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 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 AB82FC36008 for ; Mon, 24 Mar 2025 19:39:12 +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:Content-Transfer-Encoding: Content-Type:MIME-Version:Message-ID:In-Reply-To:Date:From:Cc:To:Subject: Reply-To:Content-ID:Content-Description:Resent-Date:Resent-From:Resent-Sender :Resent-To:Resent-Cc:Resent-Message-ID:References:List-Owner; bh=dMfQea7xSO0kQipkV+BSfV7TUzpMwwNyiKkQPOfAfYg=; b=NmPfVONCVQc9bgGvx1MUsmhuvt 2fIT1dY/vK4SYmQFgZzEQvhRm+kfojGBLHq5J7J51ptlYubetAx25HqK6zwJWu/Q011z3RRJD+PVj viLjWMzMcWjTI6jECqREsSiNyj8HZ0wmgebvT676/2Md+08zjg1BSMO9Ui4qe3Oat34omA2ydV5uR 6yKpAJnkIEA4r2qNmr7DXbQnOWpDui5lKjziRmW+zDtwoSP6UOjRFoMEedF9EOD+84cNPFUMox6hs SZbIXcSkq91xztfDSDs7iXTy0TeqTM+6bCv3GOXe4AWfvyQIQqpU1nwzZa5AR31+GPXhp0R0sCL8G OTO/Tytg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1twndY-0000000466w-0vuS; Mon, 24 Mar 2025 19:39:04 +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 1twn2R-000000040YW-1aOE for linux-arm-kernel@lists.infradead.org; Mon, 24 Mar 2025 19:00:45 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id DB51F5C014A; Mon, 24 Mar 2025 18:58:25 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 63592C4CEE4; Mon, 24 Mar 2025 19:00:42 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1742842842; bh=J2S+Lv5BWjXt0yK/pyBR8FIhxgiGWlr1lgLVl1VE8bM=; h=Subject:To:Cc:From:Date:In-Reply-To:From; b=05HgBDQeslUIUY/vJ1dLJYwJvx06M1BHpFtq2SPcG/JnnDUcnGl/yLWXUtKX/1Dq9 g1g9z3zdTkWAEi7bHcAah0n21MBlcXw3NJ/9XbnZBhG8X87UqWBrvbyOWGtRQ2GNGQ FRBXjdmjTUmC0KF5ahknL4R3K/xUOU6gynRK2RiU= Subject: Patch "KVM: arm64: Remove VHE host restore of CPACR_EL1.ZEN" has been added to the 6.12-stable tree To: broonie@kernel.org,catalin.marinas@arm.com,gregkh@linuxfoundation.org,joey.gouly@arm.com,kvmarm@lists.linux.dev,linux-arm-kernel@lists.infradead.org,mark.rutland@arm.com,maz@kernel.org,oliver.upton@linux.dev,suzuki.poulose@arm.com,tabba@google.com,will@kernel.org Cc: From: Date: Mon, 24 Mar 2025 11:59:05 -0700 In-Reply-To: <20250321-stable-sve-6-12-v2-4-417ca2278d18@kernel.org> Message-ID: <2025032405-dizzy-promotion-0062@gregkh> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit X-stable: commit X-Patchwork-Hint: ignore X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20250324_120043_513299_AA980ED5 X-CRM114-Status: GOOD ( 20.05 ) 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 This is a note to let you know that I've just added the patch titled KVM: arm64: Remove VHE host restore of CPACR_EL1.ZEN to the 6.12-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: kvm-arm64-remove-vhe-host-restore-of-cpacr_el1.zen.patch and it can be found in the queue-6.12 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >From broonie@kernel.org Thu Mar 20 17:13:41 2025 From: Mark Brown Date: Fri, 21 Mar 2025 00:13:00 +0000 Subject: KVM: arm64: Remove VHE host restore of CPACR_EL1.ZEN To: Greg Kroah-Hartman , Marc Zyngier , Oliver Upton , Joey Gouly , 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 Message-ID: <20250321-stable-sve-6-12-v2-4-417ca2278d18@kernel.org> From: Mark Rutland [ Upstream commit 459f059be702056d91537b99a129994aa6ccdd35 ] When KVM is in VHE mode, the host kernel tries to save and restore the configuration of CPACR_EL1.ZEN (i.e. CPTR_EL2.ZEN