From nobody Tue Sep 16 05:47:10 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id A5916C61DB3 for ; Fri, 6 Jan 2023 09:22:28 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233564AbjAFJWR (ORCPT ); Fri, 6 Jan 2023 04:22:17 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43898 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233028AbjAFJUW (ORCPT ); Fri, 6 Jan 2023 04:20:22 -0500 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 54C266B58B; Fri, 6 Jan 2023 01:20:21 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1672996821; x=1704532821; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=LJAXoIH5EY7acqY4mtQFvimkQPN5qKlFIb9dyMRhzXM=; b=eV0H27GQYlqMgaya4dgP2IlOXjLQCB+bVXLuARXTMjjPbyh5mhZpY0WC neVCAXjW36Qur9sAPUZwsRyrNUuHSj+aNlaK45qOwviAbg4KYZAdjrIlG t1YgcJ+AhM5DeMoh+HWD+zqQuLySUDosO+V3iKmzcxcL9M+c6WeHJAH43 +/8V7Xowz3yPdbLifJUae/I4M29sl2iwOyg+SLCQXieTS5oCLiQEcNsI5 UGk5PjhYV/vTJ4MCBfZdEilwQ9ImlR7D3n/BLo8jr1qwLffU3X3JHSfHy 6jSWFJoNpf3gLprST6iLDzuWXfEUrTKWJSfR1tgwHX/RD8NuiZxIyU2Gc Q==; X-IronPort-AV: E=McAfee;i="6500,9779,10581"; a="322511523" X-IronPort-AV: E=Sophos;i="5.96,304,1665471600"; d="scan'208";a="322511523" Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 06 Jan 2023 01:20:15 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=McAfee;i="6500,9779,10581"; a="719139403" X-IronPort-AV: E=Sophos;i="5.96,304,1665471600"; d="scan'208";a="719139403" Received: from unknown (HELO fred..) ([172.25.112.68]) by fmsmga008.fm.intel.com with ESMTP; 06 Jan 2023 01:20:15 -0800 From: Xin Li To: linux-kernel@vger.kernel.org, x86@kernel.org, kvm@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, dave.hansen@linux.intel.com, hpa@zytor.com, peterz@infradead.org, andrew.cooper3@citrix.com, seanjc@google.com, pbonzini@redhat.com, ravi.v.shankar@intel.com Subject: [RFC PATCH v2 17/32] x86/fred: add a page fault entry stub for FRED Date: Fri, 6 Jan 2023 00:56:02 -0800 Message-Id: <20230106085617.17248-18-xin3.li@intel.com> X-Mailer: git-send-email 2.34.1 In-Reply-To: <20230106085617.17248-1-xin3.li@intel.com> References: <20230106085617.17248-1-xin3.li@intel.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" From: "H. Peter Anvin (Intel)" Add a page fault entry stub for FRED. On a FRED system, the faulting address (CR2) is passed on the stack, to avoid the problem of transient state. Thus we get the page fault address from the stack instead of CR2. Signed-off-by: H. Peter Anvin (Intel) Signed-off-by: Xin Li --- arch/x86/include/asm/fred.h | 2 ++ arch/x86/mm/fault.c | 20 ++++++++++++++++++-- 2 files changed, 20 insertions(+), 2 deletions(-) diff --git a/arch/x86/include/asm/fred.h b/arch/x86/include/asm/fred.h index f4de2cdd1c7f..de300bda60ee 100644 --- a/arch/x86/include/asm/fred.h +++ b/arch/x86/include/asm/fred.h @@ -94,6 +94,8 @@ static __always_inline unsigned long fred_event_data(stru= ct pt_regs *regs) #define DEFINE_FRED_HANDLER(f) noinstr DECLARE_FRED_HANDLER(f) typedef DECLARE_FRED_HANDLER((*fred_handler)); =20 +DECLARE_FRED_HANDLER(fred_exc_page_fault); + #endif /* __ASSEMBLY__ */ =20 #endif /* CONFIG_X86_FRED */ diff --git a/arch/x86/mm/fault.c b/arch/x86/mm/fault.c index 7b0d4ab894c8..f31053f32048 100644 --- a/arch/x86/mm/fault.c +++ b/arch/x86/mm/fault.c @@ -33,6 +33,7 @@ #include /* kvm_handle_async_pf */ #include /* fixup_vdso_exception() */ #include +#include /* fred_event_data() */ =20 #define CREATE_TRACE_POINTS #include @@ -1528,9 +1529,10 @@ handle_page_fault(struct pt_regs *regs, unsigned lon= g error_code, } } =20 -DEFINE_IDTENTRY_RAW_ERRORCODE(exc_page_fault) +static __always_inline void page_fault_common(struct pt_regs *regs, + unsigned int error_code, + unsigned long address) { - unsigned long address =3D read_cr2(); irqentry_state_t state; =20 prefetchw(¤t->mm->mmap_lock); @@ -1577,3 +1579,17 @@ DEFINE_IDTENTRY_RAW_ERRORCODE(exc_page_fault) =20 irqentry_exit(regs, state); } + +DEFINE_IDTENTRY_RAW_ERRORCODE(exc_page_fault) +{ + page_fault_common(regs, error_code, read_cr2()); +} + +#ifdef CONFIG_X86_FRED + +DEFINE_FRED_HANDLER(fred_exc_page_fault) +{ + page_fault_common(regs, regs->orig_ax, fred_event_data(regs)); +} + +#endif /* CONFIG_X86_FRED */ --=20 2.34.1