bhyve should not zero lowmem on reboot
During the porting effort for bhyve, some erroneous behavior with an old version of the bootrom was worked around by explicitly zeroing lowmem (< 3GB) during instance reinit (as done for reboot). Upstream bhyve has never needed anything like this, although that may be due to less usage of that specific bootrom. (ROM-less
bhyveload boot, and the uefi-only ROM seem much more common there). It would be nice to revisit this workaround and remove it if possible.
Updated by Patrick Mooney 4 months ago
With #13840 diagnosed and addressed with a work-around to include with this change, I set out to test the typical battery of guests on AMD and Intel hardware. (Hitting both vendors here is particularly pertinent, given that the Tianocore bootrom chooses different code paths depending on CPU vendor) The usual guests booted and rebooted fine without incident. A specially configured Alpine guest using the CSM-enabled ROM was also able to boot and reboot successfully.
Updated by Electric Monk 4 months ago
- Status changed from In Progress to Closed
- % Done changed from 0 to 100
commit 9e6c6f2f3ab9c8f1f042b97c0432e8ccc9650309 Author: Patrick Mooney <email@example.com> Date: 2021-06-03T01:52:27.000Z 13835 bhyve should not zero lowmem on reboot 13840 bhyve hostbridge should feign PAM0 emulation Reviewed by: Andy Fiddaman <firstname.lastname@example.org> Reviewed by: Dan Cross <email@example.com> Approved by: Robert Mustacchi <firstname.lastname@example.org>