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 32E30C282EC for ; Thu, 13 Mar 2025 16:17:26 +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=1e/wzRtkjEqmZ49m2uPgN+Qy63leIVB1XfPm2MOTT2M=; b=YUPPNjAAOmgmf9x1e4AOKfzmxI JR8aerN2tY4wPESGALC93eY+doTV5o8ZUzReWK7GMUVdgCcnkFkhwPKX0asxTNdP7FxTzqU9JcENA FsqCSMNPadgRD7CiL4n0l9SoUT9Y4FTPpvdBZ/PCNf8CWCV8oGSPIbi5jHIw3dbHvHRS6Pu/1GCJD d0t1cabGahRMwKGl0VSHauWFFKNbX84U53SauhIhTrV779EudKCRoBS2uOHfVC5jla09OSvBWyTi7 he9nTOQaSURDrMorWNaBbBW/mxg77xnwYfCKxaz5bjLpIqMPDStf+YiQCu1mYUnYAVl7TElU6p91G pKtWoStA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98 #2 (Red Hat Linux)) id 1tslFE-0000000BnQF-0GmE; Thu, 13 Mar 2025 16:17:16 +0000 Received: from nyc.source.kernel.org ([2604:1380:45d1:ec00::3]) by bombadil.infradead.org with esmtps (Exim 4.98 #2 (Red Hat Linux)) id 1tsl86-0000000BlZ0-30DT for linux-arm-kernel@lists.infradead.org; Thu, 13 Mar 2025 16:09:56 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id 0F884A470FE; Thu, 13 Mar 2025 16:04:24 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 33AE9C4CEDD; Thu, 13 Mar 2025 16:09:53 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1741882193; bh=KSITSAAWbQUBU7eirTkrbzwKHesmMZf0VeZkD7/lFC4=; h=Subject:To:Cc:From:Date:In-Reply-To:From; b=MdZ+pXe2ANhIhSSeTHK/wPZUn4XlX55W1TMvmBUZ8YluvzqCoMYjg9ukdRZy6vY6U C/umu7ul7pr8jQA5/LnWNmgfD1ib7Vnj198T3/lJexbP4XsKTsEaMmAAb74/yEavLY fR+mz9kbsnO9vgJIgBDJB0CeJrf/ibDhODm7TBcQ= Subject: Patch "KVM: arm64: Remove VHE host restore of CPACR_EL1.ZEN" has been added to the 6.13-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: Thu, 13 Mar 2025 17:09:29 +0100 In-Reply-To: <20250312-stable-sve-6-13-v1-4-c7ba07a6f4f7@kernel.org> Message-ID: <2025031329-unstuck-scapegoat-1ed4@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-20250313_090954_884846_8B354330 X-CRM114-Status: GOOD ( 19.65 ) 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 6.13-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-6.13 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >From stable+bounces-124195-greg=kroah.com@vger.kernel.org Thu Mar 13 00:50:19 2025 From: Mark Brown Date: Wed, 12 Mar 2025 23:49:12 +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: <20250312-stable-sve-6-13-v1-4-c7ba07a6f4f7@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 @@ -902,8 +902,6 @@ 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-6.13/kvm-arm64-remove-host-fpsimd-saving-for-non-protected-kvm.patch queue-6.13/kvm-arm64-mark-some-header-functions-as-inline.patch queue-6.13/kvm-arm64-eagerly-switch-zcr_el-1-2.patch queue-6.13/kvm-arm64-unconditionally-save-flush-host-fpsimd-sve-sme-state.patch queue-6.13/kvm-arm64-refactor-exit-handlers.patch queue-6.13/kvm-arm64-remove-vhe-host-restore-of-cpacr_el1.zen.patch queue-6.13/kvm-arm64-remove-vhe-host-restore-of-cpacr_el1.smen.patch queue-6.13/kvm-arm64-calculate-cptr_el2-traps-on-activating-traps.patch