Messages in this thread | | | Date | Mon, 13 Sep 2021 18:14:14 +0200 | From | Joerg Roedel <> | Subject | Re: [PATCH v2 00/12] x86/sev: KEXEC/KDUMP support for SEV-ES guests |
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On Mon, Sep 13, 2021 at 09:02:38AM -0700, Dave Hansen wrote: > On 9/13/21 8:55 AM, Joerg Roedel wrote: > > 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
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