From fd17dc7b9a8d57150ee0121c4c83edbb7e26eece Mon Sep 17 00:00:00 2001 From: Preeti U Murthy <preeti@linux.vnet.ibm.com> Date: Fri, 11 Apr 2014 16:01:58 +0530 Subject: [PATCH] ppc/kvm: Set the runlatch bit of a CPU just before starting guest The secondary threads in the core are kept offline before launching guests in kvm on powerpc: "371fefd6f2dc4666:KVM: PPC: Allow book3s_hv guests to use SMT processor modes." Hence their runlatch bits are cleared. When the secondary threads are called in to start a guest, their runlatch bits need to be set to indicate that they are busy. The primary thread has its runlatch bit set though, but there is no harm in setting this bit once again. Hence set the runlatch bit for all threads before they start guest. Signed-off-by: Preeti U Murthy <preeti@linux.vnet.ibm.com> Acked-by: Paul Mackerras <paulus@samba.org> Reviewed-by: Srivatsa S. Bhat <srivatsa.bhat@linux.vnet.ibm.com> Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org> --- arch/powerpc/kvm/book3s_hv_rmhandlers.S | 6 ++++++ 1 file changed, 6 insertions(+) diff --git a/arch/powerpc/kvm/book3s_hv_rmhandlers.S b/arch/powerpc/kvm/book3s_hv_rmhandlers.S index ffbb871c2bd8..b25407533618 100644 --- a/arch/powerpc/kvm/book3s_hv_rmhandlers.S +++ b/arch/powerpc/kvm/book3s_hv_rmhandlers.S @@ -242,6 +242,12 @@ kvm_novcpu_exit: */ .globl kvm_start_guest kvm_start_guest: + + /* Set runlatch bit the minute you wake up from nap */ + mfspr r1, SPRN_CTRLF + ori r1, r1, 1 + mtspr SPRN_CTRLT, r1 + ld r2,PACATOC(r13) li r0,KVM_HWTHREAD_IN_KVM -- GitLab