Hi there, We were trying to assigned the SSD (Crucial M500) to the KVM guest under the VFIO framework and with the Intel VT-d support. When the guest directly read from or wrote to the SSD (O_DIRECT), there were many VM exits due to EPT_MISCONFIG. After gathering information from the internet and the KVM code, starting from "handle_ept_misconfig", it seemed the exits were related to the MMIO operations. As far as we understood about the PCI device passthrough, the guest could control the PCI device without the hypervisor intervention. In our case, the KVM hypervisor trapped and emulated the MMIO operations. We were wondering if we understood this correctly? What would be the reasons for such a traps and emulations? It would be great if there Best, Kevin
