From nobody Wed Dec 17 21:27:35 2025 Received: from galois.linutronix.de (Galois.linutronix.de [193.142.43.55]) (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 866251FF7AC; Fri, 6 Dec 2024 10:16:47 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=193.142.43.55 ARC-Seal: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733480209; cv=none; b=Yao4PO3YV1iHB+kotNeKJpmeXwuDudCKqOA/liax7wppx31Lclhd1cH86uNAzw5meClnzTJIHFnjYNwhyZlBpxgcDYODUKeTgWXRCa6jPkdwuX13IrfklmwwCRdTk9cXsCVJQSKtk7yD4ulY0Oc+wM6XKZkMdNOt03mG/Kk2Xtw= ARC-Message-Signature: i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733480209; c=relaxed/simple; bh=uo6jgoyTB9RBqNSHvd6Qsk0dDh2pcRgV2pmlSGICkA4=; h=Date:From:To:Subject:Cc:In-Reply-To:References:MIME-Version: Message-ID:Content-Type; b=oFEjI7VEw8slwRupRLddFckyuLENLfghfU26qyfS2CdWj7/Ll1E9kr2jk58eeSpH2/TZTachtJOG0hXw4bbJXD7OjCmg3BBSs8p4EKSbfFg6iL7o05HJY8qKIdQoMtX4BqV/ARaIPX1sEKH2pQWz7d6U6HWUg8GD8ijeEN525IU= ARC-Authentication-Results: i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de; spf=pass smtp.mailfrom=linutronix.de; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=en2Fvn/x; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b=ekzJP/9b; arc=none smtp.client-ip=193.142.43.55 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linutronix.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linutronix.de Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="en2Fvn/x"; dkim=permerror (0-bit key) header.d=linutronix.de header.i=@linutronix.de header.b="ekzJP/9b" Date: Fri, 06 Dec 2024 10:16:45 -0000 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020; t=1733480205; h=from:from:sender:sender:reply-to:reply-to:subject:subject: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=2uNY76JKDMptvZ3ZZH2ykHka+gt7LlO+hkSRCYbVkS8=; b=en2Fvn/xjteyLAbJrxWC3BVvdZGt9eIOWHOPwun4T4/e+NMst9phvIRQW3z7z8PiIcK9wU erNu1FIFmOGIS4lLqIKzJgX9507ZRlQUQH6eC/AcK3fj4xBjU6hf9Sy55JMofOkYU/HKLl BpN2q0OCVKkeLUMDiA4+7NFRW7wyxOGnEzP/oR0CASkUm2uvLk9qgwnOpoQ9uoYQxIwZz7 3b6asR7zVdYm+CKc1Jzv3OyfSigoxMA/WCnXlkqXdlr8krHVyKjeZozezF/q8K1eIruLXL PlZjGX4BFDqG8hHz98zuynItoqwAgYCf8ZnpcERoK/Hm4MidqGcNg2ODD++ROg== DKIM-Signature: v=1; a=ed25519-sha256; c=relaxed/relaxed; d=linutronix.de; s=2020e; t=1733480205; h=from:from:sender:sender:reply-to:reply-to:subject:subject: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=2uNY76JKDMptvZ3ZZH2ykHka+gt7LlO+hkSRCYbVkS8=; b=ekzJP/9b+xgsh51LorOI9FMInSxOnEAz1IUzPV+6r1IiNZ0q9N9nxVvOpTPEZPkfkTRpbJ rHvW6LW4rZsje7AA== From: "tip-bot2 for David Woodhouse" Sender: tip-bot2@linutronix.de Reply-to: linux-kernel@vger.kernel.org To: linux-tip-commits@vger.kernel.org Subject: [tip: x86/boot] x86/kexec: Drop page_list argument from relocate_kernel() Cc: David Woodhouse , Ingo Molnar , Baoquan He , Vivek Goyal , Dave Young , Eric Biederman , Ard Biesheuvel , "H. Peter Anvin" , x86@kernel.org, linux-kernel@vger.kernel.org In-Reply-To: <20241205153343.3275139-11-dwmw2@infradead.org> References: <20241205153343.3275139-11-dwmw2@infradead.org> Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Message-ID: <173348020509.412.16473323990956408472.tip-bot2@tip-bot2> Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails Precedence: bulk Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable The following commit has been merged into the x86/boot branch of tip: Commit-ID: b3adabae8a96fee62184f4236bf60313b35244e9 Gitweb: https://git.kernel.org/tip/b3adabae8a96fee62184f4236bf60313b= 35244e9 Author: David Woodhouse AuthorDate: Thu, 05 Dec 2024 15:05:16=20 Committer: Ingo Molnar CommitterDate: Fri, 06 Dec 2024 10:42:00 +01:00 x86/kexec: Drop page_list argument from relocate_kernel() The kernel's virtual mapping of the relocate_kernel page currently needs to be RWX because it is written to before the %cr3 switch. Now that the relocate_kernel page has its own .data section and local variables, it can also have *global* variables. So eliminate the separate page_list argument, and write the same information directly to variables in the relocate_kernel page instead. This way, the relocate_kernel code itself doesn't need to copy it. Signed-off-by: David Woodhouse Signed-off-by: Ingo Molnar Cc: Baoquan He Cc: Vivek Goyal Cc: Dave Young Cc: Eric Biederman Cc: Ard Biesheuvel Cc: "H. Peter Anvin" Link: https://lore.kernel.org/r/20241205153343.3275139-11-dwmw2@infradead.o= rg --- arch/x86/include/asm/kexec.h | 12 +++------ arch/x86/kernel/machine_kexec_64.c | 18 +++++--------- arch/x86/kernel/relocate_kernel_64.S | 36 +++++++++------------------ 3 files changed, 24 insertions(+), 42 deletions(-) diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h index ccb8ff3..48e4f44 100644 --- a/arch/x86/include/asm/kexec.h +++ b/arch/x86/include/asm/kexec.h @@ -8,12 +8,6 @@ # define PA_PGD 2 # define PA_SWAP_PAGE 3 # define PAGES_NR 4 -#else -# define PA_CONTROL_PAGE 0 -# define VA_CONTROL_PAGE 1 -# define PA_TABLE_PAGE 2 -# define PA_SWAP_PAGE 3 -# define PAGES_NR 4 #endif =20 # define KEXEC_CONTROL_PAGE_SIZE 4096 @@ -60,6 +54,10 @@ struct kimage; =20 /* The native architecture */ # define KEXEC_ARCH KEXEC_ARCH_X86_64 + +extern unsigned long kexec_va_control_page; +extern unsigned long kexec_pa_table_page; +extern unsigned long kexec_pa_swap_page; #endif =20 /* @@ -122,7 +120,7 @@ relocate_kernel(unsigned long indirection_page, #else unsigned long relocate_kernel(unsigned long indirection_page, - unsigned long page_list, + unsigned long pa_control_page, unsigned long start_address, unsigned int preserve_context, unsigned int host_mem_enc_active); diff --git a/arch/x86/kernel/machine_kexec_64.c b/arch/x86/kernel/machine_k= exec_64.c index 63dca5c..c9fd60f 100644 --- a/arch/x86/kernel/machine_kexec_64.c +++ b/arch/x86/kernel/machine_kexec_64.c @@ -315,6 +315,11 @@ int machine_kexec_prepare(struct kimage *image) result =3D init_pgtable(image, __pa(control_page)); if (result) return result; + kexec_va_control_page =3D (unsigned long)control_page; + kexec_pa_table_page =3D (unsigned long)__pa(image->arch.pgd); + + if (image->type =3D=3D KEXEC_TYPE_DEFAULT) + kexec_pa_swap_page =3D page_to_pfn(image->swap_page) << PAGE_SHIFT; =20 __memcpy(control_page, __relocate_kernel_start, reloc_end - reloc_start); =20 @@ -339,12 +344,11 @@ void machine_kexec_cleanup(struct kimage *image) void machine_kexec(struct kimage *image) { unsigned long (*relocate_kernel_ptr)(unsigned long indirection_page, - unsigned long page_list, + unsigned long pa_control_page, unsigned long start_address, unsigned int preserve_context, unsigned int host_mem_enc_active); unsigned long reloc_start =3D (unsigned long)__relocate_kernel_start; - unsigned long page_list[PAGES_NR]; unsigned int host_mem_enc_active; int