From patchwork Wed Aug 7 10:33:32 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?SsO8cmdlbiBHcm/Dnw==?= X-Patchwork-Id: 13756106 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 8F715C52D6F for ; Wed, 7 Aug 2024 10:33:58 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.773300.1183747 (Exim 4.92) (envelope-from ) id 1sbdzL-00063o-AN; Wed, 07 Aug 2024 10:33:51 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 773300.1183747; Wed, 07 Aug 2024 10:33:51 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1sbdzL-00063h-7t; Wed, 07 Aug 2024 10:33:51 +0000 Received: by outflank-mailman (input) for mailman id 773300; Wed, 07 Aug 2024 10:33:49 +0000 Received: from se1-gles-flk1-in.inumbo.com ([94.247.172.50] helo=se1-gles-flk1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1sbdzJ-0005nD-9Q for xen-devel@lists.xenproject.org; Wed, 07 Aug 2024 10:33:49 +0000 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) by se1-gles-flk1.inumbo.com (Halon) with ESMTPS id 84639a3e-54a8-11ef-8776-851b0ebba9a2; Wed, 07 Aug 2024 12:33:42 +0200 (CEST) Received: from imap1.dmz-prg2.suse.org (unknown [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 3BC0F1F8BD; Wed, 7 Aug 2024 10:33:47 +0000 (UTC) Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id E0A1013297; Wed, 7 Aug 2024 10:33:46 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id 2lNkNYpNs2blHwAAD6G6ig (envelope-from ); Wed, 07 Aug 2024 10:33:46 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 84639a3e-54a8-11ef-8776-851b0ebba9a2 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1723026827; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=5V+UOas05CCJX1lp+n/kvQ+Bo/4QFe3PiFfjQw3draY=; b=XMzAC1YMl90C7b1lVoVe6deG5bKZooG8TmMQhahGnwg6aWvmq0vJFZ9nmZPrBRF534vb66 xGDhq+YFNo0Q8FG5uvGfspmj9WNymK02YjHn4RwxOoPJ1sMl0sSvT1YZ/PtiMEJ9HbmN97 2tfpQijyy76Q81Pl+n7mvY/4AFs4iWs= Authentication-Results: smtp-out2.suse.de; none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1723026827; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=5V+UOas05CCJX1lp+n/kvQ+Bo/4QFe3PiFfjQw3draY=; b=XMzAC1YMl90C7b1lVoVe6deG5bKZooG8TmMQhahGnwg6aWvmq0vJFZ9nmZPrBRF534vb66 xGDhq+YFNo0Q8FG5uvGfspmj9WNymK02YjHn4RwxOoPJ1sMl0sSvT1YZ/PtiMEJ9HbmN97 2tfpQijyy76Q81Pl+n7mvY/4AFs4iWs= From: Juergen Gross To: linux-kernel@vger.kernel.org, x86@kernel.org Cc: Juergen Gross , Boris Ostrovsky , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , xen-devel@lists.xenproject.org Subject: [PATCH 1/5] xen: use correct end address of kernel for conflict checking Date: Wed, 7 Aug 2024 12:33:32 +0200 Message-ID: <20240807103338.22007-2-jgross@suse.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240807103338.22007-1-jgross@suse.com> References: <20240807103338.22007-1-jgross@suse.com> MIME-Version: 1.0 X-Spamd-Result: default: False [-3.30 / 50.00]; BAYES_HAM(-3.00)[100.00%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; RCPT_COUNT_SEVEN(0.00)[10]; RCVD_TLS_ALL(0.00)[]; FUZZY_BLOCKED(0.00)[rspamd.com]; TO_DN_SOME(0.00)[]; FROM_HAS_DN(0.00)[]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; FROM_EQ_ENVFROM(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.com:email] When running as a Xen PV dom0 the kernel is loaded by the hypervisor using a different memory map than that of the host. In order to minimize the required changes in the kernel, the kernel adapts its memory map to that of the host. In order to do that it is checking for conflicts of its load address with the host memory map. Unfortunately the tested memory range does not include the .brk area, which might result in crashes or memory corruption when this area does conflict withe the memory map of the host. Fix the test by using the _end label instead of __bss_stop. Fixes: 808fdb71936c ("xen: check for kernel memory conflicting with memory layout") Signed-off-by: Juergen Gross Marek Marczykowski-Górecki --- arch/x86/xen/setup.