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ppc/kvm: Set the runlatch bit of a CPU just before starting guest

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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>
This commit is contained in:
Preeti U Murthy 2014-04-11 16:01:58 +05:30 committed by Benjamin Herrenschmidt
parent f203891117
commit fd17dc7b9a
1 changed files with 6 additions and 0 deletions
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6
arch/powerpc/kvm/book3s_hv_rmhandlers.S
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@ -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