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Diffstat (limited to 'arch/x86/xen/setup.c')
| -rw-r--r-- | arch/x86/xen/setup.c | 988 |
1 files changed, 988 insertions, 0 deletions
diff --git a/arch/x86/xen/setup.c b/arch/x86/xen/setup.c new file mode 100644 index 0000000000..b3e3796106 --- /dev/null +++ b/arch/x86/xen/setup.c @@ -0,0 +1,988 @@ +// SPDX-License-Identifier: GPL-2.0 +/* + * Machine specific setup for xen + * + * Jeremy Fitzhardinge <jeremy@xensource.com>, XenSource Inc, 2007 + */ + +#include <linux/init.h> +#include <linux/iscsi_ibft.h> +#include <linux/sched.h> +#include <linux/kstrtox.h> +#include <linux/mm.h> +#include <linux/pm.h> +#include <linux/memblock.h> +#include <linux/cpuidle.h> +#include <linux/cpufreq.h> +#include <linux/memory_hotplug.h> + +#include <asm/elf.h> +#include <asm/vdso.h> +#include <asm/e820/api.h> +#include <asm/setup.h> +#include <asm/acpi.h> +#include <asm/numa.h> +#include <asm/idtentry.h> +#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/features.h> +#include <xen/hvc-console.h> +#include "xen-ops.h" +#include "mmu.h" + +#define GB(x) ((uint64_t)(x) * 1024 * 1024 * 1024) + +/* Amount of extra memory space we add to the e820 ranges */ +struct xen_memory_region xen_extra_mem[XEN_EXTRA_MEM_MAX_REGIONS] __initdata; + +/* Number of pages released from the initial allocation. */ +unsigned long xen_released_pages; + +/* Memory map would allow PCI passthrough. */ +bool xen_pv_pci_possible; + +/* E820 map used during setting up memory. */ +static struct e820_table xen_e820_table __initdata; + +/* + * Buffer used to remap identity mapped pages. We only need the virtual space. + * The physical page behind this address is remapped as needed to different + * buffer pages. + */ +#define REMAP_SIZE (P2M_PER_PAGE - 3) +static struct { + unsigned long next_area_mfn; + unsigned long target_pfn; + unsigned long size; + unsigned long mfns[REMAP_SIZE]; +} xen_remap_buf __initdata __aligned(PAGE_SIZE); +static unsigned long xen_remap_mfn __initdata = INVALID_P2M_ENTRY; + +/* + * 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 bool xen_512gb_limit __initdata = IS_ENABLED(CONFIG_XEN_512GB); + +static void __init xen_parse_512gb(void) +{ + bool val = false; + char *arg; + + arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit"); + if (!arg) + return; + + arg = strstr(xen_start_info->cmd_line, "xen_512gb_limit="); + if (!arg) + val = true; + else if (kstrtobool(arg + strlen("xen_512gb_limit="), &val)) + return; + + xen_512gb_limit = val; +} + +static void __init xen_add_extra_mem(unsigned long start_pfn, + unsigned long n_pfns) +{ + int i; + + /* + * No need to check for zero size, should happen rarely and will only + * write a new entry regarded to be unused due to zero size. + */ + for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { + /* Add new region. */ + if (xen_extra_mem[i].n_pfns == 0) { + xen_extra_mem[i].start_pfn = start_pfn; + xen_extra_mem[i].n_pfns = n_pfns; + break; + } + /* Append to existing region. */ + if (xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns == + start_pfn) { + xen_extra_mem[i].n_pfns += n_pfns; + break; + } + } + if (i == XEN_EXTRA_MEM_MAX_REGIONS) + printk(KERN_WARNING "Warning: not enough extra memory regions\n"); + + memblock_reserve(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns)); +} + +static void __init xen_del_extra_mem(unsigned long