[PATCH v5] Fix interrupt latency of HVM PCI passthroughdevices.

[Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>]

>From Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> # This line is ignored.
From: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Subject: [PATCH v5]  Fix interrupt latency of HVM PCI passthroughdevices.
In-Reply-To: 

Hey Jan, and other maintainers which scripts/get_maintainer.pl spit out,

Changelog since v4 (http://lists.xen.org/archives/html/xen-devel/2014-09/msg01676.html):
 - Ditch the domain centric mechansim.
 - Fix issues raised by Jan.

The big change is on ditching of having a domain centric view and
focus on having it all revolve around 'struct hvm_pirq_dpci'
structure. That all works - except that we must be very careful
with the 'dom' field. I haven't been able to trigger an assert but
there is one edge case (see the second patch) which required some
an bounded loop in case of a race. I would welcome feedback of
what the prefer way is of resolving it.

If this mechanism seems a bit cumbersome I can switch back to
the v4 design - which was based on the struct domain having the
state and list.

Please review!

 xen/arch/x86/domain.c         |   4 +-
 xen/arch/x86/irq.c            |   6 ++
 xen/drivers/passthrough/io.c  | 230 +++++++++++++++++++++++++++++++++++++-----
 xen/drivers/passthrough/pci.c |  27 +++--
 xen/include/xen/hvm/irq.h     |   5 +-
 xen/include/xen/pci.h         |   2 +-
 xen/include/xen/softirq.h     |   3 +
 7 files changed, 240 insertions(+), 37 deletions(-)


Konrad Rzeszutek Wilk (3):
      dpci: Replace tasklet with an softirq (v5)
      dpci: Safeguard against race with hvm_dirq_assist crashing and pt_irq_[create|destroy]_bind
      dpci: In hvm_dirq_assist stop using pt_pirq_iterate