From: Anthony Yznaga <anthony.yznaga@oracle.com> To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, rppt@kernel.org, akpm@linux-foundation.org, ebiederm@xmission.com, keescook@chromium.org, graf@amazon.com, jason.zeng@intel.com, lei.l.li@intel.com, steven.sistare@oracle.com, fam.zheng@bytedance.com, mgalaxy@akamai.com, kexec@lists.infradead.org Subject: [RFC v3 21/21] x86/boot/compressed/64: use 1GB pages for mappings Date: Wed, 26 Apr 2023 17:08:57 -0700 [thread overview] Message-ID: <1682554137-13938-22-git-send-email-anthony.yznaga@oracle.com> (raw) In-Reply-To: <1682554137-13938-1-git-send-email-anthony.yznaga@oracle.com> pkram kaslr code can incur multiple page faults when it walks its preserved ranges list called via mem_avoid_overlap(). The multiple faults can easily end up using up the small number of pages available to be allocated for page table pages. This patch hacks things so that mappings are 1GB which results in the need for far fewer page table pages. As is this breaks AMD SEV-ES which expects the mappings to be 2M. This could possibly be fixed by updating split code to split 1GB page if the aren't any other issues with using 1GB mappings. Signed-off-by: Anthony Yznaga <anthony.yznaga@oracle.com> --- arch/x86/boot/compressed/ident_map_64.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/x86/boot/compressed/ident_map_64.c b/arch/x86/boot/compressed/ident_map_64.c index 321a5011042d..1e02cf6dda3c 100644 --- a/arch/x86/boot/compressed/ident_map_64.c +++ b/arch/x86/boot/compressed/ident_map_64.c @@ -95,8 +95,8 @@ void kernel_add_identity_map(unsigned long start, unsigned long end) int ret; /* Align boundary to 2M. */ - start = round_down(start, PMD_SIZE); - end = round_up(end, PMD_SIZE); + start = round_down(start, PUD_SIZE); + end = round_up(end, PUD_SIZE); if (start >= end) return; @@ -120,6 +120,7 @@ void initialize_identity_maps(void *rmode) mapping_info.context = &pgt_data; mapping_info.page_flag = __PAGE_KERNEL_LARGE_EXEC | sme_me_mask; mapping_info.kernpg_flag = _KERNPG_TABLE; + mapping_info.direct_gbpages = true; /* * It should be impossible for this not to already be true, @@ -365,8 +366,8 @@ void do_boot_page_fault(struct pt_regs *regs, unsigned long error_code) ghcb_fault = sev_es_check_ghcb_fault(address); - address &= PMD_MASK; - end = address + PMD_SIZE; + address &= PUD_MASK; + end = address + PUD_SIZE; /* * Check for unexpected error codes. Unexpected are: -- 1.9.4
WARNING: multiple messages have this Message-ID (diff)
From: Anthony Yznaga <anthony.yznaga@oracle.com> To: linux-mm@kvack.org, linux-kernel@vger.kernel.org Cc: tglx@linutronix.de, mingo@redhat.com, bp@alien8.de, x86@kernel.org, hpa@zytor.com, dave.hansen@linux.intel.com, luto@kernel.org, peterz@infradead.org, rppt@kernel.org, akpm@linux-foundation.org, ebiederm@xmission.com, keescook@chromium.org, graf@amazon.com, jason.zeng@intel.com, lei.l.li@intel.com, steven.sistare@oracle.com, fam.zheng@bytedance.com, mgalaxy@akamai.com, kexec@lists.infradead.org Subject: [RFC v3 21/21] x86/boot/compressed/64: use 1GB pages for mappings Date: Wed, 26 Apr 2023 17:08:57 -0700 [thread overview] Message-ID: <1682554137-13938-22-git-send-email-anthony.yznaga@oracle.com> (raw) In-Reply-To: <1682554137-13938-1-git-send-email-anthony.yznaga@oracle.com> pkram kaslr code can incur multiple page faults when it walks its preserved ranges list called via mem_avoid_overlap(). The multiple faults can easily end up using up the small number of pages available to be allocated for page table pages. This patch hacks things so that mappings are 1GB which results in the need for far fewer page table pages. As is this breaks AMD SEV-ES which expects the mappings to be 2M. This could possibly be fixed by updating split code to split 1GB page if the aren't any other issues with using 1GB mappings. Signed-off-by: Anthony Yznaga <anthony.yznaga@oracle.com> --- arch/x86/boot/compressed/ident_map_64.c | 9 +++++---- 1 file changed, 5 insertions(+), 4 deletions(-) diff --git a/arch/x86/boot/compressed/ident_map_64.c b/arch/x86/boot/compressed/ident_map_64.c index 321a5011042d..1e02cf6dda3c 100644 --- a/arch/x86/boot/compressed/ident_map_64.c +++ b/arch/x86/boot/compressed/ident_map_64.c @@ -95,8 +95,8 @@ void kernel_add_identity_map(unsigned long start, unsigned long end) int ret; /* Align boundary to 2M. */ - start = round_down(start, PMD_SIZE); - end = round_up(end, PMD_SIZE); + start = round_down(start, PUD_SIZE); + end = round_up(end, PUD_SIZE); if (start >= end) return; @@ -120,6 +120,7 @@ void initialize_identity_maps(void *rmode) mapping_info.context = &pgt_data; mapping_info.page_flag = __PAGE_KERNEL_LARGE_EXEC | sme_me_mask; mapping_info.kernpg_flag = _KERNPG_TABLE; + mapping_info.direct_gbpages = true; /* * It should be impossible for this not to already be true, @@ -365,8 +366,8 @@ void do_boot_page_fault(struct pt_regs *regs, unsigned long error_code) ghcb_fault = sev_es_check_ghcb_fault(address); - address &= PMD_MASK; - end = address + PMD_SIZE; + address &= PUD_MASK; + end = address + PUD_SIZE; /* * Check for unexpected error codes. Unexpected are: -- 1.9.4 _______________________________________________ kexec mailing list kexec@lists.infradead.org http://lists.infradead.org/mailman/listinfo/kexec
