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[209.51.188.17]) by mx.google.com with ESMTPS id v18si5813799edw.435.2021.06.23.06.50.15 for (version=TLS1_2 cipher=ECDHE-ECDSA-CHACHA20-POLY1305 bits=256/256); Wed, 23 Jun 2021 06:50:16 -0700 (PDT) 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=iI9ZEckQ; 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]:54880 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1lw3Gh-0003OR-2x for patch@linaro.org; Wed, 23 Jun 2021 09:50:15 -0400 Received: from eggs.gnu.org ([2001:470:142:3::10]:38934) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1lw3EZ-0000D5-NP for qemu-devel@nongnu.org; Wed, 23 Jun 2021 09:48:03 -0400 Received: from mail-wm1-x336.google.com ([2a00:1450:4864:20::336]:45014) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1lw3EW-0005Bv-V6 for qemu-devel@nongnu.org; Wed, 23 Jun 2021 09:48:03 -0400 Received: by mail-wm1-x336.google.com with SMTP id h21-20020a1ccc150000b02901d4d33c5ca0so1398902wmb.3 for ; Wed, 23 Jun 2021 06:48:00 -0700 (PDT) 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=mRgPMmbhAqtun+sogbbBVR6R3n/yS+R8/5S7ztpD/h8=; b=iI9ZEckQ5X2aiGBIqUe2iszC34n49FpPBDvooZ/vFdpuS6EKhUkgGG9YgRu7Si5na8 SCUtFGA2vNkDWl9UnQccBA5/kpaCLfgCDY/Vp6tex7M+pMBwJ5yD3IAsJbpTzMEzfnkX tOshxCWVYYlP113N8qmrrJ/SpoxiWlSuIUslk0r5mz6r44OUvoDl1AJzIOG7G2+BJvRJ ziyP/V/sDLNLWdKhaptz7A0Snuf7OiXCPNNMHPU+YpBuNj4P52VTqoyXj7s4Y/73Uefm 8vQ6WEWXHUq96B9gpCpzB7n1ejS66E+INiwRD2jyynUkn7oO4EgenzATtpln2aet8dCA Fpgw== 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=mRgPMmbhAqtun+sogbbBVR6R3n/yS+R8/5S7ztpD/h8=; b=nfj7mPfkDws/pKUEPUnjOkQejCud9yzwNgWKV//HSkg6Y920RVJ/bKcupmQFd5jJq3 343ytW7tuzAlDsBdaQDgGVcBex7kQWV93B5D8OAjd0llciijcLcqG3tc2LCLjyfZdNnO /qHMdlsZayJ8TE5BMu7L62HsUMjh28gY9NRcry9fLKc6klqAMxtbJ5GeSFE5IG9Ihjw0 F6Rdp2/jBG0dXyPaKOq/IDtCGlj8Z/zlaihsMSlVMcCkzXv93scz6iegquBkGa4lwggG boJysi5FdYEVF/oSRMzbbVDoAX4DWf7l8j6AYffJ+22kYQLmiNGGzL8R7bYQOIydODeR mM6A== X-Gm-Message-State: AOAM531FATW+lz0Dejx+kg8shr9Dd9fKx+Lwy7ErbkGRykgU+IWNxnnE fOwaeBHQ2pE5ZphGyeFraks7yg== X-Received: by 2002:a05:600c:21c7:: with SMTP id x7mr11287648wmj.82.1624456079527; Wed, 23 Jun 2021 06:47:59 -0700 (PDT) Received: from zen.linaroharston ([51.148.130.216]) by smtp.gmail.com with ESMTPSA id v16sm120826wrr.6.2021.06.23.06.47.57 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 23 Jun 2021 06:47:57 -0700 (PDT) Received: from zen.lan (localhost [127.0.0.1]) by zen.linaroharston (Postfix) with ESMTP id 1B7C91FF87; Wed, 23 Jun 2021 14:47:57 +0100 (BST) From: =?utf-8?q?Alex_Benn=C3=A9e?= To: qemu-devel@nongnu.org Subject: [PATCH v4 1/2] semihosting/arm-compat: replace heuristic for softmmu SYS_HEAPINFO Date: Wed, 23 Jun 2021 14:47:55 +0100 Message-Id: <20210623134756.30930-2-alex.bennee@linaro.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20210623134756.30930-1-alex.bennee@linaro.org> References: <20210623134756.30930-1-alex.bennee@linaro.org> MIME-Version: 1.0 Received-SPF: pass client-ip=2a00:1450:4864:20::336; envelope-from=alex.bennee@linaro.org; helo=mail-wm1-x336.google.com X-Spam_score_int: -20 X-Spam_score: -2.1 X-Spam_bar: -- X-Spam_report: (-2.1 / 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, RCVD_IN_DNSWL_NONE=-0.0001, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=ham 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: peter.maydell@linaro.org, Keith Packard , qemu-arm@nongnu.org, =?utf-8?q?Alex_Benn=C3=A9e?= , Andrew Strauss 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> --- 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 --- include/hw/loader.h | 16 +++++ hw/core/loader.c | 74 +++++++++++++++++++ semihosting/arm-compat-semi.c | 129 ++++++++++++++++++---------------- 3 files changed, 158 insertions(+), 61 deletions(-) -- 2.20.1 diff --git a/include/hw/loader.h b/include/hw/loader.h index cbfc184873..f2cdb82b59 100644 --- a/include/hw/loader.h +++ b/include/hw/loader.h @@ -349,4 +349,20 @@ int rom_add_option(const char *file, int32_t bootindex); * overflow on real hardware too. */ #define UBOOT_MAX_GUNZIP_BYTES (64 << 20) +/** + * rom_find_largest_gap_between: return highest address of ROM in region + * + * This function is used to find the highest ROM address (or loaded + * blob) so we can advise where true heap memory may be. + * + * Returns: RomGap, describing the largest section not intersected by + * a ROM region. + */ +typedef struct RomGap { + hwaddr base; + size_t size; +} RomGap; + +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 5b34869a54..d4893fa8d8 100644 --- a/hw/core/loader.c +++ b/hw/core/loader.c @@ -1310,6 +1310,80 @@ static Rom *find_rom(hwaddr addr, size_t size) return NULL; } +typedef struct RomSec { + hwaddr base; + int se; /* start/end flag */ +} RomSec; + + +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 ? -1 : 1; + } + return ra->base > rb->base ? 1 : -1; +} + +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 real rom blobs */ + 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 */ + cand = g_new(RomSec, 1); + cand->base = rom->addr; + cand->se = 1; + secs = g_list_append(secs, cand); + + if (rom->addr + rom->romsize < base + size) { + cand = g_new(RomSec, 1); + cand->base = rom->addr + rom->romsize; + cand->se = -1; + secs = g_list_append(secs, cand); + } + } + + 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 1c29146dcf..f50c1474bc 100644 --- a/semihosting/arm-compat-semi.c +++ b/semihosting/arm-compat-semi.c @@ -44,6 +44,7 @@ #else #include "exec/gdbstub.h" #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) { + 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++) {