[PATCH v4 0/6] Nonatomic interrupt injection

Avi Kivity
2010-08-30T11:37:04Z

This patchset changes interrupt injection to be done from normal process
context instead of interrupts disabled context. This is useful for real
mode interrupt injection on Intel without the current hacks (injecting as
a software interrupt of a vm86 task), reducing latencies, and later, for
allowing nested virtualization code to use kvm_read_guest()/kvm_write_guest()
instead of kmap() to access the guest vmcb/vmcs.

Seems to survive a hack that cancels every 16th entry, after injection has
already taken place.

With the PIC reset fix posted earlier, this passes autotest on both AMD and
Intel, with in-kernel irqchip. I'll run -no-kvm-irqchip tests shortly.

Please review carefully, esp. the first patch. Any missing kvm_make_request()
there may result in a hung guest.

v4: add KVM_REQ_EVENT after lapic restore

v3: close new race between injection and entry
fix Intel real-mode injection cancellation

v2: svm support (easier than expected)
fix silly vmx warning

Avi Kivity (6):
KVM: Check for pending events before attempting injection
KVM: VMX: Split up vmx_complete_interrupts()
KVM: VMX: Move real-mode interrupt injection fixup to
vmx_complete_interrupts()
KVM: VMX: Parameterize vmx_complete_interrupts() for both exit and
entry
KVM: Non-atomic interrupt injection
KVM: VMX: Move fixup_rmode_irq() to avoid forward declaration

arch/x86/include/asm/kvm_host.h | 1 +
arch/x86/kvm/i8259.c | 1 +
arch/x86/kvm/lapic.c | 13 ++++-
arch/x86/kvm/svm.c | 20 ++++++-
arch/x86/kvm/vmx.c | 116 ++++++++++++++++++++++++++------------
arch/x86/kvm/x86.c | 44 ++++++++++----
include/linux/kvm_host.h | 1 +
7 files changed, 143 insertions(+), 53 deletions(-)