diff --git a/xen/arch/x86/include/asm/cpufeatures.h b/xen/arch/x86/include/asm/cpufeatures.h
index bc108c3819..71308d9daf 100644
--- a/xen/arch/x86/include/asm/cpufeatures.h
+++ b/xen/arch/x86/include/asm/cpufeatures.h
@@ -42,6 +42,7 @@ XEN_CPUFEATURE(XEN_IBT,           X86_SYNTH(27)) /* Xen uses CET Indirect Branch
 XEN_CPUFEATURE(IBPB_ENTRY_PV,     X86_SYNTH(28)) /* MSR_PRED_CMD used by Xen for PV */
 XEN_CPUFEATURE(IBPB_ENTRY_HVM,    X86_SYNTH(29)) /* MSR_PRED_CMD used by Xen for HVM */
 XEN_CPUFEATURE(USE_VMCALL,        X86_SYNTH(30)) /* Use VMCALL instead of VMMCALL */
+XEN_CPUFEATURE(PDX_COMPRESSION,   X86_SYNTH(31)) /* PDX compression */
 
 /* Bug words follow the synthetic words. */
 #define X86_NR_BUG 1
diff --git a/xen/arch/x86/include/asm/pdx.h b/xen/arch/x86/include/asm/pdx.h
new file mode 100644
index 0000000000..6be7e1185e
--- /dev/null
+++ b/xen/arch/x86/include/asm/pdx.h
@@ -0,0 +1,71 @@
+/* SPDX-License-Identifier: GPL-2.0-only */
+
+#ifndef X86_PDX_H
+#define X86_PDX_H
+
+#include <asm/alternative.h>
+
+/*
+ * Introduce a macro to avoid repeating the same asm goto block in each helper.
+ * Note the macro is strictly tied to the code in the helpers.
+ */
+#define PDX_ASM_GOTO(label)                         \
+    asm_inline goto (                               \
+        ALTERNATIVE(                                \
+            "",                                     \
+            "jmp %l0",                              \
+            ALT_NOT(X86_FEATURE_PDX_COMPRESSION))   \
+        : : : : label )
+
+static inline unsigned long pfn_to_pdx(unsigned long pfn)
+{
+    PDX_ASM_GOTO(skip);
+
+    return pfn_to_pdx_xlate(pfn);
+
+ skip:
+    return pfn;
+}
+
+static inline unsigned long pdx_to_pfn(unsigned long pdx)
+{
+    PDX_ASM_GOTO(skip);
+
+    return pdx_to_pfn_xlate(pdx);
+
+ skip:
+    return pdx;
+}
+
+static inline unsigned long maddr_to_directmapoff(paddr_t ma)
+{
+    PDX_ASM_GOTO(skip);
+
+    return maddr_to_directmapoff_xlate(ma);
+
+ skip:
+    return ma;
+}
+
+static inline paddr_t directmapoff_to_maddr(unsigned long offset)
+{
+    PDX_ASM_GOTO(skip);
+
+    return directmapoff_to_maddr_xlate(offset);
+
+ skip:
+    return offset;
+}
+
+#undef PDX_ASM_GOTO_SKIP
+
+#endif /* X86_PDX_H */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
diff --git a/xen/arch/x86/srat.c b/xen/arch/x86/srat.c
index 747607439f..42ccb0c0f3 100644
--- a/xen/arch/x86/srat.c
+++ b/xen/arch/x86/srat.c
@@ -298,7 +298,8 @@ void __init srat_parse_regions(paddr_t addr)
 	acpi_table_parse_srat(ACPI_SRAT_TYPE_MEMORY_AFFINITY,
 			      srat_parse_region, 0);
 
-	pfn_pdx_compression_setup(addr);
+	if (!pfn_pdx_compression_setup(addr))
+		return;
 
 	/* Ensure all RAM ranges in the e820 are covered. */
 	for (i = 0; i < e820.nr_map; i++) {
@@ -318,6 +319,9 @@ void __init srat_parse_regions(paddr_t addr)
 			return;
 		}
 	}
+
+	/* If we got this far compression is working as expected. */
+	setup_force_cpu_cap(X86_FEATURE_PDX_COMPRESSION);
 }
 
 unsigned int numa_node_to_arch_nid(nodeid_t n)
diff --git a/xen/common/pdx.c b/xen/common/pdx.c
index f4a3dcf6cb..c9ec867291 100644
--- a/xen/common/pdx.c
+++ b/xen/common/pdx.c
@@ -215,7 +215,7 @@ static uint64_t __init pdx_init_mask(uint64_t base_addr)
                          (uint64_t)1 << (MAX_ORDER + PAGE_SHIFT)) - 1);
 }
 
