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author | Steve Rutherford <srutherford@google.com> | 2015-07-29 23:21:41 -0700 |
---|---|---|
committer | Paolo Bonzini <pbonzini@redhat.com> | 2015-10-01 15:06:27 +0200 |
commit | 7543a635aa09eb138b2cbf60ac3ff19503ae6954 (patch) | |
tree | 94d181962c2a3f64019f182900ed216a2f0c3e73 /Documentation/virtual/kvm | |
parent | 49df6397edfc5a8ba8ca813b51fb9729d8e94b40 (diff) | |
download | linux-7543a635aa09eb138b2cbf60ac3ff19503ae6954.tar.bz2 |
KVM: x86: Add KVM exit for IOAPIC EOIs
Adds KVM_EXIT_IOAPIC_EOI which allows the kernel to EOI
level-triggered IOAPIC interrupts.
Uses a per VCPU exit bitmap to decide whether or not the IOAPIC needs
to be informed (which is identical to the EOI_EXIT_BITMAP field used
by modern x86 processors, but can also be used to elide kvm IOAPIC EOI
exits on older processors).
[Note: A prototype using ResampleFDs found that decoupling the EOI
from the VCPU's thread made it possible for the VCPU to not see a
recent EOI after reentering the guest. This does not match real
hardware.]
Compile tested for Intel x86.
Signed-off-by: Steve Rutherford <srutherford@google.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'Documentation/virtual/kvm')
-rw-r--r-- | Documentation/virtual/kvm/api.txt | 12 |
1 files changed, 12 insertions, 0 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt index 43e0816d0de1..0d14bf5db534 100644 --- a/Documentation/virtual/kvm/api.txt +++ b/Documentation/virtual/kvm/api.txt @@ -3309,6 +3309,18 @@ Valid values for 'type' are: to ignore the request, or to gather VM memory core dump and/or reset/shutdown of the VM. + /* KVM_EXIT_IOAPIC_EOI */ + struct { + __u8 vector; + } eoi; + +Indicates that the VCPU's in-kernel local APIC received an EOI for a +level-triggered IOAPIC interrupt. This exit only triggers when the +IOAPIC is implemented in userspace (i.e. KVM_CAP_SPLIT_IRQCHIP is enabled); +the userspace IOAPIC should process the EOI and retrigger the interrupt if +it is still asserted. Vector is the LAPIC interrupt vector for which the +EOI was received. + /* Fix the size of the union. */ char padding[256]; }; |