[Xen-devel] [PATCH v6 0/7] VMX: Properly handle pi descriptor and per-cpu blocking list

[Feng Wu <feng.wu@xxxxxxxxx>]

The current VT-d PI related code may operate incorrectly in the
following scenarios:
1. When the last assigned device is dettached from the domain, all
the PI related hooks are removed then, however, the vCPU can be
blocked, switched to another pCPU, etc, all without the aware of
PI. After the next time we attach another device to the domain,
which makes the PI realted hooks avaliable again, the status
of the pi descriptor is not true. Beside that, the blocking vcpu
may still remain in the per-cpu blocking in this case. Patch [1/7]
and [2/7] handle this.

2. After the domain is destroyed, the the blocking vcpu may also
remain in the per-cpu blocking. Handled in patch [3/7].

3. When IRTE is in posted mode, we don't need to set the irq
affinity for it, since the destination of these interrupts is
vCPU and the vCPU affinity is set during vCPU scheduling. Patch
[5/7] handles this.

4. [6/7] is a cleanup patch

5. When a pCPU is unplugged, and there might be vCPUs on its
list. Since the pCPU is offline, those vCPUs might not be woken
up again. [7/7] addresses it.

Feng Wu (7):
  VMX: Permanently assign PI hook vmx_pi_switch_to()
  VMX: Properly handle pi when all the assigned devices are removed
  VMX: Cleanup PI per-cpu blocking list when vcpu is destroyed
  VMX: Make sure PI is in proper state before install the hooks
  VT-d: No need to set irq affinity for posted format IRTE
  VT-d: Some cleanups
  VMX: Fixup PI descriptor when cpu is offline

 xen/arch/x86/hvm/vmx/vmcs.c            |  14 ++--
 xen/arch/x86/hvm/vmx/vmx.c             | 135 +++++++++++++++++++++++++++++++--
 xen/drivers/passthrough/vtd/intremap.c |  74 +++++++++++++++---
 xen/include/asm-x86/hvm/vmx/vmx.h      |   3 +
 4 files changed, 202 insertions(+), 24 deletions(-)

-- 
2.1.0


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