Messages in this thread | | | Date | Sun, 30 Aug 2015 12:12:41 +0300 | From | "Michael S. Tsirkin" <> | Subject | [PATCH RFC 0/3] kvm add ioeventfd pf capability |
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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(+)
-- MST
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