Harden the code by panicing if direct map is too small for current memory
layout taking into account possible PDX compression. Otherwise the assert
is observed:
Assertion '(mfn_to_pdx(maddr_to_mfn(ma)) - directmap_base_pdx) <
(DIRECTMAP_SIZE >> PAGE_SHIFT)' failed at ./arch/arm/include/asm/mmu/mm.h:72
At the moment, we don't set max_pdx denoting maximum usable PDX which
should be based on max_page. Consolidate setting of max_page and max_pdx
in init_pdx() for both arm32 and arm64. max_pdx will be used in the
future to set up frametable mappings respecting the PDX grouping.
Signed-off-by: Michal Orzel <michal.or...@amd.com>
---
A similar check for frametable will be introduced with other changes to
frametable setting in the future.
---
xen/arch/arm/arm32/mmu/mm.c | 1 -
xen/arch/arm/arm64/mmu/mm.c | 4 +++-
xen/arch/arm/setup.c | 6 +++++-
3 files changed, 8 insertions(+), 3 deletions(-)
diff --git a/xen/arch/arm/arm32/mmu/mm.c b/xen/arch/arm/arm32/mmu/mm.c
index 4d22f35618aa..e6d9b49acd3c 100644
--- a/xen/arch/arm/arm32/mmu/mm.c
+++ b/xen/arch/arm/arm32/mmu/mm.c
@@ -190,7 +190,6 @@ void __init setup_mm(void)
/* Frame table covers all of RAM region, including holes */
setup_frametable_mappings(ram_start, ram_end);
- max_page = PFN_DOWN(ram_end);
/*
* The allocators may need to use map_domain_page() (such as for
diff --git a/xen/arch/arm/arm64/mmu/mm.c b/xen/arch/arm/arm64/mmu/mm.c
index a0a2dd8cc762..3e64be6ae664 100644
--- a/xen/arch/arm/arm64/mmu/mm.c
+++ b/xen/arch/arm/arm64/mmu/mm.c
@@ -224,6 +224,9 @@ static void __init setup_directmap_mappings(unsigned long
base_mfn,
*/
directmap_virt_start = DIRECTMAP_VIRT_START +
(base_mfn - mfn_gb) * PAGE_SIZE;
+
+ if ( (max_pdx - directmap_base_pdx) > (DIRECTMAP_SIZE >> PAGE_SHIFT) )
+ panic("Direct map is too small\n");
}
if ( base_mfn < mfn_x(directmap_mfn_start) )
@@ -278,7 +281,6 @@ void __init setup_mm(void)
directmap_mfn_end = maddr_to_mfn(ram_end);
setup_frametable_mappings(ram_start, ram_end);
- max_page = PFN_DOWN(ram_end);
init_staticmem_pages();
init_sharedmem_pages();
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index 58acc2d0d4b8..93b730ffb5fb 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -254,7 +254,7 @@ static void __init relocate_fdt(const void **dtb_vaddr,
size_t dtb_size)
void __init init_pdx(void)
{
const struct membanks *mem = bootinfo_get_mem();
- paddr_t bank_start, bank_size, bank_end;
+ paddr_t bank_start, bank_size, bank_end, ram_end = 0;
/*
* Arm does not have any restrictions on the bits to compress. Pass 0 to
@@ -290,10 +290,14 @@ void __init init_pdx(void)
bank_start = mem->bank[bank].start;
bank_size = mem->bank[bank].size;
bank_end = bank_start + bank_size;
+ ram_end = max(ram_end, bank_end);
set_pdx_range(paddr_to_pfn(bank_start),
paddr_to_pfn(bank_end));
}
+
+ max_page = PFN_DOWN(ram_end);
+ max_pdx = pfn_to_pdx(max_page - 1) + 1;
}
size_t __read_mostly dcache_line_bytes;
--
2.25.1
