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authorXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>2013-06-07 16:51:26 +0800
committerGleb Natapov <gleb@redhat.com>2013-06-27 14:20:36 +0300
commitf8f559422b6c6a05469dfde614b67789b6142cb5 (patch)
tree6a20c82079581d5af9a9e8d4ca83bc2266e01f21 /arch/x86/kvm/mmu.h
parentb37fbea6cefc3a8ff7b6cfec9867432d1a10046d (diff)
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 <xiaoguangrong@linux.vnet.ibm.com> Reviewed-by: Gleb Natapov <gleb@redhat.com> Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch/x86/kvm/mmu.h')
-rw-r--r--arch/x86/kvm/mmu.h5
1 files changed, 4 insertions, 1 deletions
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
};