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| -rw-r--r-- | README.md | 41 |
1 files changed, 39 insertions, 2 deletions
@@ -12,8 +12,10 @@ * [ Prepare Host OS ](#ubuntu18-host) * [ Prepare VM ](#ubuntu18-prep-vm) * [ Launch SEV VM ](#ubuntu18-launch-vm) - * [ Additional resources ](#resources) - +* [ Additional resources ](#resources) +* [ FAQ ](#faq) + * [ How do I know if Hypervisor supports SEV ](#faq-1) + * [ How do I know if SEV is enabled in the guest](#faq-2) <a name="intro"></a> # Secure Encrypted Virtualization (SEV) @@ -252,3 +254,38 @@ NOTE: when guest is booting, CTRL-C is mapped to CTRL-], use CTRL-] to stop the [Qemu doc](https://git.qemu.org/?p=qemu.git;a=blob;f=docs/amd-memory-encryption.txt;h=f483795eaafed8409b1e96806ca743354338c9dc;hb=HEAD) +<a name="faq"></a> +# FAQ + +<a name="faq-1"></a> + * How do I know if hypervisor supports SEV feature ? + + a) When using libvirt >= 4.15 run the following command + + ``` + # virsh domcapabilities + ``` + If hypervisor supports SEV feature then <b>sev</b> tag will be present. See [Libvirt DomainCapabilities feature](https://libvirt.org/formatdomaincaps.html#elementsSEV) +for additional information. + + b) Use qemu QMP 'query-sev-capabilities' command to check the SEV support. If SEV is supported then command will return the full SEV capabilities (which includes host PDH, cert-chain, cbitpos and reduced-phys-bits). + + > See [QMP doc](https://github.com/qemu/qemu/blob/master/docs/devel/writing-qmp-commands.txt) for details on how to interact with QMP shell. + + <a name="faq-2"></a> + * How do I know if SEV is enabled in the guest ? + + a) Check the kernel log buffer for the following message + ``` + # dmesg | grep -i sev + AMD Secure Encrypted Virtualization (SEV) active + ``` + + b) MSR 0xc0010131 (MSR_AMD64_SEV) can be used to determine if SEV is active + + ``` + # rdmsr -a 0xc0010131 + + Bit[0] 0 = SEV is not active + 1 = SEV is active + ``` |
