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 7DB83C35FFC for ; Tue, 25 Mar 2025 11:41:05 +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=xe38b0Voso+oPam8VoUgY4Ac5inKyiuxiIxM4eBkb78=; b=lKez16ABfeNHlM3tU81L5BjtSS hqcSytDqWHJvM7J44+Tpo502r54Mm9vKI6hqYNng+PDlScUOl3kraMlI6m+eWgaBetwXQalkDkjB4 jKWeGsKlZ3IMTGcN9KSTKtNHmyFyuFo1zQspAZqItgTATBcekWU/E/7dhUJfRG16670tHbW+ETNNL jhoJ9+A1twFlVPpZdY00y8sZYmCx3o4zJ2+P7CramIWrTysmzJuYFYhFG2m5xNBwInT2lsbYYX9pY ChjeQxlGBwaggAtJIG1mw/NOHWaEq7EWTsjlbY1Vd5vItXQm72uyQnbYSPnZAdG54HjqHIZXJcmgg 76RSfVjg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.1 #2 (Red Hat Linux)) id 1tx2eL-00000005fKB-3AGX; Tue, 25 Mar 2025 11:40:53 +0000 Received: from nyc.source.kernel.org ([2604:1380:45d1:ec00::3]) by bombadil.infradead.org with esmtps (Exim 4.98.1 #2 (Red Hat Linux)) id 1tx2UN-00000005djU-1yH9 for linux-arm-kernel@lists.infradead.org; Tue, 25 Mar 2025 11:30:36 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by nyc.source.kernel.org (Postfix) with ESMTP id A9A56A4A681; Tue, 25 Mar 2025 11:25:05 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 38894C4CEE4; Tue, 25 Mar 2025 11:30:34 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1742902234; bh=9p26Ucq76mncIc0Qr9yGm+jGQhnsiQsxzsXsY8XHLk4=; h=Subject:To:Cc:From:Date:In-Reply-To:From; b=GCfmhugf2Q67WeyCMPzmWxsqKa44FcpnwK085Jcg0PBshwht+NRLtjIZ4MK7MoqqT gfotgnRCe4AOtAwN6wIEgXVzB+LSxIG8Wh8WYx+jqaiWwwoU9CYtpv8505UbkCeVss lcgL565YtO/qkNHv0AGQfT45z4MuPwJjvwbkLavw= Subject: Patch "KVM: arm64: Remove VHE host restore of CPACR_EL1.ZEN" has been added to the 6.6-stable tree To: broonie@kernel.org,catalin.marinas@arm.com,gregkh@linuxfoundation.org,james.morse@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: Tue, 25 Mar 2025 07:28:56 -0400 In-Reply-To: <20250321-stable-sve-6-6-v1-4-0b3a6a14ea53@kernel.org> Message-ID: <2025032556-docile-unknowing-7dec@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-20250325_043035_644736_0EDE5785 X-CRM114-Status: GOOD ( 20.57 ) 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 6.6-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-6.6 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 20:18:28 2025 From: Mark Brown Date: Fri, 21 Mar 2025 00:16:04 +0000 Subject: KVM: arm64: Remove VHE host restore of CPACR_EL1.ZEN 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 Message-ID: <20250321-stable-sve-6-6-v1-4-0b3a6a14ea53@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 @@ -717,8 +717,6 @@ struct kvm_vcpu_arch { /* vcpu running in HYP context */ #define VCPU_HYP_CONTEXT __vcpu_single_flag(iflags, BIT(7)) -/* 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 @@ -88,10 +88,6 @@ void kvm_arch_vcpu_load_fp(struct kvm_vc fpsimd_save_and_flush_cpu_state(); vcpu->arch.fp_state = 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) @@ -189,18 +185,6 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcp } 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-6.6/kvm-arm64-calculate-cptr_el2-traps-on-activating-traps.patch queue-6.6/regulator-check-that-dummy-regulator-has-been-probed-before-using-it.patch queue-6.6/kvm-arm64-eagerly-switch-zcr_el-1-2.patch queue-6.6/kvm-arm64-mark-some-header-functions-as-inline.patch queue-6.6/kvm-arm64-remove-host-fpsimd-saving-for-non-protected-kvm.patch queue-6.6/regulator-dummy-force-synchronous-probing.patch queue-6.6/kvm-arm64-refactor-exit-handlers.patch queue-6.6/kvm-arm64-unconditionally-save-flush-host-fpsimd-sve-sme-state.patch queue-6.6/kvm-arm64-remove-vhe-host-restore-of-cpacr_el1.smen.patch queue-6.6/kvm-arm64-remove-vhe-host-restore-of-cpacr_el1.zen.patch