On Thu, Aug 15, 2019 at 10:23 AM Sean Christopherson <sean.j.christopherson@xxxxxxxxx> wrote: > > KVM implementations that wrap struct kvm_vcpu with a vendor specific > struct, e.g. struct vcpu_vmx, must place the vcpu member at offset 0, > otherwise the usercopy region intended to encompass struct kvm_vcpu_arch > will instead overlap random chunks of the vendor specific struct. > E.g. padding a large number of bytes before struct kvm_vcpu triggers > a usercopy warn when running with CONFIG_HARDENED_USERCOPY=y. > > Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx> X86 parts: Reviewed-by: Jim Mattson <jmattson@xxxxxxxxxx>