[virt-tools-list] [virt-install PATCH 0/7] Introduce initial support for AMD SEV launch security

Singh, Brijesh brijesh.singh at amd.com
Thu Jun 6 12:47:17 UTC 2019


Hi Erik,

Thanks for the patch series.

On 6/6/19 5:00 AM, Erik Skultety wrote:
> This series introduces a new cmdline parameter --launch-security. All of the
> options the argument takes are either completely optional or there is a
> reasonable default provided. More details are available in the individual
> patches.
> 
> One thing that this series doesn't address is handling virtio devices with SEV.
> See, to successfully use SEV with virtio devices, there are basically 2
> conditions:
> 1) the boot disk cannot be virtio-blk, as that doesn't work with SEV, but
> virtio-scsi is fine (which means handling the virtio-scsi controller)


There was a virtio-blk driver bug in older kernel which was seen with
SWIOTLB. The DMA buffers in SEV was allocated using the swiotlb so we
were hitting this bug. The bug has been fixed in recent kernel (5.1).

Here is the kernel commit which fixes it:

https://github.com/torvalds/linux/commit/fd1068e1860e44aaaa337b516df4518d1ce98da1

> 
> 2) for the rest of the virtio devices, driver.iommu needs to be turned on as
> the IOMMU flag enables usage of encrypted DMA.
> 
> So rather then spend more time on figuring out how to properly handle that, I
> decided to start with the basic support first and continue from there.
> 
> Resolves:
> https://bugzilla.redhat.com/show_bug.cgi?id=1501608
> 
> Erik Skultety (7):
>    Introduce real-world AMD SEV domain capabilities
>    virtinst: cli: Introduce parser support for SEV launch security
>    virtinst: cli: Provide a default value for the 'policy' argument
>    virtinst: guest: Fill in SEV platform specific data automatically
>    virtins: guest: Provide further SEV support checks
>    man: Provide a documentation for the SEV feature
>    DO NOT MERGE: showcase a functional SEV cmdline in a simple script
> 
>   man/virt-install.pod                          |  75 ++++++++-
>   .../kvm-x86_64-amd-domcaps-q35.xml            | 146 ++++++++++++++++++
>   ...nstall-x86_64-launch-security-sev-full.xml |  63 ++++++++
>   ...irt-install-x86_64-launch-security-sev.xml |  61 ++++++++
>   tests/clitest.py                              |  10 ++
>   tests/utils.py                                |   2 +
>   virt-install-sev.sh                           |  19 +++
>   virtinst/cli.py                               |  62 ++++++++
>   virtinst/domain/__init__.py                   |   1 +
>   virtinst/domain/launch_security.py            |  37 +++++
>   virtinst/domcapabilities.py                   |  22 +++
>   virtinst/guest.py                             |  25 ++-
>   12 files changed, 521 insertions(+), 2 deletions(-)
>   create mode 100644 tests/capabilities-xml/kvm-x86_64-amd-domcaps-q35.xml
>   create mode 100644 tests/cli-test-xml/compare/virt-install-x86_64-launch-security-sev-full.xml
>   create mode 100644 tests/cli-test-xml/compare/virt-install-x86_64-launch-security-sev.xml
>   create mode 100644 virt-install-sev.sh
>   create mode 100644 virtinst/domain/launch_security.py
> 
> --
> 2.20.1
> 




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