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[209.51.188.17]) by mx.google.com with ESMTPS id b62si13939097ybc.773.2022.02.10.03.38.30 for (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Thu, 10 Feb 2022 03:38:30 -0800 (PST) Received-SPF: pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; Authentication-Results: mx.google.com; dkim=fail header.i=@linaro.org header.s=google header.b=gAaJXt9+; spf=pass (google.com: domain of qemu-devel-bounces+patch=linaro.org@nongnu.org designates 209.51.188.17 as permitted sender) smtp.mailfrom="qemu-devel-bounces+patch=linaro.org@nongnu.org"; dmarc=fail (p=NONE sp=NONE dis=NONE) header.from=linaro.org Received: from localhost ([::1]:36566 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1nI7mQ-0000FB-3r for patch@linaro.org; Thu, 10 Feb 2022 06:38:30 -0500 Received: from eggs.gnu.org ([209.51.188.92]:42386) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1nI7ee-0003hr-4T for qemu-devel@nongnu.org; Thu, 10 Feb 2022 06:30:28 -0500 Received: from [2a00:1450:4864:20::62f] (port=33735 helo=mail-ej1-x62f.google.com) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1nI7eb-0002VP-L2 for qemu-devel@nongnu.org; Thu, 10 Feb 2022 06:30:27 -0500 Received: by mail-ej1-x62f.google.com with SMTP id fy20so14507929ejc.0 for ; Thu, 10 Feb 2022 03:30:25 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=linaro.org; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references :mime-version:content-transfer-encoding; bh=A473qbjGyhHnN0ZQyd0Yg8rCuTL/rArhdYtN54HK9fc=; b=gAaJXt9+Pcc1amrW6/4raCME0JCmTtXkvfAoifDAYnAAfJImvW83uWbgKA3lXjYwIv 7Azi9V/6J0StO/FmWDwqer49IjhmSaCtVLxZhHomVetfjKlRJs/b8TXUzHL/dSs3UTs3 V7Qqnjw8Q8GiTuuqVEiOfsyN2LSR+pxAHZ7aa4oKzTi4tmY7GtDUzg2bb+5ZHOX4Xxrm 1V40GlO6N09cfOO+QqDCp1/uCRsYL+pj8bwzIMHA07xMALlpp84cyjeKW0KMzFufzG8i Zw5KjAjAtDoXbEG1v3obWaDzc0ecUkg1qCRw5kDJXh2FXFfsfD1WtPjzc4oS7XKNyCEy pvyg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references:mime-version:content-transfer-encoding; bh=A473qbjGyhHnN0ZQyd0Yg8rCuTL/rArhdYtN54HK9fc=; b=BWQEBUhPUz+n7tyA4CcZPZMj4DglIdwRuk2R8rcw7+uOGoTApr0KkmUdv3k3+YNEE+ xS6CCOjF0RY2tjKMMj80U/Yab9TVUaXb3bx9ZKgKSTf7oYYrD1s13dd1YQ6yornD9me/ E/JeXIEnQRCHW9j+Q0AMmlaQiJHwAaRI+uq/ijofD9oNM83PyPt/EZbpzfQbJ1ju/eBP 5yQLVrTeCQo9WpG+cpN0DnLPOXrzb/yij2VReZC+E0o8b0c8XX2Sss4FVHyf/fA9Pays aOSLYNIADnt0n/d+ukDaBFZjY3/EZE6xpu/EPpiQWVsJS/f5pLNqd1J7Gzv7Au7RKuaS sdJg== X-Gm-Message-State: AOAM5304Ocn8ASmOU7wPb6wwQ8uURB2FiyHZR3JaeFXMVkUojZb6eqn6 MtU/U9BKv4cglFweNVUfJYx0/Q== X-Received: by 2002:a17:907:3da1:: with SMTP id he33mr5997248ejc.207.1644492624027; Thu, 10 Feb 2022 03:30:24 -0800 (PST) Received: from zen.linaroharston ([51.148.130.216]) by smtp.gmail.com with ESMTPSA id m4sm1910267ejl.45.2022.02.10.03.30.22 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Thu, 10 Feb 2022 03:30:22 -0800 (PST) Received: from zen.lan (localhost [127.0.0.1]) by zen.linaroharston (Postfix) with ESMTP id A04971FFB8; Thu, 10 Feb 2022 11:30:21 +0000 (GMT) From: =?utf-8?q?Alex_Benn=C3=A9e?