From patchwork Tue Mar 25 18:48:20 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 14029383 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 9B81FC3600D for ; Tue, 25 Mar 2025 19:00:33 +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=m0v2KC2nIgBeR2daRWI9yUc7Gx6SuN9IeVia6+uoY+Q=; b=Jv1kJ2RzhzkCS1Dtgtb02Jh55d s2NCzMCzeLEonsBDDQqBu+Ac7XOwIbyoYX8/LNT8MC4ioORlD02sCUg0ZJe05GuQA3C2fTP5fQ13l aMTOj3cOsMNeuoVtu20ea2fH+sH9cl8okpEEWLfw8z5K7jzufjWqqj/OErI8MR9T7yFzzXvQh7zRq EkcXmRM1hKofMuTNCK+dgkZ4ccTaVlDXciRjRZpcM34I8fMDmZ9q1GNrRfQhYjJWOoz6uB04MyDWe RWAbhoQ5XZaNQA96/P1h3f3KtpGI9D+VnwkzoMUpYZSQVRZcrkrJ2Ekec6H5VvVA5b4Laifw1w4Bj LIiEv2Zw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.1 #2 (Red Hat Linux)) id 1tx9VW-00000006nUf-0eTM; Tue, 25 Mar 2025 19:00:14 +0000 Received: from dfw.source.kernel.org ([2604:1380:4641:c500::1]) by bombadil.infradead.org with esmtps (Exim 4.98.1 #2 (Red Hat Linux)) id 1tx9LL-00000006lUs-1zjG for linux-arm-kernel@lists.infradead.org; Tue, 25 Mar 2025 18:49:44 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id D9DED5C642A; Tue, 25 Mar 2025 18:47:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 20C8DC4CEEE; Tue, 25 Mar 2025 18:49:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1742928582; bh=ONHqmQTU63FaZh8cGmEzfPnyfUbijj0z1ke0L3d5q0w=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=LTf6miupkjPl9N8anUfRgeP1Co/m1rVJyTHgcNuaKPn9XRQPnuaMpI+DghKYakrBR VLOH/cDJkoUCKfDYpvlL3vNm4dhMXeOhch51IpTdIRDnvnOSwEJ8zkPeBmIdMWvl4S hrz3twYL0p7mSUpfTqrrW0tsvKM4MkK2d+gIveLI389Rvke60dhqdnO+ozLOgmAtLI 6XWINOskoa+SUhuLQUTIMyvlcLvUrij44KAKCwccmWsJQO9pmctUIkva3lR55dBxYC /zBj79J7W/P/JPU0XPaJJSyI2xx/KKP80OCm+IAwArmAkcimbj7XizuetS3kkEnW9o 27/Pk0aUJDJ4w== From: Mark Brown Date: Tue, 25 Mar 2025 18:48:20 +0000 Subject: [PATCH 6.1 06/12] KVM: arm64: Remove host FPSIMD saving for non-protected KVM MIME-Version: 1.0 Message-Id: <20250325-stable-sve-6-1-v1-6-83259d427d84@kernel.org> References: <20250325-stable-sve-6-1-v1-0-83259d427d84@kernel.org> In-Reply-To: <20250325-stable-sve-6-1-v1-0-83259d427d84@kernel.org> To: Catalin Marinas , Will Deacon , Marc Zyngier , James Morse , Suzuki K Poulose , Oliver Upton , Oleg Nesterov Cc: linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, kvmarm@lists.linux.dev, kvmarm@lists.cs.columbia.edu, Mark Brown , Mark Rutland , Fuad Tabba X-Mailer: b4 0.15-dev-1b0d6 X-Developer-Signature: v=1; a=openpgp-sha256; l=3205; i=broonie@kernel.org; h=from:subject:message-id; bh=0NzIpXAxU01MpifJfCvdhXaQGfCJ7I1Q/ycBr5g/AJY=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBn4vqq7qRv8/r/FdSc2iFgMkvOxm6CFV9MTjPLsOKV G6zh3WKJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZ+L6qgAKCRAk1otyXVSH0KdBB/ 0ZzAF42xKYF0NWGIgB42sAXL1YAERJx8UfWGp0/wIsQh3KyZL1QkVQe0UigkQssVf52jS7YgBrAIIb zl7fm51J0KTiITQ6LSxs4FIOjbtCtwTt0U1zx0/CCB0qT2DlhIwIOQefejiQ5ECd0673U+N+7wfRTH v4wpG60OhA5jLFAYDndbgZ1JR5OGKDtKO99M/tizpkcA/fxKIepfusy0u9hMsPC1UcCSW5fiqtxkgT Jsqgf2RTzxIiPNvWr2gYzqS2sGoIP1PE38G7qtNc4QRD4/TOHR26cWR5VFwbh5OjKz17BPp21CiYkn s2pf+0zcPpdJ8eU8hceTxGhM0h2Ci7 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-20250325_114943_634262_96AC1E4B X-CRM114-Status: GOOD ( 17.08 ) 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 ---- 3 files changed, 7 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index 0e9b093adc6726770e0ff701ae9441ab31e448a5..7f187ac24e5d37369ef0af4154fdb17890f28798 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -380,7 +380,6 @@ 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 1765f723afd493255010c71d9bd4a2ddef819565..ee7c59f96451fcb217957c9fdbbd76046393bef3 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 081aca8f432ef3ee303feb437a9556a0e917d6c1..50e6f3fcc27cd35822246144c1e5f7761e316746 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -207,10 +207,6 @@ 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);