From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mga14.intel.com (mga14.intel.com [192.55.52.115]) (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 C342F33F2 for ; Fri, 9 Dec 2022 13:25:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=intel.com; i=@intel.com; q=dns/txt; s=Intel; t=1670592340; x=1702128340; h=from:to:cc:subject:date:message-id:in-reply-to: references:mime-version:content-transfer-encoding; bh=5keQeb9S+KFaicFjIjAGLohVdO9xiTEtldY0S8UVDYw=; b=QgU9iTsGlSUi+eeDAT/D/4fIQM2sDaOBZzKxkO5tekR38kn+OM1/wUtd KuZ86idVpfNXDop5uU6YNQhwDm0f+bCWDykoz3V9h9f9WNppvxPbciqP8 j8ACoE2RNvZPqHO9mRHrGNhJ1uHiJTXHcB91yFw3XolUJOnbZuQjBFol4 gKL6ZQ79F5ZSa/cq6CWxVlMM9H2mpM0PWm/47yk+MvpZemAJ5NjXQ6Ruv ufdpeRfrhONOg5D23CrxFOLw1q7H1orBRe1/D1l09ZloXLgUw6dimEDNG 05HOY7DwKqIL6kxP7ALoMb+h4yyMcE988JdUMWK6w+9Bkf/Np864QWV8y w==; X-IronPort-AV: E=McAfee;i="6500,9779,10556"; a="317483302" X-IronPort-AV: E=Sophos;i="5.96,230,1665471600"; d="scan'208";a="317483302" Received: from fmsmga006.fm.intel.com ([10.253.24.20]) by fmsmga103.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Dec 2022 05:25:36 -0800 X-IronPort-AV: E=McAfee;i="6500,9779,10556"; a="892670378" X-IronPort-AV: E=Sophos;i="5.96,230,1665471600"; d="scan'208";a="892670378" Received: from elinares-mobl.ger.corp.intel.com (HELO box.shutemov.name) ([10.249.38.98]) by fmsmga006-auth.fm.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 09 Dec 2022 05:25:33 -0800 Received: by box.shutemov.name (Postfix, from userid 1000) id 4B536109CE4; Fri, 9 Dec 2022 16:25:31 +0300 (+03) From: "Kirill A. Shutemov" To: Dave Hansen , Borislav Petkov , Andy Lutomirski Cc: Kuppuswamy Sathyanarayanan , Thomas Gleixner , Elena Reshetova , x86@kernel.org, linux-coco@lists.linux.dev, linux-kernel@vger.kernel.org, "Kirill A. Shutemov" Subject: [PATCH 2/4] x86/tdx: Use ReportFatalError to report missing SEPT_VE_DISABLE Date: Fri, 9 Dec 2022 16:25:22 +0300 Message-Id: <20221209132524.20200-3-kirill.shutemov@linux.intel.com> X-Mailer: git-send-email 2.38.0 In-Reply-To: <20221209132524.20200-1-kirill.shutemov@linux.intel.com> References: <20221209132524.20200-1-kirill.shutemov@linux.intel.com> Precedence: bulk X-Mailing-List: linux-coco@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Transfer-Encoding: 8bit The check for SEPT_VE_DISABLE happens early in the kernel boot where earlyprintk is not yet functional. Kernel successfully detect broken TD configuration and stops the kernel with panic(), but it cannot communicate the reason to the user. Use TDG.VP.VMCALL to report the error. The hypercall can encode message up to 64 bytes in eight registers. Signed-off-by: Kirill A. Shutemov --- arch/x86/coco/tdx/tdx.c | 38 +++++++++++++++++++++++++++++++++++++- 1 file changed, 37 insertions(+), 1 deletion(-) diff --git a/arch/x86/coco/tdx/tdx.c b/arch/x86/coco/tdx/tdx.c index cfd4c95b9f04..8ad04d101270 100644 --- a/arch/x86/coco/tdx/tdx.c +++ b/arch/x86/coco/tdx/tdx.c @@ -22,6 +22,7 @@ /* TDX hypercall Leaf IDs */ #define TDVMCALL_MAP_GPA 0x10001 +#define TDVMCALL_REPORT_FATAL_ERROR 0x10003 /* MMIO direction */ #define EPT_READ 0 @@ -140,6 +141,41 @@ int tdx_mcall_get_report0(u8 *reportdata, u8 *tdreport) } EXPORT_SYMBOL_GPL(tdx_mcall_get_report0); +static void __noreturn tdx_panic(const char *msg) +{ + struct tdx_hypercall_args args = { + .r10 = TDX_HYPERCALL_STANDARD, + .r11 = TDVMCALL_REPORT_FATAL_ERROR, + .r12 = 0, /* Error code: 0 is Panic */ + }; + union { + /* Define register order according to the GHCI */ + struct { u64 r14, r15, rbx, rdi, rsi, r8, r9, rdx; }; + + char str[64]; + } message; + + /* VMM assumes '\0' in byte 65, if the message took all 64 bytes */ + strncpy(message.str, msg, 64); + + args.r8 = message.r8; + args.r9 = message.r9; + args.r14 = message.r14; + args.r15 = message.r15; + args.rdi = message.rdi; + args.rsi = message.rsi; + args.rbx = message.rbx; + args.rdx = message.rdx; + + /* + * Keep calling the hypercall in case VMM did not terminated + * the TD as it must. + */ + while (1) { + __tdx_hypercall(&args, 0); + } +} + static void tdx_parse_tdinfo(u64 *cc_mask) { struct tdx_module_output out; @@ -172,7 +208,7 @@ static void tdx_parse_tdinfo(u64 *cc_mask) */ td_attr = out.rdx; if (!(td_attr & ATTR_SEPT_VE_DISABLE)) - panic("TD misconfiguration: SEPT_VE_DISABLE attibute must be set.\n"); + tdx_panic("TD misconfiguration: SEPT_VE_DISABLE attribute must be set."); } /* -- 2.38.0