On 3/27/2023 4:37 PM, Mathias Krause wrote:
On 27.03.23 10:33, Xiaoyao Li wrote:
On 3/22/2023 9:37 AM, Mathias Krause wrote:
Guests like grsecurity that make heavy use of CR0.WP to implement kernel
level W^X will suffer from the implied VMEXITs.
With EPT there is no need to intercept a guest change of CR0.WP, so
simply make it a guest owned bit if we can do so.
I'm interested in the performance gain. Do you have data like Patch 2?
It's mentioned in the cover letter[1], quoted below:
Sorry I missed it. The data of not intercepting CR0.WP looks great as well.
[1]
https://lore.kernel.org/kvm/20230322013731.102955-1-minipli@xxxxxxxxxxxxxx/
: I used 'ssdd 10 50000' from rt-tests[5] as a micro-benchmark, running on a
: grsecurity L1 VM. Below table shows the results (runtime in seconds, lower
: is better):
:
: legacy TDP shadow
: kvm-x86/next@d8708b 8.43s 9.45s 70.3s
: + patches 1-3 5.39s 5.63s 70.2s
: + patches 4-6 3.51s 3.47s 67.8s
Thanks,
Mathias
