Re: [PATCH v4 00/75] x86: SEV-ES Guest Support
From: Joerg Roedel <hidden>
Date: 2020-07-22 09:04:48
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Hi Erdem, On Tue, Jul 21, 2020 at 09:48:51AM -0700, Erdem Aktas wrote:
Yes, I am using OVMF with SEV-ES (sev-es-v12 patches applied). I am running Ubuntu 18.04 distro. My grub target is x86_64-efi. I also tried installing the grub-efi-amd64 package. In all cases, the grub is running in 64bit but enters the startup_32 in 32 bit mode. I think there should be a 32bit #VC handler just something very similar in the OVMF patches to handle the cpuid when the CPU is still in 32bit mode. As it is now, it will be a huge problem to support different distro images. I wonder if I am the only one having this problem.
I havn't heard from anyone else that the startup_32 boot-path is being used for SEV-ES. What OVMF binary do you use for your guest? In general it is not that difficult to support that boot-path too, but I'd like to keep that as a future addition, as the patch-set is already quite large. In the startup_32 path there is already a GDT set up, so whats needed is an IDT and a 32-bit #VC handler using the MRS-based protocol (and hoping that there will only be CPUID intercepts until it reaches long-mode). Regards, Joerg