diff options
Diffstat (limited to 'arch/x86/xen/setup.c')
-rw-r--r-- | arch/x86/xen/setup.c | 190 |
1 files changed, 185 insertions, 5 deletions
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c index ad0047f47cd4..b1dbdaa23ecc 100644 --- a/arch/x86/xen/setup.c +++ b/arch/x86/xen/setup.c @@ -8,6 +8,7 @@ #include <linux/sched.h> #include <linux/mm.h> #include <linux/pm.h> +#include <linux/memblock.h> #include <asm/elf.h> #include <asm/vdso.h> @@ -17,9 +18,12 @@ #include <asm/xen/hypervisor.h> #include <asm/xen/hypercall.h> +#include <xen/xen.h> #include <xen/page.h> #include <xen/interface/callback.h> +#include <xen/interface/memory.h> #include <xen/interface/physdev.h> +#include <xen/interface/memory.h> #include <xen/features.h> #include "xen-ops.h" @@ -32,25 +36,177 @@ extern void xen_sysenter_target(void); 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; + +/* + * The maximum amount of extra memory compared to the base size. The + * main scaling factor is the size of struct page. At extreme ratios + * of base:extra, all the base memory can be filled with page + * structures for the extra memory, leaving no space for anything + * else. + * + * 10x seems like a reasonable balance between scaling flexibility and + * leaving a practically usable system. + */ +#define EXTRA_MEM_RATIO (10) + +static __init void xen_add_extra_mem(unsigned long pages) +{ + u64 size = (u64)pages * PAGE_SIZE; + u64 extra_start = xen_extra_mem_start + xen_extra_mem_size; + + if (!pages) + return; + + e820_add_region(extra_start, size, E820_RAM); + sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map); + + memblock_x86_reserve_range(extra_start, extra_start + size, "XEN EXTRA"); + + xen_extra_mem_size += size; + + xen_max_p2m_pfn = PFN_DOWN(extra_start + size); +} + +static unsigned long __init xen_release_chunk(phys_addr_t start_addr, + phys_addr_t end_addr) +{ + struct xen_memory_reservation reservation = { + .address_bits = 0, + .extent_order = 0, + .domid = DOMID_SELF + }; + unsigned long start, end; + unsigned long len = 0; + unsigned long pfn; + int ret; + + start = PFN_UP(start_addr); + end = PFN_DOWN(end_addr); + + if (end <= start) + return 0; + + printk(KERN_INFO "xen_release_chunk: looking at area pfn %lx-%lx: ", + start, end); + for(pfn = start; pfn < end; pfn++) { + unsigned long mfn = pfn_to_mfn(pfn); + + /* Make sure pfn exists to start with */ + if (mfn == INVALID_P2M_ENTRY || mfn_to_pfn(mfn) != pfn) + continue; + + set_xen_guest_handle(reservation.extent_start, &mfn); + reservation.nr_extents = 1; + + ret = HYPERVISOR_memory_op(XENMEM_decrease_reservation, + &reservation); + WARN(ret != 1, "Failed to release memory %lx-%lx err=%d\n", + start, end, ret); + if (ret == 1) { + set_phys_to_machine(pfn, INVALID_P2M_ENTRY); + len++; + } + } + printk(KERN_CONT "%ld pages freed\n", len); + + return len; +} + +static unsigned long __init xen_return_unused_memory(unsigned long max_pfn, + const struct e820map *e820) +{ + phys_addr_t max_addr = PFN_PHYS(max_pfn); + phys_addr_t last_end = 0; + unsigned long released = 0; + int i; + + for (i = 0; i < e820->nr_map && last_end < max_addr; i++) { + phys_addr_t end = e820->map[i].addr; + end = min(max_addr, end); + + released += xen_release_chunk(last_end, end); + last_end = e820->map[i].addr + e820->map[i].size; + } + + if (last_end < max_addr) + released += xen_release_chunk(last_end, max_addr); + + printk(KERN_INFO "released %ld pages of unused memory\n", released); + return