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. -Erdem On Tue, Jul 21, 2020 at 5:50 AM Joerg Roedel <jroedel@xxxxxxx> wrote: > > Hi, > > On Mon, Jul 20, 2020 at 06:09:19PM -0700, Erdem Aktas wrote: > > It looks like there is an expectation that the bootloader will start > > from the 64bit entry point in header_64.S. With the current patch > > series, it will not boot up if the bootloader jumps to the startup_32 > > entry, which might break some default distro images. > > What are supported bootloaders and configurations? > > I am using grub ( 2.02-2ubuntu8.15) and it fails to boot because of > > this reason. I am not a grub expert, so I would appreciate any > > pointers on this. > > This is right, the only supported boot path is via the 64bit EFI entry > point. The reason is that SEV-ES requires support in the firmware too, > and currently only OVMF is supported in that regard. The firmware needs > to setup the AP jump-table, for example. > > Other boot-paths have not been implemented. Booting via startup_32 would > require exception handling in the 32bit-part of the boot-strap code, > because verify_cpu is called there. Also an AMD specific MSR can't be > accessed there because this would #GP on non-AMD/SEV-ES machines and, > as I said, there is no way yet to handle them. > > How did you get into the startup_32 entry-point, do you have an SEV-ES > BIOS supporting this? If it is really needed it could be implemented at > a later point. > > Regards, > > Joerg >
