From: Luca Fancellu <luca.fancellu@arm.com>
To: xen-devel@lists.xenproject.org
Cc: bertrand.marquis@arm.com, wei.chen@arm.com,
Stefano Stabellini <sstabellini@kernel.org>,
Julien Grall <julien@xen.org>,
Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>
Subject: [PATCH v4 3/4] xen/arm: Clarify how the domid is decided in create_domUs()
Date: Wed, 14 Apr 2021 10:14:03 +0100 [thread overview]
Message-ID: <20210414091404.14215-4-luca.fancellu@arm.com> (raw)
In-Reply-To: <20210414091404.14215-1-luca.fancellu@arm.com>
This patch adds a comment in create_domUs() right before
domain_create() to explain the importance of the pre-increment
operator on the variable max_init_domid, to ensure that the
domid 0 is allocated only during start_xen() function by the
create_dom0() and not on any other possible code path to the
domain_create() function.
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
---
Changes in v4:
- Change to the commit title
Changes in v3:
- removed check introduced in v2.
---
xen/arch/arm/domain_build.c | 5 +++++
1 file changed, 5 insertions(+)
diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 359957dc1b..b1d7b9849f 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -2508,6 +2508,11 @@ void __init create_domUs(void)
GUEST_VPL011_SPI - 32 + 1);
}
+ /*
+ * The variable max_init_domid is initialized with zero, so here it's
+ * very important to use the pre-increment operator to call
+ * domain_create() with a domid > 0. (domid == 0 is reserved for Dom0)
+ */
d = domain_create(++max_init_domid, &d_cfg, false);
if ( IS_ERR(d) )
panic("Error creating domain %s\n", dt_node_name(node));
--
2.17.1
next prev parent reply other threads:[~2021-04-14 9:14 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-14 9:14 [PATCH v4 0/4] xen/arm: Prevent Dom0 to be loaded when using dom0less Luca Fancellu
2021-04-14 9:14 ` [PATCH v4 1/4] xen/arm: Move dom0 creation in domain_build.c Luca Fancellu
2021-04-14 10:14 ` Bertrand Marquis
2021-04-14 9:14 ` [PATCH v4 2/4] xen/arm: Handle cases when hardware_domain is NULL Luca Fancellu
2021-04-14 10:14 ` Bertrand Marquis
2021-04-14 11:16 ` Julien Grall
2021-04-14 11:29 ` Luca Fancellu
2021-04-14 13:45 ` Julien Grall
2021-04-14 13:47 ` Luca Fancellu
2021-04-14 20:35 ` Stefano Stabellini
2021-04-15 17:17 ` Julien Grall
2021-04-14 9:14 ` Luca Fancellu [this message]
2021-04-14 10:14 ` [PATCH v4 3/4] xen/arm: Clarify how the domid is decided in create_domUs() Bertrand Marquis
2021-04-14 11:17 ` Julien Grall
2021-04-14 9:14 ` [PATCH v4 4/4] xen/arm: Prevent Dom0 to be loaded when using dom0less Luca Fancellu
2021-04-14 10:14 ` Bertrand Marquis
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20210414091404.14215-4-luca.fancellu@arm.com \
--to=luca.fancellu@arm.com \
--cc=Volodymyr_Babchuk@epam.com \
--cc=bertrand.marquis@arm.com \
--cc=julien@xen.org \
--cc=sstabellini@kernel.org \
--cc=wei.chen@arm.com \
--cc=xen-devel@lists.xenproject.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).