-void __init pfn_pdx_compression_setup(paddr_t base)
+bool __init pfn_pdx_compression_setup(paddr_t base)
 {
     unsigned int i, j, bottom_shift = 0, hole_shift = 0;
     unsigned long mask = pdx_init_mask(base) >> PAGE_SHIFT;
@@ -224,7 +224,7 @@ void __init pfn_pdx_compression_setup(paddr_t base)
     {
         printk(XENLOG_DEBUG "PFN compression disabled%s\n",
                pdx_compress ? ": no ranges provided" : "");
-        return;
+        return false;
     }
 
     if ( nr_ranges > ARRAY_SIZE(ranges) )
@@ -232,7 +232,7 @@ void __init pfn_pdx_compression_setup(paddr_t base)
         printk(XENLOG_WARNING
                "Too many PFN ranges (%u > %zu), not attempting PFN compression\n",
                nr_ranges, ARRAY_SIZE(ranges));
-        return;
+        return false;
     }
 
     for ( i = 0; i < nr_ranges; i++ )
@@ -263,7 +263,7 @@ void __init pfn_pdx_compression_setup(paddr_t base)
         }
     }
     if ( !hole_shift )
-        return;
+        return false;
 
     printk(KERN_INFO "PFN compression on bits %u...%u\n",
            bottom_shift, bottom_shift + hole_shift - 1);
@@ -274,6 +274,8 @@ void __init pfn_pdx_compression_setup(paddr_t base)
     pfn_hole_mask       = ((1UL << hole_shift) - 1) << bottom_shift;
     pfn_top_mask        = ~(pfn_pdx_bottom_mask | pfn_hole_mask);
     ma_top_mask         = pfn_top_mask << PAGE_SHIFT;
+
+    return true;
 }
 
 void __init pfn_pdx_compression_reset(void)
diff --git a/xen/include/xen/pdx.h b/xen/include/xen/pdx.h
index 10153da98b..425d45e9f0 100644
--- a/xen/include/xen/pdx.h
+++ b/xen/include/xen/pdx.h
@@ -114,7 +114,7 @@ extern unsigned long pfn_top_mask, ma_top_mask;
  * @param pfn Frame number
  * @return Obtained pdx after compressing the pfn
  */
-static inline unsigned long pfn_to_pdx(unsigned long pfn)
+static inline unsigned long pfn_to_pdx_xlate(unsigned long pfn)
 {
     return (pfn & pfn_pdx_bottom_mask) |
            ((pfn & pfn_top_mask) >> pfn_pdx_hole_shift);
@@ -126,7 +126,7 @@ static inline unsigned long pfn_to_pdx(unsigned long pfn)
  * @param pdx Page index
  * @return Obtained pfn after decompressing the pdx
  */
-static inline unsigned long pdx_to_pfn(unsigned long pdx)
+static inline unsigned long pdx_to_pfn_xlate(unsigned long pdx)
 {
     return (pdx & pfn_pdx_bottom_mask) |
            ((pdx << pfn_pdx_hole_shift) & pfn_top_mask);
@@ -139,7 +139,7 @@ static inline unsigned long pdx_to_pfn(unsigned long pdx)
  * @return Offset on the direct map where that
  *         machine address can be accessed
  */
-static inline unsigned long maddr_to_directmapoff(paddr_t ma)
+static inline unsigned long maddr_to_directmapoff_xlate(paddr_t ma)
 {
     return (((ma & ma_top_mask) >> pfn_pdx_hole_shift) |
             (ma & ma_va_bottom_mask));
@@ -151,7 +151,7 @@ static inline unsigned long maddr_to_directmapoff(paddr_t ma)
  * @param offset Offset into the direct map
  * @return Corresponding machine address of that virtual location
  */
-static inline paddr_t directmapoff_to_maddr(unsigned long offset)
+static inline paddr_t directmapoff_to_maddr_xlate(unsigned long offset)
 {
     return ((((paddr_t)offset << pfn_pdx_hole_shift) & ma_top_mask) |
             (offset & ma_va_bottom_mask));
@@ -181,8 +181,9 @@ static inline void pfn_pdx_add_region(paddr_t base, paddr_t size)
 {
 }
 
-static inline void pfn_pdx_compression_setup(paddr_t base)
+static inline bool pfn_pdx_compression_setup(paddr_t base)
 {
+    return false;
 }
 
 static inline void pfn_pdx_compression_reset(void)
@@ -191,6 +192,21 @@ static inline void pfn_pdx_compression_reset(void)
 
 #else /* !CONFIG_PDX_NONE */
 
+/*
+ * Allow each architecture to define its (possibly optimized) versions of the
+ * translation functions.
+ *
+ * Do not use _xlate suffixed functions, always use the non _xlate variants.
+ */
+#if __has_include(<asm/pdx.h>)
+# include <asm/pdx.h>
+#else
+# define pdx_to_pfn pdx_to_pfn_xlate
+# define pfn_to_pdx pfn_to_pdx_xlate
+# define maddr_to_directmapoff maddr_to_directmapoff_xlate
+# define directmapoff_to_maddr directmapoff_to_maddr_xlate
+#endif
+
 /* Shared functions implemented by all PDX compressions. */
 
 /**
@@ -215,8 +231,9 @@ void pfn_pdx_add_region(paddr_t base, paddr_t size);
  * range of the current memory regions.
  *
  * @param base address to start compression from.
+ * @return True if PDX compression has been enabled.
  */
-void pfn_pdx_compression_setup(paddr_t base);
+bool pfn_pdx_compression_setup(paddr_t base);
 
 /**
  * Reset the global variables to it's default values, thus disabling PFN