KVM: SVM: force new asid on vcpu migration

KVM: SVM: force new asid on vcpu migration

If a migrated vcpu matches the asid_generation value of the target pcpu,
there will be no TLB flush via TLB_CONTROL_FLUSH_ALL_ASID.

The check for vcpu.cpu in pre_svm_run is meaningless since svm_vcpu_load
already updated it on schedule in.

Such vcpu will VMRUN with stale TLB entries.

Based on original patch from Joerg Roedel (http://patchwork.kernel.org/patch/10021/)

Signed-off-by: Marcelo Tosatti <[email protected]>
Acked-by: Joerg Roedel <[email protected]>
Signed-off-by: Avi Kivity <[email protected]>