= To: qemu-devel@nongnu.org, peter.maydell@linaro.org Subject: [PATCH v5 1/2] semihosting/arm-compat: replace heuristic for softmmu SYS_HEAPINFO Date: Thu, 10 Feb 2022 11:30:20 +0000 Message-Id: <20220210113021.3799514-2-alex.bennee@linaro.org> X-Mailer: git-send-email 2.30.2 In-Reply-To: <20220210113021.3799514-1-alex.bennee@linaro.org> References: <20220210113021.3799514-1-alex.bennee@linaro.org> MIME-Version: 1.0 X-Host-Lookup-Failed: Reverse DNS lookup failed for 2a00:1450:4864:20::62f (failed) Received-SPF: pass client-ip=2a00:1450:4864:20::62f; envelope-from=alex.bennee@linaro.org; helo=mail-ej1-x62f.google.com X-Spam_score_int: -12 X-Spam_score: -1.3 X-Spam_bar: - X-Spam_report: (-1.3 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, PDS_HP_HELO_NORDNS=0.001, RCVD_IN_DNSWL_NONE=-0.0001, RDNS_NONE=0.793, SPF_HELO_NONE=0.001, SPF_PASS=-0.001, T_SCC_BODY_TEXT_LINE=-0.01 autolearn=no autolearn_force=no X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Andrew Strauss , Keith Packard , qemu-arm@nongnu.org, =?utf-8?q?Alex_Benn=C3=A9e?= Errors-To: qemu-devel-bounces+patch=linaro.org@nongnu.org Sender: "Qemu-devel" The previous numbers were a guess at best and rather arbitrary without taking into account anything that might be loaded. Instead of using guesses based on the state of registers implement a new function that: a) scans the MemoryRegions for the largest RAM block b) iterates through all "ROM" blobs looking for the biggest gap The "ROM" blobs include all code loaded via -kernel and the various -device loader techniques. Signed-off-by: Alex Bennée Cc: Andrew Strauss Cc: Keith Packard Message-Id: <20210601090715.22330-1-alex.bennee@linaro.org> Reviewed-by: Philippe Mathieu-Daudé Reviewed-by: Peter Maydell --- v2 - report some known information (limits) - reword the commit message v3 - rework to use the ROM blob scanning suggested by Peter - drop arch specific wrappers - dropped rb/tb tags as it's a rework v4 - search for the largest RAM which should be the main RAM - implement the biggest gap algorithm - make stackbase the inverse of heap info v5 - move rom_find_largest_gap description to above fn and reword - add documentation of sort behaviour - handle matching se flags (- -1 -1) and (- 1 1) == 0 - add helper function and sentinal - fix off-by-ones in comparisons - allow a rambase at 0 squash! semihosting/arm-compat: replace heuristic for softmmu SYS_HEAPINFO --- include/hw/loader.h | 14 ++++ hw/core/loader.c | 86 +++++++++++++++++++++++ semihosting/arm-compat-semi.c | 129 ++++++++++++++++++---------------- 3 files changed, 168 insertions(+), 61 deletions(-) diff --git a/include/hw/loader.h b/include/hw/loader.h index 4fa485bd61..5572108ba5 100644 --- a/include/hw/loader.h +++ b/include/hw/loader.h @@ -343,4 +343,18 @@ int rom_add_option(const char *file, int32_t bootindex); * overflow on real hardware too. */ #define UBOOT_MAX_GUNZIP_BYTES (64 << 20) +typedef struct RomGap { + hwaddr base; + size_t size; +} RomGap; + +/** + * rom_find_largest_gap_between: return largest gap between ROMs in given range + * + * Given a range of addresses, this function finds the largest + * contiguous subrange which has no ROMs loaded to it. That is, + * it finds the biggest gap which is free for use for other things. + */ +RomGap rom_find_largest_gap_between(hwaddr base, size_t size); + #endif diff --git a/hw/core/loader.c b/hw/core/loader.c index 19edb928e9..ca2f2431fb 100644 --- a/hw/core/loader.c +++ b/hw/core/loader.c @@ -1333,6 +1333,92 @@ static Rom *find_rom(hwaddr addr, size_t size) return NULL; } +typedef struct RomSec { + hwaddr base; + int se; /* start/end flag */ +} RomSec; + + +/* + * Sort into address order. We break ties between rom-startpoints + * and rom-endpoints in favour of the startpoint, by sorting the 0->1 + * transition before the 1->0 transition. Either way round would + * work, but this way saves a little work later by avoiding + * dealing with "gaps" of 0 length. + */ +static gint sort_secs(gconstpointer a, gconstpointer b) +{ + RomSec *ra = (RomSec *) a; + RomSec *rb = (RomSec *) b; + + if (ra->base == rb->base) { + return ra->se - rb->se; + } + return ra->base > rb->base ? 1 : -1; +} + +static GList *add_romsec_to_list(GList *secs, hwaddr base, int se) +{ + RomSec *cand = g_new(RomSec, 1); + cand->base = base; + cand->se = se; + return g_list_prepend(secs, cand); +} + +RomGap rom_find_largest_gap_between(hwaddr base, size_t size) +{ + Rom *rom; + RomSec *cand; + RomGap res = {0, 0}; + hwaddr gapstart = base; + GList *it, *secs = NULL; + int count = 0; + + QTAILQ_FOREACH(rom, &roms, next) { + /* Ignore blobs being loaded to special places */ + if (rom->mr || rom->fw_file) { + continue; + } + /* ignore anything finishing bellow base */ + if (rom->addr + rom->romsize <= base) { + continue; + } + /* ignore anything starting above the region */ + if (rom->addr >= base + size) { + continue; + } + + /* Save the start and end of each relevant ROM */ + secs = add_romsec_to_list(secs, rom->addr, 1); + + if (rom->addr + rom->romsize < base + size) { + secs = add_romsec_to_list(secs, rom->addr + rom->romsize, -1); + } + } + + /* sentinel */ + secs = add_romsec_to_list(secs, base + size, 1); + + secs = g_list_sort(secs, sort_secs); + + for (it = g_list_first(secs); it; it = g_list_next(it)) { + cand = (RomSec *) it->data; + if (count == 0 && count + cand->se == 1) { + size_t gap = cand->base - gapstart; + if (gap > res.size) { + res.base = gapstart; + res.size = gap; + } + } else if (count == 1 && count + cand->se == 0) { + gapstart = cand->base; + } + count += cand->se; + } + + g_list_free_full(secs, g_free); + return res; +} + /* * Copies memory from registered ROMs to dest. Any memory that is contained in * a ROM between addr and addr + size is copied. Note that this can involve diff --git a/semihosting/arm-compat-semi.c b/semihosting/arm-compat-semi.c index 37963becae..3704b250b2 100644 --- a/semihosting/arm-compat-semi.c +++ b/semihosting/arm-compat-semi.c @@ -44,6 +44,7 @@ #define COMMON_SEMI_HEAP_SIZE (128 * 1024 * 1024) #else #include "qemu/cutils.h" +#include "hw/loader.h" #ifdef TARGET_ARM #include "hw/arm/boot.h" #endif @@ -144,33 +145,69 @@ typedef struct GuestFD { static GArray *guestfd_array; #ifndef CONFIG_USER_ONLY -#include "exec/address-spaces.h" -/* - * Find the base of a RAM region containing the specified address + +/** + * common_semi_find_bases: find information about ram and heap base + * + * This function attempts to provide meaningful numbers for RAM and + * HEAP base addresses. The rambase is simply the lowest addressable + * RAM position. For the heapbase we ask the loader to scan the + * address space and the largest available gap by querying the "ROM" + * regions. + * + * Returns: a structure with the numbers we need. */ -static inline hwaddr -common_semi_find_region_base(hwaddr addr) + +typedef struct LayoutInfo { + target_ulong rambase; + size_t ramsize; + hwaddr heapbase; + hwaddr heaplimit; +} LayoutInfo; + +static bool find_ram_cb(Int128 start, Int128 len, const MemoryRegion *mr, + hwaddr offset_in_region, void *opaque) +{ + LayoutInfo *info = (LayoutInfo *) opaque; + uint64_t size = int128_get64(len); + + if (!mr->ram || mr->readonly) { + return false; + } + + if (size > info->ramsize) { + info->rambase = int128_get64(start); + info->ramsize = size; + } + + /* search exhaustively for largest RAM */ + return false; +} + +static LayoutInfo common_semi_find_bases(CPUState *cs) { - MemoryRegion *subregion; + FlatView *fv; + LayoutInfo info = { 0, 0, 0, 0 }; + + RCU_READ_LOCK_GUARD(); + + fv = address_space_to_flatview(cs->as); + flatview_for_each_range(fv, find_ram_cb, &info); /* - * Find the chunk of R/W memory containing the address. This is - * used for the SYS_HEAPINFO semihosting call, which should - * probably be using information from the loaded application. + * If we have found the RAM lets iterate through the ROM blobs to + * workout the best place for the remainder of RAM and split it + * equally between stack and heap. */ - QTAILQ_FOREACH(subregion, &get_system_memory()->subregions, - subregions_link) { - if (subregion->ram && !subregion->readonly) { - Int128 top128 = int128_add(int128_make64(subregion->addr), - subregion->size); - Int128 addr128 = int128_make64(addr); - if (subregion->addr <= addr && int128_lt(addr128, top128)) { - return subregion->addr; - } - } + if (info.rambase || info.ramsize > 0) { + RomGap gap = rom_find_largest_gap_between(info.rambase, info.ramsize); + info.heapbase = gap.base; + info.heaplimit = gap.base + gap.size; } - return 0; + + return info; } + #endif #ifdef TARGET_ARM @@ -204,28 +241,6 @@ common_semi_sys_exit_extended(CPUState *cs, int nr) return (nr == TARGET_SYS_EXIT_EXTENDED || is_a64(cs->env_ptr)); } -#ifndef CONFIG_USER_ONLY -#include "hw/arm/boot.h" -static inline target_ulong -common_semi_rambase(CPUState *cs) -{ - CPUArchState *env = cs->env_ptr; - const struct arm_boot_info *info = env->boot_info; - target_ulong sp; - - if (info) { - return info->loader_start; - } - - if (is_a64(env)) { - sp = env->xregs[31]; - } else { - sp = env->regs[13]; - } - return common_semi_find_region_base(sp); -} -#endif - #endif /* TARGET_ARM */ #ifdef TARGET_RISCV @@ -251,17 +266,6 @@ common_semi_sys_exit_extended(CPUState *cs, int nr) return (nr == TARGET_SYS_EXIT_EXTENDED || sizeof(target_ulong) == 8); } -#ifndef CONFIG_USER_ONLY - -static inline target_ulong -common_semi_rambase(CPUState *cs) -{ - RISCVCPU *cpu = RISCV_CPU(cs); - CPURISCVState *env = &cpu->env; - return common_semi_find_region_base(env->gpr[xSP]); -} -#endif - #endif /* @@ -1165,12 +1169,12 @@ target_ulong do_common_semihosting(CPUState *cs) case TARGET_SYS_HEAPINFO: { target_ulong retvals[4]; - target_ulong limit; int i; #ifdef CONFIG_USER_ONLY TaskState *ts = cs->opaque; + target_ulong limit; #else - target_ulong rambase = common_semi_rambase(cs); + LayoutInfo info = common_semi_find_bases(cs); #endif GET_ARG(0); @@ -1201,12 +1205,15 @@ target_ulong do_common_semihosting(CPUState *cs) retvals[2] = ts->stack_base; retvals[3] = 0; /* Stack limit. */ #else - limit = current_machine->ram_size; - /* TODO: Make this use the limit of the loaded application. */ - retvals[0] = rambase + limit / 2; - retvals[1] = rambase + limit; - retvals[2] = rambase + limit; /* Stack base */ - retvals[3] = rambase; /* Stack limit. */ + /* + * Reporting 0 indicates we couldn't calculate the real + * values which should force most software to fall back to + * using information it has. + */ + retvals[0] = info.heapbase; /* Heap Base */ + retvals[1] = info.heaplimit; /* Heap Limit */ + retvals[2] = info.heaplimit; /* Stack base */ + retvals[3] = info.heapbase; /* Stack limit. */ #endif for (i = 0; i < ARRAY_SIZE(retvals); i++) {