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 41091CD5BAC for ; Thu, 21 May 2026 13:26:28 +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: MIME-Version:References:In-Reply-To:Message-Id:Date:Subject:Cc:To:From: Reply-To:Content-Type:Content-ID:Content-Description:Resent-Date:Resent-From: Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=DGUgQC8U9j93xMce/C73Qa1eK3CV/OLG54Lqchw1M1Q=; b=JUQ/yIc9ip5PoE3KVIHYh91uqE VrZuVqkgW8J8VI6ErMIWTtLINyZgexQbn8lV9h2dihK9QrJcjT7AsNODbOqC0UHKVHMVHt81K+y+n 9uQ+k1klDpv05qS0GMP4ptafBqSecf5p+Blr5eumUsIzrz+OateL5VTCouxHBwDJWvxSlIv4JZmvh MqSuxOl/gcBF0FxOfv4gnT4hdpuBzPJL9AR0CJJc7SXJHZYobUutEl8o/NlVDdq6DD3bOHIOZV/Wv ZTiSLPa0b4+d5lDHUQ3QaC3lbUj52X3xhxsU5UNRCsFmkUEp+pkMAF3U3nJIBTvn0Wx8cZQo9W2QU TRHnC+WA==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wQ3Pq-00000007rum-1Vpw; Thu, 21 May 2026 13:26:22 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.99.1 #2 (Red Hat Linux)) id 1wQ3Pf-00000007rqA-0y48 for linux-arm-kernel@lists.infradead.org; Thu, 21 May 2026 13:26:12 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 6E9E43585; Thu, 21 May 2026 06:26:04 -0700 (PDT) Received: from lakrids.cambridge.arm.com (usa-sjc-imap-foss1.foss.arm.com [10.121.207.14]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPA id 383383F7B4; Thu, 21 May 2026 06:26:08 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=simple/simple; d=arm.com; s=foss; t=1779369969; bh=GD2Z64GQx9VlwmIyMGKKYTOCh00j0sXnGkP8oGm4WOg=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=rOvYu1PR611KpFAlzCWniwnRZDgQHVXxtR7KrWHOdRKMQ4I63j3qP89eV774XFjk3 Sb9CX4oSorX1u4LR2o5a1hyAKmnqXO4AEXIiVT4DTwNrVKmHMrfKu/XEBcyZ7lIvoU FnxUkg6VcUrh83WjDjKFbxElMXcRm0chg/CDJC0s= From: Mark Rutland To: linux-arm-kernel@lists.infradead.org, kvmarm@lists.linux.dev Cc: broonie@kernel.org, catalin.marinas@arm.com, james.morse@arm.com, mark.rutland@arm.com, maz@kernel.org, oupton@kernel.org, tabba@google.com, will@kernel.org Subject: [PATCH 02/18] KVM: arm64: Don't override FFR save/restore argument Date: Thu, 21 May 2026 14:25:40 +0100 Message-Id: <20260521132556.584676-3-mark.rutland@arm.com> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20260521132556.584676-1-mark.rutland@arm.com> References: <20260521132556.584676-1-mark.rutland@arm.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.9.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20260521_062611_318123_09872716 X-CRM114-Status: GOOD ( 11.59 ) 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 The __sve_save_state() and __sve_restore_state() functions take a parameter describing whether to save/restore the FFR, but both functions silently override this with '1'. This has always been benign (and callers have all passed 'true' since the parameter was introduced), but clearly this is not intentional. Historically, the functions always saved/restored the FFR, and there was no parameter to control this. In v5.16, the sve_save and sve_load assembly macros used by __sve_save_state() and __sve_restore_state() were changed to make saving/restoring FFR optional. The implementations of __sve_save_state() and __sve_restore_state() were changed to pass '1' to their respective macros, and the prototypes of __sve_save_state() and __sve_restore_state() were unchanged. See commit: 9f5848665788 ("arm64/sve: Make access to FFR optional") In v6.10, the prototypes of __sve_save_state() and __sve_restore_state() were changed to add 'save_ffr' and 'restore_ffr' parameters respectively, but the implementations were not changed to stop passing 1 to their respective macros. All callers were changed to pass 'true' to __sve_save_state() and __sve_restore_state(). See commit: 45f4ea9bcfe9 ("KVM: arm64: Fix prototype for __sve_save_state/__sve_restore_state") This is all benign, but clearly unintentional, and it gets in the way of cleaning up the FPSIMD/SVE/SME code. Remove the unnecessary overriding. Signed-off-by: Mark Rutland Cc: Catalin Marinas Cc: Fuad Tabba Cc: James Morse Cc: Marc Zyngier Cc: Mark Brown Cc: Oliver Upton Cc: Will Deacon --- arch/arm64/kvm/hyp/fpsimd.S | 2 -- 1 file changed, 2 deletions(-) diff --git a/arch/arm64/kvm/hyp/fpsimd.S b/arch/arm64/kvm/hyp/fpsimd.S index e950875e31cee..6e16cbfc5df27 100644 --- a/arch/arm64/kvm/hyp/fpsimd.S +++ b/arch/arm64/kvm/hyp/fpsimd.S @@ -21,13 +21,11 @@ SYM_FUNC_START(__fpsimd_restore_state) SYM_FUNC_END(__fpsimd_restore_state) SYM_FUNC_START(__sve_restore_state) - mov x2, #1 sve_load 0, x1, x2, 3 ret SYM_FUNC_END(__sve_restore_state) SYM_FUNC_START(__sve_save_state) - mov x2, #1 sve_save 0, x1, x2, 3 ret SYM_FUNC_END(__sve_save_state) -- 2.30.2