From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 70CC4C43334 for ; Wed, 8 Jun 2022 16:43:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender: Content-Transfer-Encoding:Content-Type:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:MIME-Version:References:In-Reply-To: Subject:Cc:To:From:Message-ID:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=tnNOqLRVDnIkRZLR7/ysp1qAfMkTzFMYDn83UP3nuoI=; b=nbB/RlXQd6JZVh /ZbYZBeBtAc4hJpHcjTBvKNQdbVFF7viXTOe1aj5oB8kMusk6PopPXY2qLXEuVlQBs5V+HdytBXtm uVBuoo/3IDdzcM6z6wzU2mFyzZ8yB0DA0iNLnttVi/YN7/51jX/R+gY/+3zVjqfN605+qKNq6OwKV l3LdRZ8+k/K9FJpcPMMtbYKFQCqz87No5TbLQqmAd1ac8OxBXk2CtF+V5aJE5kJr56roS30mnf9Oz qfE9dKnfUBhqJSxQaIQ8h9QLHBHRB9vzQLHP1CGuNbYpLPZ4WedanBamgZ0fWr83RrLVw/3kmQPV/ 8tPR45MIuE8Se4w0HhlA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.94.2 #2 (Red Hat Linux)) id 1nyylB-00EOyC-Sk; Wed, 08 Jun 2022 16:42:22 +0000 Received: from ams.source.kernel.org ([2604:1380:4601:e00::1]) by bombadil.infradead.org with esmtps (Exim 4.94.2 #2 (Red Hat Linux)) id 1nyyl7-00EOwd-Rs for linux-arm-kernel@lists.infradead.org; Wed, 08 Jun 2022 16:42:19 +0000 Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 85F46B823D1; Wed, 8 Jun 2022 16:42:15 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 501F4C34116; Wed, 8 Jun 2022 16:42:14 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1654706534; bh=lJgUM8GOBIZ/XpsvzLcQSc3ckUaWGitjs+t1n/9XY24=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=rrItJ2rwFonOwxdPvvc0pXC7XD7UusALImPpjOUHeJAKo5PBvgwfYKjd1eggKhjcR /HPPDq6UUeaShJRdddnBjZXLbaiQC9YHrjGnMFNVSBcZNCo1ZCZ/ugF6puNGsIoeGg syjVpcPjkK4js73Mk0z6U0shldBy8HTFoVd0Z5ffxatM9w4NYwatCcCaFCt+OCAdU8 jzP1wNq7zOr2Uvf5FZK1459gq9nrZvpw3qHvwLXAUANafupIIvwg9rW+hSL9m0ZKeo 1LCqstNIOUV2FtnSzmkJxR2rqNW29q+2MZyBxOAJt4WdccUkRcaodTLJqYeNs5WTDG RXos3xpuzKZpQ== Received: from sofa.misterjones.org ([185.219.108.64] helo=why.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1nyyl1-00GfTt-Rb; Wed, 08 Jun 2022 17:42:11 +0100 Date: Wed, 08 Jun 2022 17:42:11 +0100 Message-ID: <87h74v3y58.wl-maz@kernel.org> From: Marc Zyngier To: Fuad Tabba Cc: kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, James Morse , Suzuki K Poulose , Alexandru Elisei , Oliver Upton , Will Deacon , Quentin Perret , Mark Brown , kernel-team@android.com Subject: Re: [PATCH 15/18] KVM: arm64: Warn when PENDING_EXCEPTION and INCREMENT_PC are set together In-Reply-To: References: <20220528113829.1043361-1-maz@kernel.org> <20220528113829.1043361-16-maz@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/27.1 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: tabba@google.com, kvmarm@lists.cs.columbia.edu, kvm@vger.kernel.org, linux-arm-kernel@lists.infradead.org, james.morse@arm.com, suzuki.poulose@arm.com, alexandru.elisei@arm.com, oupton@google.com, will@kernel.org, qperret@google.com, broonie@kernel.org, kernel-team@android.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20220608_094218_217717_D3B15BE7 X-CRM114-Status: GOOD ( 26.00 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Wed, 08 Jun 2022 16:16:55 +0100, Fuad Tabba wrote: > > Hi Marc, > > On Sat, May 28, 2022 at 12:49 PM Marc Zyngier wrote: > > > > We really don't want PENDING_EXCEPTION and INCREMENT_PC to ever be > > set at the same time, as they are mutually exclusive. Add checks > > that will generate a warning should this ever happen. > > > > Signed-off-by: Marc Zyngier > > --- > > arch/arm64/include/asm/kvm_emulate.h | 1 + > > arch/arm64/kvm/hyp/nvhe/sys_regs.c | 2 ++ > > arch/arm64/kvm/inject_fault.c | 8 ++++++++ > > 3 files changed, 11 insertions(+) > > > > diff --git a/arch/arm64/include/asm/kvm_emulate.h b/arch/arm64/include/asm/kvm_emulate.h > > index 46e631cd8d9e..861fa0b24a7f 100644 > > --- a/arch/arm64/include/asm/kvm_emulate.h > > +++ b/arch/arm64/include/asm/kvm_emulate.h > > @@ -473,6 +473,7 @@ static inline unsigned long vcpu_data_host_to_guest(struct kvm_vcpu *vcpu, > > > > static __always_inline void kvm_incr_pc(struct kvm_vcpu *vcpu) > > { > > + WARN_ON(vcpu_get_flag(vcpu, PENDING_EXCEPTION)); > > vcpu_set_flag(vcpu, INCREMENT_PC); > > } > > > > diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c > > index 2841a2d447a1..04973984b6db 100644 > > --- a/arch/arm64/kvm/hyp/nvhe/sys_regs.c > > +++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c > > @@ -38,6 +38,8 @@ static void inject_undef64(struct kvm_vcpu *vcpu) > > *vcpu_pc(vcpu) = read_sysreg_el2(SYS_ELR); > > *vcpu_cpsr(vcpu) = read_sysreg_el2(SYS_SPSR); > > > > + WARN_ON(vcpu_get_flag(vcpu, INCREMENT_PC)); > > + > > vcpu_set_flag(vcpu, PENDING_EXCEPTION); > > vcpu_set_flag(vcpu, EXCEPT_AA64_EL1_SYNC); > > > > diff --git a/arch/arm64/kvm/inject_fault.c b/arch/arm64/kvm/inject_fault.c > > index a9a7b513f3b0..2f4b9afc16ec 100644 > > --- a/arch/arm64/kvm/inject_fault.c > > +++ b/arch/arm64/kvm/inject_fault.c > > @@ -20,6 +20,8 @@ static void inject_abt64(struct kvm_vcpu *vcpu, bool is_iabt, unsigned long addr > > bool is_aarch32 = vcpu_mode_is_32bit(vcpu); > > u32 esr = 0; > > > > + WARN_ON(vcpu_get_flag(vcpu, INCREMENT_PC)); > > + > > Minor nit: While we're at it, should we just create a helper for > setting PENDING_EXCEPTION, same as we have for INCREMENT_PC? That > might make the code clearer and save us from the hassle of having this > WARN_ON before every instance of setting PENDING_EXCEPTION? Good point. I ended up with this: #define kvm_pend_exception(v, e) \ do { \ WARN_ON(vcpu_get_flag((v), INCREMENT_PC)); \ vcpu_set_flag((v), PENDING_EXCEPTION); \ vcpu_set_flag((v), e); \ } while (0) It has to be a macro in order to deal with the flag expansion, but is otherwise a welcome cleanup. Thanks, M. -- Without deviation from the norm, progress is not possible. _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel