y
 CONFIG_DRM_BRIDGE=y
+CONFIG_DRM_CLIENT=y
+CONFIG_DRM_CLIENT_LIB=y
+CONFIG_DRM_CLIENT_SELECTION=y
+CONFIG_DRM_CLIENT_SETUP=y
 CONFIG_DRM_FBDEV_EMULATION=y
 CONFIG_DRM_FBDEV_OVERALLOC=100
 CONFIG_DRM_GEM_SHMEM_HELPER=y
-# CONFIG_DRM_HYPERV is not set
+CONFIG_DRM_HYPERV=y
 CONFIG_DRM_KMS_HELPER=y
 CONFIG_DRM_PANEL=y
 CONFIG_DRM_PANEL_BRIDGE=y
 CONFIG_DRM_PANEL_ORIENTATION_QUIRKS=y
+CONFIG_DRM_SIMPLEDRM=y
+CONFIG_DRM_SYSFB_HELPER=y
 CONFIG_DRM_TTM=y
 CONFIG_DRM_TTM_HELPER=y
 CONFIG_DRM_VIRTIO_GPU=y
@@ -108,27 +114,14 @@ CONFIG_EFI_STUB=y
 # CONFIG_EFI_TEST is not set
 # CONFIG_EL3 is not set
 CONFIG_FAILOVER=y
-CONFIG_FB=y
-CONFIG_FB_CFB_COPYAREA=y
-CONFIG_FB_CFB_FILLRECT=y
-CONFIG_FB_CFB_IMAGEBLIT=y
 CONFIG_FB_CORE=y
 CONFIG_FB_DEFERRED_IO=y
-CONFIG_FB_DEVICE=y
-CONFIG_FB_EFI=y
-CONFIG_FB_HYPERV=y
-# CONFIG_FB_I810 is not set
-CONFIG_FB_IOMEM_FOPS=y
-CONFIG_FB_IOMEM_HELPERS=y
-CONFIG_FB_IOMEM_HELPERS_DEFERRED=y
-CONFIG_FB_SIMPLE=y
 CONFIG_FB_SYSMEM_FOPS=y
 CONFIG_FB_SYSMEM_HELPERS=y
 CONFIG_FB_SYSMEM_HELPERS_DEFERRED=y
 CONFIG_FB_SYS_COPYAREA=y
 CONFIG_FB_SYS_FILLRECT=y
 CONFIG_FB_SYS_IMAGEBLIT=y
-# CONFIG_FB_VESA is not set
 CONFIG_FIRMWARE_TABLE=y
 CONFIG_FONT_8x16=y
 CONFIG_FONT_8x8=y
@@ -384,6 +377,7 @@ CONFIG_SPLIT_PTE_PTLOCKS=y
 CONFIG_SWIOTLB=y
 CONFIG_SYNC_FILE=y
 CONFIG_SYSFB=y
+CONFIG_SYSFB_SIMPLEFB=y
 # CONFIG_SYSTEM76_ACPI is not set
 CONFIG_SYS_HYPERVISOR=y
 CONFIG_TASKSTATS=y
@@ -460,7 +454,6 @@ CONFIG_XEN_BLKDEV_FRONTEND=y
 CONFIG_XEN_COMPAT_XENFS=y
 CONFIG_XEN_DEBUG_FS=y
 CONFIG_XEN_DEV_EVTCHN=y
-CONFIG_XEN_FBDEV_FRONTEND=y
 CONFIG_XEN_GNTDEV=y
 CONFIG_XEN_GRANT_DEV_ALLOC=y
 CONFIG_XEN_GRANT_DMA_OPS=y