[RFC PATCH 0/2] Boot time cpupools

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>,
	Andrew Cooper <andrew.cooper3@citrix.com>,
	George Dunlap <george.dunlap@citrix.com>,
	Ian Jackson <iwj@xenproject.org>, Jan Beulich <jbeulich@suse.com>,
	Wei Liu <wl@xen.org>, Juergen Gross <jgross@suse.com>,
	Dario Faggioli <dfaggioli@suse.com>,
	Anthony PERARD <anthony.perard@citrix.com>
Subject: [RFC PATCH 0/2] Boot time cpupools
Date: Wed, 17 Nov 2021 09:57:09 +0000	[thread overview]
Message-ID: <20211117095711.26596-1-luca.fancellu@arm.com> (raw)

Currently Xen creates a default cpupool0 that contains all the cpu brought up
during boot and it assumes that the platform has only one kind of CPU.
This assumption does not hold on big.LITTLE platform, but putting different
type of CPU in the same cpupool can result in instability and security issues
for the domains running on the pool.

For this reason this serie introduces an architecture specific way to create
different cpupool at boot time, this is particularly useful on ARM big.LITTLE
platform where there might be the need to have different cpupools for each type
of core, but also systems using NUMA can have different cpu pool for each node.

To test this serie, the hmp_unsafe Xen boot argument is passed to allow Xen
starting different CPUs from the boot core.

Luca Fancellu (2):
  xen/cpupool: Create different cpupools at boot time
  tools/cpupools: Give a name to unnamed cpupools

 tools/libs/light/libxl_utils.c | 13 ++++--
 xen/arch/arm/Kconfig           | 15 ++++++
 xen/arch/arm/Makefile          |  1 +
 xen/arch/arm/cpupool.c         | 84 ++++++++++++++++++++++++++++++++++
 xen/common/sched/cpupool.c     |  5 +-
 xen/include/xen/cpupool.h      | 30 ++++++++++++
 6 files changed, 142 insertions(+), 6 deletions(-)
 create mode 100644 xen/arch/arm/cpupool.c
 create mode 100644 xen/include/xen/cpupool.h

-- 
2.17.1