mirror of
https://github.com/projectacrn/acrn-hypervisor.git
synced 2026-01-24 14:14:52 +00:00
b98096ea06
PCI spec says that the procedure of sizing a BAR is as follows: 1) disable the decode via command register 2) save the original value of BAR register 3) write all-1 to the BAR register 4) read BAR register back, calculate the size 5) restore the original value to BAR register 6) re-enable the decode via command register Some driver does not disable the decode of BAR register via the command register before sizing a BAR. This will lead to a overlay of the BAR addresses when trying to register the intermediate BAR address via register_bar. A stateful variable sizing is used to keep track of such kind of BAR address changes and workaroud this violation. Currently this issue is only found when audio device is passed through to Windows 10 guest. When it is fixed in the Windows audio driver, this patch should be reverted. v1 -> v2: - change the commit message to add the procedure of BAR sizing from PCI spec Tracked-On: #2962 Signed-off-by: Jian Jun Chen <jian.jun.chen@intel.com> Reviewed-by: Binbin Wu <binbin.wu@intel.com> Acked-by: Yu Wang <yu1.wang@intel.com>
ACRN Device Model ################# Introduction ============ The ACRN Device Model provides **device sharing** capabilities between the Service OS and Guest OSs. It is a component that is used in conjunction with the `ACRN Hypervisor`_ and this is installed within the Service OS. You can find out more about Project ACRN on the `Project ACRN documentation`_ website. .. _`ACRN Hypervisor`: https://github.com/projectacrn/acrn-hypervisor .. _`Project ACRN documentation`: https://projectacrn.github.io/