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author | Cornelia Huck <cohuck@redhat.com> | 2022-02-09 09:08:56 +0100 |
---|---|---|
committer | Cédric Le Goater <clg@kaod.org> | 2022-02-09 09:08:56 +0100 |
commit | 96a46def58b3b7938d200fca6bd4916c3640d2f3 (patch) | |
tree | faa69a99ef05c970a0ce6369f98e6dc4957e3e38 | |
parent | 205eb5a89e06f790831b7f6903c92e0dc78b6805 (diff) | |
download | qemu-96a46def58b3b7938d200fca6bd4916c3640d2f3.zip qemu-96a46def58b3b7938d200fca6bd4916c3640d2f3.tar.gz qemu-96a46def58b3b7938d200fca6bd4916c3640d2f3.tar.bz2 |
docs: rstfy confidential guest documentation
Also rstfy the documentation for AMD SEV, and link it.
The documentation for PEF had been merged into the pseries doc,
fix the reference.
Signed-off-by: Cornelia Huck <cohuck@redhat.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <20220204161251.241877-1-cohuck@redhat.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
-rw-r--r-- | MAINTAINERS | 2 | ||||
-rw-r--r-- | docs/system/confidential-guest-support.rst (renamed from docs/confidential-guest-support.txt) | 15 | ||||
-rw-r--r-- | docs/system/i386/amd-memory-encryption.rst (renamed from docs/amd-memory-encryption.txt) | 102 | ||||
-rw-r--r-- | docs/system/index.rst | 1 | ||||
-rw-r--r-- | docs/system/ppc/pseries.rst | 2 | ||||
-rw-r--r-- | docs/system/target-i386.rst | 1 |
6 files changed, 67 insertions, 56 deletions
diff --git a/MAINTAINERS b/MAINTAINERS index 9814580..8944fb5 100644 --- a/MAINTAINERS +++ b/MAINTAINERS @@ -408,7 +408,7 @@ M: Paolo Bonzini <pbonzini@redhat.com> M: Marcelo Tosatti <mtosatti@redhat.com> L: kvm@vger.kernel.org S: Supported -F: docs/amd-memory-encryption.txt +F: docs/system/i386/amd-memory-encryption.rst F: docs/system/i386/sgx.rst F: target/i386/kvm/ F: target/i386/sev* diff --git a/docs/confidential-guest-support.txt b/docs/system/confidential-guest-support.rst index 71d07ba..0c490db 100644 --- a/docs/confidential-guest-support.txt +++ b/docs/system/confidential-guest-support.rst @@ -19,10 +19,10 @@ Running a Confidential Guest To run a confidential guest you need to add two command line parameters: -1. Use "-object" to create a "confidential guest support" object. The +1. Use ``-object`` to create a "confidential guest support" object. The type and parameters will vary with the specific mechanism to be used -2. Set the "confidential-guest-support" machine parameter to the ID of +2. Set the ``confidential-guest-support`` machine parameter to the ID of the object from (1). Example (for AMD SEV):: @@ -37,13 +37,8 @@ Supported mechanisms Currently supported confidential guest mechanisms are: -AMD Secure Encrypted Virtualization (SEV) - docs/amd-memory-encryption.txt - -POWER Protected Execution Facility (PEF) - docs/papr-pef.txt - -s390x Protected Virtualization (PV) - docs/system/s390x/protvirt.rst +* AMD Secure Encrypted Virtualization (SEV) (see :doc:`i386/amd-memory-encryption`) +* POWER Protected Execution Facility (PEF) (see :ref:`power-papr-protected-execution-facility-pef`) +* s390x Protected Virtualization (PV) (see :doc:`s390x/protvirt`) Other mechanisms may be supported in future. diff --git a/docs/amd-memory-encryption.txt b/docs/system/i386/amd-memory-encryption.rst index ffca382..215946f 100644 --- a/docs/amd-memory-encryption.txt +++ b/docs/system/i386/amd-memory-encryption.rst @@ -1,3 +1,6 @@ +AMD Secure Encrypted Virtualization (SEV) +========================================= + Secure Encrypted Virtualization (SEV) is a feature found on AMD processors. SEV is an extension to the AMD-V architecture which supports running encrypted @@ -24,17 +27,18 @@ the hypervisor to satisfy the requested function. Launching --------- + Boot images (such as bios) must be encrypted before a guest can be booted. The -MEMORY_ENCRYPT_OP ioctl provides commands to encrypt the images: LAUNCH_START, -LAUNCH_UPDATE_DATA, LAUNCH_MEASURE and LAUNCH_FINISH. These four commands +``MEMORY_ENCRYPT_OP`` ioctl provides