Messages in this thread | | | Date | Tue, 10 Oct 2023 21:03:38 +0300 | From | José Pekkarinen <> | Subject | Re: [PATCH] kvm/sev: make SEV/SEV-ES asids configurable |
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On 2023-10-10 19:49, Peter Gonda wrote: > On Tue, Oct 10, 2023 at 5:22 AM José Pekkarinen > <jose.pekkarinen@foxhound.fi> wrote: >> >> There are bioses that doesn't allow to configure the >> number of asids allocated for SEV/SEV-ES, for those >> cases, the default behaviour allocates all the asids >> for SEV, leaving no room for SEV-ES to have some fun. >> If the user request SEV-ES to be enabled, it will >> find the kernel just run out of resources and ignored >> user request. This following patch will address this >> issue by making the number of asids for SEV/SEV-ES >> configurable over kernel module parameters. >> > > All this patch does is introduce an error case right? Because if the > BIOS hasn't actually configured those SEV-ES asids and KVM tries to > use an SEV as an SEV-ES asid commands to the ASP will fail, right? > > What happens when you try to create an SEV-ES VM with this patch, when > the BIOS hasn't allocated any SEV-ES asids?
It still doesn't enable SEV-ES since the cpu exposes min_sev_asids as 1, and there is a check to bail out in the hardware setup function, so definitely this is not fixing anything. I may not being understanding something here though, since my BIOS doesn't seem to have any options nor hints about SEV-ES, so I'm not quite sure it really does something to provide the functionality. For the records it is a Supermicro H11SSL-NC.
Thanks!
José.
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