Re: [PATCHv12 4/9] x86/boot/compressed: Handle unaccepted memory

From: "Kirill A. Shutemov" <kirill@shutemov.name>
To: "Kirill A. Shutemov" <kirill.shutemov@linux.intel.com>
Cc: Borislav Petkov <bp@alien8.de>, Andy Lutomirski <luto@kernel.org>,
	Dave Hansen <dave.hansen@intel.com>,
	Sean Christopherson <seanjc@google.com>,
	Andrew Morton <akpm@linux-foundation.org>,
	Joerg Roedel <jroedel@suse.de>, Ard Biesheuvel <ardb@kernel.org>,
	Andi Kleen <ak@linux.intel.com>,
	Kuppuswamy Sathyanarayanan
	<sathyanarayanan.kuppuswamy@linux.intel.com>,
	David Rientjes <rientjes@google.com>,
	Vlastimil Babka <vbabka@suse.cz>,
	Tom Lendacky <thomas.lendacky@amd.com>,
	Thomas Gleixner <tglx@linutronix.de>,
	Peter Zijlstra <peterz@infradead.org>,
	Paolo Bonzini <pbonzini@redhat.com>,
	Ingo Molnar <mingo@redhat.com>,
	Dario Faggioli <dfaggioli@suse.com>,
	Mike Rapoport <rppt@kernel.org>,
	David Hildenbrand <david@redhat.com>,
	Mel Gorman <mgorman@techsingularity.net>,
	marcelo.cerri@canonical.com, tim.gardner@canonical.com,
	khalid.elmously@canonical.com, philip.cox@canonical.com,
	aarcange@redhat.com, peterx@redhat.com, x86@kernel.org,
	linux-mm@kvack.org, linux-coco@lists.linux.dev,
	linux-efi@vger.kernel.org, linux-kernel@vger.kernel.org,
	Liam Merwick <liam.merwick@oracle.com>
Subject: Re: [PATCHv12 4/9] x86/boot/compressed: Handle unaccepted memory
Date: Fri, 19 May 2023 13:16:41 +0300	[thread overview]
Message-ID: <20230519101641.nka7ty3fttntymci@box.shutemov.name> (raw)
In-Reply-To: <20230518231434.26080-5-kirill.shutemov@linux.intel.com>

On Fri, May 19, 2023 at 02:14:29AM +0300, Kirill A. Shutemov wrote:
> diff --git a/arch/x86/boot/compressed/mem.c b/arch/x86/boot/compressed/mem.c
> index 67594fcb11d9..87372b96d613 100644
> --- a/arch/x86/boot/compressed/mem.c
> +++ b/arch/x86/boot/compressed/mem.c
> @@ -1,9 +1,32 @@
>  // SPDX-License-Identifier: GPL-2.0-only
>  
>  #include "error.h"
> +#include "misc.h"
>  
>  void arch_accept_memory(phys_addr_t start, phys_addr_t end)
>  {
>  	/* Platform-specific memory-acceptance call goes here */
>  	error("Cannot accept memory");
>  }
> +
> +void init_unaccepted_memory(void)
> +{
> +	guid_t guid =  LINUX_EFI_UNACCEPTED_MEM_TABLE_GUID;
> +	struct efi_unaccepted_memory *unaccepted_table;
> +	unsigned long cfg_table_pa;
> +	unsigned int cfg_table_len;
> +	int ret;
> +
> +	ret = efi_get_conf_table(boot_params, &cfg_table_pa, &cfg_table_len);
> +	if (ret)
> +		error("EFI config table not found.");
> +
> +	unaccepted_table = (void *)efi_find_vendor_table(boot_params,
> +							 cfg_table_pa,
> +							 cfg_table_len,
> +							 guid);
> +	if (unaccepted_table->version != 1)
> +		error("Unknown version of unaccepted memory table\n");
> +
> +	set_unaccepted_table(unaccepted_table);
> +}

0-day reported boot failure outdise TDX guest with CONFIG_INTEL_TDX_GUEST=y.

The fixup:

diff --git a/arch/x86/boot/compressed/mem.c b/arch/x86/boot/compressed/mem.c
index 0108c97399a5..8df3d988ae69 100644
--- a/arch/x86/boot/compressed/mem.c
+++ b/arch/x86/boot/compressed/mem.c
@@ -56,6 +56,9 @@ void init_unaccepted_memory(void)
 							 cfg_table_pa,
 							 cfg_table_len,
 							 guid);
+	if (!unaccepted_table)
+		return;
+
 	if (unaccepted_table->version != 1)
 		error("Unknown version of unaccepted memory table\n");
 
-- 
  Kiryl Shutsemau / Kirill A. Shutemov
