[PATCH v7 0/7] Use eoi to track RTC interrupt delivery status

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

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

Current interrupt coalescing logci which only used by RTC has conflict
with Posted Interrupt.

This patch introduces a new mechinism to use eoi to track interrupt:
When delivering an interrupt to vcpu, the pending_eoi set to number of
vcpu that received the interrupt. And decrease it when each vcpu writing
eoi. No subsequent RTC interrupt can deliver to vcpu until all vcpus
write eoi.

Changes from v6 to v7
* Only track the RTC interrupt when userspace uses *_LINE_* ioctl.
* Call rtc_irq_restore() after lapic is restored.
* Rebase on top of KVM.
 
Changes from v5 to v6
* Move set dest_map logic into __apic_accept_irq().
* Use RTC_GSI to distinguish different platform, and drop all CONFIG_X86.
* Rebase on top of KVM.

Changes from v4 to v5
* Calculate destination vcpu on interrupt injection not hook into ioapic
  modification.
* Rebase on top of KVM.

Yang Zhang (7):
  KVM: Add vcpu info to ioapic_update_eoi()
  KVM: Introduce struct rtc_status
  KVM : Return destination vcpu on interrupt injection
  KVM: Add reset/restore rtc_status support
  KVM : Force vmexit with virtual interrupt delivery
  KVM: Let ioapic know the irq line status
  KVM: Use eoi to track RTC interrupt delivery status

 arch/x86/kvm/i8254.c     |    4 +-
 arch/x86/kvm/lapic.c     |   36 ++++++++++----
 arch/x86/kvm/lapic.h     |    7 ++-
 arch/x86/kvm/x86.c       |    6 ++-
 include/linux/kvm_host.h |   11 +++--
 virt/kvm/assigned-dev.c  |   13 +++--
 virt/kvm/eventfd.c       |   15 ++++--
 virt/kvm/ioapic.c        |  115 +++++++++++++++++++++++++++++++++++++++------
 virt/kvm/ioapic.h        |   20 +++++++-
 virt/kvm/irq_comm.c      |   31 +++++++-----
 virt/kvm/kvm_main.c      |    3 +-
 11 files changed, 196 insertions(+), 65 deletions(-)