when HCR_EL2.E2H=1) across kvm_arch_vcpu_load_fp() and kvm_arch_vcpu_put_fp(), since the configuration may be clobbered by hyp when running a vCPU. This logic is currently redundant. The VHE hyp code unconditionally configures CPTR_EL2.ZEN to 0b01 when returning to the host, permitting host kernel usage of SVE. Now that the host eagerly saves and unbinds its own FPSIMD/SVE/SME state, there's no need to save/restore the state of the EL0 SVE trap. The kernel can safely save/restore state without trapping, as described above, and will restore userspace state (including trap controls) before returning to userspace. Remove the redundant logic. 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/20250210195226.1215254-4-mark.rutland@arm.com Signed-off-by: Marc Zyngier [Rework for refactoring of where the flags are stored -- broonie] Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- arch/arm64/include/asm/kvm_host.h | 2 -- arch/arm64/kvm/fpsimd.c | 16 ---------------- 2 files changed, 18 deletions(-) --- a/arch/arm64/include/asm/kvm_host.h +++ b/arch/arm64/include/asm/kvm_host.h @@ -891,8 +891,6 @@ struct kvm_vcpu_arch { /* Save TRBE context if active */ #define DEBUG_STATE_SAVE_TRBE __vcpu_single_flag(iflags, BIT(6)) -/* SVE enabled for host EL0 */ -#define HOST_SVE_ENABLED __vcpu_single_flag(sflags, BIT(0)) /* SME enabled for EL0 */ #define HOST_SME_ENABLED __vcpu_single_flag(sflags, BIT(1)) /* Physical CPU not in supported_cpus */ --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -65,10 +65,6 @@ void kvm_arch_vcpu_load_fp(struct kvm_vc fpsimd_save_and_flush_cpu_state(); *host_data_ptr(fp_owner) = FP_STATE_FREE; - vcpu_clear_flag(vcpu, HOST_SVE_ENABLED); - if (read_sysreg(cpacr_el1) & CPACR_EL1_ZEN_EL0EN) - vcpu_set_flag(vcpu, HOST_SVE_ENABLED); - if (system_supports_sme()) { vcpu_clear_flag(vcpu, HOST_SME_ENABLED); if (read_sysreg(cpacr_el1) & CPACR_EL1_SMEN_EL0EN) @@ -202,18 +198,6 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcp * when needed. */ fpsimd_save_and_flush_cpu_state(); - } else if (has_vhe() && system_supports_sve()) { - /* - * The FPSIMD/SVE state in the CPU has not been touched, and we - * have SVE (and VHE): CPACR_EL1 (alias CPTR_EL2) has been - * reset by kvm_reset_cptr_el2() in the Hyp code, disabling SVE - * for EL0. To avoid spurious traps, restore the trap state - * seen by kvm_arch_vcpu_load_fp(): - */ - if (vcpu_get_flag(vcpu, HOST_SVE_ENABLED)) - sysreg_clear_set(CPACR_EL1, 0, CPACR_EL1_ZEN_EL0EN); - else - sysreg_clear_set(CPACR_EL1, CPACR_EL1_ZEN_EL0EN, 0); } local_irq_restore(flags); Patches currently in stable-queue which might be from broonie@kernel.org are queue-6.12/kvm-arm64-calculate-cptr_el2-traps-on-activating-traps.patch queue-6.12/regulator-check-that-dummy-regulator-has-been-probed-before-using-it.patch queue-6.12/kvm-arm64-eagerly-switch-zcr_el-1-2.patch queue-6.12/kvm-arm64-mark-some-header-functions-as-inline.patch queue-6.12/kvm-arm64-remove-host-fpsimd-saving-for-non-protected-kvm.patch queue-6.12/regulator-dummy-force-synchronous-probing.patch queue-6.12/kvm-arm64-refactor-exit-handlers.patch queue-6.12/kvm-arm64-unconditionally-save-flush-host-fpsimd-sve-sme-state.patch queue-6.12/kvm-arm64-remove-vhe-host-restore-of-cpacr_el1.smen.patch queue-6.12/kvm-arm64-remove-vhe-host-restore-of-cpacr_el1.zen.patch