start_pfn, + unsigned long n_pfns) +{ + int i; + unsigned long start_r, size_r; + + for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { + start_r = xen_extra_mem[i].start_pfn; + size_r = xen_extra_mem[i].n_pfns; + + /* Start of region. */ + if (start_r == start_pfn) { + BUG_ON(n_pfns > size_r); + xen_extra_mem[i].start_pfn += n_pfns; + xen_extra_mem[i].n_pfns -= n_pfns; + break; + } + /* End of region. */ + if (start_r + size_r == start_pfn + n_pfns) { + BUG_ON(n_pfns > size_r); + xen_extra_mem[i].n_pfns -= n_pfns; + break; + } + /* Mid of region. */ + if (start_pfn > start_r && start_pfn < start_r + size_r) { + BUG_ON(start_pfn + n_pfns > start_r + size_r); + xen_extra_mem[i].n_pfns = start_pfn - start_r; + /* Calling memblock_reserve() again is okay. */ + xen_add_extra_mem(start_pfn + n_pfns, start_r + size_r - + (start_pfn + n_pfns)); + break; + } + } + memblock_phys_free(PFN_PHYS(start_pfn), PFN_PHYS(n_pfns)); +} + +/* + * Called during boot before the p2m list can take entries beyond the + * hypervisor supplied p2m list. Entries in extra mem are to be regarded as + * invalid. + */ +unsigned long __ref xen_chk_extra_mem(unsigned long pfn) +{ + int i; + + for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { + if (pfn >= xen_extra_mem[i].start_pfn && + pfn < xen_extra_mem[i].start_pfn + xen_extra_mem[i].n_pfns) + return INVALID_P2M_ENTRY; + } + + return IDENTITY_FRAME(pfn); +} + +/* + * Mark all pfns of extra mem as invalid in p2m list. + */ +void __init xen_inv_extra_mem(void) +{ + unsigned long pfn, pfn_s, pfn_e; + int i; + + for (i = 0; i < XEN_EXTRA_MEM_MAX_REGIONS; i++) { + if (!xen_extra_mem[i].n_pfns) + continue; + pfn_s = xen_extra_mem[i].start_pfn; + pfn_e = pfn_s + xen_extra_mem[i].n_pfns; + for (pfn = pfn_s; pfn < pfn_e; pfn++) + set_phys_to_machine(pfn, INVALID_P2M_ENTRY); + } +} + +/* + * Finds the next RAM pfn available in the E820 map after min_pfn. + * This function updates min_pfn with the pfn found and returns + * the size of that range or zero if not found. + */ +static unsigned long __init xen_find_pfn_range(unsigned long *min_pfn) +{ + const struct e820_entry *entry = xen_e820_table.entries; + unsigned int i; + unsigned long done = 0; + + for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) { + unsigned long s_pfn; + unsigned long e_pfn; + + if (entry->type != E820_TYPE_RAM) + continue; + + e_pfn = PFN_DOWN(entry->addr + entry->size); + + /* We only care about E820 after this */ + if (e_pfn <= *min_pfn) + continue; + + s_pfn = PFN_UP(entry->addr); + + /* If min_pfn falls within the E820 entry, we want to start + * at the min_pfn PFN. + */ + if (s_pfn <= *min_pfn) { + done = e_pfn - *min_pfn; + } else { + done = e_pfn - s_pfn; + *min_pfn = s_pfn; + } + break; + } + + return done; +} + +static int __init xen_free_mfn(unsigned long mfn) +{ + struct xen_memory_reservation reservation = { + .address_bits = 0, + .extent_order = 0, + .domid = DOMID_SELF + }; + + set_xen_guest_handle(reservation.extent_start, &mfn); + reservation.nr_extents = 1; + + return HYPERVISOR_memory_op(XENMEM_decrease_reservation, &reservation); +} + +/* + * This releases a chunk of memory and then does the identity map. It's used + * as a fallback if the remapping fails. + */ +static void __init xen_set_identity_and_release_chunk(unsigned long start_pfn, + unsigned long end_pfn, unsigned long nr_pages) +{ + unsigned long pfn, end; + int ret; + + WARN_ON(start_pfn > end_pfn); + + /* Release pages first. */ + end = min(end_pfn, nr_pages); + for (pfn = start_pfn; 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; + + ret = xen_free_mfn(mfn); + WARN(ret != 1, "Failed to release pfn %lx err=%d\n", pfn, ret); + + if (ret == 1) { + xen_released_pages++; + if (!