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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id BCE04C61DA4 for ; Thu, 16 Mar 2023 00:31:08 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233006AbjCPAbH (ORCPT ); Wed, 15 Mar 2023 20:31:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:33622 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231701AbjCPAbG (ORCPT ); Wed, 15 Mar 2023 20:31:06 -0400 Received: from mail-pg1-x534.google.com (mail-pg1-x534.google.com [IPv6:2607:f8b0:4864:20::534]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4FD7F88DAF; Wed, 15 Mar 2023 17:31:05 -0700 (PDT) Received: by mail-pg1-x534.google.com with SMTP id s17so30476pgv.4; Wed, 15 Mar 2023 17:31:05 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; t=1678926665; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:from:to:cc:subject:date:message-id:reply-to; bh=9KhrkJGSUOYiiVfotnNQfrQRu80N+GO4LCzY8Gnj/3w=; b=WB/xmzCsZRZtBIneo/AO01OwGLTrzzIQLgaUwzbND73RDg+PHC/zVOVnq3CrJHOlSc ++cFP2P+wFQzuZ+g4e04Dyj8WZQ+4n96gQNzpFvGmSzaWeTUsAdiTRyQbOpZKqVxn+oY yDP1LnIiYSeyvlhR53U5wE9LM2tyWJj94g4OSGAygyMlAbKEQ71n8+B5ZowXN07WRJXa NMD2sh4JrrS4pFPy59RNoGDrvKU+oRHnx49Dh2cg8t6dfAi5HnruloXaNPpXQISEiyCz HERy92y62Nn80x7R9As/vuFZlznBDV6PYVD/9oUjdujytkNa9Ym3pRrTqDKxVqRJGsZf WWSQ== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; t=1678926665; h=in-reply-to:content-disposition:mime-version:references:message-id :subject:cc:to:from:date:x-gm-message-state:from:to:cc:subject:date :message-id:reply-to; bh=9KhrkJGSUOYiiVfotnNQfrQRu80N+GO4LCzY8Gnj/3w=; b=js+Cl8h99J0yPqmReJpu0tKaVSlXPJJlD04vbQtHDXUVhba02JrO9s/Xk0Rj0b9v5+ K9/N35FGiTXjL8LT7hFQPhKroUlIBcb0/Oj1cKdRbmjEF/e0/+65/6D9SCXZK3zUnRqu HCj57iwRyWnbypOX3NYbsk57efGFIcoReggH9OXM26i1NXUala6izbTp2REe4GULThYn wVz+pSbcmbrJb02EiDE+fR4l5ZkF8MC8dKcHCU4xjzjoAe/Fy2JJ5WXkau5eWG6EJYT7 6DTweOp9AijE1S4wPKlbiI+Ls66NdyBvcFkXk073L1tvs8CL9txpNo9ECw1+8vEVmsI6 0Llg== X-Gm-Message-State: AO0yUKVUjZ4Y+rn8qfBYx7fgmDq8v+PcTllfj6GbnnUpTG94PhmTGEsg 1OpN4jydK+2GLlMAOBTwg9o= X-Google-Smtp-Source: AK7set/esHi5avqDM2fH/I0qVxsmqc3WYu3IkEKKVsSeLWv7mYXWdyRBXofbNOj9imT11r//7zi6Ow== X-Received: by 2002:aa7:9591:0:b0:625:290:e303 with SMTP id z17-20020aa79591000000b006250290e303mr1504683pfj.14.1678926664681; Wed, 15 Mar 2023 17:31:04 -0700 (PDT) Received: from localhost ([192.55.54.55]) by smtp.gmail.com with ESMTPSA id e4-20020a62ee04000000b00587fda4a260sm4100324pfi.9.2023.03.15.17.31.03 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 15 Mar 2023 17:31:04 -0700 (PDT) Date: Wed, 15 Mar 2023 17:31:02 -0700 From: Isaku Yamahata To: Kai Huang Cc: linux-kernel@vger.kernel.org, kvm@vger.kernel.org, linux-mm@kvack.org, dave.hansen@intel.com, peterz@infradead.org, tglx@linutronix.de, seanjc@google.com, pbonzini@redhat.com, dan.j.williams@intel.com, rafael.j.wysocki@intel.com, kirill.shutemov@linux.intel.com, ying.huang@intel.com, reinette.chatre@intel.com, len.brown@intel.com, tony.luck@intel.com, ak@linux.intel.com, isaku.yamahata@intel.com, chao.gao@intel.com, sathyanarayanan.kuppuswamy@linux.intel.com, david@redhat.com, bagasdotme@gmail.com, sagis@google.com, imammedo@redhat.com, isaku.yamahata@gmail.com Subject: Re: [PATCH v10 05/16] x86/virt/tdx: Add skeleton to enable TDX on demand Message-ID: <20230316003102.GB197448@ls.amr.corp.intel.com> References: MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: Precedence: bulk List-ID: X-Mailing-List: kvm@vger.kernel.org On Tue, Mar 07, 2023 at 03:13:50AM +1300, Kai Huang wrote: > +static int try_init_module_global(void) > +{ > + int ret; > + > + /* > + * The TDX module global initialization only needs to be done > + * once on any cpu. > + */ > + spin_lock(&tdx_global_init_lock); If I use tdx_cpu_enable() via kvm hardware_enable_all(), this function is called in the context IPI callback and the lockdep complains. Here is my patch to address it >From 0c4022ffe8cd68dfb455c418eb65538e4e100115 Mon Sep 17 00:00:00 2001 Message-Id: <0c4022ffe8cd68dfb455c418eb65538e4e100115.1678926123.git.isaku.yamahata@intel.com> In-Reply-To: References: From: Isaku Yamahata Date: Wed, 15 Mar 2023 14:26:37 -0700 Subject: [PATCH] x86/virt/vmx/tdx: Use raw spin lock instead of spin lock tdx_cpu_enable() can be called by IPI handler. The lockdep complains about spin lock as follows. Use raw spin lock. ============================= [ BUG: Invalid wait context ] 6.3.0-rc1-tdx-kvm-upstream+ #389 Not tainted ----------------------------- swapper/154/0 is trying to lock: ffffffffa7875e58 (tdx_global_init_lock){....}-{3:3}, at: tdx_cpu_enable+0x67/0x180 other info that might help us debug this: context-{2:2} no locks held by swapper/154/0. stack backtrace: Call Trace: dump_stack_lvl+0x64/0xb0 dump_stack+0x10/0x20 __lock_acquire+0x912/0xc30 lock_acquire.part.0+0x99/0x220 lock_acquire+0x60/0x170 _raw_spin_lock_irqsave+0x43/0x70 tdx_cpu_enable+0x67/0x180 vt_hardware_enable+0x3b/0x60 kvm_arch_hardware_enable+0xe7/0x2e0 hardware_enable_nolock+0x33/0x80 __flush_smp_call_function_queue+0xc4/0x590 generic_smp_call_function_single_interrupt+0x1a/0xb0 __sysvec_call_function+0x48/0x200 sysvec_call_function+0xad/0xd0 Signed-off-by: Isaku Yamahata --- arch/x86/virt/vmx/tdx/tdx.c | 7 ++++--- 1 file changed, 4 insertions(+), 3 deletions(-) diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c index 2ee37a5dedcf..e1c8ffad7406 100644 --- a/arch/x86/virt/vmx/tdx/tdx.c +++ b/arch/x86/virt/vmx/tdx/tdx.c @@ -41,7 +41,7 @@ static u32 tdx_guest_keyid_start __ro_after_init; static u32 tdx_nr_guest_keyids __ro_after_init; static unsigned int tdx_global_init_status; -static DEFINE_SPINLOCK(tdx_global_init_lock); +static DEFINE_RAW_SPINLOCK(tdx_global_init_lock); #define TDX_GLOBAL_INIT_DONE _BITUL(0) #define TDX_GLOBAL_INIT_FAILED _BITUL(1) @@ -349,6 +349,7 @@ static void tdx_trace_seamcalls(u64 level) static int try_init_module_global(void) { + unsigned long flags; u64 tsx_ctrl; int ret; @@ -356,7 +357,7 @@ static int try_init_module_global(void) * The TDX module global initialization only needs to be done * once on any cpu. */ - spin_lock(&tdx_global_init_lock); + raw_spin_lock_irqsave(&tdx_global_init_lock, flags); if (tdx_global_init_status & TDX_GLOBAL_INIT_DONE) { ret = tdx_global_init_status & TDX_GLOBAL_INIT_FAILED ? @@ -373,7 +374,7 @@ static int try_init_module_global(void) if (ret) tdx_global_init_status |= TDX_GLOBAL_INIT_FAILED; out: - spin_unlock(&tdx_global_init_lock); + raw_spin_unlock_irqrestore(&tdx_global_init_lock, flags); if (ret) { if (trace_boot_seamcalls) -- 2.25.1 -- Isaku Yamahata