Hi,
I have posted the pachset to make OVMF happy and have CCed you guys,
could you please check it if it works for you?
On 07/15/2015 05:15 AM, Paolo Bonzini wrote:
The long delay that Alex reported (for the case when all guest memory
was set to UC up-front) is due to the fact that the SEC phase of OVMF
decompresses an approximately 1712 KB sized, LZMA-compressed blob, to
approx. 896 KB worth of PEI drivers and 8192 KB worth of DXE and UEFI
drivers -- and this decompression is extremely memory-intensive.
(When Jordan implemented that reset vector first, we saw similar
performance degradation on AMD hosts (albeit not due to MTRR but due to
page attributes). See
<https://github.com/tianocore/edk2/commit/98f378a7>. I'm only mentioning
it here because it makes me appreciate the current problem report.)
Anyway, the reset vector's page table building is implemented in
"OvmfPkg/ResetVector/Ia32/PageTables64.asm". The decompression in SEC
can be found in "OvmfPkg/Sec/SecMain.c", function DecompressMemFvs().
Perhaps the OVMF reset vector should initialize the MTRRs for the BSP?
I think SEC doesn't do any MMIO, so it should be enough to enable MTRRs
and set the default type to writeback.
In any case we're going to have to quirk it, because of the broken
guests in the wild.
Paolo
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