__set_phys_to_machine(pfn, INVALID_P2M_ENTRY)) + break; + } else + break; + } + + set_phys_range_identity(start_pfn, end_pfn); +} + +/* + * Helper function to update the p2m and m2p tables and kernel mapping. + */ +static void __init xen_update_mem_tables(unsigned long pfn, unsigned long mfn) +{ + struct mmu_update update = { + .ptr = ((uint64_t)mfn << PAGE_SHIFT) | MMU_MACHPHYS_UPDATE, + .val = pfn + }; + + /* Update p2m */ + if (!set_phys_to_machine(pfn, mfn)) { + WARN(1, "Failed to set p2m mapping for pfn=%ld mfn=%ld\n", + pfn, mfn); + BUG(); + } + + /* Update m2p */ + if (HYPERVISOR_mmu_update(&update, 1, NULL, DOMID_SELF) < 0) { + WARN(1, "Failed to set m2p mapping for mfn=%ld pfn=%ld\n", + mfn, pfn); + BUG(); + } + + if (HYPERVISOR_update_va_mapping((unsigned long)__va(pfn << PAGE_SHIFT), + mfn_pte(mfn, PAGE_KERNEL), 0)) { + WARN(1, "Failed to update kernel mapping for mfn=%ld pfn=%ld\n", + mfn, pfn); + BUG(); + } +} + +/* + * This function updates the p2m and m2p tables with an identity map from + * start_pfn to start_pfn+size and prepares remapping the underlying RAM of the + * original allocation at remap_pfn. The information needed for remapping is + * saved in the memory itself to avoid the need for allocating buffers. The + * complete remap information is contained in a list of MFNs each containing + * up to REMAP_SIZE MFNs and the start target PFN for doing the remap. + * This enables us to preserve the original mfn sequence while doing the + * remapping at a time when the memory management is capable of allocating + * virtual and physical memory in arbitrary amounts, see 'xen_remap_memory' and + * its callers. + */ +static void __init xen_do_set_identity_and_remap_chunk( + unsigned long start_pfn, unsigned long size, unsigned long remap_pfn) +{ + unsigned long buf = (unsigned long)&xen_remap_buf; + unsigned long mfn_save, mfn; + unsigned long ident_pfn_iter, remap_pfn_iter; + unsigned long ident_end_pfn = start_pfn + size; + unsigned long left = size; + unsigned int i, chunk; + + WARN_ON(size == 0); + + mfn_save = virt_to_mfn((void *)buf); + + for (ident_pfn_iter = start_pfn, remap_pfn_iter = remap_pfn; + ident_pfn_iter < ident_end_pfn; + ident_pfn_iter += REMAP_SIZE, remap_pfn_iter += REMAP_SIZE) { + chunk = (left < REMAP_SIZE) ? left : REMAP_SIZE; + + /* Map first pfn to xen_remap_buf */ + mfn = pfn_to_mfn(ident_pfn_iter); + set_pte_mfn(buf, mfn, PAGE_KERNEL); + + /* Save mapping information in page */ + xen_remap_buf.next_area_mfn = xen_remap_mfn; + xen_remap_buf.target_pfn = remap_pfn_iter; + xen_remap_buf.size = chunk; + for (i = 0; i < chunk; i++) + xen_remap_buf.mfns[i] = pfn_to_mfn(ident_pfn_iter + i); + + /* Put remap buf into list. */ + xen_remap_mfn = mfn; + + /* Set identity map */ + set_phys_range_identity(ident_pfn_iter, ident_pfn_iter + chunk); + + left -= chunk; + } + + /* Restore old xen_remap_buf mapping */ + set_pte_mfn(buf, mfn_save, PAGE_KERNEL); +} + +/* + * This function takes a contiguous pfn range that needs to be identity mapped + * and: + * + * 1) Finds a new range of pfns to use to