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[23.128.96.18]) by mx.google.com with ESMTP id ay4si3663647ejb.630.2020.11.12.05.04.20; Thu, 12 Nov 2020 05:04:48 -0800 (PST) Received-SPF: pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) client-ip=23.128.96.18; Authentication-Results: mx.google.com; spf=pass (google.com: domain of linux-kernel-owner@vger.kernel.org designates 23.128.96.18 as permitted sender) smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727942AbgKLNC2 (ORCPT + 99 others); Thu, 12 Nov 2020 08:02:28 -0500 Received: from szxga04-in.huawei.com ([45.249.212.190]:7179 "EHLO szxga04-in.huawei.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727819AbgKLNC2 (ORCPT ); Thu, 12 Nov 2020 08:02:28 -0500 Received: from DGGEMS411-HUB.china.huawei.com (unknown [172.30.72.60]) by szxga04-in.huawei.com (SkyGuard) with ESMTP id 4CX1vp4xN3z15VD8; Thu, 12 Nov 2020 21:01:58 +0800 (CST) Received: from [10.174.176.61] (10.174.176.61) by DGGEMS411-HUB.china.huawei.com (10.3.19.211) with Microsoft SMTP Server id 14.3.487.0; Thu, 12 Nov 2020 21:02:01 +0800 Subject: Re: [PATCH v13 4/8] x86: kdump: move reserve_crashkernel[_low]() into crash_core.c To: Mike Rapoport References: <20201031074437.168008-1-chenzhou10@huawei.com> <20201031074437.168008-5-chenzhou10@huawei.com> <20201112081152.GK4758@kernel.org> CC: , , , , , , , , , , , , , , , , , , , , , , From: chenzhou Message-ID: <2aa47a25-ca1b-fdc1-5208-12e93f28f9a0@huawei.com> Date: Thu, 12 Nov 2020 21:01:59 +0800 User-Agent: Mozilla/5.0 (Windows NT 10.0; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.7.1 MIME-Version: 1.0 In-Reply-To: <20201112081152.GK4758@kernel.org> Content-Type: text/plain; charset="windows-1252" Content-Transfer-Encoding: 7bit X-Originating-IP: [10.174.176.61] X-CFilter-Loop: Reflected Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 2020/11/12 16:11, Mike Rapoport wrote: > On Sat, Oct 31, 2020 at 03:44:33PM +0800, Chen Zhou wrote: >> Make the functions reserve_crashkernel[_low]() as generic. >> Arm64 will use these to reimplement crashkernel=X. >> >> Signed-off-by: Chen Zhou >> Tested-by: John Donnelly >> --- >> arch/x86/include/asm/kexec.h | 25 ++++++ >> arch/x86/kernel/setup.c | 151 +------------------------------- >> include/linux/crash_core.h | 4 + >> include/linux/kexec.h | 2 - >> kernel/crash_core.c | 164 +++++++++++++++++++++++++++++++++++ >> kernel/kexec_core.c | 17 ---- >> 6 files changed, 195 insertions(+), 168 deletions(-) >> >> diff --git a/arch/x86/include/asm/kexec.h b/arch/x86/include/asm/kexec.h >> index 8cf9d3fd31c7..34afa7b645f9 100644 >> --- a/arch/x86/include/asm/kexec.h >> +++ b/arch/x86/include/asm/kexec.h >> @@ -21,6 +21,27 @@ >> /* 2M alignment for crash kernel regions */ >> #define CRASH_ALIGN SZ_16M >> >> +/* >> + * Keep the crash kernel below this limit. >> + * >> + * Earlier 32-bits kernels would limit the kernel to the low 512 MB range >> + * due to mapping restrictions. >> + * >> + * 64-bit kdump kernels need to be restricted to be under 64 TB, which is >> + * the upper limit of system RAM in 4-level paging mode. Since the kdump >> + * jump could be from 5-level paging to 4-level paging, the jump will fail if >> + * the kernel is put above 64 TB, and during the 1st kernel bootup there's >> + * no good way to detect the paging mode of the target kernel which will be >> + * loaded for dumping. >> + */ >> +#ifdef CONFIG_X86_32 >> +# define CRASH_ADDR_LOW_MAX SZ_512M >> +# define CRASH_ADDR_HIGH_MAX SZ_512M >> +#else >> +# define CRASH_ADDR_LOW_MAX SZ_4G >> +# define CRASH_ADDR_HIGH_MAX