[PATCH v6 0/5] KVM: VMX: Add Posted Interrupt supporting

[Yang Zhang <yang.z.zhang@intel.com>]

From: Yang Zhang <yang.z.zhang@Intel.com>

The follwoing patches are adding the Posted Interrupt supporting to KVM:
The first patch enables the feature 'acknowledge interrupt on vmexit'.Since
it is required by Posted interrupt, we need to enable it firstly.

And the subsequent patches are adding the posted interrupt supporting:
Posted Interrupt allows APIC interrupts to inject into guest directly
without any vmexit.

- When delivering a interrupt to guest, if target vcpu is running,
  update Posted-interrupt requests bitmap and send a notification event
  to the vcpu. Then the vcpu will handle this interrupt automatically,
  without any software involvemnt.

- If target vcpu is not running or there already a notification event
  pending in the vcpu, do nothing. The interrupt will be handled by
  next vm entry

NOTE: We don't turn on the Posted Interrupt until the coalesced issue is
solved.

Changes from v5 to v6:
* Split sync_pir_to_irr into two functions one to query whether PIR is empty
  and the other to perform the sync.
* Add comments to explain how vmx_sync_pir_to_irr() work.
* Rebase on top of KVM upstream.
  
Changes from v4 to v5:
* Add per cpu count for posted IPI handler.
* Dont' check irr when delivering interrupt. Since we can not get interrupt
  coalesced info with Posted Interrupt. So there is no need to check the irr.
  There is another patch will changed current interrupt coalesced logic. Before
  it, we will not turn on Posted Interrupt.
* Clear outstanding notification bit after call local_irq_disable, but before
  check request. As Marcelo suggested, we can ensure the IPI not lost in this
  way
* Remove the spinlock. Same as item 2, if not need to get coalesced info, then no
  need the lock.
* Rebase on top of KVM upstream.

Yang Zhang (5):
  KVM: VMX: Enable acknowledge interupt on vmexit
  KVM: VMX: Register a new IPI for posted interrupt
  KVM: VMX: Check the posted interrupt capability
  KVM: VMX: Add the algorithm of deliver posted interrupt
  KVM : VMX: Use posted interrupt to deliver virtual interrupt

 arch/x86/include/asm/entry_arch.h  |    4 +
 arch/x86/include/asm/hardirq.h     |    3 +
 arch/x86/include/asm/hw_irq.h      |    1 +
 arch/x86/include/asm/irq_vectors.h |    5 +
 arch/x86/include/asm/kvm_host.h    |    5 +
 arch/x86/include/asm/vmx.h         |    4 +
 arch/x86/kernel/entry_64.S         |    5 +
 arch/x86/kernel/irq.c              |   22 ++++
 arch/x86/kernel/irqinit.c          |    4 +
 arch/x86/kvm/irq.c                 |    3 +-
 arch/x86/kvm/lapic.c               |   29 ++++-
 arch/x86/kvm/lapic.h               |    2 +
 arch/x86/kvm/svm.c                 |   30 +++++
 arch/x86/kvm/vmx.c                 |  223 ++++++++++++++++++++++++++++++++----
 arch/x86/kvm/x86.c                 |    8 +-
 virt/kvm/kvm_main.c                |    1 +
 16 files changed, 320 insertions(+), 29 deletions(-)