remap based on E820 and remap_pfn. + * 2) Calls the do_ function to actually do the mapping/remapping work. + * + * The goal is to not allocate additional memory but to remap the existing + * pages. In the case of an error the underlying memory is simply released back + * to Xen and not remapped. + */ +static unsigned long __init xen_set_identity_and_remap_chunk( + unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages, + unsigned long remap_pfn) +{ + unsigned long pfn; + unsigned long i = 0; + unsigned long n = end_pfn - start_pfn; + + if (remap_pfn == 0) + remap_pfn = nr_pages; + + while (i < n) { + unsigned long cur_pfn = start_pfn + i; + unsigned long left = n - i; + unsigned long size = left; + unsigned long remap_range_size; + + /* Do not remap pages beyond the current allocation */ + if (cur_pfn >= nr_pages) { + /* Identity map remaining pages */ + set_phys_range_identity(cur_pfn, cur_pfn + size); + break; + } + if (cur_pfn + size > nr_pages) + size = nr_pages - cur_pfn; + + remap_range_size = xen_find_pfn_range(&remap_pfn); + if (!remap_range_size) { + pr_warn("Unable to find available pfn range, not remapping identity pages\n"); + xen_set_identity_and_release_chunk(cur_pfn, + cur_pfn + left, nr_pages); + break; + } + /* Adjust size to fit in current e820 RAM region */ + if (size > remap_range_size) + size = remap_range_size; + + xen_do_set_identity_and_remap_chunk(cur_pfn, size, remap_pfn); + + /* Update variables to reflect new mappings. */ + i += size; + remap_pfn += size; + } + + /* + * If the PFNs are currently mapped, their VA mappings need to be + * zapped. + */ + for (pfn = start_pfn; pfn <= max_pfn_mapped && pfn < end_pfn; pfn++) + (void)HYPERVISOR_update_va_mapping( + (unsigned long)__va(pfn << PAGE_SHIFT), + native_make_pte(0), 0); + + return remap_pfn; +} + +static unsigned long __init xen_count_remap_pages( + unsigned long start_pfn, unsigned long end_pfn, unsigned long nr_pages, + unsigned long remap_pages) +{ + if (start_pfn >= nr_pages) + return remap_pages; + + return remap_pages + min(end_pfn, nr_pages) - start_pfn; +} + +static unsigned long __init xen_foreach_remap_area(unsigned long nr_pages, + unsigned long (*func)(unsigned long start_pfn, unsigned long end_pfn, + unsigned long nr_pages, unsigned long last_val)) +{ + phys_addr_t start = 0; + unsigned long ret_val = 0; + const struct e820_entry *entry = xen_e820_table.entries; + int i; + + /* + * Combine non-RAM regions and gaps until a RAM region (or the + * end of the map) is reached, then call the provided function + * to perform its duty on the non-RAM region. + * + * The combined non-RAM regions are rounded to a whole number + * of pages so any partial pages are accessible via the 1:1 + * mapping. This is needed for some BIOSes that put (for + * example) the DMI tables in a reserved region that begins on + * a non-page boundary. + */ + for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) { + phys_addr_t end = entry->addr + entry->size; + if (entry->type == E820_TYPE_RAM || i == xen_e820_table.nr_entries - 1) { + unsigned long start_pfn = PFN_DOWN(start); + unsigned long end_pfn = PFN_UP(end); + + if (entry->type == E820_TYPE_RAM) + end_pfn = PFN_UP(entry->addr); + + if (start_pfn < end_pfn) + ret_val = func(start_pfn, end_pfn, nr_pages, + ret_val); + start = end; + } + } + + return ret_val; +} + +/* + * Remap the memory prepared in