From patchwork Wed May 23 07:02:01 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Simon Guo X-Patchwork-Id: 918871 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) (using TLSv1.2 with cipher ADH-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 40rQrQ3GGyz9s15 for ; Wed, 23 May 2018 18:37:58 +1000 (AEST) Authentication-Results: ozlabs.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="p8D2oRWr"; dkim-atps=neutral Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 40rQrQ1c0PzF0Ws for ; Wed, 23 May 2018 18:37:58 +1000 (AEST) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: lists.ozlabs.org; dkim=fail reason="signature verification failed" (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="p8D2oRWr"; dkim-atps=neutral X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=pass (mailfrom) smtp.mailfrom=gmail.com (client-ip=2607:f8b0:400e:c01::241; helo=mail-pl0-x241.google.com; envelope-from=wei.guo.simon@gmail.com; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=pass (p=none dis=none) header.from=gmail.com Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=gmail.com header.i=@gmail.com header.b="p8D2oRWr"; dkim-atps=neutral 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 40rPkr3X4yzDrnr for ; Wed, 23 May 2018 17:48:04 +1000 (AEST) Received: by mail-pl0-x241.google.com with SMTP id i5-v6so12512987plt.2 for ; Wed, 23 May 2018 00:48:04 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=6ACv+jmr95fsRYlHoimgbUkMGRfAvdXlIQIZ6TPsBgY=; b=p8D2oRWr/xcen2dmbZpCcfW/EeI08LkgK683G8EPoKq2Oqe5+Dvh9rN305iEiBF31X 1wnGKus8akTFjgA2/WVsZ5bZXkwYAC9h9U8ArEoL0cc9CP6KHZ+ppQiBCgcjcI8a/ebX ASDcEdYD4phS7bTADcjmdoyS3v3CIP+W15CPT+VR0w/vHKwWBHctN5lOenbjQpt39nLP OBDEGL/D4Nq/7Rrko0sK0WxEo78hnbGMNkQlzeYrG5mbp4MCeqYqd6kneZR4abiQ2e1L Gtijq7NK3gVheq9RIc/PWAuADzpTOHm1Osg7nHAJAVqsggBrOJg2PdQP1C3yAvU+TYCc rHtA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=6ACv+jmr95fsRYlHoimgbUkMGRfAvdXlIQIZ6TPsBgY=; b=GxZCxRtlPlrL1ulkGHUsUfSQjoYlkUG8EQadflrh30IuAeRFlKtjpP3gk5eJGZu4Jx HJWA0KeolbE9gyausqCbwxlM6MLMQMacKVCiKrRjXDJFe1DehlTR2m6avaCPgXkluoKb aQGiR1sKMJr+raVQZ2uk13sZkCxwyK8vRrwBXiL9r3Co/W7s9msepBhETQ8Q0rrVKQdd UmNVFNOZsmlt4MEBXaSPQ/hb89AmKV51mswrhiyksZEYJSN3a8Qe8zkz+OVFDz3Xt6Nc Pu4ekWAZsXTzXhEa1wwjAQt4jwVM67Rq7nSFz9d5oF0qBzE18mfr2b/UVeCuy9oLr4Ud 9POw== X-Gm-Message-State: ALKqPwf4tl/+io8lgokv8ZzV0AvY9qBYaNuTWek7+gCl4wkXfct8CNJy Jt/3+DrjGxhSKLL0iBUiK+r5GQ== X-Google-Smtp-Source: AB8JxZoxnTm/wBZsQH+GE6rG+UuhO50V6iz/JlGYhFXdhfjw5OTxfCvthesFACOoASGvp6FaNavJNw== X-Received: by 2002:a17:902:43a4:: with SMTP id j33-v6mr1913715pld.118.1527061682536; Wed, 23 May 2018 00:48:02 -0700 (PDT) Received: from simonLocalRHEL7.cn.ibm.com ([112.73.0.89]) by smtp.gmail.com with ESMTPSA id a4-v6sm39079171pfj.19.2018.05.23.00.48.00 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 23 May 2018 00:48:02 -0700 (PDT) From: wei.guo.simon@gmail.com To: linuxppc-dev@lists.ozlabs.org Subject: [PATCH v4 18/29] KVM: PPC: Book3S PR: always fail transaction in guest privilege state Date: Wed, 23 May 2018 15:02:01 +0800 Message-Id: <1527058932-7434-19-git-send-email-wei.guo.simon@gmail.com> X-Mailer: git-send-email 1.8.3.1 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> X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.26 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Simon Guo , kvm-ppc@vger.kernel.org, kvm@vger.kernel.org Errors-To: linuxppc-dev-bounces+patchwork-incoming=ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" From: Simon Guo Currently kernel doesn't use transaction memory. And there is an issue for privilege guest that: tbegin/tsuspend/tresume/tabort TM instructions can impact MSR TM bits without trap into PR host. So following code will lead to a false mfmsr result: tbegin <- MSR bits update to Transaction active. beq <- failover