From nobody Wed Dec 17 14:38:14 2025 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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 86D15C4332F for ; Mon, 30 Oct 2023 14:26:21 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233523AbjJ3O0U (ORCPT ); Mon, 30 Oct 2023 10:26:20 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:43378 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233771AbjJ3OZv (ORCPT ); Mon, 30 Oct 2023 10:25:51 -0400 Received: from smtp-out2.suse.de (smtp-out2.suse.de [IPv6:2001:67c:2178:6::1d]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EF67C11A for ; Mon, 30 Oct 2023 07:25:41 -0700 (PDT) Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by smtp-out2.suse.de (Postfix) with ESMTPS id 43C071FE71; Mon, 30 Oct 2023 14:25:40 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1698675940; h=from:from:reply-to:date:date:message-id:message-id:to:to:cc:cc: mime-version:mime-version: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=9Xm3XX0lpogqG4X8OBm0jw7upX4JQzBbrWGV4vURmd8=; b=B367c5izNqhlevT5ZziUYl9KghzgVkFfXEMKLDYFKP0ichZbM8O8GWZzHoO0MgTKEuqNsF lMRDyd4MN5Wh84wrUMybsEZxSy4sq7668FHRXybQv+cF9uoKIjR5vlEGTqIkAWiXFP1mqC gw94y2URnBmB+uazBpE6+3esyaWI8lE= Received: from imap2.suse-dmz.suse.de (imap2.suse-dmz.suse.de [192.168.254.74]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-521) server-digest SHA512) (No client certificate requested) by imap2.suse-dmz.suse.de (Postfix) with ESMTPS id D5584138F8; Mon, 30 Oct 2023 14:25:39 +0000 (UTC) Received: from dovecot-director2.suse.de ([192.168.254.65]) by imap2.suse-dmz.suse.de with ESMTPSA id HPi7MuO8P2UfQQAAMHmgww (envelope-from ); Mon, 30 Oct 2023 14:25:39 +0000 From: Juergen Gross To: linux-kernel@vger.kernel.org, x86@kernel.org, virtualization@lists.linux-foundation.org Cc: Juergen Gross , Ajay Kaher , Alexey Makhalov , VMware PV-Drivers Reviewers , Thomas Gleixner , Ingo Molnar , Borislav Petkov , Dave Hansen , "H. Peter Anvin" , Peter Zijlstra Subject: [PATCH v4 5/5] x86/paravirt: remove no longer needed paravirt patching code Date: Mon, 30 Oct 2023 15:25:08 +0100 Message-Id: <20231030142508.1407-6-jgross@suse.com> X-Mailer: git-send-email 2.35.3 In-Reply-To: <20231030142508.1407-1-jgross@suse.com> References: <20231030142508.1407-1-jgross@suse.com> MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Type: text/plain; charset="utf-8" Now that paravirt is using the alternatives patching infrastructure, remove the paravirt patching code. Signed-off-by: Juergen Gross Acked-by: Peter Zijlstra (Intel) --- arch/x86/include/asm/paravirt.h | 18 -------- arch/x86/include/asm/paravirt_types.h | 40 ---------------- arch/x86/include/asm/text-patching.h | 12 ----- arch/x86/kernel/alternative.c | 66 +-------------------------- arch/x86/kernel/paravirt.c | 30 ------------ arch/x86/kernel/vmlinux.lds.S | 13 ------ arch/x86/tools/relocs.c | 2 +- 7 files changed, 3 insertions(+), 178 deletions(-) diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravir= t.h index 9c6c5cfa9fe2..f09acce9432c 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -725,31 +725,13 @@ void native_pv_lock_init(void) __init; =20 #else /* __ASSEMBLY__ */ =20 -#define _PVSITE(ptype, ops, word, algn) \ -771:; \ - ops; \ -772:; \ - .pushsection .parainstructions,"a"; \ - .align algn; \ - word 771b; \ - .byte ptype; \ - .byte 772b-771b; \ - _ASM_ALIGN; \ - .popsection - - #ifdef CONFIG_X86_64 #ifdef CONFIG_PARAVIRT_XXL #ifdef CONFIG_DEBUG_ENTRY =20 -#define PARA_PATCH(off) ((off) / 8) -#define PARA_SITE(ptype, ops) _PVSITE(ptype, ops, .quad, 8) #define PARA_INDIRECT(addr) *addr(%rip) =20 .macro PARA_IRQ_save_fl - PARA_SITE(PARA_PATCH(PV_IRQ_save_fl), - ANNOTATE_RETPOLINE_SAFE; - call PARA_INDIRECT(pv_ops+PV_IRQ_save_fl);) ANNOTATE_RETPOLINE_SAFE; call PARA_INDIRECT(pv_ops+PV_IRQ_save_fl); .endm diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/p= aravirt_types.h index 9b0526967d69..15d2b83ce410 100644 --- a/arch/x86/include/asm/paravirt_types.h +++ b/arch/x86/include/asm/paravirt_types.h @@ -2,15 +2,6 @@ #ifndef _ASM_X86_PARAVIRT_TYPES_H #define _ASM_X86_PARAVIRT_TYPES_H =20 -#ifndef __ASSEMBLY__ -/* These all sit in the .parainstructions section to tell us what to patch= . */ -struct paravirt_patch_site { - u8 *instr; /* original instructions */ - u8 type; /* type of this instruction */ - u8 len; /* length of original instruction */ -}; -#endif - #ifdef CONFIG_PARAVIRT =20 #ifndef __ASSEMBLY__ @@ -250,34 +241,6 @@ struct paravirt_patch_template { extern struct pv_info pv_info; extern struct paravirt_patch_template pv_ops; =20 -#define PARAVIRT_PATCH(x) \ - (offsetof(struct paravirt_patch_template, x) / sizeof(void *)) - -#define paravirt_type(op) \ - [paravirt_typenum] "i" (PARAVIRT_PATCH(op)), \ - [paravirt_opptr] "m" (pv_ops.op) -/* - * Generate some code, and mark it as patchable by the - * apply_paravirt() alternate instruction patcher. - */ -#define _paravirt_alt(insn_string, type) \ - "771:\n\t" insn_string "\n" "772:\n" \ - ".pushsection .parainstructions,\"a\"\n" \ - _ASM_ALIGN "\n" \ - _ASM_PTR " 771b\n" \ - " .byte " type "\n" \ - " .byte 772b-771b\n" \ - _ASM_ALIGN "\n" \ - ".popsection\n" - -/* Generate patchable code, with the default asm parameters. */ -#define paravirt_alt(insn_string) \ - _paravirt_alt(insn_string, "%c[paravirt_typenum]") - -/* Simple instruction patching code. */ -#define NATIVE_LABEL(a,x,b) "\n\t.globl " a #x "_" #b "\n" a #x "_" #b ":\= n\t" - -unsigned int paravirt_patch(u8 type, void *insn_buff, unsigned long addr, = unsigned int len); #define paravirt_ptr(op) [paravirt_opptr] "m" (pv_ops.op) =20 int paravirt_disable_iospace(void); @@ -545,9 +508,6 @@ unsigned long pv_native_read_cr2(void); =20 #define paravirt_nop ((void *)nop_func) =20 -extern struct paravirt_patch_site __parainstructions[], - __parainstructions_end[]; - #endif /* __ASSEMBLY__ */ =20 #define ALT_NOT_XEN ALT_NOT(X86_FEATURE_XENPV) diff --git a/arch/x86/include/asm/text-patching.h b/arch/x86/include/asm/te= xt-patching.h index 29832c338cdc..0b70653a98c1 100644 --- a/arch/x86/include/asm/text-patching.h +++ b/arch/x86/include/asm/text-patching.h @@ -6,18 +6,6 @@ #include #include =20 -struct paravirt_patch_site; -#ifdef CONFIG_PARAVIRT -void apply_paravirt(struct paravirt_patch_site *start, - struct paravirt_patch_site *end); -#else -static inline void apply_paravirt(struct paravirt_patch_site *start, - struct paravirt_patch_site *end) -{} -#define __parainstructions NULL -#define __parainstructions_end NULL -#endif - /* * Currently, the max observed size in the kernel code is * JUMP_LABEL_NOP_SIZE/RELATIVEJUMP_SIZE, which are 5. diff --git a/arch/x86/kernel/alternative.c b/arch/x86/kernel/alternative.c index dd14db12c573..2474335e264b 100644 --- a/arch/x86/kernel/alternative.c +++ b/arch/x86/kernel/alternative.c @@ -160,7 +160,6 @@ extern s32 __retpoline_sites[], __retpoline_sites_end[]; extern s32 __return_sites[], __return_sites_end[]; extern s32 __cfi_sites[], __cfi_sites_end[]; extern s32 __ibt_endbr_seal[], __ibt_endbr_seal_end[]; -extern struct alt_instr __alt_instructions[], __alt_instructions_end[]; extern s32 __smp_locks[], __smp_locks_end[]; void text_poke_early(void *addr, const void *opcode, size_t len); =20 @@ -1466,46 +1465,6 @@ int alternatives_text_reserved(void *start, void *en= d) } #endif /* CONFIG_SMP */ =20 -#ifdef CONFIG_PARAVIRT - -/* Use this to add nops to a buffer, then text_poke the whole buffer. */ -static void __init_or_module add_nops(void *insns, unsigned int len) -{ - while (len > 0) { - unsigned int noplen =3D len; - if (noplen > ASM_NOP_MAX) - noplen =3D ASM_NOP_MAX; - memcpy(insns, x86_nops[noplen], noplen); - insns +=3D noplen; - len -=3D noplen; - } -} - -void __init_or_module apply_paravirt(struct paravirt_patch_site *start, - struct paravirt_patch_site *end) -{ - struct paravirt_patch_site *p; - char insn_buff[MAX_PATCH_LEN]; - - for (p =3D start; p < end; p++) { - unsigned int used; - - BUG_ON(p->len > MAX_PATCH_LEN); - /* prep the buffer with the original instructions */ - memcpy(insn_buff, p->instr, p->len); - used =3D paravirt_patch(p->type, insn_buff, (unsigned long)p->instr, p->= len); - - BUG_ON(used > p->len); - - /* Pad the rest with nops */ - add_nops(insn_buff + used, p->len - used); - text_poke_early(p->instr, insn_buff, p->len); - } -} -extern struct paravirt_patch_site __start_parainstructions[], - __stop_parainstructions[]; -#endif /* CONFIG_PARAVIRT */ - /* * Self-test for the INT3 based CALL emulation code. * @@ -1641,28 +1600,11 @@ void __init alternative_instructions(void) */ =20 /* - * Paravirt patching and alternative patching can be combined to - * replace a function call with a short direct code sequence (e.g. - * by setting a constant return value instead of doing that in an - * external function). - * In order to make this work the following sequence is required: - * 1. set (artificial) features depending on used paravirt - * functions which can later influence alternative patching - * 2. apply paravirt patching (generally replacing an indirect - * function call with a direct one) - * 3. apply alternative patching (e.g. replacing a direct function - * call with a custom code sequence) - * Doing paravirt patching after alternative patching would clobber - * the optimization of the custom code with a function call again. + * Make sure to set (artificial) features depending on used paravirt + * functions which can later influence alternative patching. */ paravirt_set_cap(); =20 - /* - * First patch paravirt functions, such that we overwrite the indirect - * call with the direct call. - */ - apply_paravirt(__parainstructions, __parainstructions_end); - __apply_fineibt(__retpoline_sites, __retpoline_sites_end, __cfi_sites, __cfi_sites_end, true); =20 @@ -1673,10 +1615,6 @@ void __init alternative_instructions(void) apply_retpolines(__retpoline_sites, __retpoline_sites_end); apply_returns(__return_sites, __return_sites_end); =20 - /* - * Then patch alternatives, such that those paravirt calls that are in - * alternatives can be overwritten by their immediate fragments. - */ apply_alternatives(__alt_instructions, __alt_instructions_end); =20 /* diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index acc5b1004f0f..5358d43886ad 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -43,14 +43,6 @@ void __init default_banner(void) pv_info.name); } =20 -static unsigned paravirt_patch_call(void *insn_buff, const void *target, - unsigned long addr, unsigned len) -{ - __text_gen_insn(insn_buff, CALL_INSN_OPCODE, - (void *)addr, target, CALL_INSN_SIZE); - return CALL_INSN_SIZE; -} - #ifdef CONFIG_PARAVIRT_XXL DEFINE_ASM_FUNC(_paravirt_ident_64, "mov %rdi, %rax", .text); DEFINE_ASM_FUNC(pv_native_save_fl, "pushf; pop %rax", .noinstr.text); @@ -73,28 +65,6 @@ static void native_tlb_remove_table(struct mmu_gather *t= lb, void *table) tlb_remove_page(tlb, table); } =20 -unsigned int paravirt_patch(u8 type, void *insn_buff, unsigned long addr, - unsigned int len) -{ - /* - * Neat trick to map patch type back to the call within the - * corresponding structure. - */ - void *opfunc =3D *((void **)&pv_ops + type); - unsigned ret; - - if (opfunc =3D=3D NULL) - /* If there's no function, patch it with BUG_func() */ - ret =3D paravirt_patch_call(insn_buff, BUG_func, addr, len); - else if (opfunc =3D=3D nop_func) - ret =3D 0; - else - /* Otherwise call the function. */ - ret =3D paravirt_patch_call(insn_buff, opfunc, addr, len); - - return ret; -} - struct static_key paravirt_steal_enabled; struct static_key paravirt_steal_rq_enabled; =20 diff --git a/arch/x86/kernel/vmlinux.lds.S b/arch/x86/kernel/vmlinux.lds.S index f15fb71f280e..1a3153dfaea8 100644 --- a/arch/x86/kernel/vmlinux.lds.S +++ b/arch/x86/kernel/vmlinux.lds.S @@ -270,19 +270,6 @@ SECTIONS } #endif =20 - /* - * start address and size of operations which during runtime - * can be patched with virtualization friendly instructions or - * baremetal native ones. Think page table operations. - * Details in paravirt_types.h - */ - . =3D ALIGN(8); - .parainstructions : AT(ADDR(.parainstructions) - LOAD_OFFSET) { - __parainstructions =3D .; - *(.parainstructions) - __parainstructions_end =3D .; - } - #ifdef CONFIG_RETPOLINE /* * List of instructions that call/jmp/jcc to retpoline thunks diff --git a/arch/x86/tools/relocs.c b/arch/x86/tools/relocs.c index d30949e25ebd..a3bae2b24626 100644 --- a/arch/x86/tools/relocs.c +++ b/arch/x86/tools/relocs.c @@ -66,7 +66,7 @@ static const char * const sym_regex_kernel[S_NSYMTYPES] = =3D { [S_REL] =3D "^(__init_(begin|end)|" "__x86_cpu_dev_(start|end)|" - "(__parainstructions|__alt_instructions)(_end)?|" + "__alt_instructions(_end)?|" "(__iommu_table|__apicdrivers|__smp_locks)(_end)?|" "__(start|end)_pci_.*|" #if CONFIG_FW_LOADER --=20 2.35.3