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index 806ddb2391d9..4bcc70a71b7d 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -825,7 +825,7 @@ char * __init xen_memory_setup(void) * to relocating (and even reusing) pages with kernel text or data. */ if (xen_is_e820_reserved(__pa_symbol(_text), - __pa_symbol(__bss_stop) - __pa_symbol(_text))) { + __pa_symbol(_end) - __pa_symbol(_text))) { xen_raw_console_write("Xen hypervisor allocated kernel memory conflicts with E820 map\n"); BUG(); } From patchwork Wed Aug 7 10:33:33 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?SsO8cmdlbiBHcm/Dnw==?= X-Patchwork-Id: 13756107 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E4999C52D6F for ; Wed, 7 Aug 2024 10:34:02 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.773301.1183758 (Exim 4.92) (envelope-from ) id 1sbdzP-0006Lw-Hk; Wed, 07 Aug 2024 10:33:55 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 773301.1183758; Wed, 07 Aug 2024 10:33:55 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1sbdzP-0006Lp-FD; Wed, 07 Aug 2024 10:33:55 +0000 Received: by outflank-mailman (input) for mailman id 773301; Wed, 07 Aug 2024 10:33:54 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1sbdzO-0006Kl-M4 for xen-devel@lists.xenproject.org; Wed, 07 Aug 2024 10:33:54 +0000 Received: from smtp-out2.suse.de (smtp-out2.suse.de [195.135.223.131]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 8af31eb0-54a8-11ef-bc04-fd08da9f4363; Wed, 07 Aug 2024 12:33:53 +0200 (CEST) Received: from imap1.dmz-prg2.suse.org (imap1.dmz-prg2.suse.org [IPv6:2a07:de40:b281:104:10:150:64:97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 112DA1FB8C; Wed, 7 Aug 2024 10:33:53 +0000 (UTC) Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id A339513297; Wed, 7 Aug 2024 10:33:52 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id WypzJpBNs2boHwAAD6G6ig (envelope-from ); Wed, 07 Aug 2024 10:33:52 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 8af31eb0-54a8-11ef-bc04-fd08da9f4363 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1723026833; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BZ7eaJU0nEL6OIQnax25lzy77xjuIx0p2h07T/rBkxA=; b=gK5TgjAU1LY1lov2apQWsmY2WEIO2sn1L7VGiYyGcB0ktwaUPzNwDTD66hdL43tdiMCkPl TPqsrEG03Ovb5hbIis4zBiVEYbAd+uBOtLE4WY9VKcMTIukCVM3L5qQ8rD/ay66HQ9pYDf LppKSi4h8xaR/wKuUg9xqJZXniMbp1Q= Authentication-Results: smtp-out2.suse.de; dkim=pass header.d=suse.com header.s=susede1 header.b=gK5TgjAU DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1723026833; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=BZ7eaJU0nEL6OIQnax25lzy77xjuIx0p2h07T/rBkxA=; b=gK5TgjAU1LY1lov2apQWsmY2WEIO2sn1L7VGiYyGcB0ktwaUPzNwDTD66hdL43tdiMCkPl TPqsrEG03Ovb5hbIis4zBiVEYbAd+uBOtLE4WY9VKcMTIukCVM3L5qQ8rD/ay66HQ9pYDf LppKSi4h8xaR/wKuUg9xqJZXniMbp1Q= From: Juergen Gross To: linux-kernel@vger.kernel.org, x86@kernel.org Cc: Juergen Gross , Boris Ostrovsky , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , xen-devel@lists.xenproject.org Subject: [PATCH 2/5] xen: introduce generic helper checking for memory map conflicts Date: Wed, 7 Aug 2024 12:33:33 +0200 Message-ID: <20240807103338.22007-3-jgross@suse.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240807103338.22007-1-jgross@suse.com> References: <20240807103338.22007-1-jgross@suse.com> MIME-Version: 1.0 X-Rspamd-Action: no action X-Rspamd-Queue-Id: 112DA1FB8C X-Spamd-Result: default: False [-3.51 / 50.00]; BAYES_HAM(-3.00)[100.00%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; R_DKIM_ALLOW(-0.20)[suse.com:s=susede1]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; MX_GOOD(-0.01)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; FUZZY_BLOCKED(0.00)[rspamd.com]; MIME_TRACE(0.00)[0:+]; RCPT_COUNT_SEVEN(0.00)[10]; RCVD_TLS_ALL(0.00)[]; TO_DN_SOME(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; FROM_HAS_DN(0.00)[]; DNSWL_BLOCKED(0.00)[2a07:de40:b281:104:10:150:64:97:from]; RCVD_COUNT_TWO(0.00)[2]; TO_MATCH_ENVRCPT_ALL(0.00)[]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.com:dkim,suse.com:email]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; DKIM_TRACE(0.00)[suse.com:+] X-Rspamd-Server: rspamd1.dmz-prg2.suse.org When booting as a Xen PV dom0 the memory layout of the dom0 is modified to match that