From patchwork Sun Nov 8 23:24:23 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Joelle van Dyne X-Patchwork-Id: 11890037 Return-Path: Received: from mail.kernel.org (pdx-korg-mail-1.web.codeaurora.org [172.30.200.123]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 62B5A16C0 for ; Sun, 8 Nov 2020 23:32:01 +0000 (UTC) Received: from lists.gnu.org (lists.gnu.org [209.51.188.17]) (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 59B67206DB for ; Sun, 8 Nov 2020 23:32:01 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 59B67206DB Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=getutm.app Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Received: from localhost ([::1]:46196 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1kbuAC-0005sZ-5R for patchwork-qemu-devel@patchwork.kernel.org; Sun, 08 Nov 2020 18:32:00 -0500 Received: from eggs.gnu.org ([2001:470:142:3::10]:45310) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1kbu34-0000tc-A4 for qemu-devel@nongnu.org; Sun, 08 Nov 2020 18:24:38 -0500 Received: from mail-pg1-f196.google.com ([209.85.215.196]:41151) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1kbu32-0000GM-5Q for qemu-devel@nongnu.org; Sun, 08 Nov 2020 18:24:37 -0500 Received: by mail-pg1-f196.google.com with SMTP id f18so769794pgi.8 for ; Sun, 08 Nov 2020 15:24:35 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=oqTRRse3ML08CbYMBMir3imYmfVxmJCy/vR5/9jdsfA=; b=uee72tzzBOfOSt4ecT17oG9023oMrORREMO3hjRXfisVbAHYquuODTy6F412UCP0Nc y/J3au5d02j/9l6AUW7b7W8ks4tP5YfmzOxuuolS6mVE1X4pm4ZQrzrvjRiVlmD1mAgG IoBam8MzuSGbtDTNubH4tP6mGSEOmyDnQBycjpO4ngBwsvawvevTuKNUE4SosiYptmib 4o3Gj/DmnrCeUl0BBlg/YPWhY+7aJ5sMApqGhq1SnmKpOs8U4XxmiTl6oXP2YMGu9jDN 1o5vh0Yg0BTKgPnhHcLZVI0Gw1CqiLhrGp10Z6dpkYRVxIR8B/FAD3lLl9OweV5vxykH fqAw== X-Gm-Message-State: AOAM533VIuZmNY33nPGYrmSttnihi64hQFbb+tgKN4crQkhX0U5cVLIp 7C8pdbumVZL162MZyf+BGza7WpNveDM= X-Google-Smtp-Source: ABdhPJz2CwfqeamI2DkpxiOMaVyE2ZHBUiqZGfpwcmep4NXMYEmMpOVPvKocMnINVZRo3D8Ddna/LQ== X-Received: by 2002:a17:90a:5204:: with SMTP id v4mr9427428pjh.188.1604877874671; Sun, 08 Nov 2020 15:24:34 -0800 (PST) Received: from localhost.localdomain ([73.93.154.215]) by smtp.gmail.com with ESMTPSA id z3sm8275171pgl.73.2020.11.08.15.24.33 (version=TLS1_2 cipher=ECDHE-ECDSA-AES128-GCM-SHA256 bits=128/128); Sun, 08 Nov 2020 15:24:34 -0800 (PST) From: Joelle van Dyne To: qemu-devel@nongnu.org Subject: [PATCH v5 6/7] tcg: implement JIT for iOS and Apple Silicon Date: Sun, 8 Nov 2020 15:24:23 -0800 Message-Id: <20201108232425.1705-7-j@getutm.app> X-Mailer: git-send-email 2.28.0 In-Reply-To: <20201108232425.1705-1-j@getutm.app> References: <20201108232425.1705-1-j@getutm.app> MIME-Version: 1.0 Received-SPF: pass client-ip=209.85.215.196; envelope-from=osy86github@gmail.com; helo=mail-pg1-f196.google.