From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.15]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 5CEA01B21BC; Mon, 13 Jan 2025 19:28:15 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.15 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736796497; cv=none; b=LVKzQ1zMW9/wm905gOiQhvXoQ92Q8RDM6b7YN1eN/YNpUA9bDQDg74Rdey2Xtvd7E8lAtofnkFqmwl/C1glukn4X6BWjI9Ju9bqn870J2VsIEpmucsoZRbhHQFMjWXhGt6mU1t7j/C1KgHMfFHe9eCX1Q/R4wMyB0v4KDLLrx7E= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1736796497; c=relaxed/simple; bh=qK/UqylcwZbg+H1qXrkKeVQEmW/bacTD3dMGwHWzRaE=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=blmSAphbPNh24XttviH1rnsKeBsg9y38pCkDpYBWpqHjzKCrREaAZjZv2XsO+LYsJ6IQQyhGexnSBCKMehN7I5AqzWxUXaipq6y7ps4vqBn1wSxshPD84rJSdAzTW+JeiluOWOxBRT2r1fx7Oq6RRoh7+KQbkELMRdkAnnkVUIY= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com; spf=pass smtp.mailfrom=intel.com; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b=dU8pHlto; arc=none smtp.client-ip=198.175.65.15 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=intel.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=intel.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=intel.com header.i=@intel.com header.b="dU8pHlto" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1736796495; x=1768332495; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=qK/UqylcwZbg+H1qXrkKeVQEmW/bacTD3dMGwHWzRaE=; b=dU8pHltoQI+T2Ai0LcTVgG309RKSmghUQGfE6Xf6YeeG/mb7wzc917gb jAIeLap7oFodRPL3eZOmR/gsMvOaL5dl8I8f5KWvMoP1pOTmjEqL793vi n8hPy3YDN1Abx8nvdIrogZhAgiXXJWonePLY24Whzs75OXK1AbQsuuBkJ 7YvuIQ5w+kOBV3AaQMKkyvtELN4nUSI9QyS9jLbKA54WkH1qOX9+ra8bl 4NYloYw4yfPYDOpWAwQd76a6hv3szRdv6hGPZ+DOCcKTR8+VijxQ077E3 N7eg4k8myGFtYeUfCs+JmtC2Cssmdc2lilh51I9BRXjd/mJ2v14LENrC7 Q==; X-CSE-ConnectionGUID: FcgNUrXxQT2CXUdvt4Tesg== X-CSE-MsgGUID: Q8sjQSGoQIGZ6rImUCMcDg== X-IronPort-AV: E=McAfee;i="6700,10204,11314"; a="40752798" X-IronPort-AV: E=Sophos;i="6.12,312,1728975600"; d="scan'208";a="40752798" Received: from orviesa009.jf.intel.com ([10.64.159.149]) by orvoesa107.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jan 2025 11:28:15 -0800 X-CSE-ConnectionGUID: nTcjnS0ORv6RayhXdkIjJQ== X-CSE-MsgGUID: WYzs63liSOqC4imFQ+ZYVQ== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.12,312,1728975600"; d="scan'208";a="104343628" Received: from ahunter6-mobl1.ger.corp.intel.com (HELO [10.0.2.15]) ([10.246.16.163]) by orviesa009-auth.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 13 Jan 2025 11:28:10 -0800 Message-ID: Date: Mon, 13 Jan 2025 21:28:01 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [PATCH 4/7] KVM: TDX: restore host xsave state when exit from the guest TD To: Sean Christopherson Cc: Chao Gao , pbonzini@redhat.com, kvm@vger.kernel.org, dave.hansen@linux.intel.com, rick.p.edgecombe@intel.com, kai.huang@intel.com, reinette.chatre@intel.com, xiaoyao.li@intel.com, tony.lindgren@linux.intel.com, binbin.wu@linux.intel.com, dmatlack@google.com, isaku.yamahata@intel.com, nik.borisov@suse.com, linux-kernel@vger.kernel.org, x86@kernel.org, yan.y.zhao@intel.com, weijiang.yang@intel.com References: <20241121201448.36170-1-adrian.hunter@intel.com> <20241121201448.36170-5-adrian.hunter@intel.com> <487a32e6-54cd-43b7-bfa6-945c725a313d@intel.com> <96f7204b-6eb4-4fac-b5bb-1cd5c1fc6def@intel.com> Content-Language: en-US From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 9/01/25 21:11, Sean Christopherson wrote: > My vote would to KVM_BUG_ON() before entering the guest. I notice if KVM_BUG_ON() is called with interrupts disabled smp_call_function_many_cond() generates a warning: WARNING: CPU: 223 PID: 4213 at kernel/smp.c:807 smp_call_function_many_cond+0x421/0x560 static void smp_call_function_many_cond(const struct cpumask *mask, smp_call_func_t func, void *info, unsigned int scf_flags, smp_cond_func_t cond_func) { int cpu, last_cpu, this_cpu = smp_processor_id(); struct call_function_data *cfd; bool wait = scf_flags & SCF_WAIT; int nr_cpus = 0; bool run_remote = false; bool run_local = false; lockdep_assert_preemption_disabled(); /* * Can deadlock when called with interrupts disabled. * We allow cpu's that are not yet online though, as no one else can * send smp call function interrupt to this cpu and as such deadlocks * can't happen. */ if (cpu_online(this_cpu) && !oops_in_progress && !early_boot_irqs_disabled) lockdep_assert_irqs_enabled(); <------------- here Do we need to care about that?