Re: [PATCH v4 0/7] TDX host: kexec/kdump support

From: Paolo Bonzini
Date: Tue Jul 22 2025 - 09:51:00 EST


On 7/17/25 23:46, Kai Huang wrote:
This series is the latest attempt to support kexec on TDX host following
Dave's suggestion to use a percpu boolean to control WBINVD during
kexec.

Hi Boris/Tom,

As requested, I added the first patch to cleanup the last two 'unsigned
int' parameters of the relocate_kernel() into one 'unsigned int' and pass
flags instead. The patch 2 (patch 1 in v3) also gets updated based on
that. Would you help to review? Thanks.

I tested that both normal kexec and preserve_context kexec works (using
the tools/testing/selftests/kexec/test_kexec_jump.sh). But I don't have
SME capable machine to test.

Hi Tom, I added your Reviewed-by and Tested-by in the patch 2 anyway
since I believe the change is trivial and straightforward). But due to
the cleanup patch, I appreciate if you can help to test the first two
patches again. Thanks a lot!

I guess we're just waiting for a v5 with testb and an augmented comment in patch 1?

(Frankly, I am not sure I see any improvement with respect to v3. When assembly is involved, what looks like a cleanup can make register usage more messy. But since the code is there, I'm not going to ask Kai or anyone else to do anything).

Paolo