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/11/08 18:24:29 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -13 X-Spam_score: -1.4 X-Spam_bar: - X-Spam_report: (-1.4 / 5.0 requ) BAYES_00=-1.9, FREEMAIL_FORGED_FROMDOMAIN=0.25, FREEMAIL_FROM=0.001, HEADER_FROM_DIFFERENT_DOMAINS=0.25, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H3=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Paolo Bonzini , Joelle van Dyne , Richard Henderson Errors-To: qemu-devel-bounces+patchwork-qemu-devel=patchwork.kernel.org@nongnu.org Sender: "Qemu-devel" When entitlements are available (macOS or jailbroken iOS), a hardware feature called APRR exists on newer Apple Silicon that can cheaply mark JIT pages as either RX or RW. Reverse engineered functions from libsystem_pthread.dylib are implemented to handle this. The following rules apply for JIT write protect: * JIT write-protect is enabled before tcg_qemu_tb_exec() * JIT write-protect is disabled after tcg_qemu_tb_exec() returns * JIT write-protect is disabled inside do_tb_phys_invalidate() but if it is called inside of tcg_qemu_tb_exec() then write-protect will be enabled again before returning. * JIT write-protect is disabled by cpu_loop_exit() for interrupt handling. * JIT write-protect is disabled everywhere else. See https://developer.apple.com/documentation/apple_silicon/porting_just-in-time_compilers_to_apple_silicon Signed-off-by: Joelle van Dyne --- include/exec/exec-all.h | 2 + include/tcg/tcg-apple-jit.h | 86 +++++++++++++++++++++++++++++++++++++ include/tcg/tcg.h | 3 ++ accel/tcg/cpu-exec-common.c | 2 + accel/tcg/cpu-exec.c | 2 + accel/tcg/translate-all.c | 46 ++++++++++++++++++++ tcg/tcg.c | 4 ++ 7 files changed, 145 insertions(+) create mode 100644 include/tcg/tcg-apple-jit.h diff --git a/include/exec/exec-all.h b/include/exec/exec-all.h index aa65103702..3829f3d470 100644 --- a/include/exec/exec-all.h +++ b/include/exec/exec-all.h @@ -549,6 +549,8 @@ TranslationBlock *tb_htable_lookup(CPUState *cpu, target_ulong pc, target_ulong cs_base, uint32_t flags, uint32_t cf_mask); void tb_set_jmp_target(TranslationBlock *tb, int n, uintptr_t addr); +void tb_exec_lock(void); +void tb_exec_unlock(void); /* GETPC is the true target of the return instruction that we'll execute. */ #if defined(CONFIG_TCG_INTERPRETER) diff --git a/include/tcg/tcg-apple-jit.h b/include/tcg/tcg-apple-jit.h new file mode 100644 index 0000000000..9efdb2000d --- /dev/null +++ b/include/tcg/tcg-apple-jit.h @@ -0,0 +1,86 @@ +/* + * Apple Silicon functions for JIT handling + * + * Copyright (c) 2020 osy + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with this library; if not, see . + */ + +#ifndef TCG_APPLE_JIT_H +#define TCG_APPLE_JIT_H + +/* + * APRR handling + * Credits to: https://siguza.github.io/APRR/ + * Reversed from /usr/lib/system/libsystem_pthread.dylib + */ + +#if defined(__aarch64__) && defined(CONFIG_DARWIN) + +#define _COMM_PAGE_START_ADDRESS (0x0000000FFFFFC000ULL) /* In TTBR0 */ +#define _COMM_PAGE_APRR_SUPPORT (_COMM_PAGE_START_ADDRESS + 0x10C) +#define _COMM_PAGE_APPR_WRITE_ENABLE (_COMM_PAGE_START_ADDRESS + 0x110) +#define _COMM_PAGE_APRR_WRITE_DISABLE (_COMM_PAGE_START_ADDRESS + 0x118) + +static __attribute__((__always_inline__)) bool jit_write_protect_supported(void) +{ + /* Access shared kernel page at fixed memory location. */ + uint8_t aprr_support = *(volatile uint8_t *)_COMM_PAGE_APRR_SUPPORT; + return aprr_support > 0; +} + +/* write protect enable = write disable */ +static __attribute__((__always_inline__)) void jit_write_protect(int enabled) +{ + /* Access shared kernel page at fixed memory location. */ + uint8_t aprr_support = *(volatile uint8_t *)_COMM_PAGE_APRR_SUPPORT; + if (aprr_support == 0 || aprr_support > 3) { + return; + } else if (aprr_support == 1) { + __asm__ __volatile__ ( + "mov x0, %0\n" + "ldr x0, [x0]\n" + "msr S3_4_c15_c2_7, x0\n" + "isb sy\n" + :: "r" (enabled ? _COMM_PAGE_APRR_WRITE_DISABLE + : _COMM_PAGE_APPR_WRITE_ENABLE) + : "memory", "x0" + ); + } else { + __asm__ __volatile__ ( + "mov x0, %0\n" + "ldr x0, [x0]\n" + "msr S3_6_c15_c1_5, x0\n" + "isb sy\n" + :: "r" (enabled ? _COMM_PAGE_APRR_WRITE_DISABLE + : _COMM_PAGE_APPR_WRITE_ENABLE) + : "memory", "x0" + ); + } +} + +#else /* defined(__aarch64__) && defined(CONFIG_DARWIN) */ + +static __attribute__((__always_inline__)) bool jit_write_protect_supported(void) +{ + return false; +} + +static __attribute__((__always_inline__)) void jit_write_protect(int enabled) +{ +} + +#endif + +#endif /* define TCG_APPLE_JIT_H */ diff --git a/include/tcg/tcg.h b/include/tcg/tcg.h index 477919aeb6..b16b687d0b 100644 --- a/include/tcg/tcg.h +++ b/include/tcg/tcg.h @@ -625,6 +625,9 @@ struct TCGContext { size_t code_gen_buffer_size; void *code_gen_ptr; void *data_gen_ptr; +#if defined(CONFIG_DARWIN) && !defined(CONFIG_TCG_INTERPRETER) + bool code_gen_locked; /* on Darwin each thread tracks W^X flags */ +#endif /* Threshold to flush the translated code buffer. */ void *code_gen_highwater; diff --git a/accel/tcg/cpu-exec-common.c b/accel/tcg/cpu-exec-common.c index 12c1e3e974..f1eb767b02 100644 --- a/accel/tcg/cpu-exec-common.c +++ b/accel/tcg/cpu-exec-common.c @@ -64,6 +64,8 @@ void cpu_reloading_memory_map(void) void cpu_loop_exit(CPUState *cpu) { + /* Unlock JIT write protect if applicable. */ + tb_exec_unlock(); /* Undo the setting in cpu_tb_exec. */ cpu->can_do_io = 1; siglongjmp(cpu->jmp_env, 1); diff --git a/accel/tcg/cpu-exec.c b/accel/tcg/cpu-exec.c index 8df0a1782e..960e0c1f36 100644 --- a/accel/tcg/cpu-exec.c +++ b/accel/tcg/cpu-exec.c @@ -176,7 +176,9 @@ static inline TranslationBlock *cpu_tb_exec(CPUState *cpu, } #endif /* DEBUG_DISAS */ + tb_exec_lock(); ret = tcg_qemu_tb_exec(env, tb_ptr); + tb_exec_unlock(); cpu->can_do_io = 1; /* * TODO: Delay swapping back to the read-write region of the TB diff --git a/accel/tcg/translate-all.c b/accel/tcg/translate-all.c index 06102871e7..5773c561cb 100644 --- a/accel/tcg/translate-all.c +++ b/accel/tcg/translate-all.c @@ -27,6 +27,9 @@ #include "disas/disas.h" #include "exec/exec-all.h" #include "tcg/tcg.h" +#if defined(CONFIG_DARWIN) +#include "tcg/tcg-apple-jit.h" +#endif #if defined(CONFIG_USER_ONLY) #include "qemu.h" #if defined(__FreeBSD__) || defined(__FreeBSD_kernel__) @@ -61,6 +64,9 @@ #include "sysemu/tcg.h" #include "qapi/error.h" +static bool tb_exec_is_locked(void); +static void tb_exec_change(bool locked); + /* #define DEBUG_TB_INVALIDATE */ /* #define DEBUG_TB_FLUSH */ /* make various TB consistency checks */ @@ -1339,6 +1345,7 @@ void tcg_exec_init(unsigned long tb_size, int splitwx) splitwx, &error_fatal); assert(ok); + tb_exec_unlock(); #if defined(CONFIG_SOFTMMU) /* There's no guest base to take into account, so go ahead and initialize the prologue now. */ @@ -1615,8 +1622,11 @@ static void do_tb_phys_invalidate(TranslationBlock *tb, bool rm_from_page_list) PageDesc *p; uint32_t h; tb_page_addr_t phys_pc; + bool code_gen_locked; assert_memory_lock(); + code_gen_locked = tb_exec_is_locked(); + tb_exec_unlock(); /* make sure no further incoming jumps will be chained to this TB */ qemu_spin_lock(&tb->jmp_lock); @@ -1629,6 +1639,7 @@ static void do_tb_phys_invalidate(TranslationBlock *tb, bool rm_from_page_list) tb->trace_vcpu_dstate); if (!(tb->cflags & CF_NOCACHE) && !qht_remove(&tb_ctx.htable, tb, h)) { + tb_exec_change(code_gen_locked); return; } @@ -1661,6 +1672,8 @@ static void do_tb_phys_invalidate(TranslationBlock *tb, bool rm_from_page_list) qatomic_set(&tcg_ctx->tb_phys_invalidate_count, tcg_ctx->tb_phys_invalidate_count + 1); + + tb_exec_change(code_gen_locked); } static void tb_phys_invalidate__locked(TranslationBlock *tb) @@ -2899,3 +2912,36 @@ void tcg_flush_softmmu_tlb(CPUState *cs) tlb_flush(cs); #endif } + +#if defined(CONFIG_DARWIN) && !defined(CONFIG_TCG_INTERPRETER) +static bool tb_exec_is_locked(void) +{ + return tcg_ctx->code_gen_locked; +} + +static void tb_exec_change(bool locked) +{ + if (jit_write_protect_supported()) { + jit_write_protect(locked); + } + tcg_ctx->code_gen_locked = locked; +} +#else /* not needed on non-Darwin platforms */ +static bool tb_exec_is_locked(void) +{ + return false; +} + +static void tb_exec_change(bool locked) {} +#endif + +void tb_exec_lock(void) +{ + /* assumes sys_icache_invalidate already called */ + tb_exec_change(true); +} + +void tb_exec_unlock(void) +{ + tb_exec_change(false); +} diff --git a/tcg/tcg.c b/tcg/tcg.c index d3052031cb..5ed79d2724 100644 --- a/tcg/tcg.c +++ b/tcg/tcg.c @@ -809,6 +809,8 @@ static void alloc_tcg_plugin_context(TCGContext *s) void tcg_register_thread(void) { tcg_ctx = &tcg_init_ctx; + + tb_exec_unlock(); } #else void tcg_register_thread(void) @@ -843,6 +845,8 @@ void tcg_register_thread(void) err = tcg_region_initial_alloc__locked(tcg_ctx); g_assert(!err); qemu_mutex_unlock(®ion.lock); + + tb_exec_unlock(); } #endif /* !CONFIG_USER_ONLY */