SZ_64T >> +#endif >> + >> #ifndef __ASSEMBLY__ >> >> #include >> @@ -200,6 +221,10 @@ typedef void crash_vmclear_fn(void); >> extern crash_vmclear_fn __rcu *crash_vmclear_loaded_vmcss; >> extern void kdump_nmi_shootdown_cpus(void); >> >> +#ifdef CONFIG_KEXEC_CORE >> +extern void __init reserve_crashkernel(void); >> +#endif >> + >> #endif /* __ASSEMBLY__ */ >> >> #endif /* _ASM_X86_KEXEC_H */ >> diff --git a/arch/x86/kernel/setup.c b/arch/x86/kernel/setup.c >> index 1289f079ad5f..00b3840d30f9 100644 >> --- a/arch/x86/kernel/setup.c >> +++ b/arch/x86/kernel/setup.c >> @@ -25,8 +25,6 @@ >> >> #include >> >> -#include >> - >> #include >> #include >> #include >> @@ -38,6 +36,7 @@ >> #include >> #include >> #include >> +#include >> #include >> #include >> #include >> @@ -389,153 +388,7 @@ static void __init memblock_x86_reserve_range_setup_data(void) >> } >> } >> >> -/* >> - * --------- Crashkernel reservation ------------------------------ >> - */ >> - >> -#ifdef CONFIG_KEXEC_CORE >> - >> -/* >> - * Keep the crash kernel below this limit. >> - * >> - * Earlier 32-bits kernels would limit the kernel to the low 512 MB range >> - * due to mapping restrictions. >> - * >> - * 64-bit kdump kernels need to be restricted to be under 64 TB, which is >> - * the upper limit of system RAM in 4-level paging mode. Since the kdump >> - * jump could be from 5-level paging to 4-level paging, the jump will fail if >> - * the kernel is put above 64 TB, and during the 1st kernel bootup there's >> - * no good way to detect the paging mode of the target kernel which will be >> - * loaded for dumping. >> - */ >> -#ifdef CONFIG_X86_32 >> -# define CRASH_ADDR_LOW_MAX SZ_512M >> -# define CRASH_ADDR_HIGH_MAX SZ_512M >> -#else >> -# define CRASH_ADDR_LOW_MAX SZ_4G >> -# define CRASH_ADDR_HIGH_MAX SZ_64T >> -#endif >> - >> -static int __init reserve_crashkernel_low(void) >> -{ >> -#ifdef CONFIG_X86_64 >> - unsigned long long base, low_base = 0, low_size = 0; >> - unsigned long low_mem_limit; >> - int ret; >> - >> - low_mem_limit = min(memblock_phys_mem_size(), CRASH_ADDR_LOW_MAX); >> - >> - /* crashkernel=Y,low */ >> - ret = parse_crashkernel_low(boot_command_line, low_mem_limit, &low_size, &base); >> - if (ret) { >> - /* >> - * two parts from kernel/dma/swiotlb.c: >> - * -swiotlb size: user-specified with swiotlb= or default. >> - * >> - * -swiotlb overflow buffer: now hardcoded to 32k. We round it >> - * to 8M for other buffers that may need to stay low too. Also >> - * make sure we allocate enough extra low memory so that we >> - * don't run out of DMA buffers for 32-bit devices. >> - */ >> - low_size = max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20); >> - } else { >> - /* passed with crashkernel=0,low ? */ >> - if (!low_size) >> - return 0; >> - } >> - >> - low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, CRASH_ALIGN, CRASH_ADDR_LOW_MAX); >> - if (!low_base) { >> - pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n", >> - (unsigned long)(low_size >> 20)); >> - return -ENOMEM; >> - } >> - >> - pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (low RAM limit: %ldMB)\n", >> - (unsigned long)(low_size >> 20), >> - (unsigned long)(low_base >> 20), >> - (unsigned long)(low_mem_limit >> 20)); >> - >> - crashk_low_res.start = low_base; >> - crashk_low_res.end = low_base + low_size - 1; >> - insert_resource(&iomem_resource, &crashk_low_res); >> -#endif >> - return 0; >> -} >> - >> -static void __init reserve_crashkernel(void) >> -{ >> - unsigned long long crash_size, crash_base, total_mem; >> - bool