On Wed, Dec 03, 2014 at 05:50:33PM +0800, Zhang Haoyu wrote: > Hi, > > EXIT_REASON_EPT_VIOLATION's corresponding handle is handle_ept_violation(), > and EXIT_REASON_EPT_MISCONFIG's corresponding handle is handle_ept_misconfig(), > what's the difference between them? > > I read the SDM-3C 28.2.3 EPT-Induced VM Exits, and found below description, > "An EPT misconfiguration occurs when, in the course of translating > a guest-physical address, the logical processor encounters an EPT > paging-structure entry that contains an unsupported value. An EPT > violation occurs when there is no EPT misconfiguration but the EPT > paging-structure entries disallow an access using the guest physical > address." > > According to above description, EPT-MISCONFIG is from error settings , > but from the its exit-handle handle_ept_misconfig(), > it seems that handle_ept_misconfig() handles mmio pagefault, > I'm really confused, I think I'm missing something, > any advices? > EXIT_REASON_EPT_VIOLATION is similar to a "page not present" pagefault EXIT_REASON_EPT_MISCONFIG is similar to a "reserved bit set" pagefault. handle_ept_misconfig() handles mmio pagefault because KVM has an optimization that uses reserved bits to mark mmio regions. -- Gleb. -- To unsubscribe from this list: send the line "unsubscribe kvm" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