of the host, as this requires less changes in the kernel for supporting Xen. There are some cases, though, which are problematic, as it is the Xen hypervisor selecting the kernel's load address plus some other data, which might conflict with the host's memory map. These conflicts are detected at boot time and result in a boot error. In order to support handling at least some of these conflicts in future, introduce a generic helper function which will later gain the ability to adapt the memory layout when possible. Add the missing check for the xen_start_info area. Signed-off-by: Juergen Gross Marek Marczykowski-Górecki --- arch/x86/xen/mmu_pv.c | 5 +---- arch/x86/xen/setup.c | 34 ++++++++++++++++++++++++++++------ arch/x86/xen/xen-ops.h | 3 ++- 3 files changed, 31 insertions(+), 11 deletions(-) diff --git a/arch/x86/xen/mmu_pv.c b/arch/x86/xen/mmu_pv.c index f1ce39d6d32c..839e6613753d 100644 --- a/arch/x86/xen/mmu_pv.c +++ b/arch/x86/xen/mmu_pv.c @@ -2018,10 +2018,7 @@ void __init xen_reserve_special_pages(void) void __init xen_pt_check_e820(void) { - if (xen_is_e820_reserved(xen_pt_base, xen_pt_size)) { - xen_raw_console_write("Xen hypervisor allocated page table memory conflicts with E820 map\n"); - BUG(); - } + xen_chk_is_e820_usable(xen_pt_base, xen_pt_size, "page table"); } static unsigned char dummy_mapping[PAGE_SIZE] __page_aligned_bss; diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index 4bcc70a71b7d..96765180514b 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -567,7 +567,7 @@ static void __init xen_ignore_unusable(void) } } -bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size) +static bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size) { struct e820_entry *entry; unsigned mapcnt; @@ -624,6 +624,23 @@ phys_addr_t __init xen_find_free_area(phys_addr_t size) return 0; } +/* + * Check for an area in physical memory to be usable for non-movable purposes. + * An area is considered to usable if the used E820 map lists it to be RAM. + * In case the area is not usable, crash the system with an error message. + */ +void __init xen_chk_is_e820_usable(phys_addr_t start, phys_addr_t size, + const char *component) +{ + if (!xen_is_e820_reserved(start, size)) + return; + + xen_raw_console_write("Xen hypervisor allocated "); + xen_raw_console_write(component); + xen_raw_console_write(" memory conflicts with E820 map\n"); + BUG(); +} + /* * Like memcpy, but with physical addresses for dest and src. */ @@ -824,11 +841,16 @@ char * __init xen_memory_setup(void) * Failing now is better than running into weird problems later due * to relocating (and even reusing) pages with kernel text or data. */ - if (xen_is_e820_reserved(__pa_symbol(_text), - __pa_symbol(_end) - __pa_symbol(_text))) { - xen_raw_console_write("Xen hypervisor allocated kernel memory conflicts with E820 map\n"); - BUG(); - } + xen_chk_is_e820_usable(__pa_symbol(_text), + __pa_symbol(_end) - __pa_symbol(_text), + "kernel"); + + /* + * Check for a conflict of the xen_start_info memory with the target + * E820 map. + */ + xen_chk_is_e820_usable(__pa(xen_start_info), sizeof(*xen_start_info), + "xen_start_info"); /* * Check for a conflict of the hypervisor supplied page tables with diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h index 0cf16fc79e0b..9a27d1d653d3 100644 --- a/arch/x86/xen/xen-ops.h +++ b/arch/x86/xen/xen-ops.h @@ -48,7 +48,8 @@ void xen_mm_unpin_all(void); void __init xen_relocate_p2m(void); #endif -bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size); +void __init xen_chk_is_e820_usable(phys_addr_t start, phys_addr_t size, + const char *component); unsigned long __ref xen_chk_extra_mem(unsigned long pfn); void __init xen_inv_extra_mem(void); void __init xen_remap_memory(void); From patchwork Wed Aug 7 10:33:34 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?SsO8cmdlbiBHcm/Dnw==?= X-Patchwork-Id: 13756108 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 6820BC52D6F for ; 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Peter Anvin" , xen-devel@lists.xenproject.org Subject: [PATCH 3/5] xen: move checks for e820 conflicts further up Date: Wed, 7 Aug 2024 12:33:34 +0200 Message-ID: <20240807103338.22007-4-jgross@suse.