From: Simon Guo <wei.guo.simon@xxxxxxxxx> Currently kvmppc_handle_fac() will not update NV GPRs and thus it can return with GUEST_RESUME. However PR KVM guest always disables MSR_TM bit at privilege state. If PR privilege guest are trying to read TM SPRs, it will trigger TM facility unavailable exception and fall into kvmppc_handle_fac(). Then the emulation will be done by kvmppc_core_emulate_mfspr_pr(). The mfspr instruction can include a RT with NV reg. So it is necessary to restore NV GPRs at this case, to reflect the update to NV RT. This patch make kvmppc_handle_fac() return GUEST_RESUME_NV at TM fac exception and with guest privilege state. Signed-off-by: Simon Guo <wei.guo.simon@xxxxxxxxx> Reviewed-by: Paul Mackerras <paulus@xxxxxxxxxx> --- arch/powerpc/kvm/book3s_pr.c | 15 +++++++++++++-- 1 file changed, 13 insertions(+), 2 deletions(-) diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index 82e1a74..f31f9de 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -998,6 +998,18 @@ static int kvmppc_handle_fac(struct kvm_vcpu *vcpu, ulong fac) break; } +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + /* Since we disabled MSR_TM at privilege state, the mfspr instruction + * for TM spr can trigger TM fac unavailable. In this case, the + * emulation is handled by kvmppc_emulate_fac(), which invokes + * kvmppc_emulate_mfspr() finally. But note the mfspr can include + * RT for NV registers. So it need to restore those NV reg to reflect + * the update. + */ + if ((fac == FSCR_TM_LG) && !(kvmppc_get_msr(vcpu) & MSR_PR)) + return RESUME_GUEST_NV; +#endif + return RESUME_GUEST; } @@ -1359,8 +1371,7 @@ int kvmppc_handle_exit_pr(struct kvm_run *run, struct kvm_vcpu *vcpu, } #ifdef CONFIG_PPC_BOOK3S_64 case BOOK3S_INTERRUPT_FAC_UNAVAIL: - kvmppc_handle_fac(vcpu, vcpu->arch.shadow_fscr >> 56); - r = RESUME_GUEST; + r = kvmppc_handle_fac(vcpu, vcpu->arch.shadow_fscr >> 56); break; #endif case BOOK3S_INTERRUPT_MACHINE_CHECK: -- 1.8.3.1
