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/paging_tmpl.h | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) (limited to 'arch/x86/kvm/paging_tmpl.h') diff --git a/arch/x86/kvm/paging_tmpl.h b/arch/x86/kvm/paging_tmpl.h index fb50fa64f36..7769699d48a 100644 --- a/arch/x86/kvm/paging_tmpl.h +++ b/arch/x86/kvm/paging_tmpl.h @@ -552,9 +552,12 @@ static int FNAME(page_fault)(struct kvm_vcpu *vcpu, gva_t addr, u32 error_code, pgprintk("%s: addr %lx err %x\n", __func__, addr, error_code); - if (unlikely(error_code & PFERR_RSVD_MASK)) - return handle_mmio_page_fault(vcpu, addr, error_code, + if (unlikely(error_code & PFERR_RSVD_MASK)) { + r = handle_mmio_page_fault(vcpu, addr, error_code, mmu_is_nested(vcpu)); + if (likely(r != RET_MMIO_PF_INVALID)) + return r; + }; r = mmu_topup_memory_caches(vcpu); if (r) -- cgit v1.2.3-18-g5258