From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-pg0-x242.google.com (mail-pg0-x242.google.com [IPv6:2607:f8b0:400e:c05::242]) (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 40fXYQ38CFzF157 for ; Mon, 7 May 2018 16:20:42 +1000 (AEST) Received: by mail-pg0-x242.google.com with SMTP id n9-v6so19495547pgq.5 for ; Sun, 06 May 2018 23:20:42 -0700 (PDT) From: wei.guo.simon@gmail.com To: kvm-ppc@vger.kernel.org Cc: Paul Mackerras , kvm@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, Simon Guo Subject: [PATCH v2 03/10] KVM: PPC: Fix a mmio_host_swabbed uninitialized usage issue when VMX store Date: Mon, 7 May 2018 14:20:09 +0800 Message-Id: <1525674016-6703-4-git-send-email-wei.guo.simon@gmail.com> In-Reply-To: <1525674016-6703-1-git-send-email-wei.guo.simon@gmail.com> References: <1525674016-6703-1-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 When KVM emulates VMX store, it will invoke kvmppc_get_vmx_data() to retrieve VMX reg val. kvmppc_get_vmx_data() will check mmio_host_swabbed to decide which double word of vr[] to be used. But the mmio_host_swabbed can be uninitiazed during VMX store procedure: kvmppc_emulate_loadstore \- kvmppc_handle_store128_by2x64 \- kvmppc_get_vmx_data So vcpu->arch.mmio_host_swabbed is not meant to be used at all for emulation of store instructions, and this patch makes that true for VMX stores. This patch also initializes mmio_host_swabbed to avoid invisble trouble. Signed-off-by: Simon Guo --- arch/powerpc/kvm/emulate_loadstore.c | 1 + arch/powerpc/kvm/powerpc.c | 2 +- 2 files changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/kvm/emulate_loadstore.c b/arch/powerpc/kvm/emulate_loadstore.c index a382e15..b8a3aef 100644 --- a/arch/powerpc/kvm/emulate_loadstore.c +++ b/arch/powerpc/kvm/emulate_loadstore.c @@ -111,6 +111,7 @@ int kvmppc_emulate_loadstore(struct kvm_vcpu *vcpu) vcpu->arch.mmio_sp64_extend = 0; vcpu->arch.mmio_sign_extend = 0; vcpu->arch.mmio_vmx_copy_nums = 0; + vcpu->arch.mmio_host_swabbed = 0; switch (get_op(inst)) { case 31: diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c index 4e38764..bef27b1 100644 --- a/arch/powerpc/kvm/powerpc.c +++ b/arch/powerpc/kvm/powerpc.c @@ -1374,7 +1374,7 @@ static inline int kvmppc_get_vmx_data(struct kvm_vcpu *vcpu, int rs, u64 *val) if (di > 1) return -1; - if (vcpu->arch.mmio_host_swabbed) + if (kvmppc_need_byteswap(vcpu)) di = 1 - di; w0 = vrs.u[di * 2]; -- 1.8.3.1