high = false; >> - int ret; >> - >> - total_mem = memblock_phys_mem_size(); >> - >> - /* crashkernel=XM */ >> - ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base); >> - if (ret != 0 || crash_size <= 0) { >> - /* crashkernel=X,high */ >> - ret = parse_crashkernel_high(boot_command_line, total_mem, >> - &crash_size, &crash_base); >> - if (ret != 0 || crash_size <= 0) >> - return; >> - high = true; >> - } >> - >> - if (xen_pv_domain()) { >> - pr_info("Ignoring crashkernel for a Xen PV domain\n"); >> - return; >> - } > This is relevant only to x86, maybe we could move this check to > setup_arch before calling reserve_crashkernel() to keep it in x86? Yes, we could move this check to setup_arch. > >> - >> - /* 0 means: find the address automatically */ >> - if (!crash_base) { >> - /* >> - * Set CRASH_ADDR_LOW_MAX upper bound for crash memory, >> - * crashkernel=x,high reserves memory over CRASH_ADDR_LOW_MAX, >> - * also allocates 256M extra low memory for DMA buffers >> - * and swiotlb. >> - * But the extra memory is not required for all machines. >> - * So try low memory first and fall back to high memory >> - * unless "crashkernel=size[KMG],high" is specified. >> - */ >> - if (!high) >> - crash_base = memblock_phys_alloc_range(crash_size, >> - CRASH_ALIGN, CRASH_ALIGN, >> - CRASH_ADDR_LOW_MAX); >> - if (!crash_base) >> - crash_base = memblock_phys_alloc_range(crash_size, >> - CRASH_ALIGN, CRASH_ALIGN, >> - CRASH_ADDR_HIGH_MAX); >> - if (!crash_base) { >> - pr_info("crashkernel reservation failed - No suitable area found.\n"); >> - return; >> - } >> - } else { >> - unsigned long long start; >> - >> - start = memblock_phys_alloc_range(crash_size, CRASH_ALIGN, crash_base, >> - crash_base + crash_size); >> - if (start != crash_base) { >> - pr_info("crashkernel reservation failed - memory is in use.\n"); >> - return; >> - } >> - } >> - >> - if (crash_base >= CRASH_ADDR_LOW_MAX && reserve_crashkernel_low()) { >> - memblock_free(crash_base, crash_size); >> - return; >> - } >> - >> - pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System RAM: %ldMB)\n", >> - (unsigned long)(crash_size >> 20), >> - (unsigned long)(crash_base >> 20), >> - (unsigned long)(total_mem >> 20)); >> - >> - crashk_res.start = crash_base; >> - crashk_res.end = crash_base + crash_size - 1; >> - insert_resource(&iomem_resource, &crashk_res); >> -} >> -#else >> +#ifndef CONFIG_KEXEC_CORE >> static void __init reserve_crashkernel(void) >> { >> } >> diff --git a/include/linux/crash_core.h b/include/linux/crash_core.h >> index 206bde8308b2..5021d7c70aee 100644 >> --- a/include/linux/crash_core.h >> +++ b/include/linux/crash_core.h >> @@ -69,6 +69,9 @@ extern unsigned char *vmcoreinfo_data; >> extern size_t vmcoreinfo_size; >> extern u32 *vmcoreinfo_note; >> >> +extern struct resource crashk_res; >> +extern struct resource crashk_low_res; >> + >> /* raw contents of kernel .notes section */ >> extern const void __start_notes __weak; >> extern const void __stop_notes __weak; >> @@ -83,5 +86,6 @@ int parse_crashkernel_high(char *cmdline, unsigned long long system_ram, >> unsigned long long *crash_size, unsigned long long *crash_base); >> int parse_crashkernel_low(char *cmdline, unsigned long long system_ram, >> unsigned long long *crash_size, unsigned long long *crash_base); >> +int __init reserve_crashkernel_low(void); >> >> #endif /* LINUX_CRASH_CORE_H */ >> diff --git a/include/linux/kexec.h b/include/linux/kexec.h >> index 9e93bef52968..f301f2f5cfc4 100644 >> --- a/include/linux/kexec.h >> +++ b/include/linux/kexec.h >> @@ -337,8 +337,6 @@ extern int kexec_load_disabled; >> >> /* Location of a reserved region to hold the crash kernel. >> */ >> -extern struct resource crashk_res; >> -extern struct resource crashk_low_res; >> extern note_buf_t __percpu *crash_notes; >> >> /* flag to track if kexec reboot is in progress */ >> diff --git a/kernel/crash_core.c b/kernel/crash_core.c >> index 106e4500fd53..d39892bdb9ae 100644 >> --- a/kernel/crash_core.c >> +++ b/kernel/crash_core.c >> @@ -7,7 +7,12 @@ >> #include >> #include >> #include >> +#include >> +#include >> >> +#include >> + >> +#include >> #include >> #include >> >> @@ -21,6 +26,22 @@ u32 *vmcoreinfo_note; >> /* trusted vmcoreinfo, e.g. we can make a copy in the crash memory */ >> static unsigned char *vmcoreinfo_data_safecopy; >> >> +/* Location of the reserved area for the crash kernel */ >> +struct resource crashk_res = { >> + .name = "Crash kernel", >> + .start = 0, >> + .end = 0, >> + .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, >> + .desc = IORES_DESC_CRASH_KERNEL >> +}; >> +struct resource crashk_low_res = { >> + .name = "Crash kernel", >> + .start = 0, >> + .end = 0, >> + .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, >> + .desc = IORES_DESC_CRASH_KERNEL >> +}; >> + >> /* >> * parsing the "crashkernel" commandline >> * >> @@ -294,6 +315,149 @@ int __init parse_crashkernel_low(char *cmdline, >> "crashkernel=", suffix_tbl[SUFFIX_LOW]); >> } >> >> +/* >> + * --------- Crashkernel reservation ------------------------------ >> + */ >> + >> +int __init reserve_crashkernel_low(void) > static? Ok, i will update in next version. > >> +{ >> +#ifdef CONFIG_X86_64 >> + unsigned long long base, low_base = 0, low_size = 0; >> + unsigned long low_mem_limit; >> + int ret; >> + >> + low_mem_limit = min(memblock_phys_mem_size(), CRASH_ADDR_LOW_MAX); >> + >> + /* crashkernel=Y,low */ >> + ret = parse_crashkernel_low(boot_command_line, low_mem_limit, &low_size, &base); >> + if (ret) { >> + /* >> + * two parts from kernel/dma/swiotlb.c: >> + * -swiotlb size: user-specified with swiotlb= or default. >> + * >> + * -swiotlb overflow buffer: now hardcoded to 32k. We round it >> + * to 8M for other buffers that may need to stay low too. Also >> + * make sure we allocate enough extra low memory so that we >> + * don't run out of DMA buffers for 32-bit devices. >> + */ >> + low_size = max(swiotlb_size_or_default() + (8UL << 20), 256UL << 20); >> + } else { >> + /* passed with crashkernel=0,low ? */ >> + if (!low_size) >> + return 0; >> + } >> + >> + low_base = memblock_phys_alloc_range(low_size, CRASH_ALIGN, CRASH_ALIGN, >> + CRASH_ADDR_LOW_MAX); >> + if (!low_base) { >> + pr_err("Cannot reserve %ldMB crashkernel low memory, please try smaller size.\n", >> + (unsigned long)(low_size >> 20)); >> + return -ENOMEM; >> + } >> + >> + pr_info("Reserving %ldMB of low memory at %ldMB for crashkernel (low RAM limit: %ldMB)\n", >> + (unsigned long)(low_size >> 20), >> + (unsigned long)(low_base >> 20), >> + (unsigned long)(low_mem_limit >> 20)); >> + >> + crashk_low_res.start = low_base; >> + crashk_low_res.end = low_base + low_size - 1; >> + insert_resource(&iomem_resource, &crashk_low_res); >> +#endif >> + return 0; >> +} >> + >> +#ifdef CONFIG_X86 >> +#ifdef CONFIG_KEXEC_CORE >> +/* >> + * reserve_crashkernel() - reserves memory for crash kernel >> + * >> + * This function reserves memory area given in "crashkernel=" kernel command >> + * line parameter. The memory reserved is used by dump capture kernel when >> + * primary kernel is crashing. >> + */ >> +void __init