On 08/19/19 16:10, Paolo Bonzini wrote:
On 19/08/19 01:00, Yao, Jiewen wrote:Alex, thank you for the help! Please let us know if we should remove youin real world, we deprecate AB-seg usage because they are vulnerableIndeed the SMRR would not cover the A-seg on real hardware. However, if
from the CC list, in order not to clutter your inbox. (I've kept your
address for now, for saying thanks. Feel free to stop reading here. Thanks!)
For OVMFSo what is Igor's idea? Please do spoon-feed it to me. I've seen the POC
patch but the memory region manipulation isn't obvious to me.
Regarding TSEG, QEMU doesn't implement it differently from normal RAM.
Instead, if memory serves, there is an extra "black hole" region that is
overlaid, which hides the RAM contents when TSEG is supposed to be
closed (and the guest is not running in SMM).
But this time we're doing something else, right? Is the idea to overlay
the RAM range at 0x30000 with a window (alias) into the "compatible"
SMRAM at 0xA0000-0xBFFFF?
I don't know how the "compatible" SMRAM is implemented in QEMU. Does the
compatible SMRAM behave in sync with TSEG? OVMF doesn't configure or
touch compatible SMRAM at all, at the moment.