Messages in this thread | | | Subject | Re: [PATCH v3 4/4] KVM: SVM: Support #GP handling for the case of nested on nested | From | Paolo Bonzini <> | Date | Tue, 26 Jan 2021 12:39:16 +0100 |
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On 26/01/21 09:18, Wei Huang wrote: > Under the case of nested on nested (L0->L1->L2->L3), #GP triggered by > SVM instructions can be hided from L1. Instead the hypervisor can inject > the proper #VMEXIT to inform L1 of what is happening. Thus L1 can avoid > invoking the #GP workaround. For this reason we turns on guest VM's > X86_FEATURE_SVME_ADDR_CHK bit for KVM running inside VM to receive the > notification and change behavior.
Slightly reworked commit message:
KVM: SVM: Fix #GP handling for doubly-nested virtualization
Under the case of nested on nested (L0, L1, L2 are all hypervisors), #GP triggered by SVM instructions can be hidden from L1. Because we do not support emulation of the vVMLOAD/VMSAVE feature, the L0 hypervisor can inject the proper #VMEXIT to inform L1 of what is happening and L1 can avoid invoking the #GP workaround.
Thanks,
Paolo
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