[Xen-changelog] [xen staging] xen/arm32: setup: Give a xenheap page to the boot allocator

[patchbot@xxxxxxx]

commit ae84f55353475f569daddb9a81ac0a6bc7772c90
Author:     Julien Grall <julien.grall@xxxxxxx>
AuthorDate: Fri Sep 20 10:31:30 2019 +0100
Commit:     Stefano Stabellini <sstabellini@xxxxxxxxxx>
CommitDate: Fri Sep 20 08:20:14 2019 -0700

    xen/arm32: setup: Give a xenheap page to the boot allocator
    
    After commit 6e3e771203 "xen/arm: setup: Relocate the Device-Tree later on
    in the boot", the boot allocator will not receive any xenheap page (i.e.
    mapped page) on Arm32.
    
    However, the boot allocator implicitly relies on having the first page
    already mapped and therefore result to break boot on Arm32.
    
    The easiest way for now is to give a xenheap page to the boot allocator.
    We may want to rethink the interface in the future.
    
    [stefano: fix grammar in commit message]
    
    Fixes: 6e3e771203 ('xen/arm: setup: Relocate the Device-Tree later on in 
the boot')
    Signed-off-by: Julien Grall <julien.grall@xxxxxxx>
    Signed-off-by: Stefano Stabellini <stefano.stabellini@xxxxxxxxxx>
    Reviewed-by: Jan Beulich <jbeulich@xxxxxxxx>
    Reviewed-by: Stefano Stabellini <sstabellini@xxxxxxxxxx>
---
 xen/arch/arm/setup.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index 581b262655..fca7e68cba 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -593,6 +593,7 @@ static void __init setup_mm(void)
     unsigned long heap_pages, xenheap_pages, domheap_pages;
     int i;
     const uint32_t ctr = READ_CP32(CTR);
+    mfn_t boot_mfn_start, boot_mfn_end;
 
     if ( !bootinfo.mem.nr_banks )
         panic("No memory bank\n");
@@ -665,6 +666,11 @@ static void __init setup_mm(void)
 
     setup_xenheap_mappings((e >> PAGE_SHIFT) - xenheap_pages, xenheap_pages);
 
+    /* We need a single mapped page for populating bootmem_region_list. */
+    boot_mfn_start = mfn_add(xenheap_mfn_end, -1);
+    boot_mfn_end = xenheap_mfn_end;
+    init_boot_pages(mfn_to_maddr(boot_mfn_start), mfn_to_maddr(boot_mfn_end));
+
     /* Add non-xenheap memory */
     for ( i = 0; i < bootinfo.mem.nr_banks; i++ )
     {
@@ -710,7 +716,7 @@ static void __init setup_mm(void)
 
     /* Add xenheap memory that was not already added to the boot allocator. */
     init_xenheap_pages(mfn_to_maddr(xenheap_mfn_start),
-                       mfn_to_maddr(xenheap_mfn_end));
+                       mfn_to_maddr(boot_mfn_start));
 }
 #else /* CONFIG_ARM_64 */
 static void __init setup_mm(void)
--
generated by git-patchbot for /home/xen/git/xen.git#staging

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