reserve_crashkernel(void) >> +{ >> + unsigned long long crash_size, crash_base, total_mem; >> + bool high = false; >> + int ret; >> + >> + total_mem = memblock_phys_mem_size(); >> + >> + /* crashkernel=XM */ >> + ret = parse_crashkernel(boot_command_line, total_mem, &crash_size, &crash_base); >> + if (ret != 0 || crash_size <= 0) { >> + /* crashkernel=X,high */ >> + ret = parse_crashkernel_high(boot_command_line, total_mem, >> + &crash_size, &crash_base); >> + if (ret != 0 || crash_size <= 0) >> + return; >> + high = true; >> + } >> + >> + if (xen_pv_domain()) { >> + pr_info("Ignoring crashkernel for a Xen PV domain\n"); >> + return; >> + } >> + >> + /* 0 means: find the address automatically */ >> + if (!crash_base) { >> + /* >> + * Set CRASH_ADDR_LOW_MAX upper bound for crash memory, >> + * crashkernel=x,high reserves memory over CRASH_ADDR_LOW_MAX, >> + * also allocates 256M extra low memory for DMA buffers >> + * and swiotlb. >> + * But the extra memory is not required for all machines. >> + * So try low memory first and fall back to high memory >> + * unless "crashkernel=size[KMG],high" is specified. >> + */ >> + if (!high) >> + crash_base = memblock_phys_alloc_range(crash_size, >> + CRASH_ALIGN, CRASH_ALIGN, >> + CRASH_ADDR_LOW_MAX); >> + if (!crash_base) >> + crash_base = memblock_phys_alloc_range(crash_size, >> + CRASH_ALIGN, CRASH_ALIGN, >> + CRASH_ADDR_HIGH_MAX); >> + if (!crash_base) { >> + pr_info("crashkernel reservation failed - No suitable area found.\n"); >> + return; >> + } >> + } else { >> + /* User specifies base address explicitly. */ >> + unsigned long long start; >> + >> + if (!IS_ALIGNED(crash_base, CRASH_ALIGN)) { >> + pr_warn("cannot reserve crashkernel: base address is not %ldMB aligned\n", >> + (unsigned long)CRASH_ALIGN >> 20); >> + return; >> + } >> + >> + start = memblock_phys_alloc_range(crash_size, CRASH_ALIGN, crash_base, >> + crash_base + crash_size); >> + if (start != crash_base) { >> + pr_info("crashkernel reservation failed - memory is in use.\n"); >> + return; >> + } >> + } >> + >> + if (crash_base >= CRASH_ADDR_LOW_MAX && reserve_crashkernel_low()) { >> + memblock_free(crash_base, crash_size); >> + return; >> + } >> + >> + pr_info("Reserving %ldMB of memory at %ldMB for crashkernel (System RAM: %ldMB)\n", >> + (unsigned long)(crash_size >> 20), >> + (unsigned long)(crash_base >> 20), >> + (unsigned long)(total_mem >> 20)); >> + >> + crashk_res.start = crash_base; >> + crashk_res.end = crash_base + crash_size - 1; >> + insert_resource(&iomem_resource, &crashk_res); >> +} >> +#endif /* CONFIG_KEXEC_CORE */ >> +#endif >> + >> Elf_Word *append_elf_note(Elf_Word *buf, char *name, unsigned int type, >> void *data, size_t data_len) >> { >> diff --git a/kernel/kexec_core.c b/kernel/kexec_core.c >> index 8798a8183974..2ca887514145 100644 >> --- a/kernel/kexec_core.c >> +++ b/kernel/kexec_core.c >> @@ -53,23 +53,6 @@ note_buf_t __percpu *crash_notes; >> /* Flag to indicate we are going to kexec a new kernel */ >> bool kexec_in_progress = false; >> >> - >> -/* Location of the reserved area for the crash kernel */ >> -struct resource crashk_res = { >> - .name = "Crash kernel", >> - .start = 0, >> - .end = 0, >> - .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, >> - .desc = IORES_DESC_CRASH_KERNEL >> -}; >> -struct resource crashk_low_res = { >> - .name = "Crash kernel", >> - .start = 0, >> - .end = 0, >> - .flags = IORESOURCE_BUSY | IORESOURCE_SYSTEM_RAM, >> - .desc = IORES_DESC_CRASH_KERNEL >> -}; >> - >> int kexec_should_crash(struct task_struct *p) >> { >> /* >> -- >> 2.20.1 >>