mbox series

[v1,0/2] i386/a-b-bootblock: zero the first byte of each page on start

Message ID 20230907193051.1609310-1-d-tatianin@yandex-team.ru (mailing list archive)
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Series i386/a-b-bootblock: zero the first byte of each page on start | expand

Message

Daniil Tatianin Sept. 7, 2023, 7:30 p.m. UTC 
This series fixes an issue where the outcome of the migration qtest
relies on the initial memory contents all being the same across the
first 100MiB of RAM, which is a very fragile invariant.

We fix this by making sure we zero the first byte of every testable page
in range beforehand.

Daniil Tatianin (2):
  i386/a-b-bootblock: factor test memory addresses out into constants
  i386/a-b-bootblock: zero the first byte of each page on start

 tests/migration/i386/a-b-bootblock.S | 18 +++++++++++++++---
 tests/migration/i386/a-b-bootblock.h | 16 ++++++++--------
 2 files changed, 23 insertions(+), 11 deletions(-)

Comments

Peter Xu Sept. 13, 2023, 7:22 p.m. UTC | #1 
On Thu, Sep 07, 2023 at 10:30:49PM +0300, Daniil Tatianin wrote:
> This series fixes an issue where the outcome of the migration qtest
> relies on the initial memory contents all being the same across the
> first 100MiB of RAM, which is a very fragile invariant.
> 
> We fix this by making sure we zero the first byte of every testable page
> in range beforehand.
> 
> Daniil Tatianin (2):
>   i386/a-b-bootblock: factor test memory addresses out into constants
>   i386/a-b-bootblock: zero the first byte of each page on start

Thanks, sorry for being slow on review.

Reviewed-by: Peter Xu <peterx@redhat.com>

How about other archs (arm/s390)?   It seems to me arm is all fine, but not
sure about s390.