1 files changed, 33 insertions, 0 deletions
diff --git a/kernel/main.c b/kernel/main.c
index 0a1ebc2..45c34ab 100644
--- a/kernel/main.c
+++ b/kernel/main.c
@@ -755,6 +755,39 @@ static ssize_t nv_vgpu_vfio_dev_write(struct vfio_device *vdev, const char __use
 		return ret;
 	}
 
+	/* BAR0 region (register space). Most guest accesses hit the mmap'd
+	 * shadow directly, but region writes also arrive here (e.g. when QEMU
+	 * handles a trapped access). They must be applied to the shadow and to
+	 * the trap table - dropping them makes the guest driver poll a
+	 * register that never changes and spin forever. */
+	if (pos >= 0 && (u64)pos < vgpu->bars[0].size && count <= 8) {
+		u8 tmp[8];
+		ssize_t ret;
+
+		if (!vgpu->bar_emul_ctx)
+			return -ENODEV;
+		if (copy_from_user(tmp, buf, count))
+			return -EFAULT;
+
+		ret = nv_vgpu_bar_emul_write(vgpu, 0, (u64)pos, tmp, count);
+		if (ret)
+			return ret;
+		*ppos += count;
+		return count;
+	}
+
+	/* BAR1 region (VRAM): same for the emulated vidmem backing. */
+	if (pos >= (1ULL << 40) &&
+	    (u64)pos < (1ULL << 40) + vgpu->bars[1].size &&
+	    vgpu->bars[1].vaddr && count <= 8) {
+		u64 bar1_off = (u64)pos - (1ULL << 40);
+
+		if (copy_from_user(vgpu->bars[1].vaddr + bar1_off, buf, count))
+			return -EFAULT;
+		*ppos += count;
+		return count;
+	}
+
 	return 0;
 }