released; +} /** * machine_specific_memory_setup - Hook for machine specific memory setup. **/ - char * __init xen_memory_setup(void) { + static struct e820entry map[E820MAX] __initdata; + unsigned long max_pfn = xen_start_info->nr_pages; + unsigned long long mem_end; + int rc; + struct xen_memory_map memmap; + unsigned long extra_pages = 0; + unsigned long extra_limit; + int i; + int op; max_pfn = min(MAX_DOMAIN_PAGES, max_pfn); + mem_end = PFN_PHYS(max_pfn); + + memmap.nr_entries = E820MAX; + set_xen_guest_handle(memmap.buffer, map); + + op = xen_initial_domain() ? + XENMEM_machine_memory_map : + XENMEM_memory_map; + rc = HYPERVISOR_memory_op(op, &memmap); + if (rc == -ENOSYS) { + memmap.nr_entries = 1; + map[0].addr = 0ULL; + map[0].size = mem_end; + /* 8MB slack (to balance backend allocations). */ + map[0].size += 8ULL << 20; + map[0].type = E820_RAM; + rc = 0; + } + BUG_ON(rc); e820.nr_map = 0; + xen_extra_mem_start = mem_end; + for (i = 0; i < memmap.nr_entries; i++) { + unsigned long long end = map[i].addr + map[i].size; + + if (map[i].type == E820_RAM) { + if (map[i].addr < mem_end && end > mem_end) { + /* Truncate region to max_mem. */ + u64 delta = end - mem_end; - e820_add_region(0, PFN_PHYS((u64)max_pfn), E820_RAM); + map[i].size -= delta; + extra_pages += PFN_DOWN(delta); + + end = mem_end; + } + } + + if (end > xen_extra_mem_start) + xen_extra_mem_start = end; + + /* If region is non-RAM or below mem_end, add what remains */ + if ((map[i].type != E820_RAM || map[i].addr < mem_end) && + map[i].size > 0) + e820_add_region(map[i].addr, map[i].size, map[i].type); + } /* * Even though this is normal, usable memory under Xen, reserve * ISA memory anyway because too many things think they can poke * about in there. + * + * In a dom0 kernel, this region is identity mapped with the + * hardware ISA area, so it really is out of bounds. */ e820_add_region(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_RESERVED); @@ -61,12 +217,36 @@ char * __init xen_memory_setup(void) * - xen_start_info * See comment above "struct start_info" in <xen/interface/xen.h> */ - reserve_early(__pa(xen_start_info->mfn_list), + memblock_x86_reserve_range(__pa(xen_start_info->mfn_list), __pa(xen_start_info->pt_base), "XEN START INFO"); sanitize_e820_map(e820.map, ARRAY_SIZE(e820.map), &e820.nr_map); + extra_pages += xen_return_unused_memory(xen_start_info->nr_pages, &e820); + + /* + * Clamp the amount of extra memory to a EXTRA_MEM_RATIO + * factor the base size. On non-highmem systems, the base + * size is the full initial memory allocation; on highmem it + * is limited to the max size of lowmem, so that it doesn't + * get completely filled. + * + * In principle there could be a problem in lowmem systems if + * the initial memory is also very large with respect to + * lowmem, but we won't try to deal with that here. + */ + extra_limit = min(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)), + max_pfn + extra_pages); + + if (extra_limit >= max_pfn) + extra_pages = extra_limit - max_pfn; + else + extra_pages = 0; + + if (!xen_initial_domain()) + xen_add_extra_mem(extra_pages); + return "Xen"; } @@ -156,6 +336,8 @@ void __init xen_arch_setup(void) struct physdev_set_iopl set_iopl; int rc; + xen_panic_handler_init(); + HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_4gb_segments); HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables); @@ -188,7 +370,5 @@ void __init xen_arch_setup(void) pm_idle = xen_idle; - paravirt_disable_iospace(); - fiddle_vdso(); } |