handler branch mfmsr <- still read MSR bits from magic page with transaction inactive. It is not an issue for non-privilege guest since its mfmsr is not patched with magic page and will always trap into PR host. This patch will always fail tbegin attempt for privilege guest, so that the above issue is prevented. It is benign since currently (guest) kernel doesn't initiate a transaction. Test case: https://github.com/justdoitqd/publicFiles/blob/master/test_tbegin_pr.c Signed-off-by: Simon Guo --- arch/powerpc/include/asm/kvm_book3s.h | 2 ++ arch/powerpc/kvm/book3s_emulate.c | 40 +++++++++++++++++++++++++++++++++++ arch/powerpc/kvm/book3s_pr.c | 11 +++++++++- 3 files changed, 52 insertions(+), 1 deletion(-) diff --git a/arch/powerpc/include/asm/kvm_book3s.h b/arch/powerpc/include/asm/kvm_book3s.h index 43e8bb1..c1cea82 100644 --- a/arch/powerpc/include/asm/kvm_book3s.h +++ b/arch/powerpc/include/asm/kvm_book3s.h @@ -262,9 +262,11 @@ extern void kvmppc_update_lpcr(struct kvm *kvm, unsigned long lpcr, #ifdef CONFIG_PPC_TRANSACTIONAL_MEM void kvmppc_save_tm_pr(struct kvm_vcpu *vcpu); void kvmppc_restore_tm_pr(struct kvm_vcpu *vcpu); +void kvmppc_restore_tm_sprs(struct kvm_vcpu *vcpu); #else static inline void kvmppc_save_tm_pr(struct kvm_vcpu *vcpu) {} static inline void kvmppc_restore_tm_pr(struct kvm_vcpu *vcpu) {} +static inline void kvmppc_restore_tm_sprs(struct kvm_vcpu *vcpu) {} #endif extern int kvm_irq_bypass; diff --git a/arch/powerpc/kvm/book3s_emulate.c b/arch/powerpc/kvm/book3s_emulate.c index c4e3ec6..570339b 100644 --- a/arch/powerpc/kvm/book3s_emulate.c +++ b/arch/powerpc/kvm/book3s_emulate.c @@ -23,6 +23,7 @@ #include #include #include +#include #include "book3s.h" #include @@ -48,6 +49,8 @@ #define OP_31_XOP_EIOIO 854 #define OP_31_XOP_SLBMFEE 915 +#define OP_31_XOP_TBEGIN 654 + /* DCBZ is actually 1014, but we patch it to 1010 so we get a trap */ #define OP_31_XOP_DCBZ 1010 @@ -363,6 +366,43 @@ int kvmppc_core_emulate_op_pr(struct kvm_run *run, struct kvm_vcpu *vcpu, break; } +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + case OP_31_XOP_TBEGIN: + { + if (!cpu_has_feature(CPU_FTR_TM)) + break; + + if (!(kvmppc_get_msr(vcpu) & MSR_TM)) { + kvmppc_trigger_fac_interrupt(vcpu, FSCR_TM_LG); + emulated = EMULATE_AGAIN; + break; + } + + if (!(kvmppc_get_msr(vcpu) & MSR_PR)) { + preempt_disable(); + vcpu->arch.cr = (CR0_TBEGIN_FAILURE | + (vcpu->arch.cr & ~(CR0_MASK << CR0_SHIFT))); + + vcpu->arch.texasr = (TEXASR_FS | TEXASR_EXACT | + (((u64)(TM_CAUSE_EMULATE | TM_CAUSE_PERSISTENT)) + << TEXASR_FC_LG)); + + if ((inst >> 21) & 0x1) + vcpu->arch.texasr |= TEXASR_ROT; + + if (kvmppc_get_msr(vcpu) & MSR_HV) + vcpu->arch.texasr |= TEXASR_HV; + + vcpu->arch.tfhar = kvmppc_get_pc(vcpu) + 4; + vcpu->arch.tfiar = kvmppc_get_pc(vcpu); + + kvmppc_restore_tm_sprs(vcpu); + preempt_enable(); + } else + emulated = EMULATE_FAIL; + break; + } +#endif default: emulated = EMULATE_FAIL; } diff --git a/arch/powerpc/kvm/book3s_pr.c b/arch/powerpc/kvm/book3s_pr.c index e8e7f3a..9becca1 100644 --- a/arch/powerpc/kvm/book3s_pr.c +++ b/arch/powerpc/kvm/book3s_pr.c @@ -207,6 +207,15 @@ static void kvmppc_recalc_shadow_msr(struct kvm_vcpu *vcpu) #ifdef CONFIG_PPC_BOOK3S_64 smsr |= MSR_ISF | MSR_HV; #endif +#ifdef CONFIG_PPC_TRANSACTIONAL_MEM + /* + * in guest privileged state, we want to fail all TM transactions. + * So disable MSR TM bit so that all tbegin. will be able to be + * trapped into host. + */ + if (!(guest_msr & MSR_PR)) + smsr &= ~MSR_TM; +#endif vcpu->arch.shadow_msr = smsr; } @@ -299,7 +308,7 @@ static inline void kvmppc_save_tm_sprs(struct kvm_vcpu *vcpu) tm_disable(); } -static inline void kvmppc_restore_tm_sprs(struct kvm_vcpu *vcpu) +void kvmppc_restore_tm_sprs(struct kvm_vcpu *vcpu) { tm_enable(); mtspr(SPRN_TFHAR, vcpu->arch.tfhar);