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240807103338.22007-1-jgross@suse.com> References: <20240807103338.22007-1-jgross@suse.com> MIME-Version: 1.0 X-Spamd-Result: default: False [-3.30 / 50.00]; BAYES_HAM(-3.00)[100.00%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; TO_MATCH_ENVRCPT_ALL(0.00)[]; FUZZY_BLOCKED(0.00)[rspamd.com]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; MIME_TRACE(0.00)[0:+]; ARC_NA(0.00)[]; FROM_HAS_DN(0.00)[]; RCVD_TLS_ALL(0.00)[]; RCVD_VIA_SMTP_AUTH(0.00)[]; FROM_EQ_ENVFROM(0.00)[]; TO_DN_SOME(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; RCPT_COUNT_SEVEN(0.00)[10]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.com:email] Move the checks for e820 memory map conflicts using the xen_chk_is_e820_usable() helper further up in order to prepare resolving some of the possible conflicts by doing some e820 map modifications, which must happen before evaluating the RAM layout. Signed-off-by: Juergen Gross Marek Marczykowski-Górecki --- arch/x86/xen/setup.c | 44 ++++++++++++++++++++++---------------------- 1 file changed, 22 insertions(+), 22 deletions(-) diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index 96765180514b..dba68951ed6b 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -764,6 +764,28 @@ char * __init xen_memory_setup(void) /* Make sure the Xen-supplied memory map is well-ordered. */ e820__update_table(&xen_e820_table); + /* + * Check whether the kernel itself conflicts with the target E820 map. + * Failing now is better than running into weird problems later due + * to relocating (and even reusing) pages with kernel text or data. + */ + xen_chk_is_e820_usable(__pa_symbol(_text), + __pa_symbol(_end) - __pa_symbol(_text), + "kernel"); + + /* + * Check for a conflict of the xen_start_info memory with the target + * E820 map. + */ + xen_chk_is_e820_usable(__pa(xen_start_info), sizeof(*xen_start_info), + "xen_start_info"); + + /* + * Check for a conflict of the hypervisor supplied page tables with + * the target E820 map. + */ + xen_pt_check_e820(); + max_pages = xen_get_max_pages(); /* How many extra pages do we need due to remapping? */ @@ -836,28 +858,6 @@ char * __init xen_memory_setup(void) e820__update_table(e820_table); - /* - * Check whether the kernel itself conflicts with the target E820 map. - * Failing now is better than running into weird problems later due - * to relocating (and even reusing) pages with kernel text or data. - */ - xen_chk_is_e820_usable(__pa_symbol(_text), - __pa_symbol(_end) - __pa_symbol(_text), - "kernel"); - - /* - * Check for a conflict of the xen_start_info memory with the target - * E820 map. - */ - xen_chk_is_e820_usable(__pa(xen_start_info), sizeof(*xen_start_info), - "xen_start_info"); - - /* - * Check for a conflict of the hypervisor supplied page tables with - * the target E820 map. - */ - xen_pt_check_e820(); - xen_reserve_xen_mfnlist(); /* Check for a conflict of the initrd with the target E820 map. */ From patchwork Wed Aug 7 10:33:35 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?SsO8cmdlbiBHcm/Dnw==?= X-Patchwork-Id: 13756109 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 155D6C52D6F for ; Wed, 7 Aug 2024 10:34:14 +0000 (UTC) Received: from list by lists.xenproject.org with outflank-mailman.773312.1183778 (Exim 4.92) (envelope-from ) id 1sbdzb-0007GH-3K; Wed, 07 Aug 2024 10:34:07 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 773312.1183778; Wed, 07 Aug 2024 10:34:07 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1sbdza-0007Fy-Vo; Wed, 07 Aug 2024 10:34:06 +0000 Received: by outflank-mailman (input) for mailman id 773312; Wed, 07 Aug 2024 10:34:06 +0000 Received: from se1-gles-sth1-in.inumbo.com ([159.253.27.254] helo=se1-gles-sth1.