[Xen-devel] [Patch v11 0/3] VT-d Device-TLB flush issue

["Xu, Quan" <quan.xu@xxxxxxxxx>]

From: Quan Xu <quan.xu@xxxxxxxxx>

This patches fix current timeout concern and also allow limited ATS support:

1. add a timeout parameter for device IOTLB invalidation

 The parameter 'iommu_dev_iotlb_timeout' specifies the timeout of the device
 IOTLB invalidation in milliseconds. By default, the timeout is 1ms, which can
 be boot-time changed.

2. Synchronize for Device-TLB flush one by one

 Today we do Device-TLB flush synchronization after issuing flush
 requests for all ATS devices belonging to a VM. Doing so however
 imposes a limitation, i.e. that we can not figure out which flush
 request is blocked in the flush queue list, based on VT-d spec.

 To prepare correct Device-TLB flush timeout handling in next patch,
 we change the behavior to synchronize for every Device-TLB flush
 request. So the Device-TLB flush interface is changed a little bit,
 by checking timeout within the function instead of outside of function.

 Accordingly we also do a similar change for flush interfaces of
 IOTLB/IEC/Context, i.e. moving synchronization into the function.
 Since there is no user of a non-synced interface, we just rename
 existing ones with _sync suffix.

3. Fix vt-d Device-TLB flush timeout issue

 If Device-TLB flush timed out, we hide the target ATS device
 immediately and crash the domain owning this ATS device. If
 impacted domain is hardware domain, just throw out a warning.

 By hiding the device, we make sure it can't be assigned to any
 domain any longer (see device_assigned).


**NOTE**
   This patch set should base on one prereq patch sets:
    a). Check VT-d Device-TLB flush error.

----
Not covered in this series:

    a) Eliminate the panic() in IOMMU_WAIT_OP, used only in VT-d register 
read/write.
       Further discussion is required on whether and how to improve it.
    b) Handle IOTLB/Context/IEC flush timeout.


Quan Xu (3):
  IOMMU: add a timeout parameter for device IOTLB invalidation
  vt-d: synchronize for Device-TLB flush one by one
  vt-d: fix vt-d Device-TLB flush timeout issue

 docs/misc/xen-command-line.markdown   |   9 ++
 xen/drivers/passthrough/iommu.c       |   3 +
 xen/drivers/passthrough/pci.c         |   6 +-
 xen/drivers/passthrough/vtd/extern.h  |   6 +-
 xen/drivers/passthrough/vtd/qinval.c  | 157 ++++++++++++++++++++++++++--------
 xen/drivers/passthrough/vtd/x86/ats.c |   7 +-
 xen/include/xen/iommu.h               |   2 +
 xen/include/xen/pci.h                 |   1 +
 8 files changed, 144 insertions(+), 47 deletions(-)

-- 
1.9.1


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