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 85932C369C2 for ; Tue, 22 Apr 2025 07:11:57 +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=GPkG9oHAGqVTIXRnI2VOGFD2pdAVqslL2AXf/JrzedI=; b=xCdjt5bzXUZOli6YOJIi5V1ZkA +cf2Q4kNR+bI0fRLp9aL86HrfrKY4bI08GTAwSTEWaS/SFnm9TtvQSEPSGahddQvMWB5mKJgvC1aK T+yXOcx9ZICLuSWTH9dWeacZKtAGp4Tk0sg9xITPJetQ0jXFCAYkTAF7IApL73foF3IcYnQeQXKZj IrYEA+/KQX1zgf6pi747VCEG2vFg6zGocj1UcGaRcIUAKKiiltImNvLdjQfkYDUVpP8fHm/FmfEPo K5s9Mfh5+URR9YccJX93yMhxCPECC3qLQKMbgyvo1hnuJG/nAs3yc9uhsHYqRLTRDNMn/TF+LgO44 6dRUYhQw==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.98.2 #2 (Red Hat Linux)) id 1u77nF-0000000651S-17fJ; Tue, 22 Apr 2025 07:11:45 +0000 Received: from dfw.source.kernel.org ([139.178.84.217]) by bombadil.infradead.org with esmtps (Exim 4.98.2 #2 (Red Hat Linux)) id 1u77Nl-000000061PF-3TIF for linux-arm-kernel@lists.infradead.org; Tue, 22 Apr 2025 06:45:27 +0000 Received: from smtp.kernel.org (transwarp.subspace.kernel.org [100.75.92.58]) by dfw.source.kernel.org (Postfix) with ESMTP id 689115C59C5; Tue, 22 Apr 2025 06:43:07 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7911EC4CEEA; Tue, 22 Apr 2025 06:45:23 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1745304323; bh=ThtEtJhwulDTi/Q73gJnIpEtvkNpQeP47zssn9oX/IQ=; h=Subject:To:Cc:From:Date:In-Reply-To:From; b=rQArGvj8pT0MwClKbSVAF3w0qWKo7f3CwKuzkX6Y27/iaz4e0O/11Gl/1qBFT6T7a ksNe9BOr8sdvIiPbDcoGeIF8lUXEdIOhDa0qSXgu5+ILTFQGYVc/4dhY2w19jGXRiK TR1MhHqvNSSiVBn+IxKwHvpdUVeeQsR/9eIMiYM0= Subject: Patch "arm64/fpsimd: Stop using TIF_SVE to manage register saving in KVM" has been added to the 5.15-stable tree To: broonie@kernel.org,catalin.marinas@arm.com,gregkh@linuxfoundation.org,james.morse@arm.com,kvmarm@lists.cs.columbia.edu,linux-arm-kernel@lists.infradead.org,mark.rutland@arm.com,maz@kernel.org,oleg@redhat.com,oliver.upton@linux.dev,suzuki.poulose@arm.com,will@kernel.org Cc: From: Date: Tue, 22 Apr 2025 08:45:13 +0200 In-Reply-To: <20250408-stable-sve-5-15-v3-6-ca9a6b850f55@kernel.org> Message-ID: <2025042213-provided-saint-00b7@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-20250421_234525_959044_AEA43710 X-CRM114-Status: GOOD ( 22.07 ) 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 arm64/fpsimd: Stop using TIF_SVE to manage register saving in KVM to the 5.15-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: arm64-fpsimd-stop-using-tif_sve-to-manage-register-saving-in-kvm.patch and it can be found in the queue-5.15 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 Tue Apr 8 20:22:36 2025 From: Mark Brown Date: Tue, 08 Apr 2025 19:10:01 +0100 Subject: arm64/fpsimd: Stop using TIF_SVE to manage register saving in KVM 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 Message-ID: <20250408-stable-sve-5-15-v3-6-ca9a6b850f55@kernel.org> From: Mark Brown [ Upstream commit 62021cc36add7b2c015b837f7893f2fb4b8c2586 ] Now that we are explicitly telling the host FP code which register state it needs to save we can remove the manipulation of TIF_SVE from the KVM code, simplifying it and allowing us to optimise our handling of normal tasks. Remove the manipulation of TIF_SVE from KVM and instead rely on to_save to ensure we save the correct data for it. There should be no functional or performance impact from this change. Signed-off-by: Mark Brown Reviewed-by: Catalin Marinas Reviewed-by: Marc Zyngier Link: https://lore.kernel.org/r/20221115094640.112848-5-broonie@kernel.org Signed-off-by: Will Deacon [ Mark: trivial backport ] Signed-off-by: Mark Rutland Signed-off-by: Mark Brown Signed-off-by: Greg Kroah-Hartman --- arch/arm64/kernel/fpsimd.c | 40 ++++++++++++++++------------------------ arch/arm64/kvm/fpsimd.c | 3 --- 2 files changed, 16 insertions(+), 27 deletions(-) --- a/arch/arm64/kernel/fpsimd.c +++ b/arch/arm64/kernel/fpsimd.c @@ -318,7 +318,13 @@ static void task_fpsimd_load(void) /* * Ensure FPSIMD/SVE storage in memory for the loaded context is up to - * date with respect to the CPU registers. + * date with respect to the CPU registers. Note carefully that the + * current context is the context last bound to the CPU stored in + * last, if KVM is involved this may be the guest VM context rather + * than the host thread for the VM pointed to by current. This means + * that we must always reference the state storage via last rather + * than via current, if we are saving KVM state then it will have + * ensured that the type of registers to save is set in last->to_save. */ static void fpsimd_save(void) { @@ -334,9 +340,15 @@ static void fpsimd_save(void) if (test_thread_flag(TIF_FOREIGN_FPSTATE)) return; - if (IS_ENABLED(CONFIG_ARM64_SVE) && - test_thread_flag(TIF_SVE)) { - if (WARN_ON(sve_get_vl() != last->sve_vl)) { + if ((last->to_save == FP_STATE_CURRENT && test_thread_flag(TIF_SVE)) || + last->to_save == FP_STATE_SVE) { + save_sve_regs = true; + vl = last->sve_vl; + } + + if (IS_ENABLED(CONFIG_ARM64_SVE) && save_sve_regs) { + /* Get the configured VL from RDVL, will account for SM */ + if (WARN_ON(sve_get_vl() != vl)) { /* * Can't save the user regs, so current would * re-enter user with corrupt state. @@ -347,26 +359,6 @@ static void fpsimd_save(void) } } - if (test_thread_flag(TIF_SVE)) { - save_sve_regs = true; - vl = last->sve_vl; - } - - /* - * Validate that an explicitly specified state to save is - * consistent with the task state. - */ - switch (last->to_save) { - case FP_STATE_CURRENT: - break; - case FP_STATE_FPSIMD: - WARN_ON_ONCE(save_sve_regs); - break; - case FP_STATE_SVE: - WARN_ON_ONCE(!save_sve_regs); - break; - } - if (IS_ENABLED(CONFIG_ARM64_SVE) && save_sve_regs) { sve_save_state((char *)last->sve_state + sve_ffr_offset(last->sve_vl), --- a/arch/arm64/kvm/fpsimd.c +++ b/arch/arm64/kvm/fpsimd.c @@ -110,7 +110,6 @@ void kvm_arch_vcpu_ctxsync_fp(struct kvm &vcpu->arch.fp_type, fp_type); clear_thread_flag(TIF_FOREIGN_FPSTATE); - update_thread_flag(TIF_SVE, vcpu_has_sve(vcpu)); } } @@ -151,7 +150,5 @@ void kvm_arch_vcpu_put_fp(struct kvm_vcp sysreg_clear_set(CPACR_EL1, CPACR_EL1_ZEN_EL0EN, 0); } - update_thread_flag(TIF_SVE, 0); - local_irq_restore(flags); } Patches currently in stable-queue which might be from broonie@kernel.org are queue-5.15/kvm-arm64-remove-host-fpsimd-saving-for-non-protected-kvm.patch queue-5.15/spi-cadence-qspi-fix-probe-on-am62a-lp-sk.patch queue-5.15/asoc-qdsp6-q6asm-dai-fix-q6asm_dai_compr_set_params-error-path.patch queue-5.15/kvm-arm64-eagerly-switch-zcr_el-1-2.patch queue-5.15/kvm-arm64-unconditionally-save-flush-host-fpsimd-sve-sme-state.patch queue-5.15/kvm-arm64-always-start-with-clearing-sve-flag-on-load.patch queue-5.15/asoc-codecs-lpass-wsa-macro-fix-vi-feedback-rate.patch queue-5.15/arm64-fpsimd-track-the-saved-fpsimd-state-type-separately-to-tif_sve.patch queue-5.15/kvm-arm64-get-rid-of-host-sve-tracking-saving.patch queue-5.15/kvm-arm64-remove-vhe-host-restore-of-cpacr_el1.zen.patch queue-5.15/asoc-fsl_audmix-register-card-device-depends-on-dais.patch queue-5.15/arm64-fpsimd-have-kvm-explicitly-say-which-fp-registers-to-save.patch queue-5.15/kvm-arm64-discard-any-sve-state-when-entering-kvm-guests.patch queue-5.15/arm64-fpsimd-stop-using-tif_sve-to-manage-register-saving-in-kvm.patch queue-5.15/asoc-codecs-lpass-wsa-macro-fix-logic-of-enabling-vi-channels.patch queue-5.15/kvm-arm64-calculate-cptr_el2-traps-on-activating-traps.patch