From: Ben Warren ben@skyportsystems.com
This patch set adds the capability to write to QEMU across the fw_cfg DMA link. It adds a higher-level command to write the BIOS-allocated address of one fw_cfg file into an arbitrary point within another, writeable fw_cfg file across the above-mentioned link.
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.
v2->v3: - fixed up the qemu_cfg_write* functions to allow writing to an arbitrary offset within the destination file. - Changed function name to COMMAND_WRITE_POINTER and its functionality to not patch memory at all, but write back to a specified offset.
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 | 37 +++++++++++++++++++++++++++++++++++++ src/fw/romfile_loader.h | 16 ++++++++++------ 4 files changed, 99 insertions(+), 6 deletions(-)