[PATCH RFC 0/3] kvm add ioeventfd pf capability

From: Michael S. Tsirkin
Date: Sun Aug 30 2015 - 05:12:53 EST

One of the reasons MMIO is slower than port IO is
because it requires a page table lookup.
For normal memory accesses, this is solved by using the TLB
cache - but MMIO entries are either not present or reserved
and so are never cached.

To fix, allow installing an ioeventfd on top of a read only
memory region, which allows the CPU to cache the translations.

Warning: svm patch is untested.

Michael S. Tsirkin (3):
vmx: allow ioeventfd for EPT violations
svm: allow ioeventfd for NPT page faults
kvm: add KVM_CAP_IOEVENTFD_PF capability

include/uapi/linux/kvm.h | 1 +
arch/x86/kvm/svm.c | 5 +++++
arch/x86/kvm/vmx.c | 5 +++++
arch/x86/kvm/x86.c | 1 +
Documentation/virtual/kvm/api.txt | 7 +++++++
5 files changed, 19 insertions(+)


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