From: Paul Mackerras Date: Mon, 26 May 2014 09:48:36 +0000 (+1000) Subject: KVM: PPC: Book3S HV: Fix check for running inside guest in global_invalidates() X-Git-Tag: omap-for-v3.16/fixes-against-rc1~39^2~8^2~1^2~7 X-Git-Url: http://git.openpandora.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=55765483e1df8135102ae9ca77dccbca9a7a6184;p=pandora-kernel.git KVM: PPC: Book3S HV: Fix check for running inside guest in global_invalidates() The global_invalidates() function contains a check that is intended to tell whether we are currently executing in the context of a hypercall issued by the guest. The reason is that the optimization of using a local TLB invalidate instruction is only valid in that context. The check was testing local_paca->kvm_hstate.kvm_vcore, which gets set when entering the guest but no longer gets cleared when exiting the guest. To fix this, we use the kvm_vcpu field instead, which does get cleared when exiting the guest, by the kvmppc_release_hwthread() calls inside kvmppc_run_core(). The effect of having the check wrong was that when kvmppc_do_h_remove() got called from htab_write() on the destination machine during a migration, it cleared the current cpu's bit in kvm->arch.need_tlb_flush. This meant that when the guest started running in the destination VM, it may miss out on doing a complete TLB flush, and therefore may end up using stale TLB entries from a previous guest that used the same LPID value. This should make migration more reliable. Signed-off-by: Paul Mackerras Signed-off-by: Alexander Graf --- Reading git-diff-tree failed