kvm-x86-ignore-ioapic-polarity.patch

   1 From 100943c54e0947a07d2c0185368fc2fd848f7f28 Mon Sep 17 00:00:00 2001
   2 From: "Gabriel L. Somlo" <gsomlo@gmail.com>
   3 Date: Thu, 27 Feb 2014 23:06:17 -0500
   4 Subject: kvm: x86: ignore ioapic polarity
   5
   6 Both QEMU and KVM have already accumulated a significant number of
   7 optimizations based on the hard-coded assumption that ioapic polarity
   8 will always use the ActiveHigh convention, where the logical and
   9 physical states of level-triggered irq lines always match (i.e.,
  10 active(asserted) == high == 1, inactive == low == 0). QEMU guests
  11 are expected to follow directions given via ACPI and configure the
  12 ioapic with polarity 0 (ActiveHigh). However, even when misbehaving
  13 guests (e.g. OS X <= 10.9) set the ioapic polarity to 1 (ActiveLow),
  14 QEMU will still use the ActiveHigh signaling convention when
  15 interfacing with KVM.
  16
  17 This patch modifies KVM to completely ignore ioapic polarity as set by
  18 the guest OS, enabling misbehaving guests to work alongside those which
  19 comply with the ActiveHigh polarity specified by QEMU's ACPI tables.
  20
  21 Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
  22 Signed-off-by: Gabriel L. Somlo <somlo@cmu.edu>
  23 [Move documentation to KVM_IRQ_LINE, add ia64. - Paolo]
  24 Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
  25
  26 diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
  27 index 53f44be..6a4309b 100644
  28 --- a/arch/ia64/kvm/kvm-ia64.c
  29 +++ b/arch/ia64/kvm/kvm-ia64.c
  30 @@ -197,6 +197,7 @@ int kvm_dev_ioctl_check_extension(long ext)
  31         case KVM_CAP_IRQCHIP:
  32         case KVM_CAP_MP_STATE:
  33         case KVM_CAP_IRQ_INJECT_STATUS:
  34 +       case KVM_CAP_IOAPIC_POLARITY_IGNORED:
  35                 r = 1;
  36                 break;
  37         case KVM_CAP_COALESCED_MMIO:
  38 diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
  39 index d906391..a37da6b 100644
  40 --- a/arch/x86/kvm/x86.c
  41 +++ b/arch/x86/kvm/x86.c
  42 @@ -1971,6 +1971,7 @@ int kvm_dev_ioctl_check_extension(long ext)
  43         case KVM_CAP_XSAVE:
  44         case KVM_CAP_GET_TSC_KHZ:
  45         case KVM_CAP_KVMCLOCK_CTRL:
  46 +       case KVM_CAP_IOAPIC_POLARITY_IGNORED:
  47                 r = 1;
  48                 break;
  49         case KVM_CAP_COALESCED_MMIO:
  50 diff --git a/include/uapi/linux/kvm.h b/include/uapi/linux/kvm.h
  51 index 7d76401..a7518be 100644
  52 --- a/include/linux/kvm.h
  53 +++ b/include/linux/kvm.h
  54 @@ -459,6 +459,7 @@ struct kvm_ppc_smmu_info {
  55  #define KVM_CAP_GET_TSC_KHZ 61
  56  #define KVM_CAP_TSC_DEADLINE_TIMER 72
  57  #define KVM_CAP_KVMCLOCK_CTRL 76
  58 +#define KVM_CAP_IOAPIC_POLARITY_IGNORED 97
  59
  60  #ifdef KVM_CAP_IRQ_ROUTING
  61
  62 diff --git a/virt/kvm/ioapic.c b/virt/kvm/ioapic.c
  63 index ce9ed99..1539d37 100644
  64 --- a/virt/kvm/ioapic.c
  65 +++ b/virt/kvm/ioapic.c
  66 @@ -206,7 +206,6 @@ int kvm_ioapic_set_irq(struct kvm_ioapic *ioapic, int irq, int irq_source_id,
  67                 int irq_level = __kvm_irq_line_state(&ioapic->irq_states[irq],
  68                                                      irq_source_id, level);
  69                 entry = ioapic->redirtbl[irq];
  70 -               irq_level ^= entry.fields.polarity;
  71                 if (!irq_level)
  72                         ioapic->irr &= ~mask;
  73                 else {
  74 --
  75 cgit v0.10.1
  76