From patchwork Tue Mar 9 13:48:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: =?utf-8?b?SsO8cmdlbiBHcm/Dnw==?= X-Patchwork-Id: 12125343 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-18.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 86A92C433E9 for ; Tue, 9 Mar 2021 13:48:55 +0000 (UTC) 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 mail.kernel.org (Postfix) with ESMTPS id 2A49D650BD for ; Tue, 9 Mar 2021 13:48:55 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 2A49D650BD Authentication-Results: mail.kernel.org; dmarc=fail (p=quarantine dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from list by lists.xenproject.org with outflank-mailman.95423.180203 (Exim 4.92) (envelope-from ) id 1lJcj9-0004d2-7S; Tue, 09 Mar 2021 13:48:47 +0000 X-Outflank-Mailman: Message body and most headers restored to incoming version Received: by outflank-mailman (output) from mailman id 95423.180203; Tue, 09 Mar 2021 13:48:47 +0000 Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lJcj9-0004co-2G; Tue, 09 Mar 2021 13:48:47 +0000 Received: by outflank-mailman (input) for mailman id 95423; Tue, 09 Mar 2021 13:48:45 +0000 Received: from all-amaz-eas1.inumbo.com ([34.197.232.57] helo=us1-amaz-eas2.inumbo.com) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1lJcj7-0003yx-NS for xen-devel@lists.xenproject.org; Tue, 09 Mar 2021 13:48:45 +0000 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 2db0731f-4296-4b86-a25b-e0a4cd46dc34; Tue, 09 Mar 2021 13:48:22 +0000 (UTC) Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id E3B23ADE3; Tue, 9 Mar 2021 13:48:21 +0000 (UTC) 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: 2db0731f-4296-4b86-a25b-e0a4cd46dc34 X-Virus-Scanned: by amavisd-new at test-mx.suse.de DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=suse.com; s=susede1; t=1615297702; 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=dBMxkHZRKnqu5bpydqyKw7Gq6TegdcdkrUPgCcZVPrk=; b=lFrrgPDdUQxhI3L1q2BmyIa+SOFdXgbqADTbGMuyipWS0A2bvVX0DjBW0al+EY21nHxjj0 00/mj2AL1y3BHdmaOMPK+HKRYHTzudYbM4czQY+Fyd7i8qdni8CXY/WbahKPX05rbaQMDr 4tdSP1lkxHYwXmbrTDvRxdCf1FDs2z0= From: Juergen Gross To: xen-devel@lists.xenproject.org, x86@kernel.org, virtualization@lists.linux-foundation.org, linux-kernel@vger.kernel.org Cc: Juergen Gross , Deep Shah , "VMware, Inc." , Thomas Gleixner , Ingo Molnar , Borislav Petkov , "H. Peter Anvin" , Boris Ostrovsky , Stefano Stabellini , Peter Zijlstra Subject: [PATCH v6 09/12] x86/paravirt: switch iret pvops to ALTERNATIVE Date: Tue, 9 Mar 2021 14:48:10 +0100 Message-Id: <20210309134813.23912-10-jgross@suse.com> X-Mailer: git-send-email 2.26.2 In-Reply-To: <20210309134813.23912-1-jgross@suse.com> References: <20210309134813.23912-1-jgross@suse.com> MIME-Version: 1.0 The iret paravirt op is rather special as it is using a jmp instead of a call instruction. Switch it to ALTERNATIVE. Signed-off-by: Juergen Gross Acked-by: Peter Zijlstra (Intel) --- V3: - use ALTERNATIVE_TERNARY --- arch/x86/include/asm/paravirt.h | 6 +++--- arch/x86/include/asm/paravirt_types.h | 5 +---- arch/x86/kernel/asm-offsets.c | 5 ----- arch/x86/kernel/paravirt.c | 26 ++------------------------ arch/x86/xen/enlighten_pv.c | 3 +-- 5 files changed, 7 insertions(+), 38 deletions(-) diff --git a/arch/x86/include/asm/paravirt.h b/arch/x86/include/asm/paravirt.h index c6496a82fad1..36cd71fa097f 100644 --- a/arch/x86/include/asm/paravirt.h +++ b/arch/x86/include/asm/paravirt.h @@ -749,9 +749,9 @@ extern void default_banner(void); #define PARA_INDIRECT(addr) *addr(%rip) #define INTERRUPT_RETURN \ - PARA_SITE(PARA_PATCH(PV_CPU_iret), \ - ANNOTATE_RETPOLINE_SAFE; \ - jmp PARA_INDIRECT(pv_ops+PV_CPU_iret);) + ANNOTATE_RETPOLINE_SAFE; \ + ALTERNATIVE_TERNARY("jmp *paravirt_iret(%rip);", \ + X86_FEATURE_XENPV, "jmp xen_iret;", "jmp native_iret;") #ifdef CONFIG_DEBUG_ENTRY #define SAVE_FLAGS(clobbers) \ diff --git a/arch/x86/include/asm/paravirt_types.h b/arch/x86/include/asm/paravirt_types.h index 45bd21647dd8..0afdac83f926 100644 --- a/arch/x86/include/asm/paravirt_types.h +++ b/arch/x86/include/asm/paravirt_types.h @@ -151,10 +151,6 @@ struct pv_cpu_ops { u64 (*read_pmc)(int counter); - /* Normal iret. Jump to this with the standard iret stack - frame set up. */ - void (*iret)(void); - void (*start_context_switch)(struct task_struct *prev); void (*end_context_switch)(struct task_struct *next); #endif @@ -294,6 +290,7 @@ struct paravirt_patch_template { extern struct pv_info pv_info; extern struct paravirt_patch_template pv_ops; +extern void (*paravirt_iret)(void); #define PARAVIRT_PATCH(x) \ (offsetof(struct paravirt_patch_template, x) / sizeof(void *)) diff --git a/arch/x86/kernel/asm-offsets.c b/arch/x86/kernel/asm-offsets.c index 736508004b30..ecd3fd6993d1 100644 --- a/arch/x86/kernel/asm-offsets.c +++ b/arch/x86/kernel/asm-offsets.c @@ -61,11 +61,6 @@ static void __used common(void) OFFSET(IA32_RT_SIGFRAME_sigcontext, rt_sigframe_ia32, uc.uc_mcontext); #endif -#ifdef CONFIG_PARAVIRT_XXL - BLANK(); - OFFSET(PV_CPU_iret, paravirt_patch_template, cpu.iret); -#endif - #ifdef CONFIG_XEN BLANK(); OFFSET(XEN_vcpu_info_mask, vcpu_info, evtchn_upcall_mask); diff --git a/arch/x86/kernel/paravirt.c b/arch/x86/kernel/paravirt.c index 44e5b0fe28cb..0553a339d850 100644 --- a/arch/x86/kernel/paravirt.c +++ b/arch/x86/kernel/paravirt.c @@ -86,25 +86,6 @@ u64 notrace _paravirt_ident_64(u64 x) { return x; } - -static unsigned paravirt_patch_jmp(void *insn_buff, const void *target, - unsigned long addr, unsigned len) -{ - struct branch *b = insn_buff; - unsigned long delta = (unsigned long)target - (addr+5); - - if (len < 5) { -#ifdef CONFIG_RETPOLINE - WARN_ONCE(1, "Failing to patch indirect JMP in %ps\n", (void *)addr); -#endif - return len; /* call too long for patch site */ - } - - b->opcode = 0xe9; /* jmp */ - b->delta = delta; - - return 5; -} #endif DEFINE_STATIC_KEY_TRUE(virt_spin_lock_key); @@ -136,9 +117,6 @@ unsigned paravirt_patch_default(u8 type, void *insn_buff, else if (opfunc == _paravirt_ident_64) ret = paravirt_patch_ident_64(insn_buff, len); - else if (type == PARAVIRT_PATCH(cpu.iret)) - /* If operation requires a jmp, then jmp */ - ret = paravirt_patch_jmp(insn_buff, opfunc, addr, len); #endif else /* Otherwise call the function. */ @@ -316,8 +294,6 @@ struct paravirt_patch_template pv_ops = { .cpu.load_sp0 = native_load_sp0, - .cpu.iret = native_iret, - #ifdef CONFIG_X86_IOPL_IOPERM .cpu.invalidate_io_bitmap = native_tss_invalidate_io_bitmap, .cpu.update_io_bitmap = native_tss_update_io_bitmap, @@ -422,6 +398,8 @@ struct paravirt_patch_template pv_ops = { NOKPROBE_SYMBOL(native_get_debugreg); NOKPROBE_SYMBOL(native_set_debugreg); NOKPROBE_SYMBOL(native_load_idt); + +void (*paravirt_iret)(void) = native_iret; #endif EXPORT_SYMBOL(pv_ops); diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c index dc0a337f985b..08dca7bebb30 100644 --- a/arch/x86/xen/enlighten_pv.c +++ b/arch/x86/xen/enlighten_pv.c @@ -1070,8 +1070,6 @@ static const struct pv_cpu_ops xen_cpu_ops __initconst = { .read_pmc = xen_read_pmc, - .iret = xen_iret, - .load_tr_desc = paravirt_nop, .set_ldt = xen_set_ldt, .load_gdt = xen_load_gdt, @@ -1235,6 +1233,7 @@ asmlinkage __visible void __init xen_start_kernel(void) pv_info = xen_info; pv_ops.init.patch = paravirt_patch_default; pv_ops.cpu = xen_cpu_ops; + paravirt_iret = xen_iret; xen_init_irq_ops(); /*