Messages in this thread | | | Date | Tue, 21 Dec 2021 10:30:47 +0100 | Subject | Re: [PATCH v2 18/23] kvm: x86: Get/set expanded xstate buffer | From | Paolo Bonzini <> |
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On 12/21/21 10:06, Wang, Wei W wrote: >> (I'm not sure if the first sentence is true in the code, but if not it is a bug that >> has to be fixed :)). > For the implementation, KVM_CHECK_EXTENSION(KVM_CAP_XSAVE2) always return kvm->vcpus[0]->arch.guest_fpu.uabi_size. > Do you want to change it to below? > > If (kvm->vcpus[0]->arch.guest_fpu.uabi_size < 4096) > return 0;
return 4096;
since the minimum size of struct kvm_xsave2 (with no extra) is 4096.
Paolo
> else > return kvm->vcpus[0]->arch.guest_fpu.uabi_size; > > If the size is less than 4096 (e.g. no dynamic xfeatures enabled), > userspace should use the old KVM_GET_XSAVE (instead of KVM_GET_XSAVE2)? > (KVM_GET_XSAVE2 supports to work with size less than 4096, so I think this isn't necessary)
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