commands to encrypt the images: ``LAUNCH_START``, +``LAUNCH_UPDATE_DATA``, ``LAUNCH_MEASURE`` and ``LAUNCH_FINISH``. These four commands together generate a fresh memory encryption key for the VM, encrypt the boot images and provide a measurement than can be used as an attestation of a successful launch. -For a SEV-ES guest, the LAUNCH_UPDATE_VMSA command is also used to encrypt the +For a SEV-ES guest, the ``LAUNCH_UPDATE_VMSA`` command is also used to encrypt the guest register state, or VM save area (VMSA), for all of the guest vCPUs. -LAUNCH_START is called first to create a cryptographic launch context within +``LAUNCH_START`` is called first to create a cryptographic launch context within the firmware. To create this context, guest owner must provide a guest policy, its public Diffie-Hellman key (PDH) and session parameters. These inputs should be treated as a binary blob and must be passed as-is to the SEV firmware. @@ -45,37 +49,37 @@ in bad measurement). The guest policy is a 4-byte data structure containing several flags that restricts what can be done on a running SEV guest. See KM Spec section 3 and 6.2 for more details. -The guest policy can be provided via the 'policy' property (see below) +The guest policy can be provided via the ``policy`` property:: -# ${QEMU} \ - sev-guest,id=sev0,policy=0x1...\ + # ${QEMU} \ + sev-guest,id=sev0,policy=0x1...\ Setting the "SEV-ES required" policy bit (bit 2) will launch the guest as a -SEV-ES guest (see below) +SEV-ES guest:: -# ${QEMU} \ - sev-guest,id=sev0,policy=0x5...\ + # ${QEMU} \ + sev-guest,id=sev0,policy=0x5...\ The guest owner provided DH certificate and session parameters will be used to establish a cryptographic session with the guest owner to negotiate keys used for the attestation. -The DH certificate and session blob can be provided via the 'dh-cert-file' and -'session-file' properties (see below) +The DH certificate and session blob can be provided via the ``dh-cert-file`` and +``session-file`` properties:: -# ${QEMU} \ - sev-guest,id=sev0,dh-cert-file=<file1>,session-file=<file2> + # ${QEMU} \ + sev-guest,id=sev0,dh-cert-file=<file1>,session-file=<file2> -LAUNCH_UPDATE_DATA encrypts the memory region using the cryptographic context -created via the LAUNCH_START command. If required, this command can be called +``LAUNCH_UPDATE_DATA`` encrypts the memory region using the cryptographic context +created via the ``LAUNCH_START`` command. If required, this command can be called multiple times to encrypt different memory regions. The command also calculates the measurement of the memory contents as it encrypts. -LAUNCH_UPDATE_VMSA encrypts all the vCPU VMSAs for a SEV-ES guest using the -cryptographic context created via the LAUNCH_START command. The command also +``LAUNCH_UPDATE_VMSA`` encrypts all the vCPU VMSAs for a SEV-ES guest using the +cryptographic context created via the ``LAUNCH_START`` command. The command also calculates the measurement of the VMSAs as it encrypts them. -LAUNCH_MEASURE can be used to retrieve the measurement of encrypted memory and, +``LAUNCH_MEASURE`` can be used to retrieve the measurement of encrypted memory and, for a SEV-ES guest, encrypted VMSAs. This measurement is a signature of the memory contents and, for a SEV-ES guest, the VMSA contents, that can be sent to the guest owner as an attestation that the memory and VMSAs were encrypted @@ -85,27 +89,28 @@ Since the guest owner knows the initial contents of the guest at boot, the attestation measurement can be verified by comparing it to what the guest owner expects. -LAUNCH_FINISH finalizes the guest launch and destroys the cryptographic +``LAUNCH_FINISH`` finalizes the guest launch and destroys the cryptographic context. -See SEV KM API Spec [1] 'Launching a guest' usage flow (Appendix A) for the +See SEV KM API Spec ([SEVKM]_) 'Launching a guest' usage flow (Appendix A) for the complete flow chart. -To launch a SEV guest +To