Revert "xen/debug: WARN_ON when identity PFN has no _PAGE_IOMAP flag set."

We don' use it anymore and there are more false positives.

This reverts commit fc25151d9ac7d809239fe68de0a1490b504bb94a.

Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

2 files changed, 0 insertions, 46 deletions

diff --git a/arch/x86/xen/Kconfig b/arch/x86/xen/Kconfig
index 5cc821cb2e0..ae559fe91c2 100644
--- a/arch/x86/xen/Kconfig
+++ b/arch/x86/xen/Kconfig
@@ -49,11 +49,3 @@ config XEN_DEBUG_FS
         help
           Enable statistics output and various tuning options in debugfs.
           Enabling this option may incur a significant performance overhead.
-
-config XEN_DEBUG
-        bool "Enable Xen debug checks"
-        depends on XEN
-        default n
-        help
-          Enable various WARN_ON checks in the Xen MMU code.
-          Enabling this option WILL incur a significant performance overhead.
diff --git a/arch/x86/xen/mmu.c b/arch/x86/xen/mmu.c
index f987bde77c4..3c9aecd09ed 100644
--- a/arch/x86/xen/mmu.c
+++ b/arch/x86/xen/mmu.c
@@ -495,41 +495,6 @@ static pte_t xen_make_pte(pteval_t pte)
 }
 PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte);
 
-#ifdef CONFIG_XEN_DEBUG
-pte_t xen_make_pte_debug(pteval_t pte)
-{
-        phys_addr_t addr = (pte & PTE_PFN_MASK);
-        phys_addr_t other_addr;
-        bool io_page = false;
-        pte_t _pte;
-
-        if (pte & _PAGE_IOMAP)
-                io_page = true;
-
-        _pte = xen_make_pte(pte);
-
-        if (!addr)
-                return _pte;
-
-        if (io_page &&
-            (xen_initial_domain() || addr >= ISA_END_ADDRESS)) {
-                other_addr = pfn_to_mfn(addr >> PAGE_SHIFT) << PAGE_SHIFT;
-                WARN_ONCE(addr != other_addr,
-                        "0x%lx is using VM_IO, but it is 0x%lx!\n",
-                        (unsigned long)addr, (unsigned long)other_addr);
-        } else {
-                pteval_t iomap_set = (_pte.pte & PTE_FLAGS_MASK) & _PAGE_IOMAP;
-                other_addr = (_pte.pte & PTE_PFN_MASK);
-                WARN_ONCE((addr == other_addr) && (!io_page) && (!iomap_set),
-                        "0x%lx is missing VM_IO (and wasn't fixed)!\n",
-                        (unsigned long)addr);
-        }
-
-        return _pte;
-}
-PV_CALLEE_SAVE_REGS_THUNK(xen_make_pte_debug);
-#endif
-
 static pgd_t xen_make_pgd(pgdval_t pgd)
 {
         pgd = pte_pfn_to_mfn(pgd);
@@ -1988,9 +1953,6 @@ void __init xen_ident_map_ISA(void)
 
 static void __init xen_post_allocator_init(void)
 {
-#ifdef CONFIG_XEN_DEBUG
-        pv_mmu_ops.make_pte = PV_CALLEE_SAVE(xen_make_pte_debug);
-#endif
         pv_mmu_ops.set_pte = xen_set_pte;
         pv_mmu_ops.set_pmd = xen_set_pmd;
         pv_mmu_ops.set_pud = xen_set_pud;