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 D0E61C4345F for ; Sat, 13 Apr 2024 13:05:54 +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-Type: Content-Transfer-Encoding:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:MIME-Version:References:Message-ID:In-Reply-To: Subject:cc:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=uoEx3XLKxoaXomvpeS48LoIYb2fUezZknKLby5wrYMI=; b=qoaz2GYIzbx4LivoJhzzLIT6+X i8S6oXkvBPIKMI8X/YjKrGNsh1cAUNrPBb0fB8CeBxDjQTe8amlTpjbLjfZOIss9wx0XVU04DrX3M WWagIg8qJqqfxCuw/5/YEsXwiaAbe0ItSgt0sgdbkMLo9UyrNqC2697bIqpvhm9YKoBaSq0cRL99b 6MugPURxAhFkSmH5KrQGGpnhjEM9wPdA43aj/2IM2KHSoiMQV2/J4ombzrI3k7meeqUd4U8AdtzjG TRy4pAxlSYkh7NC+27/ZtkY042COdxbPd7u2/QxCE4Mc7jNMOUXRtFE3wMgEtszXzFOZfW6vXjQVE h8RgzymA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rvd4i-00000003BjR-25jX; Sat, 13 Apr 2024 13:05:44 +0000 Received: from us-smtp-delivery-124.mimecast.com ([170.10.133.124]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1rvd4f-00000003Bif-15Cj for linux-arm-kernel@lists.infradead.org; Sat, 13 Apr 2024 13:05:42 +0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1713013538; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=LjC/r8afP2Rq17fs73k7VkcEwW9IeRku59pv+b0GDdk=; b=E9SUDrHgjujbIK6V4uLxulC/qGN2i7ZI2x+VISFPUaqzzgaQX0jWr1ZZUbBbT2ygsytljd J6Ol9WW5RA8T8FQLlZbjDMUZU0eqthQ8Y1AxXh/Y5vVs6pE59ojvfeezH0QygVjKsnCvQW oWGRn3e3SbPxBul9uRz9bimVdqeZtmQ= Received: from mail-wm1-f69.google.com (mail-wm1-f69.google.com [209.85.128.69]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.3, cipher=TLS_AES_256_GCM_SHA384) id us-mta-556-MgTKdwSoO_WHIiAHsqJ0sQ-1; Sat, 13 Apr 2024 09:05:33 -0400 X-MC-Unique: MgTKdwSoO_WHIiAHsqJ0sQ-1 Received: by mail-wm1-f69.google.com with SMTP id 5b1f17b1804b1-416661bb85bso9503705e9.0 for ; Sat, 13 Apr 2024 06:05:33 -0700 (PDT) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20230601; t=1713013532; x=1713618332; h=mime-version:references:message-id:in-reply-to:subject:cc:to:from :date:x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=LjC/r8afP2Rq17fs73k7VkcEwW9IeRku59pv+b0GDdk=; b=fyKTTaVDpllAQRMhkJh/2fxwDsNvAfJ07xJXzTOt+f9r8W4F9mS1ixZbFzb518rAku b5RRJd5mMXEIfr9t3qGubQc3ntCB5hg9JRLptRep4OEBK1Sk/kbjJZhGoWYMFJvHl1gs mmS5EoSoJLSLM8CA3mHmo32As6mno5T3Tq86t2tW01tSNcA8NqfJ8mT21VRDBQpAl9tj gS2KWfQoakVGJioz/aNbs6Bfqq5vhiFBinoVrexI1UqMFo68IlR4Ju4hyuvjYDCuV+Gk s4O3ZC2IyFJpc/fZyjgOY5ZjbFJbss/Qk3YJVfYJ/jrD7/3oPZxoGW9JvCbyEuHP2G5v FL3g== X-Gm-Message-State: AOJu0Yx0d+4TlB2sMVxqFdoVBmdFa7erdV/eHHL+0M8l2kRYu/IyDVqb zC4SLeHTZUVnOvirM5tDKQjyX4Dpe/ylfI2AUAf2pqIKda9c+jPJEpH0ktUYIA2Zl1wKYVJ8UE6 SlYWUAj3q7IoPkVAXBD9sO1iABdwYH2Yob7x2/5Qdnck3gkd9qBp+//bLgniXd+1ODeZElOY/ X-Received: by 2002:a05:600c:5818:b0:414:60fe:8f2b with SMTP id jz24-20020a05600c581800b0041460fe8f2bmr4636650wmb.18.1713013532600; Sat, 13 Apr 2024 06:05:32 -0700 (PDT) X-Google-Smtp-Source: AGHT+IHMW4dxiTvS7n2eWbssZJ0Xn/PGf10S4HVEPbaYyCkOe5omKF1qw+lfUNoMszIeJDG2JRMtxQ== X-Received: by 2002:a05:600c:5818:b0:414:60fe:8f2b with SMTP id jz24-20020a05600c581800b0041460fe8f2bmr4636624wmb.18.1713013532067; Sat, 13 Apr 2024 