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 6AFBA3D8C for ; Fri, 24 Feb 2023 11:05:45 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 378E7C433D2; Fri, 24 Feb 2023 11:05:45 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1677236745; bh=XEX7VRnNTIkhFRg32m665yeVGktUtrzWJaoPwljZ308=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=h6J8Wxa6UA66DhLDGBWrOOUovne9SFTStlpin19vqy7Kfx8dz6TOycwoVafCinPzE fMQb0IwRQ3s0aAuJOkwqZm4otLvfHRC8pQze8coHQ5nlRjjniy1pEUjsav8TjRC0tt M3UHGYV1ZCdrJq0E4chg+lTQNrqakF9dQ9TLnUDW4C2QyBDr+7yZrDuFbp4dFdtBU7 rkcIj+nYNdjR+HIIyThfgLPWT6IQZI8xN6PxUlsywbPyniqPBsOJL0f6wvxr7rb1OG fniCvuzIxBj4c00VdM2TbF9nhts/K6s7lQEpBkfMQeXIJbZidS0iwsMwoJ/umO/Bk/ DF7hK+NHslGWg== Received: from sofa.misterjones.org ([185.219.108.64] helo=goblin-girl.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 1pVVtW-00Cs9z-Ud; Fri, 24 Feb 2023 11:05:43 +0000 Date: Fri, 24 Feb 2023 11:05:42 +0000 Message-ID: <861qmfxr09.wl-maz@kernel.org> From: Marc Zyngier To: Reiji Watanabe Cc: Jing Zhang , KVM , KVMARM , ARMLinux , Oliver Upton , Will Deacon , Paolo Bonzini , James Morse , Alexandru Elisei , Suzuki K Poulose , Fuad Tabba , Ricardo Koller , Raghavendra Rao Ananta Subject: Re: [PATCH v2 1/6] KVM: arm64: Move CPU ID feature registers emulation into a separate file In-Reply-To: References: <20230212215830.2975485-1-jingzhangos@google.com> <20230212215830.2975485-2-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 (aarch64-unknown-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: 185.219.108.64 X-SA-Exim-Rcpt-To: reijiw@google.com, jingzhangos@google.com, kvm@vger.kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, oupton@google.com, will@kernel.org, pbonzini@redhat.com, james.morse@arm.com, alexandru.elisei@arm.com, suzuki.poulose@arm.com, tabba@google.com, ricarkol@google.com, rananta@google.com X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Fri, 24 Feb 2023 01:01:44 +0000, Reiji Watanabe wrote: [...] > > +const struct sys_reg_desc *kvm_arm_find_id_reg(const struct sys_reg_params *params) > > +{ > > You might want to check if the param indicates the ID register, > before running the binary search for the ID register table. > (I have the same comment to kvm_arm_get_id_reg() and > kvm_arm_set_id_reg()). It would be much better if the discrimination was done in emulate_sys_reg(), just like we do for NV[1]. Save yourself pointless search on the critical path, and make the decoding tree visible in one place. > > > + return find_reg(params, id_reg_descs, ARRAY_SIZE(id_reg_descs)); > > +} > > + > > +void kvm_arm_reset_id_regs(struct kvm_vcpu *vcpu) > > +{ > > + unsigned long i; > > + > > + for (i = 0; i < ARRAY_SIZE(id_reg_descs); i++) > > + if (id_reg_descs[i].reset) > > + id_reg_descs[i].reset(vcpu, &id_reg_descs[i]); > > +} > > + > > +int kvm_arm_get_id_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) > > +{ > > + return kvm_sys_reg_get_user(vcpu, reg, > > + id_reg_descs, ARRAY_SIZE(id_reg_descs)); > > +} > > + > > +int kvm_arm_set_id_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) > > +{ > > + return kvm_sys_reg_set_user(vcpu, reg, > > + id_reg_descs, ARRAY_SIZE(id_reg_descs)); > > +} > > + > > +bool kvm_arm_check_idreg_table(void) > > +{ > > + return check_sysreg_table(id_reg_descs, ARRAY_SIZE(id_reg_descs), false); > > +} > > + > > +/* Assumed ordered tables, see kvm_sys_reg_table_init. */ > > I don't think we need this comment, as the code doesn't seem to > assume that. Yeah, it only makes sense for the binary search. Thanks, M. [1] https://lore.kernel.org/linux-arm-kernel/20230131092504.2880505-1-maz@kernel.org/T/#mced7be0152816d3a1d02cf8c8b95d3ab3ef4e0c8 -- Without deviation from the norm, progress is not possible. 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Fri, 24 Feb 2023 11:05:43 +0000 Date: Fri, 24 Feb 2023 11:05:42 +0000 Message-ID: <861qmfxr09.wl-maz@kernel.org> From: Marc Zyngier To: Reiji Watanabe Cc: Jing Zhang , KVM , KVMARM , ARMLinux , Oliver Upton , Will Deacon , Paolo Bonzini , James Morse , Alexandru Elisei , Suzuki K Poulose , Fuad Tabba , Ricardo Koller , Raghavendra Rao Ananta Subject: Re: [PATCH v2 1/6] KVM: arm64: Move CPU ID feature registers emulation into a separate file In-Reply-To: References: <20230212215830.2975485-1-jingzhangos@google.com> <20230212215830.2975485-2-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 (aarch64-unknown-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: reijiw@google.com, jingzhangos@google.com, kvm@vger.kernel.org, kvmarm@lists.linux.dev, linux-arm-kernel@lists.infradead.org, oupton@google.com, will@kernel.org, pbonzini@redhat.com, james.morse@arm.com, alexandru.elisei@arm.com, suzuki.poulose@arm.com, tabba@google.com, ricarkol@google.com, rananta@google.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-20230224_030546_645164_BAD6AC86 X-CRM114-Status: GOOD ( 21.92 ) 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 Fri, 24 Feb 2023 01:01:44 +0000, Reiji Watanabe wrote: [...] > > +const struct sys_reg_desc *kvm_arm_find_id_reg(const struct sys_reg_params *params) > > +{ > > You might want to check if the param indicates the ID register, > before running the binary search for the ID register table. > (I have the same comment to kvm_arm_get_id_reg() and > kvm_arm_set_id_reg()). It would be much better if the discrimination was done in emulate_sys_reg(), just like we do for NV[1]. Save yourself pointless search on the critical path, and make the decoding tree visible in one place. > > > + return find_reg(params, id_reg_descs, ARRAY_SIZE(id_reg_descs)); > > +} > > + > > +void kvm_arm_reset_id_regs(struct kvm_vcpu *vcpu) > > +{ > > + unsigned long i; > > + > > + for (i = 0; i < ARRAY_SIZE(id_reg_descs); i++) > > + if (id_reg_descs[i].reset) > > + id_reg_descs[i].reset(vcpu, &id_reg_descs[i]); > > +} > > + > > +int kvm_arm_get_id_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) > > +{ > > + return kvm_sys_reg_get_user(vcpu, reg, > > + id_reg_descs, ARRAY_SIZE(id_reg_descs)); > > +} > > + > > +int kvm_arm_set_id_reg(struct kvm_vcpu *vcpu, const struct kvm_one_reg *reg) > > +{ > > + return kvm_sys_reg_set_user(vcpu, reg, > > + id_reg_descs, ARRAY_SIZE(id_reg_descs)); > > +} > > + > > +bool kvm_arm_check_idreg_table(void) > > +{ > > + return check_sysreg_table(id_reg_descs, ARRAY_SIZE(id_reg_descs), false); > > +} > > + > > +/* Assumed ordered tables, see kvm_sys_reg_table_init. */ > > I don't think we need this comment, as the code doesn't seem to > assume that. Yeah, it only makes sense for the binary search. Thanks, M. [1] https://lore.kernel.org/linux-arm-kernel/20230131092504.2880505-1-maz@kernel.org/T/#mced7be0152816d3a1d02cf8c8b95d3ab3ef4e0c8 -- 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