[Xen-devel] [PATCH 3/6] xen/x86/pvh: Properly set page tables for 32-bit PVH guests

[Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>]

32-bit PVH guests don't want to write-protect/pin page tables.

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
---
 arch/x86/xen/mmu.c | 22 +++++++++++++---------
 1 file changed, 13 insertions(+), 9 deletions(-)

diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index dd151b2..b473df8 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -1762,8 +1762,9 @@ void __init xen_setup_machphys_mapping(void)
                machine_to_phys_nr = MACH2PHYS_NR_ENTRIES;
        }
 #ifdef CONFIG_X86_32
-       WARN_ON((machine_to_phys_mapping + (machine_to_phys_nr - 1))
-               < machine_to_phys_mapping);
+       if (!xen_feature(XENFEAT_auto_translated_physmap))
+               WARN_ON((machine_to_phys_mapping + (machine_to_phys_nr - 1))
+                       < machine_to_phys_mapping);
 #endif
 }
 
@@ -1958,15 +1959,18 @@ void __init xen_setup_kernel_pagetable(pgd_t *pgd, 
unsigned long max_pfn)
        initial_page_table[KERNEL_PGD_BOUNDARY] =
                __pgd(__pa(initial_kernel_pmd) | _PAGE_PRESENT);
 
-       set_page_prot(initial_kernel_pmd, PAGE_KERNEL_RO);
-       set_page_prot(initial_page_table, PAGE_KERNEL_RO);
-       set_page_prot(empty_zero_page, PAGE_KERNEL_RO);
+       if (!xen_feature(XENFEAT_auto_translated_physmap)) {
+               set_page_prot(initial_kernel_pmd, PAGE_KERNEL_RO);
+               set_page_prot(initial_page_table, PAGE_KERNEL_RO);
+               set_page_prot(empty_zero_page, PAGE_KERNEL_RO);
 
-       pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
+               pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, PFN_DOWN(__pa(pgd)));
 
-       pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE,
-                         PFN_DOWN(__pa(initial_page_table)));
-       xen_write_cr3(__pa(initial_page_table));
+               pin_pagetable_pfn(MMUEXT_PIN_L3_TABLE,
+                                 PFN_DOWN(__pa(initial_page_table)));
+               xen_write_cr3(__pa(initial_page_table));
+       } else
+               native_write_cr3(__pa(initial_page_table));
 
        memblock_reserve(__pa(xen_start_info->pt_base),
                         xen_start_info->nr_pt_frames * PAGE_SIZE);
-- 
1.8.1.4


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