From patchwork Thu Aug 6 09:06:09 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Jan Beulich X-Patchwork-Id: 11703053 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 18739138C for ; Thu, 6 Aug 2020 12:01:33 +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 F38BF22D05 for ; Thu, 6 Aug 2020 12:01:32 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org F38BF22D05 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=suse.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=xen-devel-bounces@lists.xenproject.org Received: from localhost ([127.0.0.1] helo=lists.xenproject.org) by lists.xenproject.org with esmtp (Exim 4.92) (envelope-from ) id 1k3bqj-0008J7-Up; Thu, 06 Aug 2020 09:06:09 +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 1k3bqi-0008I9-B3 for xen-devel@lists.xenproject.org; Thu, 06 Aug 2020 09:06:08 +0000 X-Inumbo-ID: 75dab13f-ff1d-496c-afa3-bab25eb6db47 Received: from mx2.suse.de (unknown [195.135.220.15]) by us1-amaz-eas2.inumbo.com (Halon) with ESMTPS id 75dab13f-ff1d-496c-afa3-bab25eb6db47; Thu, 06 Aug 2020 09:06:07 +0000 (UTC) X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 276C7B1AA; Thu, 6 Aug 2020 09:06:24 +0000 (UTC) Subject: [PATCH 4/4] EFI: free unused boot mem in at least some cases From: Jan Beulich To: "xen-devel@lists.xenproject.org" References: <305c2532-408a-9f78-61fe-c90a2e86eb8e@suse.com> Message-ID: <4e2d0d0a-9d85-d704-5d61-ae9efc69256a@suse.com> Date: Thu, 6 Aug 2020 11:06:09 +0200 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:68.0) Gecko/20100101 Thunderbird/68.11.0 MIME-Version: 1.0 In-Reply-To: <305c2532-408a-9f78-61fe-c90a2e86eb8e@suse.com> Content-Language: en-US X-BeenThere: xen-devel@lists.xenproject.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Xen developer discussion List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Cc: Stefano Stabellini , Julien Grall , Wei Liu , George Dunlap , Andrew Cooper , Ian Jackson , =?utf-8?q?Roger_Pau_Monn=C3=A9?= Errors-To: xen-devel-bounces@lists.xenproject.org Sender: "Xen-devel" Address at least the primary reason why 52bba67f8b87 ("efi/boot: Don't free ebmalloc area at all") was put in place: Make xen_in_range() aware of the freed range. This is in particular relevant for EFI-enabled builds not actually running on EFI, as the entire range will be unused in this case. Signed-off-by: Jan Beulich --- The remaining issue could be addressed too, by making the area 2M in size and 2M-aligned. --- a/xen/arch/x86/efi/stub.c +++ b/xen/arch/x86/efi/stub.c @@ -52,6 +52,12 @@ bool efi_enabled(unsigned int feature) void __init efi_init_memory(void) { } +bool __hwdom_init efi_boot_mem_unused(unsigned long *start, unsigned long *end) +{ + *start = *end = (unsigned long)_end; + return false; +} + void efi_update_l4_pgtable(unsigned int l4idx, l4_pgentry_t l4e) { } bool efi_rs_using_pgtables(void) --- a/xen/arch/x86/setup.c +++ b/xen/arch/x86/setup.c @@ -608,7 +608,7 @@ static void __init kexec_reserve_area(st #endif } -static inline bool using_2M_mapping(void) +bool using_2M_mapping(void) { return !l1_table_offset((unsigned long)__2M_text_end) && !l1_table_offset((unsigned long)__2M_rodata_start) && @@ -1970,7 +1970,7 @@ int __hwdom_init xen_in_range(unsigned l paddr_t start, end; int i; - enum { region_s3, region_ro, region_rw, nr_regions }; + enum { region_s3, region_ro, region_rw, region_bss, nr_regions }; static struct { paddr_t s, e; } xen_regions[nr_regions] __hwdom_initdata; @@ -1994,7 +1994,14 @@ int __hwdom_init xen_in_range(unsigned l xen_regions[region_ro].e = __pa(&__2M_rodata_end); /* hypervisor .data + .bss */ xen_regions[region_rw].s = __pa(&__2M_rwdata_start); - xen_regions[region_rw].e = __pa(&__2M_rwdata_end); + if ( efi_boot_mem_unused(&start, &end) ) + { + xen_regions[region_rw].e = __pa(start); + xen_regions[region_bss].s = __pa(end); + xen_regions[region_bss].e = __pa(&__2M_rwdata_end); + } + else + xen_regions[region_rw].e = __pa(&__2M_rwdata_end); } start = (paddr_t)mfn << PAGE_SHIFT; --- a/xen/common/efi/ebmalloc.c +++ b/xen/common/efi/ebmalloc.c @@ -1,5 +1,9 @@ #include "efi.h" #include +#include +#ifdef CONFIG_X86 +#include +#endif #ifdef CONFIG_ARM /* @@ -21,7 +25,7 @@ static char __section(".bss.page_aligned") __aligned(PAGE_SIZE) ebmalloc_mem[EBMALLOC_SIZE]; -static unsigned long __initdata ebmalloc_allocated; +static unsigned long __read_mostly ebmalloc_allocated; /* EFI boot allocator. */ void __init *ebmalloc(size_t size) @@ -36,17 +40,32 @@ void __init *ebmalloc(size_t size) return ptr; } +bool __hwdom_init efi_boot_mem_unused(unsigned long *start, unsigned long *end) +{ + *start = (unsigned long)ebmalloc_mem + PAGE_ALIGN(ebmalloc_allocated); + *end = (unsigned long)ebmalloc_mem + sizeof(ebmalloc_mem); + + return *start < *end; +} + void __init free_ebmalloc_unused_mem(void) { -#if 0 /* FIXME: Putting a hole in the BSS breaks the IOMMU mappings for dom0. */ unsigned long start, end; - start = (unsigned long)ebmalloc_mem + PAGE_ALIGN(ebmalloc_allocated); - end = (unsigned long)ebmalloc_mem + sizeof(ebmalloc_mem); +#ifdef CONFIG_X86 + /* FIXME: Putting a hole in .bss would shatter the large page mapping. */ + if ( using_2M_mapping() ) + { + ebmalloc_allocated = sizeof(ebmalloc_mem); + return; + } +#endif + + if ( !efi_boot_mem_unused(&start, &end) ) + return; destroy_xen_mappings(start, end); init_xenheap_pages(__pa(start), __pa(end)); printk(XENLOG_INFO "Freed %lukB unused BSS memory\n", (end - start) >> 10); -#endif } --- a/xen/include/asm-x86/setup.h +++ b/xen/include/asm-x86/setup.h @@ -9,6 +9,8 @@ extern const char __2M_rodata_start[], _ extern char __2M_init_start[], __2M_init_end[]; extern char __2M_rwdata_start[], __2M_rwdata_end[]; +bool using_2M_mapping(void); + extern unsigned long xenheap_initial_phys_start; extern uint64_t boot_tsc_stamp; --- a/xen/include/xen/efi.h +++ b/xen/include/xen/efi.h @@ -33,6 +33,7 @@ struct compat_pf_efi_runtime_call; bool efi_enabled(unsigned int feature); void efi_init_memory(void); +bool efi_boot_mem_unused(unsigned long *start, unsigned long *end); bool efi_rs_using_pgtables(void); unsigned long efi_get_time(void); void efi_halt_system(void);