From: Julien Grall Date: Thu, 25 Mar 2021 10:42:46 +0000 (+0000) Subject: docs/design: Update xenstore-migration.md X-Git-Tag: archive/raspbian/4.16.0+51-g0941d6cb-1+rpi1~2^2~42^2~802 X-Git-Url: https://dgit.raspbian.org/?a=commitdiff_plain;h=7b6d288ef648c76da70fd9e41e73617631025cfe;p=xen.git docs/design: Update xenstore-migration.md It is not very clear the shared page adddress is not contained in the connection record. Additionally, it is misleading to say the grant will always point to the share paged as a domain is free to revoke the permission. The restore code would need to make sure it doesn't fail/crash if this is happening. The sentence is now replaced with a paragraph explaining why the GFN is not preserved and that the grant is not guarantee to exist during restore. Take the opportunity to replace "code" with "node" when description the permission. Reported-by: Raphael Ning Signed-off-by: Julien Grall Reviewed-by: Juergen Gross Release-Acked-by: Ian Jackson --- diff --git a/docs/designs/xenstore-migration.md b/docs/designs/xenstore-migration.md index 1a5b94b31d..5f1155273e 100644 --- a/docs/designs/xenstore-migration.md +++ b/docs/designs/xenstore-migration.md @@ -216,8 +216,10 @@ For `shared ring` connections it is as follows: | | by xenstored to communicate with `domid` | | | | -Since the ABI guarantees that entry 1 in `domid`'s grant table will always -contain the GFN of the shared page. +The GFN of the shared page is not preserved because the ABI reserves +entry 1 in `domid`'s grant table to point to the xenstore shared page. +Note there is no guarantee the page will still be valid at the time of +the restore because a domain can revoke the permission. For `socket` connections it is as follows: @@ -398,7 +400,7 @@ A node permission specifier has the following format: | | | | `domid` | The domain-id to which the permission relates | -Note that perm1 defines the domain owning the code. See [4] for more +Note that perm1 defines the domain owning the node. See [4] for more explanation of node permissions. * * *