[PATCH v13 0/7] KVM/arm/x86: dirty page logging support for ARMv7 (3.17.0-rc1)

Mario Smarduch
2014-11-07T00:40:41Z

Patch series adds support for ARMv7 and generic dirty page logging support.
As we try to move towards generic dirty page logging additional logic is moved
to generic code. Initially armv7 KVM_GET_DIRTY_LOG ioctl reuses generic code,
to be followed by armv8 and x86.

Testing:
- Generally live migration + checksumming of source/destination memory regions
is used to validate correctness.
- ARMv7 - qemu machvirt, VExpress - Exynos 5440, FastModels - lmbench + dirty
guest memory cycling. On FastModels you must set 'migrate_set_downtime=1'
for higher dirty rate (for example 2000 pges/100mS).

See https://github.com/mjsmar/arm-dirtylog-tests for details.

In addition to ARMv7 patch series was compiled for:
- x86_64 - defconfig
- ia64 - ia64-linux-gcc4.6.3 - defconfig, ia64 Kconfig defines BROKEN worked
around that to make sure new changes don't break build. Eventually build
breaks due to other reasons.
- mips - mips64-linux-gcc4.6.3 - malta_kvm_defconfig
- ppc - powerpc64-linux-gcc4.6.3 - pseries_defconfig
- s390 - s390x-linux-gcc4.6.3 - defconfig
- armv8 - aarch64-linux-gnu-gcc4.8.1 - defconfig

ARMv7 Dirty page logging implementation overivew-
- initially write protects memory region pages 2nd stage page tables
- add support to read dirty page log and again write protect dirty pages
for next pass.
- second stage huge page are dissolved into small page tables to keep track of
dirty pages at page granularity. Tracking at huge page granularity limits
migration to an almost idle system. Small page size logging supports higher
memory dirty rates.
- In the event migration is canceled, normal behavior is resumed huge pages
are rebuilt over time.

Changes since v12:
- Added Paolos and James Hogan's comments to extend kvm_get_dirty_log() to
make it further generic by adding write protection in addition to dirty bit
map handling. This led to new generic function kvm_get_dirty_log_protect().

Changes since v11:
- Implemented Alex's comments to simplify generic layer.

Changes since v10:
- addressed wanghaibin comments
- addressed Christoffers comments

Changes since v9:
- Split patches into generic and architecture specific variants for TLB Flushing
and dirty log read (patches 1,2 & 3,4,5,6)
- rebased to 3.16.0-rc1
- Applied Christoffers comments.

Mario Smarduch (7):
KVM: Add architecture-defined TLB flush support
KVM: Add generic support for dirty page logging
KVM: x86: flush TLBs last before returning from KVM_GET_DIRTY_LOG
arm: KVM: Add ARMv7 API to flush TLBs
arm: KVM: Add initial dirty page locking infrastructure
arm: KVM: dirty log read write protect support
arm: KVM: ARMv7 dirty page logging 2nd stage page fault

arch/arm/include/asm/kvm_asm.h | 1 +
arch/arm/include/asm/kvm_host.h | 14 +++
arch/arm/include/asm/kvm_mmu.h | 20 ++++
arch/arm/include/asm/pgtable-3level.h | 1 +
arch/arm/kvm/Kconfig | 1 +
arch/arm/kvm/arm.c | 17 +++
arch/arm/kvm/interrupts.S | 11 ++
arch/arm/kvm/mmu.c | 209 +++++++++++++++++++++++++++++++--
arch/x86/kvm/x86.c | 22 ++--
include/linux/kvm_host.h | 9 ++
virt/kvm/Kconfig | 3 +
virt/kvm/kvm_main.c | 96 +++++++++++++++
12 files changed, 385 insertions(+), 19 deletions(-)

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1.7.9.5