[PATCH v1 0/2] Starting AMD SEV work

[Andrei Semenov <andrei.semenov@xxxxxxxx>]

This patch series initiate work on AMD SEV technology implementation in Xen.
SEV stands for "Secure Encrypted Virtualization" and allows the memory contents
of a VM to be encrypted with a key unique to this VM. In this way the neither
other VMs nor hypervisor can't read the memory content of this "encrypted"
VM.

In order to create and to run such a VM different layers of software must
interact (bascally Xen hypevisor, Xen toolstack in dom0 and the encrypted VM
itself).

In this work we start with discovering and enabling SEV feature on the platform.
The second patch ports AMD Secure Processor driver on Xen. This AMD Secure
Processor device (a.k.a PSP) is the way the different software layers interact
with AMD firmware/hardware to manage and run the encrypted VM.

Actually there's two modes of functionning of the ASP driver. The "polling" mode
and the "interrupt" mode. The interrupt mode raises some questions about how we
put the client thread to sleep (wait for interrupt). The actual way, based on
waitqueue, have two major inconvinients.

- compatibility with Intel Control-flow Enfocement (shadow stack)
- requests serialization (locking)

So, actually if CET is enabled on the platform all requests will be done by the
driver in "polling" mode. As with requests serialization, the "interrupt" mode
actually assumes the serialization is done by the driver client.

Obviously, I hope there wll be discussions with the community  on these 2
inconvienients to find out more efficient solutions.

Andrei Semenov (2):
  Implemented AMD SEV discovery and enabling.
  Implemented Amd Secure Processor device driver

 xen/arch/x86/cpu/amd.c                 |  53 ++
 xen/arch/x86/hvm/svm/Makefile          |   1 +
 xen/arch/x86/hvm/svm/sev.c             |   4 +
 xen/arch/x86/include/asm/cpufeature.h  |   3 +
 xen/arch/x86/include/asm/cpufeatures.h |   2 +
 xen/arch/x86/include/asm/msr-index.h   |   1 +
 xen/arch/x86/include/asm/psp-sev.h     | 655 ++++++++++++++++++++
 xen/arch/x86/include/asm/sev.h         |  11 +
 xen/drivers/Kconfig                    |   2 +
 xen/drivers/Makefile                   |   1 +
 xen/drivers/crypto/Kconfig             |  10 +
 xen/drivers/crypto/Makefile            |   1 +
 xen/drivers/crypto/asp.c               | 808 +++++++++++++++++++++++++
 xen/include/xen/types.h                |   2 +-
 14 files changed, 1553 insertions(+), 1 deletion(-)
 create mode 100644 xen/arch/x86/hvm/svm/sev.c
 create mode 100644 xen/arch/x86/include/asm/psp-sev.h
 create mode 100644 xen/arch/x86/include/asm/sev.h
 create mode 100644 xen/drivers/crypto/Kconfig
 create mode 100644 xen/drivers/crypto/Makefile
 create mode 100644 xen/drivers/crypto/asp.c

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2.35.3