« Previous | Next » 

Revision f65ed4c1

IDf65ed4c1529f29a7d62d6733eaa50bed24a4b2ed

Added by aliguori over 15 years ago

KVM: Coalesced MMIO support

MMIO exits are more expensive in KVM or Xen than in QEMU because they
involve, at least, privilege transitions. However, MMIO write
operations can be effectively batched if those writes do not have side
effects.

Good examples of this include VGA pixel operations when in a planar
mode. As it turns out, we can get a nice boost in other areas too.
Laurent mentioned a 9.7% performance boost in iperf with the coalesced
MMIO changes for the e1000 when he originally posted this work for KVM.

Signed-off-by: Anthony Liguori <>

git-svn-id: svn://svn.savannah.nongnu.org/qemu/trunk@5961 c046a42c-6fe2-441c-8c8c-71466251a162

Files

  • added
  • modified
  • copied
  • renamed
  • deleted

View differences