Messages in this thread | | | Subject | Re: [PATCH v1 00/15] Add support for Nitro Enclaves | From | "Paraschiv, Andra-Irina" <> | Date | Fri, 24 Apr 2020 11:19:21 +0300 |
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On 24/04/2020 06:04, Longpeng (Mike, Cloud Infrastructure Service Product Dept.) wrote: > On 2020/4/23 21:19, Paraschiv, Andra-Irina wrote: >> >> On 22/04/2020 00:46, Paolo Bonzini wrote: >>> On 21/04/20 20:41, Andra Paraschiv wrote: >>>> An enclave communicates with the primary VM via a local communication channel, >>>> using virtio-vsock [2]. An enclave does not have a disk or a network device >>>> attached. >>> Is it possible to have a sample of this in the samples/ directory? >> I can add in v2 a sample file including the basic flow of how to use the ioctl >> interface to create / terminate an enclave. >> >> Then we can update / build on top it based on the ongoing discussions on the >> patch series and the received feedback. >> >>> I am interested especially in: >>> >>> - the initial CPU state: CPL0 vs. CPL3, initial program counter, etc. >>> >>> - the communication channel; does the enclave see the usual local APIC >>> and IOAPIC interfaces in order to get interrupts from virtio-vsock, and >>> where is the virtio-vsock device (virtio-mmio I suppose) placed in memory? >>> >>> - what the enclave is allowed to do: can it change privilege levels, >>> what happens if the enclave performs an access to nonexistent memory, etc. >>> >>> - whether there are special hypercall interfaces for the enclave >> An enclave is a VM, running on the same host as the primary VM, that launched >> the enclave. They are siblings. >> >> Here we need to think of two components: >> >> 1. An enclave abstraction process - a process running in the primary VM guest, >> that uses the provided ioctl interface of the Nitro Enclaves kernel driver to >> spawn an enclave VM (that's 2 below). >> >> How does all gets to an enclave VM running on the host? >> >> There is a Nitro Enclaves emulated PCI device exposed to the primary VM. The >> driver for this new PCI device is included in the current patch series. >> > Hi Paraschiv, > > The new PCI device is emulated in QEMU ? If so, is there any plan to send the > QEMU code ?
Hi,
Nope, not that I know of so far.
Thanks, Andra
> >> The ioctl logic is mapped to PCI device commands e.g. the NE_ENCLAVE_START ioctl >> maps to an enclave start PCI command or the KVM_SET_USER_MEMORY_REGION maps to >> an add memory PCI command. The PCI device commands are then translated into >> actions taken on the hypervisor side; that's the Nitro hypervisor running on the >> host where the primary VM is running. >> >> 2. The enclave itself - a VM running on the same host as the primary VM that >> spawned it. >> >> The enclave VM has no persistent storage or network interface attached, it uses >> its own memory and CPUs + its virtio-vsock emulated device for communication >> with the primary VM. >> >> The memory and CPUs are carved out of the primary VM, they are dedicated for the >> enclave. The Nitro hypervisor running on the host ensures memory and CPU >> isolation between the primary VM and the enclave VM. >> >> >> These two components need to reflect the same state e.g. when the enclave >> abstraction process (1) is terminated, the enclave VM (2) is terminated as well. >> >> With regard to the communication channel, the primary VM has its own emulated >> virtio-vsock PCI device. The enclave VM has its own emulated virtio-vsock device >> as well. This channel is used, for example, to fetch data in the enclave and >> then process it. An application that sets up the vsock socket and connects or >> listens, depending on the use case, is then developed to use this channel; this >> happens on both ends - primary VM and enclave VM. >> >> Let me know if further clarifications are needed. >> >>>> The proposed solution is following the KVM model and uses the KVM API to be able >>>> to create and set resources for enclaves. An additional ioctl command, besides >>>> the ones provided by KVM, is used to start an enclave and setup the addressing >>>> for the communication channel and an enclave unique id. >>> Reusing some KVM ioctls is definitely a good idea, but I wouldn't really >>> say it's the KVM API since the VCPU file descriptor is basically non >>> functional (without KVM_RUN and mmap it's not really the KVM API). >> It uses part of the KVM API or a set of KVM ioctls to model the way a VM is >> created / terminated. That's true, KVM_RUN and mmap-ing the vcpu fd are not >> included. >> >> Thanks for the feedback regarding the reuse of KVM ioctls. >> >> Andra >> >> >> >> >> Amazon Development Center (Romania) S.R.L. registered office: 27A Sf. Lazar >> Street, UBC5, floor 2, Iasi, Iasi County, 700045, Romania. Registered in >> Romania. Registration number J22/2621/2005.
Amazon Development Center (Romania) S.R.L. registered office: 27A Sf. Lazar Street, UBC5, floor 2, Iasi, Iasi County, 700045, Romania. Registered in Romania. Registration number J22/2621/2005.
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