From f8f559422b6c6a05469dfde614b67789b6142cb5 Mon Sep 17 00:00:00 2001 From: Xiao Guangrong Date: Fri, 7 Jun 2013 16:51:26 +0800 Subject: KVM: MMU: fast invalidate all mmio sptes This patch tries to introduce a very simple and scale way to invalidate all mmio sptes - it need not walk any shadow pages and hold mmu-lock KVM maintains a global mmio valid generation-number which is stored in kvm->memslots.generation and every mmio spte stores the current global generation-number into his available bits when it is created When KVM need zap all mmio sptes, it just simply increase the global generation-number. When guests do mmio access, KVM intercepts a MMIO #PF then it walks the shadow page table and get the mmio spte. If the generation-number on the spte does not equal the global generation-number, it will go to the normal #PF handler to update the mmio spte Since 19 bits are used to store generation-number on mmio spte, we zap all mmio sptes when the number is round Signed-off-by: Xiao Guangrong Reviewed-by: Gleb Natapov Reviewed-by: Marcelo Tosatti Signed-off-by: Paolo Bonzini --- arch/x86/kvm/mmu.h | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-) (limited to 'arch/x86/kvm/mmu.h') diff --git a/arch/x86/kvm/mmu.h b/arch/x86/kvm/mmu.h index ba6a19c50f27..5b59c573aba7 100644 --- a/arch/x86/kvm/mmu.h +++ b/arch/x86/kvm/mmu.h @@ -56,12 +56,15 @@ void kvm_mmu_set_mmio_spte_mask(u64 mmio_mask); /* * Return values of handle_mmio_page_fault_common: * RET_MMIO_PF_EMULATE: it is a real mmio page fault, emulate the instruction - * directly. + * directly. + * RET_MMIO_PF_INVALID: invalid spte is detected then let the real page + * fault path update the mmio spte. * RET_MMIO_PF_RETRY: let CPU fault again on the address. * RET_MMIO_PF_BUG: bug is detected. */ enum { RET_MMIO_PF_EMULATE = 1, + RET_MMIO_PF_INVALID = 2, RET_MMIO_PF_RETRY = 0, RET_MMIO_PF_BUG = -1 }; -- cgit v1.2.3