xen_do_set_identity_and_remap_chunk(). + * The remap information (which mfn remap to which pfn) is contained in the + * to be remapped memory itself in a linked list anchored at xen_remap_mfn. + * This scheme allows to remap the different chunks in arbitrary order while + * the resulting mapping will be independent from the order. + */ +void __init xen_remap_memory(void) +{ + unsigned long buf = (unsigned long)&xen_remap_buf; + unsigned long mfn_save, pfn; + unsigned long remapped = 0; + unsigned int i; + unsigned long pfn_s = ~0UL; + unsigned long len = 0; + + mfn_save = virt_to_mfn((void *)buf); + + while (xen_remap_mfn != INVALID_P2M_ENTRY) { + /* Map the remap information */ + set_pte_mfn(buf, xen_remap_mfn, PAGE_KERNEL); + + BUG_ON(xen_remap_mfn != xen_remap_buf.mfns[0]); + + pfn = xen_remap_buf.target_pfn; + for (i = 0; i < xen_remap_buf.size; i++) { + xen_update_mem_tables(pfn, xen_remap_buf.mfns[i]); + remapped++; + pfn++; + } + if (pfn_s == ~0UL || pfn == pfn_s) { + pfn_s = xen_remap_buf.target_pfn; + len += xen_remap_buf.size; + } else if (pfn_s + len == xen_remap_buf.target_pfn) { + len += xen_remap_buf.size; + } else { + xen_del_extra_mem(pfn_s, len); + pfn_s = xen_remap_buf.target_pfn; + len = xen_remap_buf.size; + } + xen_remap_mfn = xen_remap_buf.next_area_mfn; + } + + if (pfn_s != ~0UL && len) + xen_del_extra_mem(pfn_s, len); + + set_pte_mfn(buf, mfn_save, PAGE_KERNEL); + + pr_info("Remapped %ld page(s)\n", remapped); +} + +static unsigned long __init xen_get_pages_limit(void) +{ + unsigned long limit; + + limit = MAXMEM / PAGE_SIZE; + if (!xen_initial_domain() && xen_512gb_limit) + limit = GB(512) / PAGE_SIZE; + + return limit; +} + +static unsigned long __init xen_get_max_pages(void) +{ + unsigned long max_pages, limit; + domid_t domid = DOMID_SELF; + long ret; + + limit = xen_get_pages_limit(); + max_pages = limit; + + /* + * For the initial domain we use the maximum reservation as + * the maximum page. + * + * For guest domains the current maximum reservation reflects + * the current maximum rather than the static maximum. In this + * case the e820 map provided to us will cover the static + * maximum region. + */ + if (xen_initial_domain()) { + ret = HYPERVISOR_memory_op(XENMEM_maximum_reservation, &domid); + if (ret > 0) + max_pages = ret; + } + + return min(max_pages, limit); +} + +static void __init xen_align_and_add_e820_region(phys_addr_t start, + phys_addr_t size, int type) +{ + phys_addr_t end = start + size; + + /* Align RAM regions to page boundaries. */ + if (type == E820_TYPE_RAM) { + start = PAGE_ALIGN(start); + end &= ~((phys_addr_t)PAGE_SIZE - 1); +#ifdef CONFIG_MEMORY_HOTPLUG + /* + * Don't allow adding memory not in E820 map while booting the + * system. Once the balloon driver is up it will remove that + * restriction again. + */ + max_mem_size = end; +#endif + } + + e820__range_add(start, end - start, type); +} + +static void __init xen_ignore_unusable(void) +{ + struct e820_entry *entry = xen_e820_table.entries; + unsigned int i; + + for (i = 0; i < xen_e820_table.nr_entries; i++, entry++) { + if (entry->type == E820_TYPE_UNUSABLE) + entry->type = E820_TYPE_RAM; + } +} + +bool __init xen_is_e820_reserved(phys_addr_t start, phys_addr_t size) +{ + struct e820_entry *entry; + unsigned mapcnt; + phys_addr_t end; + + if (!size) + return false; + + end = start + size; + entry = xen_e820_table.entries; + + for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++) { + if (entry->type == E820_TYPE_RAM && entry->addr <= start && + (entry->addr + entry->size) >= end) + return false; + + entry++; + } + + return true; +} + +/* + * Find a free area in physical memory not yet reserved and compliant with + * E820 map. + * Used to relocate pre-allocated areas like initrd or p2m list which are in + * conflict with the to be used E820 map. + * In case no area is found, return 0. Otherwise return the physical address + * of the area which is already reserved for convenience. + */ +phys_addr_t __init xen_find_free_area(phys_addr_t size) +{ + unsigned mapcnt; + phys_addr_t addr, start; + struct e820_entry *entry = xen_e820_table.entries; + + for (mapcnt = 0; mapcnt < xen_e820_table.nr_entries; mapcnt++, entry++) { + if (entry->type != E820_TYPE_RAM || entry->size < size) + continue; + start = entry->addr; + for (addr = start; addr < start + size; addr += PAGE_SIZE) { + if (!memblock_is_reserved(addr)) + continue; + start = addr + PAGE_SIZE; + if (start + size > entry->addr + entry->size) + break; + } + if (addr >= start + size) { + memblock_reserve(start, size); + return start; + } + } + + return 0; +} + +/* + * Like memcpy, but with physical addresses for dest and src. + */ +static void __init xen_phys_memcpy(phys_addr_t dest, phys_addr_t src, + phys_addr_t n) +{ + phys_addr_t dest_off, src_off, dest_len, src_len, len; + void *from, *to; + + while (n) { + dest_off = dest & ~PAGE_MASK; + src_off = src & ~PAGE_MASK; + dest_len = n; + if (dest_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off) + dest_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - dest_off; + src_len = n; + if (src_len > (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off) + src_len = (NR_FIX_BTMAPS << PAGE_SHIFT) - src_off; + len = min(dest_len, src_len); + to = early_memremap(dest - dest_off, dest_len + dest_off); + from = early_memremap(src - src_off, src_len + src_off); + memcpy(to, from, len); + early_memunmap(to, dest_len + dest_off); + early_memunmap(from, src_len + src_off); + n -= len; + dest += len; + src += len; + } +} + +/* + * Reserve Xen mfn_list. + */ +static void __init xen_reserve_xen_mfnlist(void) +{ + phys_addr_t start, size; + + if (xen_start_info->mfn_list >= __START_KERNEL_map) { + start = __pa(xen_start_info->mfn_list); + size = PFN_ALIGN(xen_start_info->nr_pages * + sizeof(unsigned long)); + } else { + start = PFN_PHYS(xen_start_info->first_p2m_pfn); + size = PFN_PHYS(xen_start_info->nr_p2m_frames); + } + + memblock_reserve(start, size); + if (!xen_is_e820_reserved(start, size)) + return; + + xen_relocate_p2m(); + memblock_phys_free(start, size); +} + +/** + * xen_memory_setup - Hook for machine specific memory setup. + **/ +char * __init xen_memory_setup(void) +{ + unsigned long max_pfn, pfn_s, n_pfns; + phys_addr_t mem_end, addr, size, chunk_size; + u32 type; + int rc; + struct xen_memory_map memmap; + unsigned long max_pages; + unsigned long extra_pages = 0; + int i; + int op; + + xen_parse_512gb(); + max_pfn = xen_get_pages_limit(); + max_pfn = min(max_pfn, xen_start_info->nr_pages); + mem_end = PFN_PHYS(max_pfn); + + memmap.nr_entries = ARRAY_SIZE(xen_e820_table.entries); + set_xen_guest_handle(memmap.buffer, xen_e820_table.entries); + +#if defined(CONFIG_MEMORY_HOTPLUG) && defined(CONFIG_XEN_BALLOON) + xen_saved_max_mem_size = max_mem_size; +#endif + + op = xen_initial_domain() ? + XENMEM_machine_memory_map : + XENMEM_memory_map; + rc = HYPERVISOR_memory_op(op, &memmap); + if (rc == -ENOSYS) { + BUG_ON(xen_initial_domain()); + memmap.nr_entries = 1; + xen_e820_table.entries[0].addr = 0ULL; + xen_e820_table.entries[0].size = mem_end; + /* 8MB slack (to balance backend allocations). */ + xen_e820_table.entries[0].size += 8ULL << 20; + xen_e820_table.entries[0].type = E820_TYPE_RAM; + rc = 0; + } + BUG_ON(rc); + BUG_ON(memmap.nr_entries == 0); + xen_e820_table.nr_entries = memmap.nr_entries; + + if (xen_initial_domain()) { + /* + * Xen won't allow a 1:1 mapping to be created to UNUSABLE + * regions, so if we're using the machine memory map leave the + * region as RAM as it is in the pseudo-physical map. + * + * UNUSABLE regions in domUs are not handled and will need + * a patch in the future. + */ + xen_ignore_unusable(); + +#ifdef CONFIG_ISCSI_IBFT_FIND + /* Reserve 0.5 MiB to 1 MiB region so iBFT can be found */ + xen_e820_table.entries[xen_e820_table.nr_entries].addr = IBFT_START; + xen_e820_table.entries[xen_e820_table.nr_entries].size = IBFT_END - IBFT_START; + xen_e820_table.entries[xen_e820_table.nr_entries].type = E820_TYPE_RESERVED; + xen_e820_table.nr_entries++; +#endif + } + + /* Make sure the Xen-supplied memory map is well-ordered. */ + e820__update_table(&xen_e820_table); + + max_pages = xen_get_max_pages(); + + /* How many extra pages do we need due to remapping? */ + max_pages += xen_foreach_remap_area(max_pfn, xen_count_remap_pages); + + if (max_pages > max_pfn) + extra_pages += max_pages - max_pfn; + + /* + * Clamp the amount of extra memory to a EXTRA_MEM_RATIO + * factor the base size. + * + * Make sure we have no memory above max_pages, as this area + * isn't handled by the p2m management. + */ + extra_pages = min3(EXTRA_MEM_RATIO * min(max_pfn, PFN_DOWN(MAXMEM)), + extra_pages, max_pages - max_pfn); + i = 0; + addr = xen_e820_table.entries[0].addr; + size = xen_e820_table.entries[0].size; + while (i < xen_e820_table.nr_entries) { + bool discard = false; + + chunk_size = size; + type = xen_e820_table.entries[i].type; + + if (type == E820_TYPE_RESERVED) + xen_pv_pci_possible = true; + + if (type == E820_TYPE_RAM) { + if (addr < mem_end) { + chunk_size = min(size, mem_end - addr); + } else if (extra_pages) { + chunk_size = min(size, PFN_PHYS(extra_pages)); + pfn_s = PFN_UP(addr); + n_pfns = PFN_DOWN(addr + chunk_size) - pfn_s; + extra_pages -= n_pfns; + xen_add_extra_mem(pfn_s, n_pfns); + xen_max_p2m_pfn = pfn_s + n_pfns; + } else + discard = true; + } + + if (!discard) + xen_align_and_add_e820_region(addr, chunk_size, type); + + addr += chunk_size; + size -= chunk_size; + if (size == 0) { + i++; + if (i < xen_e820_table.nr_entries) { + addr = xen_e820_table.entries[i].addr; + size = xen_e820_table.entries[i].size; + } + } + } + + /* + * Set the rest as identity mapped, in case PCI BARs are + * located here. + */ + set_phys_range_identity(addr / PAGE_SIZE, ~0ul); + + /* + * In domU, the ISA region is normal, usable memory, but we + * reserve ISA memory anyway because too many things poke + * about in there. + */ + e820__range_add(ISA_START_ADDRESS, ISA_END_ADDRESS - ISA_START_ADDRESS, E820_TYPE_RESERVED); + + e820__update_table(e820_table); + + /* + * Check whether the kernel itself conflicts with the target E820 map. + * Failing now is better than running into weird problems later