From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pl0-x241.google.com (mail-pl0-x241.google.com [IPv6:2607:f8b0:400e:c01::241]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 40rPkv0XXRzDrnr for ; Wed, 23 May 2018 17:48:07 +1000 (AEST) Received: by mail-pl0-x241.google.com with SMTP id w19-v6so12509062plq.4 for ; Wed, 23 May 2018 00:48:06 -0700 (PDT) From: wei.guo.simon@gmail.com To: linuxppc-dev@lists.ozlabs.org Cc: Paul Mackerras , kvm@vger.kernel.org, kvm-ppc@vger.kernel.org, Simon Guo Subject: [PATCH v4 19/29] KVM: PPC: Book3S PR: enable NV reg restore for reading TM SPR at guest privilege state Date: Wed, 23 May 2018 15:02:02 +0800 Message-Id: <1527058932-7434-20-git-send-email-wei.guo.simon@gmail.com> In-Reply-To: <1527058932-7434-1-git-send-email-wei.guo.simon@gmail.com> References: <1527058932-7434-1-git-send-email-wei.guo.simon@gmail.com> List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , From: Simon Guo 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 Reviewed-by: Paul Mackerras --- 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 9becca1..9a72460 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -989,6 +989,18 @@ 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; } @@ -1350,8 +1362,7 @@ 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