From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pf0-x241.google.com (mail-pf0-x241.google.com [IPv6:2607:f8b0:400e:c00::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 40rPkY1QjWzDrnr for ; Wed, 23 May 2018 17:47:49 +1000 (AEST) Received: by mail-pf0-x241.google.com with SMTP id e9-v6so10080376pfi.4 for ; Wed, 23 May 2018 00:47:49 -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 12/29] KVM: PPC: Book3S PR: prevent TS bits change in kvmppc_interrupt_pr() Date: Wed, 23 May 2018 15:01:55 +0800 Message-Id: <1527058932-7434-13-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 PR KVM host usually equipped with enabled TM in its host MSR value, and with non-transactional TS value. When a guest with TM active traps into PR KVM host, the rfid at the tail of kvmppc_interrupt_pr() will try to switch TS bits from S0 (Suspended & TM disabled) to N1 (Non-transactional & TM enabled). That will leads to TM Bad Thing interrupt. This patch manually sets target TS bits unchanged to avoid this exception. Signed-off-by: Simon Guo Reviewed-by: Paul Mackerras --- arch/powerpc/kvm/book3s_segment.S | 13 +++++++++++++ 1 file changed, 13 insertions(+) diff --git a/arch/powerpc/kvm/book3s_segment.S b/arch/powerpc/kvm/book3s_segment.S index 93a180c..98ccc7e 100644 --- a/arch/powerpc/kvm/book3s_segment.S +++ b/arch/powerpc/kvm/book3s_segment.S @@ -383,6 +383,19 @@ END_FTR_SECTION_IFSET(CPU_FTR_ARCH_207S) */ PPC_LL r6, HSTATE_HOST_MSR(r13) +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + /* + * We don't want to change MSR[TS] bits via rfi here. + * The actual TM handling logic will be in host with + * recovered DR/IR bits after HSTATE_VMHANDLER. + * And MSR_TM can be enabled in HOST_MSR so rfid may + * not suppress this change and can lead to exception. + * Manually set MSR to prevent TS state change here. + */ + mfmsr r7 + rldicl r7, r7, 64 - MSR_TS_S_LG, 62 + rldimi r6, r7, MSR_TS_S_LG, 63 - MSR_TS_T_LG +#endif PPC_LL r8, HSTATE_VMHANDLER(r13) #ifdef CONFIG_PPC64 -- 1.8.3.1