due + * to relocating (and even reusing) pages with kernel text or data. + */ + if (xen_is_e820_reserved(__pa_symbol(_text), + __pa_symbol(__bss_stop) - __pa_symbol(_text))) { + xen_raw_console_write("Xen hypervisor allocated kernel memory conflicts with E820 map\n"); + BUG(); + } + + /* + * Check for a conflict of the hypervisor supplied page tables with + * the target E820 map. + */ + xen_pt_check_e820(); + + xen_reserve_xen_mfnlist(); + + /* Check for a conflict of the initrd with the target E820 map. */ + if (xen_is_e820_reserved(boot_params.hdr.ramdisk_image, + boot_params.hdr.ramdisk_size)) { + phys_addr_t new_area, start, size; + + new_area = xen_find_free_area(boot_params.hdr.ramdisk_size); + if (!new_area) { + xen_raw_console_write("Can't find new memory area for initrd needed due to E820 map conflict\n"); + BUG(); + } + + start = boot_params.hdr.ramdisk_image; + size = boot_params.hdr.ramdisk_size; + xen_phys_memcpy(new_area, start, size); + pr_info("initrd moved from [mem %#010llx-%#010llx] to [mem %#010llx-%#010llx]\n", + start, start + size, new_area, new_area + size); + memblock_phys_free(start, size); + boot_params.hdr.ramdisk_image = new_area; + boot_params.ext_ramdisk_image = new_area >> 32; + } + + /* + * Set identity map on non-RAM pages and prepare remapping the + * underlying RAM. + */ + xen_foreach_remap_area(max_pfn, xen_set_identity_and_remap_chunk); + + pr_info("Released %ld page(s)\n", xen_released_pages); + + return "Xen"; +} + +static int register_callback(unsigned type, const void *func) +{ + struct callback_register callback = { + .type = type, + .address = XEN_CALLBACK(__KERNEL_CS, func), + .flags = CALLBACKF_mask_events, + }; + + return HYPERVISOR_callback_op(CALLBACKOP_register, &callback); +} + +void xen_enable_sysenter(void) +{ + if (cpu_feature_enabled(X86_FEATURE_SYSENTER32) && + register_callback(CALLBACKTYPE_sysenter, xen_entry_SYSENTER_compat)) + setup_clear_cpu_cap(X86_FEATURE_SYSENTER32); +} + +void xen_enable_syscall(void) +{ + int ret; + + ret = register_callback(CALLBACKTYPE_syscall, xen_entry_SYSCALL_64); + if (ret != 0) { + printk(KERN_ERR "Failed to set syscall callback: %d\n", ret); + /* Pretty fatal; 64-bit userspace has no other + mechanism for syscalls. */ + } + + if (cpu_feature_enabled(X86_FEATURE_SYSCALL32) && + register_callback(CALLBACKTYPE_syscall32, xen_entry_SYSCALL_compat)) + setup_clear_cpu_cap(X86_FEATURE_SYSCALL32); +} + +static void __init xen_pvmmu_arch_setup(void) +{ + HYPERVISOR_vm_assist(VMASST_CMD_enable, VMASST_TYPE_writable_pagetables); + + if (register_callback(CALLBACKTYPE_event, + xen_asm_exc_xen_hypervisor_callback) || + register_callback(CALLBACKTYPE_failsafe, xen_failsafe_callback)) + BUG(); + + xen_enable_sysenter(); + xen_enable_syscall(); +} + +/* This function is not called for HVM domains */ +void __init xen_arch_setup(void) +{ + xen_panic_handler_init(); + xen_pvmmu_arch_setup(); + +#ifdef CONFIG_ACPI + if (!(xen_start_info->flags & SIF_INITDOMAIN)) { + printk(KERN_INFO "ACPI in unprivileged domain disabled\n"); + disable_acpi(); + } +#endif + + memcpy(boot_command_line, xen_start_info->cmd_line, + MAX_GUEST_CMDLINE > COMMAND_LINE_SIZE ? + COMMAND_LINE_SIZE : MAX_GUEST_CMDLINE); + + /* Set up idle, making sure it calls safe_halt() pvop */ + disable_cpuidle(); + disable_cpufreq(); + WARN_ON(xen_set_default_idle()); +#ifdef CONFIG_NUMA + numa_off = 1; +#endif +} |