From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id C023E20E1 for ; Tue, 22 Aug 2023 07:10:43 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 24ED4C433C9; Tue, 22 Aug 2023 07:10:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1692688243; bh=9SGUhfuXuQ+/VZ09GAPtAxCF7OjgtRbOA/Fwt1+hsHo=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=V1p0plI4UKoqvbVUrEgwadEg7nQ/8X0xHmHQCPKoYE4DW5Q76rSuqtRGfmoEwDXxk fk+twoUadr07zlSoptxX/R8QcnuW+DkVKduv2YxGfOD1gVTdxz5BMY2c0wo19nUAlk 1opz7t7zrlCIxKkxyNNx8WVr9Bc1bqGPuqYva0lq8f02MABO0ex3b7ESNSgRU16+Ei 8+9idV6lT+v6uk8gdeV/R9E2bcsK2V9KdJNtnMQpLWKqJTXb8I/92YnoBBsDgKBX/4 hQnuv/sjuwaD0fkART59pN6CP4A8T9pJqO3T/otWa5iYrWwmlyyRfadMXacW7hGUgx OM8n6pG9TqAow== Received: from ip-185-104-136-29.ptr.icomera.net ([185.104.136.29] helo=wait-a-minute.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.95) (envelope-from ) id 1qYLXB-006waI-Hv; Tue, 22 Aug 2023 08:10:39 +0100 Date: Tue, 22 Aug 2023 08:10:33 +0100 Message-ID: <877cpnpn6e.wl-maz@kernel.org> From: Marc Zyngier To: Jing Zhang Cc: KVM , KVMARM , ARMLinux , Oliver Upton , Will Deacon , Paolo Bonzini , James Morse , Alexandru Elisei , Suzuki K Poulose , Fuad Tabba , Reiji Watanabe , Raghavendra Rao Ananta , Suraj Jitindar Singh , Cornelia Huck , Shaoqin Huang Subject: Re: [PATCH v9 07/11] KVM: arm64: Enable writable for ID_AA64PFR0_EL1 In-Reply-To: <20230821212243.491660-8-jingzhangos@google.com> References: <20230821212243.491660-1-jingzhangos@google.com> <20230821212243.491660-8-jingzhangos@google.com> 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/28.2 (x86_64-pc-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: kvmarm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.104.136.29 X-SA-Exim-Rcpt-To: jingzhangos@google.com, kvm@vger.kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, oliver.upton@linux.dev, will@kernel.org, pbonzini@redhat.com, james.morse@arm.com, alexandru.elisei@arm.com, suzuki.poulose@arm.com, tabba@google.com, reijiw@google.com, rananta@google.com, surajjs@amazon.com, cohuck@redhat.com, shahuang@redhat.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Mon, 21 Aug 2023 22:22:39 +0100, Jing Zhang wrote: > > All valid fields in ID_AA64PFR0_EL1 are writable from userspace > with this change except AMU field which isn't exposed by KVM. > > Signed-off-by: Jing Zhang > --- > arch/arm64/kvm/sys_regs.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/arch/arm64/kvm/sys_regs.c b/arch/arm64/kvm/sys_regs.c > index cee5f879df19..bf716f646872 100644 > --- a/arch/arm64/kvm/sys_regs.c > +++ b/arch/arm64/kvm/sys_regs.c > @@ -2043,7 +2043,7 @@ static const struct sys_reg_desc sys_reg_descs[] = { > .get_user = get_id_reg, > .set_user = set_id_reg, > .reset = read_sanitised_id_aa64pfr0_el1, > - .val = ID_AA64PFR0_EL1_CSV2_MASK | ID_AA64PFR0_EL1_CSV3_MASK, }, > + .val = ~ID_AA64PFR0_EL1_AMU_MASK, }, > ID_SANITISED(ID_AA64PFR1_EL1), > ID_UNALLOCATED(4,2), > ID_UNALLOCATED(4,3), Same thing. Does it mean we can disable the GIC? Or FP? Have you taken my previous comment about the AMU as the only issue? M. -- Without deviation from the norm, progress is not possible.