From patchwork Fri Mar 21 00:16:03 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 14024737 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 DEFF8C28B30 for ; Fri, 21 Mar 2025 00:48:55 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:Cc:To:In-Reply-To:References :Message-Id:Content-Transfer-Encoding:Content-Type:MIME-Version:Subject:Date: From:Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=+RlBFQKcUm851xKaMijOjPf8mHiI9ukDgAYZnStDiIk=; b=S2u7/i5SuR0v91jnjNu7G3g6ys w9MUkSjNj1S7RDk6ClDHBS+aTMiOXK/upJ7qNKQ84yqFMruuWaOxjsoy9CXYf7M/eIH0ZSEpl63sF FmyoZCVfDarL9K4GS+10KnH//QcXP6iohgnc4CMpoiZSlnbJ7IyeZvMY2OX50HQUSxWFvtqoQNilg WwyhbRX0l29g9rqWnnE3uyI+hFG/cDEzt86qtsmPS/9zGQDzu2PzhuCZHaLULacJeo0pHp0Ju2MCh 4yZzMa/U5OMi99xLpuRdrepk48a8Zc+/QHxjopzvgt+7QRsj+PcqQIVbqFii6qjFxJiRN4EfBG6w8 zlTgORiA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tvQZ3-0000000Dahe-1AiR; Fri, 21 Mar 2025 00:48:45 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tvQ5i-0000000DXUO-01rH for linux-arm-kernel@lists.infradead.org; Fri, 21 Mar 2025 00:18:29 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 6E8DB5C6827; Fri, 21 Mar 2025 00:16:08 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 6BE19C4CEDD; Fri, 21 Mar 2025 00:18:22 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742516305; bh=ehJMCPrMwHOlFomdHlkXQQW8qPj0SLCNghFqe+fTFOM=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=uhok4P0S6bgzI3Z7aFQKSSP/QCgeqUlIoUmipEsI4u6KJ2HPCO3jjFiuZcXamCWG9 P3bjVGzgsz8uWUslAoCpwoK+rVvPeox3BoE1niMr10DmrUjWyt4hAFYjhQD76k4k+a QAtcb25F+gNpDsglUV1/hVjwAmr2YNkb0OVAfdQCJBtRy2uywPzuNsGPWuZR4FG+Ts Nfs1moG/y1hz79wbnkK9hQNToVmLnkw4W8K9ZbCoQ6gpOO4PQCaRu8FSxUfSeRrRmq WG13BzkxQrtouG3M+fY7goSEHoXdTb3JVc9E9kjaNZSCN7pVdTHZhQNVfoY4a82rwF B4gsMLORcLTBA== From: Mark Brown Date: Fri, 21 Mar 2025 00:16:03 +0000 Subject: [PATCH 6.6 3/8] KVM: arm64: Remove host FPSIMD saving for non-protected KVM MIME-Version: 1.0 Message-Id: <20250321-stable-sve-6-6-v1-3-0b3a6a14ea53@kernel.org> References: <20250321-stable-sve-6-6-v1-0-0b3a6a14ea53@kernel.org> In-Reply-To: <20250321-stable-sve-6-6-v1-0-0b3a6a14ea53@kernel.org> To: Greg Kroah-Hartman , Marc Zyngier , Oliver Upton , James Morse , Suzuki K Poulose , Catalin Marinas , Will Deacon Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Mark Brown , Mark Rutland , Fuad Tabba X-Mailer: b4 0.15-dev-1b0d6 X-Developer-Signature: v=1; a=openpgp-sha256; l=3882; i=broonie@kernel.org; h=from:subject:message-id; bh=RFWrMPCwzs0NH7GB08LQFJjXWfWPvpZMwKDg1phGkog=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBn3LA8ZtpxXliTO/VwpxtBvZVJylNzVfVYCbmDkzaj Xd/IK9aJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZ9ywPAAKCRAk1otyXVSH0MbzB/ wP53p1K4tkyva6gQKK/UQ2Am19w+vVgl1NQvUVQqQLG9B3EKdjC22dwXpA7xe8hotvZZdSHx9pjV7r tLOBh6K7tR4/HMm+D0XHhkhwaW7aa1kMUG/qomMwllR2qknV+1n2J6rnUZ+ZVb37Fk6MEXfAqw0ent j60z/STYlcC0O7caND8km2ZkzA1eQHCgfAO5JFacPKMAOqmEUGkU/wMx7zZlYmYMk7rJA0pMtV9LN1 ulJgMiNYrDFJ33yFuEer869qv7lQfrsDRKOE6Hv7n8kldwUgodnXc+pCqr9ba084WVPN7sUO0cF+ti 7KluJRVG4ZWjQWnlHBo+dXSO+hfwdK X-Developer-Key: i=broonie@kernel.org; a=openpgp; fpr=3F2568AAC26998F9E813A1C5C3F436CA30F5D8EB X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250320_171826_139541_0259BC00 X-CRM114-Status: GOOD ( 17.48 ) 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: , Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+linux-arm-kernel=archiver.kernel.org@lists.infradead.org From: Mark Rutland [ Upstream commit 8eca7f6d5100b6997df4f532090bc3f7e0203bef ] Now that the host eagerly saves its own FPSIMD/SVE/SME state, non-protected KVM never needs to save the host FPSIMD/SVE/SME state, and the code to do this is never used. Protected KVM still needs to save/restore the host FPSIMD/SVE state to avoid leaking guest state to the host (and to avoid revealing to the host whether the guest used FPSIMD/SVE/SME), and that code needs to be retained. Remove the unused code and data structures. To avoid the need for a stub copy of kvm_hyp_save_fpsimd_host() in the VHE hyp code, the nVHE/hVHE version is moved into the shared switch header, where it is only invoked when KVM is in protected mode. Signed-off-by: Mark Rutland Reviewed-by: Mark Brown Tested-by: Mark Brown Acked-by: Will Deacon Cc: Catalin Marinas Cc: Fuad Tabba Cc: Marc Zyngier Cc: Oliver Upton Reviewed-by: Oliver Upton Link: https://lore.kernel.org/r/20250210195226.1215254-3-mark.rutland@arm.com Signed-off-by: Marc Zyngier Signed-off-by: Mark Brown --- arch/arm64/include/asm/kvm_host.h | 1 - arch/arm64/kvm/fpsimd.c | 2 -- arch/arm64/kvm/hyp/include/hyp/switch.h | 4 ---- arch/arm64/kvm/hyp/nvhe/hyp-main.c | 1 - 4 files changed, 8 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 6a165ec5d3b74ece3e98e7bf45f3ea94cc30e6ec..3891963d42e00c8f999886dc5d7322bbacbc6c7f 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -535,7 +535,6 @@ struct kvm_vcpu_arch { struct kvm_guest_debug_arch vcpu_debug_state; struct kvm_guest_debug_arch external_debug_state; - struct user_fpsimd_state *host_fpsimd_state; /* hyp VA */ struct task_struct *parent_task; struct { diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index 8b55de502c8c220e15e3a6b782d5012b9349b612..7c36d2a7aa3196056f76acfe8f9c41763ed67d9d 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -49,8 +49,6 @@ int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu) if (ret) return ret; - vcpu->arch.host_fpsimd_state = kern_hyp_va(fpsimd); - /* * We need to keep current's task_struct pinned until its data has been * unshared with the hypervisor to make sure it is not re-used by the diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index 9cfe6bd1dbe459cb3588bccd94359369a546947e..1cdc8d161e7dd3aeeb6b03170e239b0c1ace7790 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -321,10 +321,6 @@ static bool kvm_hyp_handle_fpsimd(struct kvm_vcpu *vcpu, u64 *exit_code) } isb(); - /* Write out the host state if it's in the registers */ - if (vcpu->arch.fp_state == FP_STATE_HOST_OWNED) - __fpsimd_save_state(vcpu->arch.host_fpsimd_state); - /* Restore the guest state */ if (sve_guest) __hyp_sve_restore_guest(vcpu); diff --git a/arch/arm64/kvm/hyp/nvhe/hyp-main.c b/arch/arm64/kvm/hyp/nvhe/hyp-main.c index 67cc07283e642ab07e1c98c5745e2c6a2dd4f36e..8390173f7f5b38e01c04ae6563853df11a1c3df2 100644 --- a/arch/arm64/kvm/hyp/nvhe/hyp-main.c +++ b/arch/arm64/kvm/hyp/nvhe/hyp-main.c @@ -41,7 +41,6 @@ static void flush_hyp_vcpu(struct pkvm_hyp_vcpu *hyp_vcpu) hyp_vcpu->vcpu.arch.fp_state = host_vcpu->arch.fp_state; hyp_vcpu->vcpu.arch.debug_ptr = kern_hyp_va(host_vcpu->arch.debug_ptr); - hyp_vcpu->vcpu.arch.host_fpsimd_state = host_vcpu->arch.host_fpsimd_state; hyp_vcpu->vcpu.arch.vsesr_el2 = host_vcpu->arch.vsesr_el2;