[Xen-devel] [PATCH v4 0/7] unsafe big.LITTLE support

[Stefano Stabellini <sstabellini@xxxxxxxxxx>]

Hi all,

This series changes the initialization of two virtual registers to make
sure they match the value of the underlying physical cpu.

It also disables cpus different from the boot cpu, unless a newly
introduced command line option is specified. In that case, it explains
how to setup the system to avoid corruptions, which involves manually
specifying the cpu affinity of all domains, because the scheduler still
lacks big.LITTLE support.

In the uncommon case of a system where the cacheline sizes are different
across cores, it disables all cores that have a different dcache line size
from the boot cpu. In fact, it is not sufficient to use the dcache line
size of the current cpu, it would be necessary to use the minimum across
all dcache line sizes of all cores.  Given that it is actually uncommon
even in big.LITTLE systems, just disable cpus for now.

The first patch in the series is a fix for the way we read the dcache
line size.

Cheers,

Stefano


Julien Grall (1):
      xen/arm: Park CPUs with a MIDR different from the boot CPU.

Stefano Stabellini (6):
      xen/arm: Read the dcache line size from CTR register
      xen/arm: make processor a per cpu variable
      xen/arm: read ACTLR on the pcpu where the vcpu will run
      xen/arm: set VPIDR based on the MIDR value of the underlying pCPU
      xen/arm: update the docs about heterogeneous computing
      xen/arm: disable CPUs with different dcache line sizes

 docs/misc/arm/big.LITTLE.txt        | 46 +++++++++++++++++++++++++++++++++++++
 docs/misc/xen-command-line.markdown | 15 ++++++++++++
 xen/arch/arm/arm32/head.S           |  2 +-
 xen/arch/arm/arm64/head.S           |  2 +-
 xen/arch/arm/domain.c               | 15 ++++++------
 xen/arch/arm/processor.c            |  8 +++----
 xen/arch/arm/setup.c                | 17 ++------------
 xen/arch/arm/smpboot.c              | 39 +++++++++++++++++++++++++++++++
 xen/arch/arm/vcpreg.c               |  4 ++--
 xen/include/asm-arm/cpregs.h        |  2 ++
 xen/include/asm-arm/domain.h        |  3 ---
 xen/include/asm-arm/page.h          | 27 +++++++++++++++-------
 12 files changed, 138 insertions(+), 42 deletions(-)
 create mode 100644 docs/misc/arm/big.LITTLE.txt

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