From patchwork Tue Apr 8 18:10:03 2025 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Mark Brown X-Patchwork-Id: 14043708 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 0C341C36010 for ; Tue, 8 Apr 2025 20:58:00 +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=Qfc2Pi3v+Bb2gOAjnZ8Rj2WDjilYIvZCAJa0GQFdo30=; b=I+MLuvr1whMAvxglKu1aCYeA33 nH5TGZfDlrDkby8kqEpirzj7yf+ZVvCIFKFOe6ZaHg8fZQG2scTpvCubiDZim9o9ByD0jR70rxo7V G2cOqnEKHIojRg5OgpMqlypzvCflF5z70yQonu0XdmarspoevvwqCc1cYtaoQGNU7+4NZP4uVqG1z ocBu0ECz4baDTZYIPS+AYVLsciOGQMmmdOTY+Q2jbfoqvnWgOY2hy5EsDLI0zGC9a7ELxzLNwhijG Y8c8Cqycb1C3STTAAEZ2ki1k+uMAEQwqRAHpTFzI3OXk9tNjwJsEnyew8yRh2cJrS8mTS4DQo7wVs r9d55ONQ==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1u2G10-00000005O8q-0CIC; Tue, 08 Apr 2025 20:57:50 +0000 Received: from nyc.source.kernel.org ([147.75.193.91]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1u2Dat-000000055wQ-3TTh for linux-arm-kernel@lists.infradead.org; Tue, 08 Apr 2025 18:22:45 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id 7AEEBA48FE7; Tue, 8 Apr 2025 18:17:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 0E306C4CEE5; Tue, 8 Apr 2025 18:22:39 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1744136562; bh=e9qvF2o7uVNtfQASnyy4CdQbnEmB3uPMMDe207tDMbc=; h=From:Date:Subject:References:In-Reply-To:To:Cc:From; b=FQDJhzAfb7nvmMDonzRGZJgcy6Hot1cEy7VNFNxuAqjrYmWQfOQ/YXgmeQFwCyXya C2BIPGW6heAsTP2wRczA/JlbvT3d/oNXfevVyCytTS6AHm4u9DOIYBVZbJn+rZ8Y1b /GOQtcRzpfA3nDGV00J+WNySrrBsIpXhXGWlrgudmvuiHKA+xGeBPPRohP+KYDmyHZ UzxFehpSsMSwgkGUvmvz1xApLOPs8zpkHX3V6bLNoaTOH2nfc1p+gX/9mfTcBCSyX3 aqQcPwupK2Q1xqwrLpPb4ZXP4ZlTIiCxbGj6zO0fIl8Pevrpv3cT1Ei6IrGcJG5bf5 Y1aVEKElsJN/w== From: Mark Brown Date: Tue, 08 Apr 2025 19:10:03 +0100 Subject: [PATCH 5.15 v3 08/11] KVM: arm64: Remove host FPSIMD saving for non-protected KVM MIME-Version: 1.0 Message-Id: <20250408-stable-sve-5-15-v3-8-ca9a6b850f55@kernel.org> References: <20250408-stable-sve-5-15-v3-0-ca9a6b850f55@kernel.org> In-Reply-To: <20250408-stable-sve-5-15-v3-0-ca9a6b850f55@kernel.org> To: Greg Kroah-Hartman , Marc Zyngier , James Morse , Suzuki K Poulose , Catalin Marinas , Will Deacon , Oleg Nesterov , Oliver Upton Cc: linux-arm-kernel@lists.infradead.org, kvmarm@lists.cs.columbia.edu, linux-kernel@vger.kernel.org, stable@vger.kernel.org, Mark Brown , Mark Rutland , Fuad Tabba X-Mailer: b4 0.15-dev-c25d1 X-Developer-Signature: v=1; a=openpgp-sha256; l=2943; i=broonie@kernel.org; h=from:subject:message-id; bh=IYSm9LOHiakFHli8QpJhz4RyCAaedNNXODj93c0ElHY=; b=owEBbQGS/pANAwAKASTWi3JdVIfQAcsmYgBn9WlR+WNqKkh3Yl7jjk3LaM97k5ATftDWIUcZmY0+ QpFoGXqJATMEAAEKAB0WIQSt5miqZ1cYtZ/in+ok1otyXVSH0AUCZ/VpUQAKCRAk1otyXVSH0Lm+B/ 9XV/VfIVsrLFZ3h9eV9VQQQ5JX1xethAlNJ5u1v2QLLnuurnmNtvzXNIImCzIoJkxm9DlWYyzZvujq F26k5SWKIP0aF0uFjop96gXh/LTheFP0+8D744GZNHd2EQK7g6p7MZogkl9Z9wq6tAzdfbnmgijDkQ R3ZiltSus/XaiY2GkIryApFcCMsaO0M/fFShD6NJDWDi4pUn1CNaiZX9aVqURPmretvym1yy8gFCNJ 8TLiS/n3UvECm0dmUw+O2de6yk0+fUiSVNNbKQYKZ7LrSi+XfEBr8Mz5+qQBr0jmGLd68Q81yrPJ+f sSADzc8K5JZqllM3epXaqhQF2D4dsG 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-20250408_112243_999557_6B8B66B0 X-CRM114-Status: GOOD ( 15.43 ) 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 | 1 - arch/arm64/kvm/hyp/include/hyp/switch.h | 6 +----- 3 files changed, 1 insertion(+), 7 deletions(-) diff --git a/arch/arm64/include/asm/kvm_host.h b/arch/arm64/include/asm/kvm_host.h index ecae31b0dab3..06e8d4645ecd 100644 --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -333,7 +333,6 @@ struct kvm_vcpu_arch { struct kvm_guest_debug_arch external_debug_state; struct thread_info *host_thread_info; /* hyp VA */ - struct user_fpsimd_state *host_fpsimd_state; /* hyp VA */ struct { /* {Break,watch}point registers */ diff --git a/arch/arm64/kvm/fpsimd.c b/arch/arm64/kvm/fpsimd.c index 2afa2521bce1..1ef9d6cb91ee 100644 --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -55,7 +55,6 @@ int kvm_arch_vcpu_run_map_fp(struct kvm_vcpu *vcpu) } vcpu->arch.host_thread_info = kern_hyp_va(ti); - vcpu->arch.host_fpsimd_state = kern_hyp_va(fpsimd); error: return ret; } diff --git a/arch/arm64/kvm/hyp/include/hyp/switch.h b/arch/arm64/kvm/hyp/include/hyp/switch.h index 269ec3587210..cc102e46b0e2 100644 --- a/arch/arm64/kvm/hyp/include/hyp/switch.h +++ b/arch/arm64/kvm/hyp/include/hyp/switch.h @@ -251,11 +251,7 @@ static inline bool __hyp_handle_fpsimd(struct kvm_vcpu *vcpu) } isb(); - if (vcpu->arch.flags & KVM_ARM64_FP_HOST) { - __fpsimd_save_state(vcpu->arch.host_fpsimd_state); - vcpu->arch.flags &= ~KVM_ARM64_FP_HOST; - } - + /* Restore the guest state */ if (sve_guest) __hyp_sve_restore_guest(vcpu); else