launch a SEV guest:: -# ${QEMU} \ - -machine ...,confidential-guest-support=sev0 \ - -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=1 + # ${QEMU} \ + -machine ...,confidential-guest-support=sev0 \ + -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=1 -To launch a SEV-ES guest +To launch a SEV-ES guest:: -# ${QEMU} \ - -machine ...,confidential-guest-support=sev0 \ - -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=1,policy=0x5 + # ${QEMU} \ + -machine ...,confidential-guest-support=sev0 \ + -object sev-guest,id=sev0,cbitpos=47,reduced-phys-bits=1,policy=0x5 An SEV-ES guest has some restrictions as compared to a SEV guest. Because the guest register state is encrypted and cannot be updated by the VMM/hypervisor, a SEV-ES guest: + - Does not support SMM - SMM support requires updating the guest register state. - Does not support reboot - a system reset requires updating the guest register @@ -114,35 +119,42 @@ a SEV-ES guest: manage booting APs. Debugging ------------ +--------- + Since the memory contents of a SEV guest are encrypted, hypervisor access to the guest memory will return cipher text. If the guest policy allows debugging, then a hypervisor can use the DEBUG_DECRYPT and DEBUG_ENCRYPT commands to access the guest memory region for debug purposes. This is not supported in QEMU yet. Snapshot/Restore ------------------ +---------------- + TODO Live Migration ----------------- +--------------- + TODO References ------------------ +---------- -AMD Memory Encryption whitepaper: -https://developer.amd.com/wordpress/media/2013/12/AMD_Memory_Encryption_Whitepaper_v7-Public.pdf +`AMD Memory Encryption whitepaper +<https://developer.amd.com/wordpress/media/2013/12/AMD_Memory_Encryption_Whitepaper_v7-Public.pdf>`_ -Secure Encrypted Virtualization Key Management: -[1] http://developer.amd.com/wordpress/media/2017/11/55766_SEV-KM-API_Specification.pdf +.. [SEVKM] `Secure Encrypted Virtualization Key Management + <http://developer.amd.com/wordpress/media/2017/11/55766_SEV-KM-API_Specification.pdf>`_ KVM Forum slides: -http://www.linux-kvm.org/images/7/74/02x08A-Thomas_Lendacky-AMDs_Virtualizatoin_Memory_Encryption_Technology.pdf -https://www.linux-kvm.org/images/9/94/Extending-Secure-Encrypted-Virtualization-with-SEV-ES-Thomas-Lendacky-AMD.pdf - -AMD64 Architecture Programmer's Manual: - http://support.amd.com/TechDocs/24593.pdf - SME is section 7.10 - SEV is section 15.34 - SEV-ES is section 15.35 + +* `AMD’s Virtualization Memory Encryption (2016) + <http://www.linux-kvm.org/images/7/74/02x08A-Thomas_Lendacky-AMDs_Virtualizatoin_Memory_Encryption_Technology.pdf>`_ +* `Extending Secure Encrypted Virtualization With SEV-ES (2018) + <https://www.linux-kvm.org/images/9/94/Extending-Secure-Encrypted-Virtualization-with-SEV-ES-Thomas-Lendacky-AMD.pdf>`_ + +`AMD64 Architecture Programmer's Manual: +<http://support.amd.com/TechDocs/24593.pdf>`_ + +* SME is section 7.10 +* SEV is section 15.34 +* SEV-ES is section 15.35 diff --git a/docs/system/index.rst b/docs/system/index.rst index 73bbedb..23e30e2 100644 --- a/docs/system/index.rst +++ b/docs/system/index.rst @@ -34,3 +34,4 @@ or Hypervisor.Framework. targets security multi-process + confidential-guest-support diff --git a/docs/system/ppc/pseries.rst b/docs/system/ppc/pseries.rst index 569237d..d9b65ad 100644 --- a/docs/system/ppc/pseries.rst +++ b/docs/system/ppc/pseries.rst @@ -224,6 +224,8 @@ nested. Combinations not shown in the table are not available. .. [3] Introduced on Power10 machines. +.. _power-papr-protected-execution-facility-pef: + POWER (PAPR) Protected Execution Facility (PEF) ----------------------------------------------- diff --git a/docs/system/target-i386.rst b/docs/system/target-i386.rst index 4daa53c..96bf548 100644 --- a/docs/system/target-i386.rst +++ b/docs/system/target-i386.rst @@ -28,6 +28,7 @@ Architectural features i386/cpu i386/kvm-pv i386/sgx + i386/amd-memory-encryption .. _pcsys_005freq: |