[Xen-changelog] [xen master] x86: fix memory cut-off when using PFN compression

[patchbot@xxxxxxx]

commit 8efce9d69998a3d3c720ac7dbdb9b7e240369957
Author:     Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Thu Sep 12 09:52:53 2013 +0200
Commit:     Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Thu Sep 12 09:52:53 2013 +0200

    x86: fix memory cut-off when using PFN compression
    
    For one setup_max_pdx(), when invoked a second time (after SRAT got
    parsed), needs to start from the original max_page value again (using
    the already adjusted one from the first invocation would not allow the
    cut-off boundary to be moved up).
    
    Second, _if_ we need to cut off some part of memory, we must not allow
    this to also propagate into the NUMA accounting. Otherwise
    cutoff_node() results in nodes_cover_memory() to find some parts of
    memory apparently not having a PXM association, causing all SRAT info
    to be ignored.
    
    The only possibly problematic consumer of node_spanned_pages (the
    meaning of which gets altered here in that it now also includes memory
    Xen can't actively make use of) is XEN_SYSCTL_numainfo: At a first
    glance the potentially larger reported memory size shouldn't confuse
    tool stacks.
    
    And finally we must not put our boot time modules at addresses which
    (at that time) can't be guaranteed to be accessible later. This applies
    to both the EFI boot loader and the module relocation code.
    
    Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
    Acked-by: Keir Fraser <keir@xxxxxxx>
    Acked-by: Dario Faggioli <dario.faggioli@xxxxxxxxxx>
---
 xen/arch/x86/efi/boot.c |    3 ++-
 xen/arch/x86/setup.c    |   19 +++++++++++--------
 2 files changed, 13 insertions(+), 9 deletions(-)

diff --git a/xen/arch/x86/efi/boot.c b/xen/arch/x86/efi/boot.c
index 055ac13..66a6fdb 100644
--- a/xen/arch/x86/efi/boot.c
+++ b/xen/arch/x86/efi/boot.c
@@ -459,7 +459,8 @@ static bool_t __init read_file(EFI_FILE_HANDLE dir_handle, 
CHAR16 *name,
         what = what ?: L"Seek";
     else
     {
-        file->addr = (EFI_PHYSICAL_ADDRESS)1 << (32 + PAGE_SHIFT);
+        file->addr = min(1UL << (32 + PAGE_SHIFT),
+                         HYPERVISOR_VIRT_END - DIRECTMAP_VIRT_START);
         ret = efi_bs->AllocatePages(AllocateMaxAddress, EfiLoaderData,
                                     PFN_UP(size), &file->addr);
     }
diff --git a/xen/arch/x86/setup.c b/xen/arch/x86/setup.c
index c550e8e..637f1f9 100644
--- a/xen/arch/x86/setup.c
+++ b/xen/arch/x86/setup.c
@@ -378,9 +378,9 @@ static uint64_t __init consider_modules(
     return e;
 }
 
-static void __init setup_max_pdx(void)
+static void __init setup_max_pdx(unsigned long top_page)
 {
-    max_pdx = pfn_to_pdx(max_page - 1) + 1;
+    max_pdx = pfn_to_pdx(top_page - 1) + 1;
 
     if ( max_pdx > (DIRECTMAP_SIZE >> PAGE_SHIFT) )
         max_pdx = DIRECTMAP_SIZE >> PAGE_SHIFT;
@@ -548,7 +548,7 @@ void __init __start_xen(unsigned long mbi_p)
     unsigned int initrdidx;
     multiboot_info_t *mbi = __va(mbi_p);
     module_t *mod = (module_t *)__va(mbi->mods_addr);
-    unsigned long nr_pages, modules_headroom, *module_map;
+    unsigned long nr_pages, raw_max_page, modules_headroom, *module_map;
     int i, j, e820_warn = 0, bytes = 0;
     bool_t acpi_boot_table_init_done = 0;
     struct ns16550_defaults ns16550 = {
@@ -752,7 +752,7 @@ void __init __start_xen(unsigned long mbi_p)
     }
 
     /* Sanitise the raw E820 map to produce a final clean version. */
-    max_page = init_e820(memmap_type, e820_raw, &e820_raw_nr);
+    max_page = raw_max_page = init_e820(memmap_type, e820_raw, &e820_raw_nr);
 
     /* Create a temporary copy of the E820 map. */
     memcpy(&boot_e820, &e820, sizeof(e820));
@@ -821,7 +821,10 @@ void __init __start_xen(unsigned long mbi_p)
                              (end - s) >> PAGE_SHIFT, PAGE_HYPERVISOR);
         }
 
-        e = min_t(uint64_t, e, 1ULL << (PAGE_SHIFT + 32));
+        if ( e > min(HYPERVISOR_VIRT_END - DIRECTMAP_VIRT_START,
+                     1UL << (PAGE_SHIFT + 32)) )
+            e = min(HYPERVISOR_VIRT_END - DIRECTMAP_VIRT_START,
+                    1UL << (PAGE_SHIFT + 32));
 #define reloc_size ((__pa(&_end) + mask) & ~mask)
         /* Is the region suitable for relocating Xen? */
         if ( !xen_phys_start && e <= limit )
@@ -970,7 +973,7 @@ void __init __start_xen(unsigned long mbi_p)
     /* Late kexec reservation (dynamic start address). */
     kexec_reserve_area(&boot_e820);
 
-    setup_max_pdx();
+    setup_max_pdx(raw_max_page);
     if ( highmem_start )
         xenheap_max_mfn(PFN_DOWN(highmem_start));
 
@@ -996,7 +999,7 @@ void __init __start_xen(unsigned long mbi_p)
         {
             acpi_boot_table_init_done = 1;
             srat_parse_regions(s);
-            setup_max_pdx();
+            setup_max_pdx(raw_max_page);
         }
 
         if ( pfn_to_pdx((e - 1) >> PAGE_SHIFT) >= max_pdx )
@@ -1134,7 +1137,7 @@ void __init __start_xen(unsigned long mbi_p)
 
     acpi_numa_init();
 
-    numa_initmem_init(0, max_page);
+    numa_initmem_init(0, raw_max_page);
 
     end_boot_allocator();
     system_state = SYS_STATE_boot;
--
generated by git-patchbot for /home/xen/git/xen.git#master

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