Merge branch 'smp-hotplug-for-linus' of git://git.kernel.org/pub/scm/linux/kernel...

[mirror_ubuntu-artful-kernel.git] / arch / powerpc / kvm / book3s_hv.c

diff --git a/arch/powerpc/kvm/book3s_hv.c b/arch/powerpc/kvm/book3s_hv.c
index 48a6bd160011e0f232fa7a9021aacf5a4d31c008..773b35d16a0b61ddc3b13f02fd8a7eaca9d4976b 100644 (file)
--- a/arch/powerpc/kvm/book3s_hv.c
+++ b/arch/powerpc/kvm/book3s_hv.c
@@ -1486,6 +1486,14 @@ static int kvmppc_set_one_reg_hv(struct kvm_vcpu *vcpu, u64 id,
                r = set_vpa(vcpu, &vcpu->arch.dtl, addr, len);
                break;
        case KVM_REG_PPC_TB_OFFSET:
+               /*
+                * POWER9 DD1 has an erratum where writing TBU40 causes
+                * the timebase to lose ticks.  So we don't let the
+                * timebase offset be changed on P9 DD1.  (It is
+                * initialized to zero.)
+                */
+               if (cpu_has_feature(CPU_FTR_POWER9_DD1))
+                       break;
                /* round up to multiple of 2^24 */
                vcpu->arch.vcore->tb_offset =
                        ALIGN(set_reg_val(id, *val), 1UL << 24);
@@ -2907,12 +2915,36 @@ static int kvmppc_vcpu_run_hv(struct kvm_run *run, struct kvm_vcpu *vcpu)
 {
        int r;
        int srcu_idx;
+       unsigned long ebb_regs[3] = {}; /* shut up GCC */
+       unsigned long user_tar = 0;
+       unsigned int user_vrsave;
 
        if (!vcpu->arch.sane) {
                run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
                return -EINVAL;
        }
 
+       /*
+        * Don't allow entry with a suspended transaction, because
+        * the guest entry/exit code will lose it.
+        * If the guest has TM enabled, save away their TM-related SPRs
+        * (they will get restored by the TM unavailable interrupt).
+        */
+#ifdef CONFIG_PPC_TRANSACTIONAL_MEM
+       if (cpu_has_feature(CPU_FTR_TM) && current->thread.regs &&
+           (current->thread.regs->msr & MSR_TM)) {
+               if (MSR_TM_ACTIVE(current->thread.regs->msr)) {
+                       run->exit_reason = KVM_EXIT_FAIL_ENTRY;
+                       run->fail_entry.hardware_entry_failure_reason = 0;
+                       return -EINVAL;
+               }
+               current->thread.tm_tfhar = mfspr(SPRN_TFHAR);
+               current->thread.tm_tfiar = mfspr(SPRN_TFIAR);
+               current->thread.tm_texasr = mfspr(SPRN_TEXASR);
+               current->thread.regs->msr &= ~MSR_TM;
+       }
+#endif
+
        kvmppc_core_prepare_to_enter(vcpu);
 
        /* No need to go into the guest when all we'll do is come back out */
@@ -2934,6 +2966,15 @@ static int kvmppc_vcpu_run_hv(struct kvm_run *run, struct kvm_vcpu *vcpu)
 
        flush_all_to_thread(current);
 
+       /* Save userspace EBB and other register values */
+       if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
+               ebb_regs[0] = mfspr(SPRN_EBBHR);
+               ebb_regs[1] = mfspr(SPRN_EBBRR);
+               ebb_regs[2] = mfspr(SPRN_BESCR);
+               user_tar = mfspr(SPRN_TAR);
+       }
+       user_vrsave = mfspr(SPRN_VRSAVE);
+
        vcpu->arch.wqp = &vcpu->arch.vcore->wq;
        vcpu->arch.pgdir = current->mm->pgd;
        vcpu->arch.state = KVMPPC_VCPU_BUSY_IN_HOST;
@@ -2960,6 +3001,16 @@ static int kvmppc_vcpu_run_hv(struct kvm_run *run, struct kvm_vcpu *vcpu)
                }
        } while (is_kvmppc_resume_guest(r));
 
+       /* Restore userspace EBB and other register values */
+       if (cpu_has_feature(CPU_FTR_ARCH_207S)) {
+               mtspr(SPRN_EBBHR, ebb_regs[0]);
+               mtspr(SPRN_EBBRR, ebb_regs[1]);
+               mtspr(SPRN_BESCR, ebb_regs[2]);
+               mtspr(SPRN_TAR, user_tar);
+               mtspr(SPRN_FSCR, current->thread.fscr);
+       }
+       mtspr(SPRN_VRSAVE, user_vrsave);
+
  out:
        vcpu->arch.state = KVMPPC_VCPU_NOTREADY;
        atomic_dec(&vcpu->kvm->arch.vcpus_running);