next prev parent reply other threads:[~2023-04-27 0:10 UTC|newest] Thread overview: 64+ messages / expand[flat|nested] mbox.gz Atom feed top 2023-04-27 0:08 [RFC v3 00/21] Preserved-over-Kexec RAM Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 01/21] mm: add PKRAM API stubs and Kconfig Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 02/21] mm: PKRAM: implement node load and save functions Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 03/21] mm: PKRAM: implement object " Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 04/21] mm: PKRAM: implement folio stream operations Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 05/21] mm: PKRAM: implement byte " Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 06/21] mm: PKRAM: link nodes by pfn before reboot Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 07/21] mm: PKRAM: introduce super block Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-06-05 2:40 ` Coiby Xu 2023-06-05 2:40 ` Coiby Xu 2023-06-06 2:01 ` Anthony Yznaga 2023-06-06 2:01 ` Anthony Yznaga 2023-06-06 2:55 ` Coiby Xu 2023-06-06 2:55 ` Coiby Xu 2023-06-06 3:12 ` Anthony Yznaga 2023-06-06 3:12 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 08/21] PKRAM: track preserved pages in a physical mapping pagetable Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 09/21] PKRAM: pass a list of preserved ranges to the next kernel Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 10/21] PKRAM: prepare for adding preserved ranges to memblock reserved Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 11/21] mm: PKRAM: reserve preserved memory at boot Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 12/21] PKRAM: free the preserved ranges list Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 13/21] PKRAM: prevent inadvertent use of a stale superblock Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 14/21] PKRAM: provide a way to ban pages from use by PKRAM Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 15/21] kexec: PKRAM: prevent kexec clobbering preserved pages in some cases Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 16/21] PKRAM: provide a way to check if a memory range has preserved pages Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 17/21] kexec: PKRAM: avoid clobbering already " Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 18/21] mm: PKRAM: allow preserved memory to be freed from userspace Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 19/21] PKRAM: disable feature when running the kdump kernel Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` [RFC v3 20/21] x86/KASLR: PKRAM: support physical kaslr Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga 2023-04-27 0:08 ` Anthony Yznaga [this message] 2023-04-27 0:08 ` [RFC v3 21/21] x86/boot/compressed/64: use 1GB pages for mappings Anthony Yznaga 2023-04-27 18:40 ` H. Peter Anvin 2023-04-27 18:40 ` H. Peter Anvin 2023-04-27 22:38 ` Anthony Yznaga 2023-04-27 22:38 ` Anthony Yznaga 2023-05-26 13:57 ` [RFC v3 00/21] Preserved-over-Kexec RAM Gowans, James 2023-05-26 13:57 ` Gowans, James 2023-05-31 23:14 ` Anthony Yznaga 2023-05-31 23:14 ` Anthony Yznaga 2023-06-01 2:15 ` Baoquan He 2023-06-01 2:15 ` Baoquan He 2023-06-01 23:58 ` Anthony Yznaga 2023-06-01 23:58 ` Anthony Yznaga
Reply instructions: You may reply publicly to this message via plain-text email using any one of the following methods: * Save the following mbox file, import it into your mail client, and reply-to-all from there: mbox Avoid top-posting and favor interleaved quoting: https://en.wikipedia.org/wiki/Posting_style#Interleaved_style * Reply using the --to, --cc, and --in-reply-to switches of git-send-email(1): git send-email \ --in-reply-to=1682554137-13938-22-git-send-email-anthony.yznaga@oracle.com \ --to=anthony.yznaga@oracle.com \ --cc=akpm@linux-foundation.org \ --cc=bp@alien8.de \ --cc=dave.hansen@linux.intel.com \ --cc=ebiederm@xmission.com \ --cc=fam.zheng@bytedance.com \ --cc=graf@amazon.com \ --cc=hpa@zytor.com \ --cc=jason.zeng@intel.com \ --cc=keescook@chromium.org \ --cc=kexec@lists.infradead.org \ --cc=lei.l.li@intel.com \ --cc=linux-kernel@vger.kernel.org \ --cc=linux-mm@kvack.org \ --cc=luto@kernel.org \ --cc=mgalaxy@akamai.com \ --cc=mingo@redhat.com \ --cc=peterz@infradead.org \ --cc=rppt@kernel.org \ --cc=steven.sistare@oracle.com \ --cc=tglx@linutronix.de \ --cc=x86@kernel.org \ /path/to/YOUR_REPLY https://kernel.org/pub/software/scm/git/docs/git-send-email.html * If your mail client supports setting the In-Reply-To header via mailto: links, try the mailto: linkBe sure your reply has a Subject: header at the top and a blank line before the message body.
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.