[Qemu-devel] [PATCH 2/2] target-ppc/kvm: Enable transactional memory on POWER8 with KVM-HV, too

[Thomas Huth]

Transactional memory is also supported on POWER8 KVM-HV if the
KVM_CAP_PPC_HTM is not available in the kernel yet, so add a hack
to allow TM here, too.

Signed-off-by: Thomas Huth <th...@redhat.com>
---
 hw/ppc/spapr.c   | 2 +-
 target-ppc/kvm.c | 9 ++++++++-
 2 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
index fc37145..2f4e818 100644
--- a/hw/ppc/spapr.c
+++ b/hw/ppc/spapr.c
@@ -584,7 +584,7 @@ static void spapr_populate_pa_features(CPUPPCState *env, 
void *fdt, int offset)
          */
         pa_features[3] |= 0x20;
     }
-    if (kvmppc_has_cap_htm()) {
+    if (kvmppc_has_cap_htm() && pa_size > 24) {
         pa_features[24] |= 0x80;    /* Transactional memory support */
     }
 
diff --git a/target-ppc/kvm.c b/target-ppc/kvm.c
index dca50bc..e990cb7 100644
--- a/target-ppc/kvm.c
+++ b/target-ppc/kvm.c
@@ -567,11 +567,18 @@ int kvm_arch_init_vcpu(CPUState *cs)
 
     idle_timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, kvm_kick_cpu, cpu);
 
-    /* Some targets support access to KVM's guest TLB. */
     switch (cenv->mmu_model) {
     case POWERPC_MMU_BOOKE206:
+        /* This target supports access to KVM's guest TLB */
         ret = kvm_booke206_tlb_init(cpu);
         break;
+    case POWERPC_MMU_2_07:
+        if (!cap_htm && !kvmppc_is_pr(cs->kvm_state)) {
+            /* KVM-HV has transactional memory on POWER8 also without the
+             * KVM_CAP_PPC_HTM extension, so enable it here instead. */
+            cap_htm = true;
+        }
+        break;
     default:
         break;
     }
-- 
1.8.3.1