06:05:32 -0700 (PDT) Received: from rh (p200300c93f06ef00707ff2f902cfda41.dip0.t-ipconnect.de. [2003:c9:3f06:ef00:707f:f2f9:2cf:da41]) by smtp.gmail.com with ESMTPSA id z17-20020a05600c0a1100b00416b8da335esm8914249wmp.48.2024.04.13.06.05.31 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Sat, 13 Apr 2024 06:05:31 -0700 (PDT) Date: Sat, 13 Apr 2024 15:05:30 +0200 (CEST) From: Sebastian Ott To: Marc Zyngier cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, Oliver Upton , James Morse , Suzuki K Poulose , Catalin Marinas , Will Deacon Subject: Re: [PATCH 2/4] KVM: arm64: maintain per VM value for CTR_EL0 In-Reply-To: <86frvpshno.wl-maz@kernel.org> Message-ID: <7e9c8367-6e9e-e36b-934e-170c90522134@redhat.com> References: <20240405120108.11844-1-sebott@redhat.com> <20240405120108.11844-3-sebott@redhat.com> <86frvpshno.wl-maz@kernel.org> MIME-Version: 1.0 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240413_060541_462416_26B93662 X-CRM114-Status: GOOD ( 20.59 ) 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-Transfer-Encoding: 7bit Content-Type: text/plain; charset="us-ascii"; Format="flowed" Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sat, 13 Apr 2024, Marc Zyngier wrote: > On Fri, 05 Apr 2024 13:01:06 +0100, > Sebastian Ott wrote: >> >> In preparation for CTR_EL0 emulation maintain a per VM for this >> register and use it where appropriate. >> >> Signed-off-by: Sebastian Ott >> --- >> arch/arm64/include/asm/kvm_host.h | 1 + >> arch/arm64/kvm/sys_regs.c | 22 +++++++++++++++------- >> 2 files changed, 16 insertions(+), 7 deletions(-) >> >> diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h >> index 9e8a496fb284..481216febb46 100644 >> --- a/arch/arm64/include/asm/kvm_host.h >> +++ b/arch/arm64/include/asm/kvm_host.h >> @@ -318,6 +318,7 @@ struct kvm_arch { >> >> /* PMCR_EL0.N value for the guest */ >> u8 pmcr_n; >> + u64 ctr_el0; >> >> /* Iterator for idreg debugfs */ >> u8 idreg_debugfs_iter; > > Please consider the alignment of the fields. This leaves a 7 byte hole > that could be avoided (yes, I'm on a mission to reduce the size of the > various structures, because they are absolute pigs). OK. >> diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c >> index 131f5b0ca2b9..4d29b1a0842d 100644 >> --- a/arch/arm64/kvm/sys_regs.c >> +++ b/arch/arm64/kvm/sys_regs.c >> @@ -215,13 +215,21 @@ void vcpu_write_sys_reg(struct kvm_vcpu *vcpu, u64 val, int reg) >> /* CSSELR values; used to index KVM_REG_ARM_DEMUX_ID_CCSIDR */ >> #define CSSELR_MAX 14 >> >> +static u64 kvm_get_ctr_el0(struct kvm *kvm) >> +{ >> + if (kvm->arch.ctr_el0) >> + return kvm->arch.ctr_el0; > > Is this relying on some bits not being 0? > >> + >> + return read_sanitised_ftr_reg(SYS_CTR_EL0); > > Why isn't the shadow value always populated? The idea was for kvm->arch.ctr_el0 being non zero only if userspace set it up to differ from the host value. So it can be used to decide if we need to set up a trap for the reg access (without comparing it to the host value again). Thanks, Sebastian _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel