From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mgamail.intel.com (mgamail.intel.com [198.175.65.19]) (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 426EEC13D; Wed, 13 Mar 2024 03:44:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=198.175.65.19 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710301457; cv=none; b=l8ZOJES6o+qCb8+Cfplh337gJvZXl4pu07c5WUaaTcPDM3hq7VaMwGeqaXHMe45GcqwIkkxkWR6vAdX4r26Hc+44kxI+tSRa0tGSHOfnWWcZrtO50XuNuQEUxZzY8JabxZaTHf239tl8v9sRV8XMWXRMALSStgN9FI9YU+Ur/r0= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1710301457; c=relaxed/simple; bh=D5dYzAQq3zwc2Ykhfu8CArrsHZ7nFWtA6rWbqjK8AYg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=dJzXw4gxEd1NFSmEfynj2VkslKhuTZoiUf+7EL90TbAVdWCpS+XEe4A1tfexcVbgCljUyE1sH9GsIdiQbiNUyEGh9d54B5KDaUeaWoIHnTr5K365QJKBoUBUfVaeiNMHY5U1eI7SCXWrFdP8f0fa5ZaygpDe+cAy4QiZQRNO7KY= 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=Mr0JILKU; arc=none smtp.client-ip=198.175.65.19 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="Mr0JILKU" DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1710301456; x=1741837456; h=message-id:date:mime-version:subject:to:cc:references: from:in-reply-to:content-transfer-encoding; bh=D5dYzAQq3zwc2Ykhfu8CArrsHZ7nFWtA6rWbqjK8AYg=; b=Mr0JILKU/4IBk7etTDAbVocvOmvvkEGoGbBq9V5ltC2yOQagGPCaNTrP JYO+sa5Y+nDPr4O91LWRJ10g4Iq3haIGsFu5PR5zYwBJRW5h7rwquJVbV jOcgXaHDWPsTRPZl+mI2Vt+1bpV1DUxz0MfS/hMGbP/B6taZ6dlUOWjbV UsGYUw5Dzd17pkVa5jQn0suOHiHwgIjkC6RTTAGY6btVxCZdagdTUYET5 oLfpE5eZZ+ddd5mgWxKUrz6xFXlOtI5Zptq0SrBQLmk3wrWo04xngBePb eSIcN3YklWIXQ7WX5cAVGhuNuZm6bTsuj78kdpTJ1qspjBKMQBwiMh1AT A==; X-IronPort-AV: E=McAfee;i="6600,9927,11011"; a="4911377" X-IronPort-AV: E=Sophos;i="6.07,119,1708416000"; d="scan'208";a="4911377" Received: from fmviesa007.fm.intel.com ([10.60.135.147]) by orvoesa111.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Mar 2024 20:44:15 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="6.07,119,1708416000"; d="scan'208";a="11661215" Received: from xiaoyaol-hp-g830.ccr.corp.intel.com (HELO [10.125.243.127]) ([10.125.243.127]) by fmviesa007-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 12 Mar 2024 20:44:11 -0700 Message-ID: Date: Wed, 13 Mar 2024 11:44:08 +0800 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 5/5] x86/virt/tdx: Export global metadata read infrastructure Content-Language: en-US To: Kai Huang , linux-kernel@vger.kernel.org, kvm@vger.kernel.org Cc: x86@kernel.org, dave.hansen@intel.com, kirill.shutemov@linux.intel.com, peterz@infradead.org, tglx@linutronix.de, bp@alien8.de, mingo@redhat.com, hpa@zytor.com, seanjc@google.com, pbonzini@redhat.com, isaku.yamahata@intel.com, jgross@suse.com References: From: Xiaoyao Li In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit On 3/1/2024 7:20 PM, Kai Huang wrote: > KVM will need to read a bunch of non-TDMR related metadata to create and > run TDX guests. Export the metadata read infrastructure for KVM to use. > > Specifically, export two helpers: > > 1) The helper which reads multiple metadata fields to a buffer of a > structure based on the "field ID -> structure member" mapping table. > > 2) The low level helper which just reads a given field ID. How about introducing a helper to read a single metadata field comparing to 1) instead of the low level helper. The low level helper tdx_sys_metadata_field_read() requires the data buf to be u64 *. So the caller needs to use a temporary variable and handle the memcpy when the field is less than 8 bytes. so why not expose a high level helper to read single field, e.g., +int tdx_sys_metadata_read_single(u64 field_id, int bytes, void *buf) +{ + return stbuf_read_sys_metadata_field(field_id, 0, bytes, buf); +} +EXPORT_SYMBOL_GPL(tdx_sys_metadata_read_single); > The two helpers cover cases when the user wants to cache a bunch of > metadata fields to a certain structure and when the user just wants to > query a specific metadata field on demand. They are enough for KVM to > use (and also should be enough for other potential users). > > Signed-off-by: Kai Huang > Reviewed-by: Kirill A. Shutemov > --- > arch/x86/include/asm/tdx.h | 22 ++++++++++++++++++++++ > arch/x86/virt/vmx/tdx/tdx.c | 25 ++++++++----------------- > 2 files changed, 30 insertions(+), 17 deletions(-) > > diff --git a/arch/x86/include/asm/tdx.h b/arch/x86/include/asm/tdx.h > index eba178996d84..709b9483f9e4 100644 > --- a/arch/x86/include/asm/tdx.h > +++ b/arch/x86/include/asm/tdx.h > @@ -116,6 +116,28 @@ static inline u64 sc_retry(sc_func_t func, u64 fn, > int tdx_cpu_enable(void); > int tdx_enable(void); > const char *tdx_dump_mce_info(struct mce *m); > + > +struct tdx_metadata_field_mapping { > + u64 field_id; > + int offset; > + int size; > +}; > + > +#define TD_SYSINFO_MAP(_field_id, _struct, _member) \ > + { .field_id = MD_FIELD_ID_##_field_id, \ > + .offset = offsetof(_struct, _member), \ > + .size = sizeof(typeof(((_struct *)0)->_member)) } > + > +/* > + * Read multiple global metadata fields to a buffer of a structure > + * based on the "field ID -> structure member" mapping table. > + */ > +int tdx_sys_metadata_read(const struct tdx_metadata_field_mapping *fields, > + int nr_fields, void *stbuf); > + > +/* Read a single global metadata field */ > +int tdx_sys_metadata_field_read(u64 field_id, u64 *data); > + > #else > static inline void tdx_init(void) { } > static inline int tdx_cpu_enable(void) { return -ENODEV; } > diff --git a/arch/x86/virt/vmx/tdx/tdx.c b/arch/x86/virt/vmx/tdx/tdx.c > index 4ee4b8cf377c..dc21310776ab 100644 > --- a/arch/x86/virt/vmx/tdx/tdx.c > +++ b/arch/x86/virt/vmx/tdx/tdx.c > @@ -251,7 +251,7 @@ static int build_tdx_memlist(struct list_head *tmb_list) > return ret; > } > > -static int read_sys_metadata_field(u64 field_id, u64 *data) > +int tdx_sys_metadata_field_read(u64 field_id, u64 *data) > { > struct tdx_module_args args = {}; > int ret; > @@ -270,6 +270,7 @@ static int read_sys_metadata_field(u64 field_id, u64 *data) > > return 0; > } > +EXPORT_SYMBOL_GPL(tdx_sys_metadata_field_read); > > /* Return the metadata field element size in bytes */ > static int get_metadata_field_bytes(u64 field_id) > @@ -295,7 +296,7 @@ static int stbuf_read_sys_metadata_field(u64 field_id, > if (WARN_ON_ONCE(get_metadata_field_bytes(field_id) != bytes)) > return -EINVAL; > > - ret = read_sys_metadata_field(field_id, &tmp); > + ret = tdx_sys_metadata_field_read(field_id, &tmp); > if (ret) > return ret; > > @@ -304,19 +305,8 @@ static int stbuf_read_sys_metadata_field(u64 field_id, > return 0; > } > > -struct field_mapping { > - u64 field_id; > - int offset; > - int size; > -}; > - > -#define TD_SYSINFO_MAP(_field_id, _struct, _member) \ > - { .field_id = MD_FIELD_ID_##_field_id, \ > - .offset = offsetof(_struct, _member), \ > - .size = sizeof(typeof(((_struct *)0)->_member)) } > - > -static int read_sys_metadata(const struct field_mapping *fields, int nr_fields, > - void *stbuf) > +int tdx_sys_metadata_read(const struct tdx_metadata_field_mapping *fields, > + int nr_fields, void *stbuf) > { > int i, ret; > > @@ -331,6 +321,7 @@ static int read_sys_metadata(const struct field_mapping *fields, int nr_fields, > > return 0; > } > +EXPORT_SYMBOL_GPL(tdx_sys_metadata_read); > > #define TD_SYSINFO_MAP_TDMR_INFO(_field_id, _member) \ > TD_SYSINFO_MAP(_field_id, struct tdx_tdmr_sysinfo, _member) > @@ -338,7 +329,7 @@ static int read_sys_metadata(const struct field_mapping *fields, int nr_fields, > static int get_tdx_tdmr_sysinfo(struct tdx_tdmr_sysinfo *tdmr_sysinfo) > { > /* Map TD_SYSINFO fields into 'struct tdx_tdmr_sysinfo': */ > - const struct field_mapping fields[] = { > + const struct tdx_metadata_field_mapping fields[] = { > TD_SYSINFO_MAP_TDMR_INFO(MAX_TDMRS, max_tdmrs), > TD_SYSINFO_MAP_TDMR_INFO(MAX_RESERVED_PER_TDMR, max_reserved_per_tdmr), > TD_SYSINFO_MAP_TDMR_INFO(PAMT_4K_ENTRY_SIZE, pamt_entry_size[TDX_PS_4K]), > @@ -347,7 +338,7 @@ static int get_tdx_tdmr_sysinfo(struct tdx_tdmr_sysinfo *tdmr_sysinfo) > }; > > /* Populate 'tdmr_sysinfo' fields using the mapping structure above: */ > - return read_sys_metadata(fields, ARRAY_SIZE(fields), tdmr_sysinfo); > + return tdx_sys_metadata_read(fields, ARRAY_SIZE(fields), tdmr_sysinfo); > } > > /* Calculate the actual TDMR size */