From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Vrabel Subject: [PATCH 3/5] xen: allow balloon driver to use more than one memory region Date: Fri, 19 Aug 2011 15:57:18 +0100 Message-ID: <1313765840-22084-4-git-send-email-david.vrabel@citrix.com> References: <1313765840-22084-1-git-send-email-david.vrabel@citrix.com> Mime-Version: 1.0 Content-Type: text/plain Return-path: In-Reply-To: <1313765840-22084-1-git-send-email-david.vrabel@citrix.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xensource.com Errors-To: xen-devel-bounces@lists.xensource.com To: xen-devel@lists.xensource.com Cc: David Vrabel , Konrad Rzeszutek Wilk List-Id: xen-devel@lists.xenproject.org Allow the xen balloon driver to populate its list of extra pages from more than one region of memory. This will allow platforms to provide (for example) a region of low memory and a region of high memory. The maximum possible number of extra regions is 128 (== E820MAX) which is quite large so xen_extra_mem is placed in __initdata. This is safe as both xen_memeory_setup() and balloon_init() are in __init. The balloon regions themselves are not altered (i.e., there is still only the one region). Signed-off-by: David Vrabel --- arch/x86/xen/setup.c | 20 +++++++++--------- drivers/xen/balloon.c | 51 ++++++++++++++++++++++++++++-------------------- include/xen/page.h | 9 +++++++- 3 files changed, 48 insertions(+), 32 deletions(-) diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index c3b8d44..4720c2d 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -37,7 +37,7 @@ extern void xen_syscall_target(void); extern void xen_syscall32_target(void); /* Amount of extra memory space we add to the e820 ranges */ -phys_addr_t xen_extra_mem_start, xen_extra_mem_size; +struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata; /* * The maximum amount of extra memory compared to the base size. The @@ -56,7 +56,7 @@ static void __init xen_add_extra_mem(unsigned long pages) unsigned long pfn; u64 size = (u64)pages * PAGE_SIZE; - u64 extra_start = xen_extra_mem_start + xen_extra_mem_size; + u64 extra_start = xen_extra_mem[0].start + xen_extra_mem[0].size; if (!pages) return; @@ -66,7 +66,7 @@ static void __init xen_add_extra_mem(unsigned long pages) memblock_x86_reserve_range(extra_start, extra_start + size, "XEN EXTRA"); - xen_extra_mem_size += size; + xen_extra_mem[0].size += size; xen_max_p2m_pfn = PFN_DOWN(extra_start + size); @@ -239,7 +239,7 @@ char * __init xen_memory_setup(void) memcpy(map_raw, map, sizeof(map)); e820.nr_map = 0; - xen_extra_mem_start = mem_end; + xen_extra_mem[0].start = mem_end; for (i = 0; i < memmap.nr_entries; i++) { unsigned long long end; @@ -267,8 +267,8 @@ char * __init xen_memory_setup(void) e820_add_region(end, delta, E820_UNUSABLE); } - if (map[i].size > 0 && end > xen_extra_mem_start) - xen_extra_mem_start = end; + if (map[i].size > 0 && end > xen_extra_mem[0].start) + xen_extra_mem[0].start = end; /* Add region if any remains */ if (map[i].size > 0) @@ -276,10 +276,10 @@ char * __init xen_memory_setup(void) } /* Align the balloon area so that max_low_pfn does not get set * to be at the _end_ of the PCI gap at the far end (fee01000). - * Note that xen_extra_mem_start gets set in the loop above to be - * past the last E820 region. */ - if (xen_initial_domain() && (xen_extra_mem_start < (1ULL<<32))) - xen_extra_mem_start = (1ULL<<32); + * Note that the start of balloon area gets set in the loop above + * to be past the last E820 region. */ + if (xen_initial_domain() && (xen_extra_mem[0].start < (1ULL<<32))) + xen_extra_mem[0].start = (1ULL<<32); /* * In domU, the ISA region is normal, usable memory, but we diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c index 5814022..996cf65 100644 --- a/drivers/xen/balloon.c +++ b/drivers/xen/balloon.c @@ -555,11 +555,35 @@ void free_xenballooned_pages(int nr_pages, struct page** pages) } EXPORT_SYMBOL(free_xenballooned_pages); -static int __init balloon_init(void) +static void __init balloon_add_memory_region(unsigned long start_pfn, unsigned long pages) { - domid_t domid = DOMID_SELF; unsigned long pfn, extra_pfn_end; struct page *page; + + /* + * Initialise the balloon with excess memory space. We need + * to make sure we don't add memory which doesn't exist or + * logically exist. The E820 map can be trimmed to be smaller + * than the amount of physical memory due to the mem= command + * line parameter. And if this is a 32-bit non-HIGHMEM kernel + * on a system with memory which requires highmem to access, + * don't try to use it. + */ + extra_pfn_end = min(min(max_pfn, e820_end_of_ram_pfn()), + start_pfn + pages); + for (pfn = start_pfn; pfn < extra_pfn_end; pfn++) { + page = pfn_to_page(pfn); + /* totalram_pages and totalhigh_pages do not + include the boot-time balloon extension, so + don't subtract from it. */ + __balloon_append(page); + } +} + +static int __init balloon_init(void) +{ + domid_t domid = DOMID_SELF; + int i; int ret; if (!xen_domain()) @@ -588,25 +612,10 @@ static int __init balloon_init(void) register_memory_notifier(&xen_memory_nb); #endif - /* - * Initialise the balloon with excess memory space. We need - * to make sure we don't add memory which doesn't exist or - * logically exist. The E820 map can be trimmed to be smaller - * than the amount of physical memory due to the mem= command - * line parameter. And if this is a 32-bit non-HIGHMEM kernel - * on a system with memory which requires highmem to access, - * don't try to use it. - */ - extra_pfn_end = min(min(max_pfn, e820_end_of_ram_pfn()), - (unsigned long)PFN_DOWN(xen_extra_mem_start + xen_extra_mem_size)); - for (pfn = PFN_UP(xen_extra_mem_start); - pfn < extra_pfn_end; - pfn++) { - page = pfn_to_page(pfn); - /* totalram_pages and totalhigh_pages do not include the boot-time - balloon extension, so don't subtract from it. */ - __balloon_append(page); - } + for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) + if (xen_extra_mem[i].size) + balloon_add_memory_region(PFN_UP(xen_extra_mem[i].start), + PFN_DOWN(xen_extra_mem[i].size)); return 0; } diff --git a/include/xen/page.h b/include/xen/page.h index 0be36b9..b432c03 100644 --- a/include/xen/page.h +++ b/include/xen/page.h @@ -3,6 +3,13 @@ #include -extern phys_addr_t xen_extra_mem_start, xen_extra_mem_size; +struct xen_memory_region { + phys_addr_t start; + phys_addr_t size; +}; + +#define XEN_EXTRA_MEM_MAX_REGIONS 128 /* == E820MAX */ + +extern struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS]; #endif /* _XEN_PAGE_H */ -- 1.7.2.5