Messages in this thread | | | Date | Tue, 7 Jun 2022 17:23:38 +0200 | Subject | Re: [PATCH] KVM: x86: preserve interrupt shadow across SMM entries | From | Paolo Bonzini <> |
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On 6/7/22 17:16, Maxim Levitsky wrote: > If the #SMI happens while the vCPU is in the interrupt shadow, > (after STI or MOV SS), > we must both clear it to avoid VM entry failure on VMX, > due to consistency check vs EFLAGS.IF which is cleared on SMM entries, > and restore it on RSM so that #SMI is transparent to the non SMM code. > > To support migration, reuse upper 4 bits of > 'kvm_vcpu_events.interrupt.shadow' to store the smm interrupt shadow. > > This was lightly tested with a linux guest and smm load script, > and a unit test will be soon developed to test this better. > > For discussion: there are other ways to fix this issue: > > 1. The SMM shadow can be stored in SMRAM at some unused > offset, this will allow to avoid changes to kvm_vcpu_ioctl_x86_set_vcpu_events
Yes, that would be better (and would not require a new cap).
Paolo
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