[SeaBIOS] [PATCH v2 0/2] QEMU: Add capability to write back fw_cfg address to QEMU

From: Ben Warren

This patch set adds the capability to write to QEMU across the DMA link and
adds a higher-level command to allocate a fw_cfg file and write its address
back to another, writeable fw_cfg file.

The initial use case is for Windows VM
Generation ID, where QEMU needs to change the contents of fw_cfg
data at runtime, while still having BIOS allocate and manage the memory.

v1->v2: separated patch into two functional units
        changed so writes only occur over the DMA interface
        fixed coding style
        removed change to romfile struct definition (removed new write_back method)

Ben Warren (2):
  QEMU DMA: Add DMA write capability
  QEMU fw_cfg: Add command to write back address of file

src/fw/paravirt.c       | 49 +++++++++++++++++++++++++++++++++++++++++++++++++
 src/fw/paravirt.h       |  3 +++
 src/fw/romfile_loader.c | 38 ++++++++++++++++++++++++++++++++++++++
 src/fw/romfile_loader.h | 23 ++++++++++++++++++++---
 4 files changed, 110 insertions(+), 3 deletions(-)