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1sbdzZ-0006Kl-Vb for xen-devel@lists.xenproject.org; Wed, 07 Aug 2024 10:34:05 +0000 Received: from smtp-out1.suse.de (smtp-out1.suse.de [2a07:de40:b251:101:10:150:64:1]) by se1-gles-sth1.inumbo.com (Halon) with ESMTPS id 91a2b5e3-54a8-11ef-bc04-fd08da9f4363; Wed, 07 Aug 2024 12:34:04 +0200 (CEST) Received: from imap1.dmz-prg2.suse.org (unknown [10.150.64.97]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by smtp-out1.suse.de (Postfix) with ESMTPS id 7555621D05; Wed, 7 Aug 2024 10:34:04 +0000 (UTC) Received: from imap1.dmz-prg2.suse.org (localhost [127.0.0.1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256) (No client certificate requested) by imap1.dmz-prg2.suse.org (Postfix) with ESMTPS id 25C3613297; Wed, 7 Aug 2024 10:34:04 +0000 (UTC) Received: from dovecot-director2.suse.de ([2a07:de40:b281:106:10:150:64:167]) by imap1.dmz-prg2.suse.org with ESMTPSA id MQm1B5xNs2YBIAAAD6G6ig (envelope-from ); Wed, 07 Aug 2024 10:34:04 +0000 X-BeenThere: xen-devel@lists.xenproject.org List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xenproject.org Precedence: list Sender: "Xen-devel" X-Inumbo-ID: 91a2b5e3-54a8-11ef-bc04-fd08da9f4363 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1723026844; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=R2HRNEjKteadr0yEjLsc+mhlWZGd0BCfAetOymhMvJ4=; b=o+poM77ZPB0bP6oyzFWAYI5SPJwfn6ZZwZNaZqA7gOLjA9f5pBJUtXaeYV+7XHG2qcRfkw p75iMeTRwVZM8vL3XeVJD4ZutW1jcrhnwNT1vf23msGayGk0vLTFW5U+i4M7qfroLZuvTu XHJtVkCIldNCGBhS605Fit8/VNRPRsI= Authentication-Results: smtp-out1.suse.de; none DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1723026844; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=R2HRNEjKteadr0yEjLsc+mhlWZGd0BCfAetOymhMvJ4=; b=o+poM77ZPB0bP6oyzFWAYI5SPJwfn6ZZwZNaZqA7gOLjA9f5pBJUtXaeYV+7XHG2qcRfkw p75iMeTRwVZM8vL3XeVJD4ZutW1jcrhnwNT1vf23msGayGk0vLTFW5U+i4M7qfroLZuvTu XHJtVkCIldNCGBhS605Fit8/VNRPRsI= From: Juergen Gross To: linux-kernel@vger.kernel.org, x86@kernel.org Cc: Juergen Gross , Boris Ostrovsky , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , xen-devel@lists.xenproject.org Subject: [PATCH 4/5] xen: move max_pfn in xen_memory_setup() out of function scope Date: Wed, 7 Aug 2024 12:33:35 +0200 Message-ID: <20240807103338.22007-5-jgross@suse.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240807103338.22007-1-jgross@suse.com> References: <20240807103338.22007-1-jgross@suse.com> MIME-Version: 1.0 X-Spamd-Result: default: False [-3.30 / 50.00]; BAYES_HAM(-3.00)[100.00%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; RCPT_COUNT_SEVEN(0.00)[10]; RCVD_TLS_ALL(0.00)[]; FUZZY_BLOCKED(0.00)[rspamd.com]; TO_DN_SOME(0.00)[]; FROM_HAS_DN(0.00)[]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; FROM_EQ_ENVFROM(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.com:email] Instead of having max_pfn as a local variable of xen_memory_setup(), make it a static variable in setup.c instead. This avoids having to pass it to subfunctions, which will be needed in more cases in future. Rename it to ini_nr_pages, as the value denotes the currently usable number of memory pages as passed from the hypervisor at boot time. Signed-off-by: Juergen Gross Marek Marczykowski-Górecki --- arch/x86/xen/setup.c | 53 ++++++++++++++++++++++---------------------- 1 file changed, 27 insertions(+), 26 deletions(-) diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index dba68951ed6b..d678c0330971 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -46,6 +46,9 @@ bool xen_pv_pci_possible; /* E820 map used during setting up memory. */ static struct e820_table xen_e820_table __initdata; +/* Number of initially usable memory pages. */ +static unsigned long ini_nr_pages __initdata; + /* * Buffer used to remap identity mapped pages. We only need the virtual space. * The physical page behind this address is remapped as needed to different @@ -212,7 +215,7 @@ static int __init xen_free_mfn(unsigned long mfn) * as a fallback if the remapping fails. */ static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn, - unsigned long end_pfn, unsigned long nr_pages) + unsigned long end_pfn) { unsigned long pfn, end; int ret; @@ -220,7 +223,7 @@ static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn, WARN_ON(start_pfn > end_pfn); /* Release pages first. */ - end = min(end_pfn, nr_pages); + end = min(end_pfn, ini_nr_pages); for (pfn = start_pfn; pfn < end; pfn++) { unsigned long mfn = pfn_to_mfn(pfn); @@ -341,15 +344,14 @@ static void __init xen_do_set_identity_and_remap_chunk( * to Xen and not remapped. */ static unsigned long __init xen_set_identity_and_remap_chunk( - unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages, - unsigned long remap_pfn) + unsigned long start_pfn, unsigned long end_pfn, unsigned long remap_pfn) { unsigned long pfn; unsigned long i = 0; unsigned long n = end_pfn - start_pfn; if (remap_pfn == 0) - remap_pfn = nr_pages; + remap_pfn = ini_nr_pages; while (i < n) { unsigned long cur_pfn = start_pfn + i; @@ -358,19 +360,19 @@ static unsigned long __init xen_set_identity_and_remap_chunk( unsigned long remap_range_size; /* Do not remap pages beyond the current allocation */ - if (cur_pfn >= nr_pages) { + if (cur_pfn >= ini_nr_pages) { /* Identity map remaining pages */ set_phys_range_identity(cur_pfn, cur_pfn + size); break; } - if (cur_pfn + size > nr_pages) - size = nr_pages - cur_pfn; + if (cur_pfn + size > ini_nr_pages) + size = ini_nr_pages - cur_pfn; remap_range_size = xen_find_pfn_range(&remap_pfn); if (!remap_range_size) { pr_warn("Unable to find available pfn range, not remapping identity pages\n"); xen_set_identity_and_release_chunk(cur_pfn, - cur_pfn + left, nr_pages); + cur_pfn + left); break; } /* Adjust size to fit in current e820 RAM region */ @@ -397,18 +399,18 @@ static unsigned long __init xen_set_identity_and_remap_chunk( } static unsigned long __init xen_count_remap_pages( - unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages, + unsigned long start_pfn, unsigned long end_pfn, unsigned long remap_pages) { - if (start_pfn >= nr_pages) + if (start_pfn >= ini_nr_pages) return remap_pages; - return remap_pages + min(end_pfn, nr_pages) - start_pfn; + return remap_pages + min(end_pfn, ini_nr_pages) - start_pfn; } -static unsigned long __init xen_foreach_remap_area(unsigned long nr_pages, +static unsigned long __init xen_foreach_remap_area( unsigned long (*func)(unsigned long start_pfn, unsigned long end_pfn, - unsigned long nr_pages, unsigned long last_val)) + unsigned long last_val)) { phys_addr_t start = 0; unsigned long ret_val = 0; @@ -436,8 +438,7 @@ static unsigned long __init xen_foreach_remap_area(unsigned long nr_pages, end_pfn = PFN_UP(entry->addr); if (start_pfn < end_pfn) - ret_val = func(start_pfn, end_pfn, nr_pages, - ret_val); + ret_val = func(start_pfn, end_pfn, ret_val); start = end; } } @@ -700,7 +701,7 @@ static void __init xen_reserve_xen_mfnlist(void) **/ char * __init xen_memory_setup(void) { - unsigned long max_pfn, pfn_s, n_pfns; + unsigned long pfn_s, n_pfns; phys_addr_t mem_end, addr, size, chunk_size; u32 type; int rc; @@ -712,9 +713,9 @@ char * __init xen_memory_setup(void) int op; xen_parse_512gb(); - max_pfn = xen_get_pages_limit(); - max_pfn = min(max_pfn, xen_start_info->nr_pages); - mem_end = PFN_PHYS(max_pfn); + ini_nr_pages = xen_get_pages_limit(); + ini_nr_pages = min(ini_nr_pages, xen_start_info->nr_pages); + mem_end = PFN_PHYS(ini_nr_pages); memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries); set_xen_guest_handle(memmap.buffer, xen_e820_table.entries); @@ -789,10 +790,10 @@ char * __init xen_memory_setup(void) max_pages = xen_get_max_pages(); /* How many extra pages do we need due to remapping? */ - max_pages += xen_foreach_remap_area(max_pfn, xen_count_remap_pages); + max_pages += xen_foreach_remap_area(xen_count_remap_pages); - if (max_pages > max_pfn) - extra_pages += max_pages - max_pfn; + if (max_pages > ini_nr_pages) + extra_pages += max_pages - ini_nr_pages; /* * Clamp the amount of extra memory to a EXTRA_MEM_RATIO @@ -801,8 +802,8 @@ char * __init xen_memory_setup(void) * Make sure we have no memory above max_pages, as this area * isn't handled by the p2m management. */ - maxmem_pages = EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)); - extra_pages = min3(maxmem_pages, extra_pages, max_pages - max_pfn); + maxmem_pages = EXTRA_MEM_RATIO * min(ini_nr_pages, PFN_DOWN(MAXMEM)); + extra_pages = min3(maxmem_pages, extra_pages, max_pages - ini_nr_pages); i = 0; addr = xen_e820_table.entries[0].addr; size = xen_e820_table.entries[0].size; @@ -885,7 +886,7 @@ char * __init xen_memory_setup(void) * Set identity map on non-RAM pages and prepare remapping the * underlying RAM. */ - xen_foreach_remap_area(max_pfn, xen_set_identity_and_remap_chunk); + xen_foreach_remap_area(xen_set_identity_and_remap_chunk); pr_info("Released %ld page(s)\n", xen_released_pages); From patchwork Wed Aug 7 10:33:36 2024 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: =?utf-8?b?SsO8cmdlbiBHcm/Dnw==?= X-Patchwork-Id: 13756110 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 lists.xenproject.org (lists.xenproject.org [192.237.175.120]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id 5B4E9C3DA7F for ; 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Peter Anvin" , xen-devel@lists.xenproject.org Subject: [PATCH 5/5] xen: tolerate ACPI NVS memory overlapping with Xen allocated memory Date: Wed, 7 Aug 2024 12:33:36 +0200 Message-ID: <20240807103338.22007-6-jgross@suse.com> X-Mailer: git-send-email 2.43.0 In-Reply-To: <20240807103338.22007-1-jgross@suse.com> References: <20240807103338.22007-1-jgross@suse.com> MIME-Version: 1.0 X-Spamd-Result: default: False [-3.30 / 50.00]; BAYES_HAM(-3.00)[100.00%]; MID_CONTAINS_FROM(1.00)[]; NEURAL_HAM_LONG(-1.00)[-1.000]; NEURAL_HAM_SHORT(-0.20)[-1.000]; MIME_GOOD(-0.10)[text/plain]; RCVD_VIA_SMTP_AUTH(0.00)[]; ARC_NA(0.00)[]; MIME_TRACE(0.00)[0:+]; RCPT_COUNT_SEVEN(0.00)[10]; RCVD_TLS_ALL(0.00)[]; FUZZY_BLOCKED(0.00)[rspamd.com]; TO_DN_SOME(0.00)[]; FROM_HAS_DN(0.00)[]; DKIM_SIGNED(0.00)[suse.com:s=susede1]; FROM_EQ_ENVFROM(0.00)[]; TO_MATCH_ENVRCPT_ALL(0.00)[]; RCVD_COUNT_TWO(0.00)[2]; DBL_BLOCKED_OPENRESOLVER(0.00)[suse.com:email] In order to minimize required special handling for running as Xen PV dom0, the memory layout is modified to match that of the host. This requires to have only RAM at the locations where Xen allocated memory is living. Unfortunately there seem to be some machines, where ACPI NVS is located at 64 MB, resulting in a conflict with the loaded kernel or the initial page tables built by Xen. As ACPI NVS needs to be accessed by the kernel only for saving and restoring it across suspend operations, it can be relocated in the dom0's memory map by swapping it with unused RAM (this is possible via modification of the dom0 P2M map). While the E820 map can (and should) be modified right away, the P2M map can be updated only after memory allocation is working, as the P2M map might need to be extended. Fixes: 808fdb71936c ("xen: check for kernel memory conflicting with memory layout") Signed-off-by: Juergen Gross Marek Marczykowski-Górecki --- arch/x86/xen/setup.c | 133 ++++++++++++++++++++++++++++++++++++++++++- 1 file changed, 132 insertions(+), 1 deletion(-) diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index d678c0330971..dbb5d13ca61a 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -49,6 +49,15 @@ static struct e820_table xen_e820_table __initdata; /* Number of initially usable memory pages. */ static unsigned long ini_nr_pages __initdata; +/* Remapped non-RAM areas */ +#define NR_NONRAM_REMAP 4 +static struct nonram_remap { + unsigned long maddr; + unsigned long size; + unsigned long paddr; +} xen_nonram_remap[NR_NONRAM_REMAP] __initdata; +static unsigned int nr_nonram_remap __initdata; + /* * Buffer used to remap identity mapped pages. We only need the virtual space. * The physical page behind this address is remapped as needed to different @@ -452,6 +461,8 @@ static unsigned long __init xen_foreach_remap_area( * to be remapped memory itself in a linked list anchored at xen_remap_mfn. * This scheme allows to remap the different chunks in arbitrary order while * the resulting mapping will be independent from the order. + * In case xen_e820_resolve_conflicts() did relocate some non-RAM E820 + * entries, set the correct P2M information for the affected