Re: [PATCH v2 00/12] x86/sev: KEXEC/KDUMP support for SEV-ES guests
From: Joerg Roedel <hidden>
Date: 2021-09-13 16:14:20
Also in:
kexec, kvm, linux-coco, lkml
On Mon, Sep 13, 2021 at 09:02:38AM -0700, Dave Hansen wrote:
On 9/13/21 8:55 AM, Joerg Roedel wrote:quoted
This does not work under SEV-ES, because the hypervisor has no access to the vCPU registers and can't make modifications to them. So an SEV-ES guest needs to reset the vCPU itself and park it using the AP-reset-hold protocol. Upon wakeup the guest needs to jump to real-mode and to the reset-vector configured in the AP-Jump-Table.How does this end up looking to an end user that tries to kexec() from a an SEV-ES kernel? Does it just hang?
Yes, the kexec will just hang. This patch-set contains code to disable the kexec syscalls in situations where it would not work for that reason. Actually with the changes to the decompressor in this patch-set the kexec'ed kernel could boot, but would fail to bring up all the APs. Regards, Joerg _______________________________________________ Virtualization mailing list Virtualization@lists.linux-foundation.org https://lists.linuxfoundation.org/mailman/listinfo/virtualization