Modern VMware SVGA II guest drivers expect the 8-bit palette
emulation capability (`SVGA_CAP_8BIT_EMULATION`, bit 8) and
the two alpha-blending cursor bits (`SVGA_CAP_ALPHA_BLEND`
bit 13, `SVGA_CAP_ALPHA_CURSOR` bit 9) to be advertised by
any device that presents a modern feature set. The upstream
device already implements the machinery behind all three:
* 8-bit palette is handled by the legacy vga core that
vmware_vga extends, so advertising 8BIT_EMULATION is a
pure capability-bit change.
* ALPHA_CURSOR is satisfied by `SVGA_CMD_DEFINE_ALPHA_CURSOR`
which the FIFO command dispatcher already handles.
* ALPHA_BLEND is a generic "host supports alpha blending on
ARGB surfaces" bit; macOS's driver uses it to gate the
ARGB cursor upload path.
Without these bits, macOS's vmware_vga driver falls back to
the monochrome cursor path and the guest cursor flickers or
renders without anti-aliasing.
Signed-off-by: Matthew Jackson <[email protected]>
---
hw/display/vmware_vga.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)
--- a/hw/display/vmware_vga.c
+++ b/hw/display/vmware_vga.c
@@ -896,7 +896,18 @@ static uint32_t vmsvga_value_read(void *opaque, uint32_t
address)
break;
case SVGA_REG_CAPABILITIES:
- caps = SVGA_CAP_PITCHLOCK | SVGA_CAP_EXTENDED_FIFO;
+ /*
+ * Advertise the capability bits that modern VMware SVGA II guest
+ * drivers (Linux vmwgfx, macOS 10.13+, Windows 10+) expect at a
+ * minimum. PITCHLOCK lets the guest pin the scanout pitch across
+ * mode changes; EXTENDED_FIFO exposes the pitchlock/fence/3d-hw
+ * FIFO registers above SVGA_FIFO_STOP; 8BIT_EMULATION advertises
+ * legacy palette support; ALPHA_BLEND / ALPHA_CURSOR are
+ * required for the 32-bit ARGB hardware cursor path.
+ */
+ caps = SVGA_CAP_PITCHLOCK | SVGA_CAP_EXTENDED_FIFO |
+ SVGA_CAP_8BIT_EMULATION | SVGA_CAP_ALPHA_BLEND |
+ SVGA_CAP_ALPHA_CURSOR;
#ifdef HW_RECT_ACCEL
caps |= SVGA_CAP_RECT_COPY;
#endif
--
2.47.0
