Takuya Yoshikawa 982b3394dd KVM: x86: Optimize mmio spte zapping when creating/moving memslot ... When we create or move a memory slot, we need to zap mmio sptes. Currently, zap_all() is used for this and this is causing two problems: - extra page faults after zapping mmu pages - long mmu_lock hold time during zapping mmu pages For the latter, Marcelo reported a disastrous mmu_lock hold time during hot-plug, which made the guest unresponsive for a long time. This patch takes a simple way to fix these problems: do not zap mmu pages unless they are marked mmio cached. On our test box, this took only 50us for the 4GB guest and we did not see ms of mmu_lock hold time any more. Note that we still need to do zap_all() for other cases. So another work is also needed: Xiao's work may be the one. Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp> Signed-off-by: Gleb Natapov <gleb@redhat.com>		2013-03-14 10:21:21 +02:00
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asm	KVM: x86: Optimize mmio spte zapping when creating/moving memslot	2013-03-14 10:21:21 +02:00
uapi/asm	KVM: nVMX: Add preemption timer support	2013-03-14 10:01:21 +02:00