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author | Leonardo Garcia <lagarcia@br.ibm.com> | 2022-01-18 12:56:30 +0100 |
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committer | Cédric Le Goater <clg@kaod.org> | 2022-01-18 12:56:30 +0100 |
commit | dedc5d79dae59562b2311301d27ecbf2234acf8a (patch) | |
tree | 6434b80e8a34a94f2098d25c9f2b32a68d4f01ad /docs/specs/ppc-spapr-uv-hcalls.txt | |
parent | 2084b44d7afa2e604c52a31ee89f46a01835131b (diff) |
Rename ppc-spapr-uv-hcalls.txt to ppc-spapr-uv-hcalls.rst.
Signed-off-by: Leonardo Garcia <lagarcia@br.ibm.com>
Reviewed-by: Daniel Henrique Barboza <danielhb413@gmail.com>
Message-Id: <ea1554e3a02e093eaa64d1260faf01d525c9ecdc.1642446876.git.lagarcia@br.ibm.com>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
Diffstat (limited to 'docs/specs/ppc-spapr-uv-hcalls.txt')
-rw-r--r-- | docs/specs/ppc-spapr-uv-hcalls.txt | 89 |
1 files changed, 0 insertions, 89 deletions
diff --git a/docs/specs/ppc-spapr-uv-hcalls.txt b/docs/specs/ppc-spapr-uv-hcalls.txt deleted file mode 100644 index a00288deb3..0000000000 --- a/docs/specs/ppc-spapr-uv-hcalls.txt +++ /dev/null @@ -1,89 +0,0 @@ -=================================== -Hypervisor calls and the Ultravisor -=================================== - -On PPC64 systems supporting Protected Execution Facility (PEF), system memory -can be placed in a secured region where only an ultravisor running in firmware -can provide access to. pSeries guests on such systems can communicate with -the ultravisor (via ultracalls) to switch to a secure virtual machine (SVM) mode -where the guest's memory is relocated to this secured region, making its memory -inaccessible to normal processes/guests running on the host. - -The various ultracalls/hypercalls relating to SVM mode are currently only -documented internally, but are planned for direct inclusion into the Linux on -Power Architecture Reference document ([LoPAR]_). An internal ACR has been filed -to reserve a hypercall number range specific to this use case to avoid any -future conflicts with the IBM internally maintained Power Architecture Platform -Reference (PAPR+) documentation specification. This document summarizes some of -these details as they relate to QEMU. - -Hypercalls needed by the ultravisor -=================================== - -Switching to SVM mode involves a number of hcalls issued by the ultravisor to -the hypervisor to orchestrate the movement of guest memory to secure memory and -various other aspects of the SVM mode. Numbers are assigned for these hcalls -within the reserved range ``0xEF00-0xEF80``. The below documents the hcalls -relevant to QEMU. - -``H_TPM_COMM`` (``0xef10``) ---------------------------- - -SVM file systems are encrypted using a symmetric key. This key is then -wrapped/encrypted using the public key of a trusted system which has the private -key stored in the system's TPM. An Ultravisor will use this hcall to -unwrap/unseal the symmetric key using the system's TPM device or a TPM Resource -Manager associated with the device. - -The Ultravisor sets up a separate session key with the TPM in advance during -host system boot. All sensitive in and out values will be encrypted using the -session key. Though the hypervisor will see the in and out buffers in raw form, -any sensitive contents will generally be encrypted using this session key. - -Arguments: - - ``r3``: ``H_TPM_COMM`` (``0xef10``) - - ``r4``: ``TPM`` operation, one of: - - ``TPM_COMM_OP_EXECUTE`` (``0x1``): send a request to a TPM and receive a - response, opening a new TPM session if one has not already been opened. - - ``TPM_COMM_OP_CLOSE_SESSION`` (``0x2``): close the existing TPM session, if - any. - - ``r5``: ``in_buffer``, guest physical address of buffer containing the - request. Caller may use the same address for both request and response. - - ``r6``: ``in_size``, size of the in buffer. Must be less than or equal to - 4 KB. - - ``r7``: ``out_buffer``, guest physical address of buffer to store the - response. Caller may use the same address for both request and response. - - ``r8``: ``out_size``, size of the out buffer. Must be at least 4 KB, as this - is the maximum request/response size supported by most TPM implementations, - including the TPM Resource Manager in the linux kernel. - -Return values: - - ``r3``: one of the following values: - - ``H_Success``: request processed successfully. - - ``H_PARAMETER``: invalid TPM operation. - - ``H_P2``: ``in_buffer`` is invalid. - - ``H_P3``: ``in_size`` is invalid. - - ``H_P4``: ``out_buffer`` is invalid. - - ``H_P5``: ``out_size`` is invalid. - - ``H_RESOURCE``: problem communicating with TPM. - - ``H_FUNCTION``: TPM access is not currently allowed/configured. - - ``r4``: For ``TPM_COMM_OP_EXECUTE``, the size of the response will be stored - here upon success. |