save_ftrace_enabled; void *control_page; @@ -382,14 +386,6 @@ void machine_kexec(struct kimage *image) =20 control_page =3D page_address(image->control_code_page); =20 - page_list[PA_CONTROL_PAGE] =3D virt_to_phys(control_page); - page_list[VA_CONTROL_PAGE] =3D (unsigned long)control_page; - page_list[PA_TABLE_PAGE] =3D (unsigned long)__pa(image->arch.pgd); - - if (image->type =3D=3D KEXEC_TYPE_DEFAULT) - page_list[PA_SWAP_PAGE] =3D (page_to_pfn(image->swap_page) - << PAGE_SHIFT); - /* * Allow for the possibility that relocate_kernel might not be at * the very start of the page. @@ -417,7 +413,7 @@ void machine_kexec(struct kimage *image) =20 /* now call it */ image->start =3D relocate_kernel_ptr((unsigned long)image->head, - (unsigned long)page_list, + virt_to_phys(control_page), image->start, image->preserve_context, host_mem_enc_active); diff --git a/arch/x86/kernel/relocate_kernel_64.S b/arch/x86/kernel/relocat= e_kernel_64.S index f13866a..d52c3bb 100644 --- a/arch/x86/kernel/relocate_kernel_64.S +++ b/arch/x86/kernel/relocate_kernel_64.S @@ -34,9 +34,9 @@ SYM_DATA_LOCAL(saved_cr0, .quad 0) SYM_DATA_LOCAL(saved_cr3, .quad 0) SYM_DATA_LOCAL(saved_cr4, .quad 0) /* other data */ -SYM_DATA_LOCAL(va_control_page, .quad 0) -SYM_DATA_LOCAL(pa_table_page, .quad 0) -SYM_DATA_LOCAL(pa_swap_page, .quad 0) +SYM_DATA(kexec_va_control_page, .quad 0) +SYM_DATA(kexec_pa_table_page, .quad 0) +SYM_DATA(kexec_pa_swap_page, .quad 0) SYM_DATA_LOCAL(pa_backup_pages_map, .quad 0) =20 .section .text.relocate_kernel,"ax"; @@ -46,7 +46,7 @@ SYM_CODE_START_NOALIGN(relocate_kernel) ANNOTATE_NOENDBR /* * %rdi indirection_page - * %rsi page_list + * %rsi pa_control_page * %rdx start address * %rcx preserve_context * %r8 host_mem_enc_active @@ -79,31 +79,19 @@ SYM_CODE_START_NOALIGN(relocate_kernel) /* Save SME active flag */ movq %r8, %r12 =20 - /* - * get physical and virtual address of control page now - * this is impossible after page table switch - */ - movq PTR(PA_CONTROL_PAGE)(%rsi), %r8 - movq PTR(VA_CONTROL_PAGE)(%rsi), %r11 - - /* get physical address of page table now too */ - movq PTR(PA_TABLE_PAGE)(%rsi), %r9 - - /* get physical address of swap page now */ - movq PTR(PA_SWAP_PAGE)(%rsi), %r10 - - /* save some information for jumping back */ - movq %r9, pa_table_page(%rip) - movq %r10, pa_swap_page(%rip) + /* save indirection list for jumping back */ movq %rdi, pa_backup_pages_map(%rip) - movq %r11, va_control_page(%rip) =20 /* Save the preserve_context to %r11 as swap_pages clobbers %rcx. */ movq %rcx, %r11 =20 /* Switch to the identity mapped page tables */ + movq kexec_pa_table_page(%rip), %r9 movq %r9, %cr3 =20 + /* Physical address of control page */ + movq %rsi, %r8 + /* setup a new stack at the end of the physical control page */ lea PAGE_SIZE(%r8), %rsp =20 @@ -227,13 +215,13 @@ SYM_CODE_START_LOCAL_NOALIGN(identity_mapped) /* get the re-entry point of the peer system */ movq 0(%rsp), %rbp leaq relocate_kernel(%rip), %r8 - movq pa_swap_page(%rip), %r10 + movq kexec_pa_swap_page(%rip), %r10 movq pa_backup_pages_map(%rip), %rdi - movq pa_table_page(%rip), %rax + movq kexec_pa_table_page(%rip), %rax movq %rax, %cr3 lea PAGE_SIZE(%r8), %rsp call swap_pages - movq va_control_page(%rip), %rax + movq kexec_va_control_page(%rip), %rax addq $(virtual_mapped - relocate_kernel), %rax pushq %rax ANNOTATE_UNRET_SAFE