The core GICv4 code has been merged in 4.14, but there is some
additional nails to be hammered on that coffin, and this is what
this short series tries to achieve.
The first three patches have been posted before, and implement a
workaround for the HiSilicon Hip07 (aka D05) platform.
The following 5 patches change the way we perform VPE mappings.
Instead of always mapping all VPEs on all ITSs, it is much more
optimal to only map them on the ITSs that will dispatch interrupts the
VPEs could be interested in (i.e. the ITS that is directly connected
to a device assigned to that VM). This results in a bit of refcounting
so that we can perform mapping/unmappingas VLPIs get themselves
mapped/unmapped. In turn, VMOVP becomes much cheaper on systems that
have multiple ITSs.
Patch 9 is a small optimization to avoid spamming all the ITSs
with VINVALL when a guest emits an INVALL, since it is enough to emit
a single one on the first v4 ITS we find.
Finally, the last patch prevents irqbalance and co from messing
with the doorbell interrupts by making the affinity of those to
be only managed by the kernel. This reduces the VMOVP traffic by
a substancial amount and avoid unnecessary exits.
This has been tested on a Huawei D05 system, together with the rest of
the KVM GICv4 series[1]. I'd welcome further testing on alternative
GICv4 platforms.
M.
[1] https://lwn.net/Articles/735882/
Marc Zyngier (10):
irqchip/gic-v3-its: Add post-mortem info on command timeout
irqchip/gic-v3-its: Pass its_node pointer to each command builder
irqchip/gic-v3-its: Workaround HiSilicon Hip07 redistributor
addressing
irqchip/gic-v3-its: Track per-ITS list number
irqchip/gic-v3-its: Make GICv4_ITS_LIST_MAX globally available
irqchip/gic-v3-its: Make its_send_vinvall operate on a single ITS
irqchip/gic-v3-its: Make its_send_vmapp operate on a single ITS
irqchip/gic-v3-its: Limit scope of VPE mapping to be per ITS
irqchip/gic-v3-its: Only send VINVALL to a single ITS
irqchip/gic-v4: Make the doorbells managed affinity interrupts
Documentation/arm64/silicon-errata.txt | 1 +
arch/arm64/Kconfig | 9 ++
drivers/irqchip/irq-gic-v3-its.c | 252 +++++++++++++++++++++++++--------
drivers/irqchip/irq-gic-v4.c | 35 ++++-
include/linux/irqchip/arm-gic-v4.h | 8 ++
5 files changed, 246 insertions(+), 59 deletions(-)
--
2.11.0