pages. */ void __init xen_remap_memory(void) { @@ -495,6 +506,29 @@ void __init xen_remap_memory(void) set_pte_mfn(buf, mfn_save, PAGE_KERNEL); pr_info("Remapped %ld page(s)\n", remapped); + + if (nr_nonram_remap == 0) + return; + + remapped = 0; + for (i = 0; i < nr_nonram_remap; i++) { + struct nonram_remap *remap = xen_nonram_remap + i; + + pfn = PFN_DOWN(remap->paddr); + mfn_save = PFN_DOWN(remap->maddr); + for (len = 0; len < remap->size; len += PAGE_SIZE) { + if (!set_phys_to_machine(pfn, mfn_save)) { + WARN(1, "Failed to set p2m mapping for pfn=%ld mfn=%ld\n", + pfn, mfn_save); + BUG(); + } + pfn++; + mfn_save++; + remapped++; + } + } + + pr_info("Remapped %ld non-RAM page(s)\n", remapped); } static unsigned long __init xen_get_pages_limit(void) @@ -625,14 +659,111 @@ phys_addr_t __init xen_find_free_area(phys_addr_t size) return 0; } +/* + * Swap a non-RAM E820 map entry with RAM above ini_nr_pages. + * Note that the E820 map is modified accordingly, but the P2M map isn't yet. + * The adaption of the P2M must be deferred until page allocation is possible. + */ +static void __init xen_e820_swap_entry_with_ram(struct e820_entry *swap_entry) +{ + struct e820_entry *entry; + unsigned int mapcnt; + phys_addr_t mem_end = PFN_PHYS(ini_nr_pages); + struct nonram_remap *remap; + phys_addr_t swap_addr, swap_size, entry_end; + + if (nr_nonram_remap == NR_NONRAM_REMAP) { + xen_raw_console_write("Number of required E820 entry remapping actions exceed maximum value\n"); + BUG(); + } + + swap_addr = PAGE_ALIGN_DOWN(swap_entry->addr); + swap_size = PAGE_ALIGN(swap_entry->addr - swap_addr + swap_entry->size); + remap = xen_nonram_remap + nr_nonram_remap; + entry = xen_e820_table.entries; + + for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) { + entry_end = entry->addr + entry->size; + if (entry->type == E820_TYPE_RAM && entry->size >= swap_size && + entry_end - swap_size >= mem_end) { + /* Reduce RAM entry by needed space (whole pages). */ + entry->size -= swap_size; + + /* Add new entry at the end of E820 map. */ + entry = xen_e820_table.entries + + xen_e820_table.nr_entries; + xen_e820_table.nr_entries++; + + /* Fill new entry (keep size and page offset). */ + entry->type = swap_entry->type; + entry->addr = entry_end - swap_size + + swap_addr - swap_entry->addr; + entry->size = swap_entry->size; + + /* Convert old entry to RAM, align to pages. */ + swap_entry->type = E820_TYPE_RAM; + swap_entry->addr = swap_addr; + swap_entry->size = swap_size; + + /* Remember PFN<->MFN relation for P2M update. */ + remap->maddr = swap_addr; + remap->size = swap_size; + remap->paddr = entry_end - swap_size; + nr_nonram_remap++; + + /* Order E820 table and merge entries. */ + e820__update_table(&xen_e820_table); + + return; + } + + entry++; + } + + xen_raw_console_write("No suitable area found for required E820 entry remapping action\n"); + BUG(); +} + +/* + * Look for non-RAM memory types in a specific guest physical area and move + * those away if possible (ACPI NVS only for now). + */ +static void __init xen_e820_resolve_conflicts(phys_addr_t start, + phys_addr_t size) +{ + struct e820_entry *entry; + unsigned int mapcnt; + phys_addr_t end; + + if (!size) + return; + + end = start + size; + entry = xen_e820_table.entries; + + for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) { + if (entry->addr >= end) + return; + + if (entry->addr + entry->size > start && + entry->type == E820_TYPE_NVS) + xen_e820_swap_entry_with_ram(entry); + + entry++; + } +} + /* * Check for an area in physical memory to be usable for non-movable purposes. - * An area is considered to usable if the used E820 map lists it to be RAM. + * An area is considered to usable if the used E820 map lists it to be RAM or + * some other type which can be moved to higher PFNs while keeping the MFNs. * In case the area is not usable, crash the system with an error message. */ void __init xen_chk_is_e820_usable(phys_addr_t start, phys_addr_t size, const char *component) { + xen_e820_resolve_conflicts(start, size); + if (!xen_is_e820_reserved(start, size)) return;