[Xen-devel] [PATCH v8 00/11] toolstack-assisted approach to PVHVM guest kexec

[Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>]

This patch series provides x86 PVHVM domains with an ability to perform
kexec/kdump-style operations.

The list of currently known issues blocking kexec (and why the series is
required) is:
- Bound event channels.
- Registered vcpu_info.
- PIRQ/emuirq mappings.
- shared_info frame after XENMAPSPACE_shared_info operation.
- Active grant mappings.

Previously there were several attempts to solve these issues in different ways:
- Individual 'shutdown' hypercalls (e.g. VCPUOP_reset_vcpu_info) (we agreed
  that one 'reset everything' hypercall is better).
- Try building new domain reassigning old domain's memory (memory reassignment
  turned out being too cumbersome).
- Toolstack-less 'reset everything' (turned out being impossible because there
  is not enough knowledge in the hypervisor, e.g. interdomain channels are
  being set up by the toolstack).

This series is a mix of the previously sent 'toolstack-based' and
'reset everything' series. Here are some key points:
- No new domain is created.
- Domain is asking for soft reset with SCHEDOP_shutdown with
  SHUTDOWN_soft_reset shutdown reason.
- XEN_DOMCTL_soft_reset is being called by the toolstack.
- Device model is being restarted.

Patches from 'toolstack-based' series:
- "[PATCH v8 01/11] xen: introduce SHUTDOWN_soft_reset shutdown reason"
- "[PATCH v8 02/11] libxl: support SHUTDOWN_soft_reset shutdown reason" (with 
Ian's ack)
- "[PATCH v8 03/11] xl: introduce enum domain_restart_type" (with Ian's ack)
- "[PATCH v8 10/11] libxc: add XC_DEVICE_MODEL_SAVE_FILE" (with Ian's ack)
- "[PATCH v8 11/11] (lib)xl: soft reset support" (heavily rewritten)

Patches from 'reset everything' RFC:
- "[PATCH v8 04/11] xen: evtchn: make evtchn_reset() ready for soft reset"
- "[PATCH v8 06/11] xen: Introduce XEN_DOMCTL_soft_reset"
- "[PATCH v8 08/11] xen: arch-specific hooks for domain_soft_reset()"

New patches:
- "[PATCH v8 05/11] xen: grant_table: implement 
grant_table_warn_active_grants()"
- "[PATCH v8 07/11] flask: DOMCTL_soft_reset support"
- "[PATCH v8 09/11] libxc: support XEN_DOMCTL_soft_reset operation"

With regards to active grants. In this series we restart domain's device model,
remove it from xenstore and introduce it back. The only 'misbehaving' backend
keeping active mapping I currently observe is xenconsoled: currently it has no
interface to disconnect from a domain (it just periodically scans all domains
to determine if any of them are dead). This is not an issue for us because:
- This matches standard domain startup as this grant mapping is being set up by
  the toolstack.
- Guest domain is aware of this special page.
grant_table_warn_active_grants() is required to find possible misbehaving
backends in future. It can be easily dropped from this series.

Some changes are mentioned in individual patches.

v7 of the 'toolstack-based approach to pvhvm guest kexec' is available here:
http://lists.xenproject.org/archives/html/xen-devel/2015-05/msg03558.html

RFC of the 'reset everything approach to PVHVM guest kexec' is available here:
http://lists.xenproject.org/archives/html/xen-devel/2015-06/msg00446.html

 docs/man/xl.cfg.pod.5                        |  10 ++
 tools/flask/policy/policy/modules/xen/xen.if |   2 +-
 tools/libxc/include/xenctrl.h                |   3 +
 tools/libxc/include/xenguest.h               |   2 +
 tools/libxc/xc_domain.c                      |   9 ++
 tools/libxl/libxl.c                          |  16 ++-
 tools/libxl/libxl.h                          |  12 ++
 tools/libxl/libxl_create.c                   | 181 +++++++++++++++++++++++----
 tools/libxl/libxl_dm.c                       |   2 +-
 tools/libxl/libxl_internal.h                 |   4 +
 tools/libxl/libxl_types.idl                  |   4 +
 tools/libxl/xl.h                             |   7 ++
 tools/libxl/xl_cmdimpl.c                     |  58 ++++++---
 tools/python/xen/lowlevel/xl/xl.c            |   1 +
 xen/arch/arm/domain.c                        |   5 +
 xen/arch/x86/domain.c                        |  79 ++++++++++++
 xen/arch/x86/hvm/hvm.c                       |   2 +-
 xen/common/domain.c                          |  34 ++++-
 xen/common/domctl.c                          |   9 ++
 xen/common/event_channel.c                   |  38 +++---
 xen/common/grant_table.c                     |  31 +++++
 xen/common/shutdown.c                        |   6 +
 xen/include/asm-x86/hvm/hvm.h                |   2 +
 xen/include/public/domctl.h                  |   1 +
 xen/include/public/sched.h                   |   3 +-
 xen/include/xen/domain.h                     |   2 +
 xen/include/xen/event.h                      |   3 +
 xen/include/xen/grant_table.h                |   5 +
 xen/include/xen/sched.h                      |   2 +
 xen/xsm/flask/hooks.c                        |   3 +
 xen/xsm/flask/policy/access_vectors          |   2 +
 31 files changed, 470 insertions(+), 68 deletions(-)

-- 
2.4.2


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel