From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dave Martin Subject: Re: [PATCH v5 23/26] KVM: arm64/sve: Allow userspace to enable SVE for vcpus Date: Tue, 26 Feb 2019 12:13:55 +0000 Message-ID: <20190226121355.GU3567@e103592.cambridge.arm.com> References: <1550519559-15915-1-git-send-email-Dave.Martin@arm.com> <1550519559-15915-24-git-send-email-Dave.Martin@arm.com> <88f7a00d-019a-5ed3-5a80-6032775dc5c5@arm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from localhost (localhost [127.0.0.1]) by mm01.cs.columbia.edu (Postfix) with ESMTP id 31F344A1DF for ; Tue, 26 Feb 2019 07:14:01 -0500 (EST) Received: from mm01.cs.columbia.edu ([127.0.0.1]) by localhost (mm01.cs.columbia.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id aT+M076f8yr8 for ; Tue, 26 Feb 2019 07:13:59 -0500 (EST) Received: from foss.arm.com (foss.arm.com [217.140.101.70]) by mm01.cs.columbia.edu (Postfix) with ESMTP id D66FE49E3E for ; Tue, 26 Feb 2019 07:13:59 -0500 (EST) Content-Disposition: inline In-Reply-To: <88f7a00d-019a-5ed3-5a80-6032775dc5c5@arm.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: kvmarm-bounces@lists.cs.columbia.edu Sender: kvmarm-bounces@lists.cs.columbia.edu To: Julien Thierry Cc: Okamoto Takayuki , Christoffer Dall , Ard Biesheuvel , Marc Zyngier , Catalin Marinas , Will Deacon , Zhang Lei , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org List-Id: kvmarm@lists.cs.columbia.edu On Fri, Feb 22, 2019 at 09:05:16AM +0000, Julien Thierry wrote: > Hi Dave, > > On 18/02/2019 19:52, Dave Martin wrote: > > Now that all the pieces are in place, this patch offers a new flag > > KVM_ARM_VCPU_SVE that userspace can pass to KVM_ARM_VCPU_INIT to > > turn on SVE for the guest, on a per-vcpu basis. > > > > As part of this, support for initialisation and reset of the SVE > > vector length set and registers is added in the appropriate places. > > Allocation SVE registers is deferred until kvm_arm_vcpu_finalize(), > > by which time the size of the registers is known. > > > > Setting the vector lengths supported by the vcpu is considered > > configuration of the emulated hardware rather than runtime > > configuration, so no support is offered for changing the vector > > lengths of an existing vcpu across reset. > > > > Signed-off-by: Dave Martin > > > > --- > > > > Changes since v4: > > > > * Pull out vcpu_sve_state_size(), for use earlier in the series. > > > > * Remove unnecessary vcpu->arch.sve_vqs[], and clamp maximum guest > > vector length to 256 bytes for forwards compatibility. > > > > (See "KVM: arm64/sve: Add pseudo-register for the guest's vector > > lengths".) > > > > * Minor tidyups to make some checks less verbose. > > --- > > arch/arm64/include/asm/kvm_host.h | 2 +- > > arch/arm64/include/uapi/asm/kvm.h | 1 + > > arch/arm64/kvm/reset.c | 70 ++++++++++++++++++++++++++++++++++++++- > > 3 files changed, 71 insertions(+), 2 deletions(-) [...] > > diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c [...] > > int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu) > > { > > if (likely(kvm_arm_vcpu_finalized(vcpu))) > > return 0; > > > > + if (vcpu_has_sve(vcpu)) { > > + size_t size = vcpu_sve_state_size(vcpu); > > + > > + if (!size) > > + return -EINVAL; > > + > > + vcpu->arch.sve_state = kzalloc(size, GFP_KERNEL); > > We should probably free this in kvm_arch_vcpu_free(). Hmmm, good spot! Looks like I lost that during a previous rebase. Cheers ---Dave 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 X-Spam-Level: X-Spam-Status: No, score=-8.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 4A45EC43381 for ; Tue, 26 Feb 2019 12:14:46 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 1BD8C2087C for ; Tue, 26 Feb 2019 12:14:46 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="ZdEPN1Kz" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1BD8C2087C Authentication-Results: mail.kernel.org; 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Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gybd9-00007r-Dl; Tue, 26 Feb 2019 12:14:39 +0000 Received: from foss.arm.com ([217.140.101.70]) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1gybcV-0007yE-RQ for linux-arm-kernel@lists.infradead.org; Tue, 26 Feb 2019 12:14:08 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 881CF80D; Tue, 26 Feb 2019 04:13:59 -0800 (PST) Received: from e103592.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.72.51.249]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id BB59F3F5C1; Tue, 26 Feb 2019 04:13:57 -0800 (PST) Date: Tue, 26 Feb 2019 12:13:55 +0000 From: Dave Martin To: Julien Thierry Subject: Re: [PATCH v5 23/26] KVM: arm64/sve: Allow userspace to enable SVE for vcpus Message-ID: <20190226121355.GU3567@e103592.cambridge.arm.com> References: <1550519559-15915-1-git-send-email-Dave.Martin@arm.com> <1550519559-15915-24-git-send-email-Dave.Martin@arm.com> <88f7a00d-019a-5ed3-5a80-6032775dc5c5@arm.com> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <88f7a00d-019a-5ed3-5a80-6032775dc5c5@arm.com> User-Agent: Mutt/1.5.23 (2014-03-12) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190226_041400_246790_B422C2F2 X-CRM114-Status: GOOD ( 23.19 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Okamoto Takayuki , Christoffer Dall , Ard Biesheuvel , Marc Zyngier , Catalin Marinas , Will Deacon , Zhang Lei , kvmarm@lists.cs.columbia.edu, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Fri, Feb 22, 2019 at 09:05:16AM +0000, Julien Thierry wrote: > Hi Dave, > > On 18/02/2019 19:52, Dave Martin wrote: > > Now that all the pieces are in place, this patch offers a new flag > > KVM_ARM_VCPU_SVE that userspace can pass to KVM_ARM_VCPU_INIT to > > turn on SVE for the guest, on a per-vcpu basis. > > > > As part of this, support for initialisation and reset of the SVE > > vector length set and registers is added in the appropriate places. > > Allocation SVE registers is deferred until kvm_arm_vcpu_finalize(), > > by which time the size of the registers is known. > > > > Setting the vector lengths supported by the vcpu is considered > > configuration of the emulated hardware rather than runtime > > configuration, so no support is offered for changing the vector > > lengths of an existing vcpu across reset. > > > > Signed-off-by: Dave Martin > > > > --- > > > > Changes since v4: > > > > * Pull out vcpu_sve_state_size(), for use earlier in the series. > > > > * Remove unnecessary vcpu->arch.sve_vqs[], and clamp maximum guest > > vector length to 256 bytes for forwards compatibility. > > > > (See "KVM: arm64/sve: Add pseudo-register for the guest's vector > > lengths".) > > > > * Minor tidyups to make some checks less verbose. > > --- > > arch/arm64/include/asm/kvm_host.h | 2 +- > > arch/arm64/include/uapi/asm/kvm.h | 1 + > > arch/arm64/kvm/reset.c | 70 ++++++++++++++++++++++++++++++++++++++- > > 3 files changed, 71 insertions(+), 2 deletions(-) [...] > > diff --git a/arch/arm64/kvm/reset.c b/arch/arm64/kvm/reset.c [...] > > int kvm_arm_vcpu_finalize(struct kvm_vcpu *vcpu) > > { > > if (likely(kvm_arm_vcpu_finalized(vcpu))) > > return 0; > > > > + if (vcpu_has_sve(vcpu)) { > > + size_t size = vcpu_sve_state_size(vcpu); > > + > > + if (!size) > > + return -EINVAL; > > + > > + vcpu->arch.sve_state = kzalloc(size, GFP_KERNEL); > > We should probably free this in kvm_arch_vcpu_free(). Hmmm, good spot! Looks like I lost that during a previous rebase. Cheers ---Dave _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel