On 31/05/2022 11:53, Daniel P. Smith wrote:
On 5/31/22 05:25, Julien Grall wrote:
Hi,
On 31/05/2022 03:41, Daniel P. Smith wrote:
diff --git a/xen/arch/Kconfig b/xen/arch/Kconfig
index f16eb0df43..57b14e22c9 100644
--- a/xen/arch/Kconfig
+++ b/xen/arch/Kconfig
@@ -17,3 +17,15 @@ config NR_CPUS
For CPU cores which support Simultaneous Multi-Threading or
similar
technologies, this the number of logical threads which Xen will
support.
+
+config NR_BOOTMODS
+ int "Maximum number of boot modules that a loader can pass"
+ range 1 64
OOI, any reason to limit the size?
I modelled this entirely after NR_CPUS, which applied a limit
The limit for NR_CPUS makes sense because there are scalability issues
after that (although 4095 seems quite high) and/or the HW impose a limit.
, and it
seemed reasonable to me at the time. I choose 64 since it was double
currently what Arm had set for MAX_MODULES. As such, I have no hard
reason for there to be a limit. It can easily be removed or adjusted to
whatever the reviewers feel would be appropriate.
Ok. In which case I would drop the limit beause it also prevent a users
to create more 64 dom0less domUs (actually a bit less because some
modules are used by Xen). I don't think there are a strong reason to
prevent that, right?
+ default "8" if X86
+ default "32" if ARM
+ help
+ Controls the build-time size of various arrays allocated for
+ parsing the boot modules passed by a loader when starting Xen.
+
+ This is of particular interest when using Xen's hypervisor domain
+ capabilities such as dom0less.
diff --git a/xen/arch/arm/include/asm/setup.h
b/xen/arch/arm/include/asm/setup.h
index 2bb01ecfa8..312a3e4209 100644
--- a/xen/arch/arm/include/asm/setup.h
+++ b/xen/arch/arm/include/asm/setup.h
@@ -10,7 +10,8 @@
#define NR_MEM_BANKS 256
-#define MAX_MODULES 32 /* Current maximum useful modules */
+/* Current maximum useful modules */
+#define MAX_MODULES CONFIG_NR_BOOTMODS
There are only a handful number of use of MAX_MODULES in Arm. So I would
prefer if we replace all the use with CONFIG_NR_BOOTMODS.
No problem, as I stated above, I mimicked what was done for NR_CPUS
which did a similar #define for MAX_CPUS.
Thanks!
Cheers,
--
Julien Grall
