From 6639fd9e75cb5c3a0351205b9d89ee12ca0b5cc1 Mon Sep 17 00:00:00 2001
From: Grygorii Strashko <grygorii_strashko@xxxxxxxx>
Date: Fri, 28 Nov 2025 15:22:21 +0000
Subject: xen/x86: move d->arch.physaddr_bitsize field handling to pv32

The d->arch.physaddr_bitsize field is used only by PV32 code, so:

- move domain_set_alloc_bitsize() function into PV32 code and
  inline it into switch_compat()
- move domain_clamp_alloc_bitsize() function into PV32 code
  and convert to macro
- move d->arch.physaddr_bitsize field under PV32 ifdef into
  struct pv_domain

Signed-off-by: Grygorii Strashko <grygorii_strashko@xxxxxxxx>

diff --git a/xen/arch/x86/include/asm/domain.h b/xen/arch/x86/include/asm/domain.h
index 386ec6174589..3f2d55c2b9cf 100644
--- a/xen/arch/x86/include/asm/domain.h
+++ b/xen/arch/x86/include/asm/domain.h
@@ -279,6 +279,11 @@ struct pv_domain
 
     atomic_t nr_l4_pages;
 
+#ifdef CONFIG_PV32
+    /* Maximum physical-address bitwidth supported by this guest. */
+    unsigned int physaddr_bitsize;
+#endif
+
     /* Is a 32-bit PV guest? */
     bool is_32bit;
     /* XPTI active? */
@@ -319,9 +324,6 @@ struct arch_domain
     unsigned int hv_compat_vstart;
 #endif
 
-    /* Maximum physical-address bitwidth supported by this guest. */
-    unsigned int physaddr_bitsize;
-
     /* I/O-port admin-specified access capabilities. */
     struct rangeset *ioport_caps;
     uint32_t pci_cf8;
diff --git a/xen/arch/x86/include/asm/mm.h b/xen/arch/x86/include/asm/mm.h
index 9438f5ea0119..a308a98df2a4 100644
--- a/xen/arch/x86/include/asm/mm.h
+++ b/xen/arch/x86/include/asm/mm.h
@@ -619,8 +619,12 @@ void __iomem *ioremap_wc(paddr_t pa, size_t len);
 
 extern int memory_add(unsigned long spfn, unsigned long epfn, unsigned int pxm);
 
-unsigned int domain_clamp_alloc_bitsize(struct domain *d, unsigned int bits);
-#define domain_clamp_alloc_bitsize(d, bits) domain_clamp_alloc_bitsize(d, bits)
+#ifdef CONFIG_PV32
+#define domain_clamp_alloc_bitsize(d, bits)                                    \
+    (((d) && (d)->arch.pv.physaddr_bitsize)                                    \
+         ? min_t(uint32_t, (d)->arch.pv.physaddr_bitsize, (bits))              \
+         : (bits))
+#endif
 
 unsigned long domain_get_maximum_gpfn(struct domain *d);
 
diff --git a/xen/arch/x86/pv/dom0_build.c b/xen/arch/x86/pv/dom0_build.c
index 21158ce1812e..94f7976e819f 100644
--- a/xen/arch/x86/pv/dom0_build.c
+++ b/xen/arch/x86/pv/dom0_build.c
@@ -626,8 +626,10 @@ static int __init dom0_construct(const struct boot_domain *bd)
         initrd_mfn = paddr_to_pfn(initrd->start);
         mfn = initrd_mfn;
         count = PFN_UP(initrd_len);
-        if ( d->arch.physaddr_bitsize &&
-             ((mfn + count - 1) >> (d->arch.physaddr_bitsize - PAGE_SHIFT)) )
+
+#ifdef CONFIG_PV32
+        if ( d->arch.pv.physaddr_bitsize &&
+             ((mfn + count - 1) >> (d->arch.pv.physaddr_bitsize - PAGE_SHIFT)) )
         {
             order = get_order_from_pages(count);
             page = alloc_domheap_pages(d, order, MEMF_no_scrub);
@@ -650,6 +652,7 @@ static int __init dom0_construct(const struct boot_domain *bd)
             initrd->start = pfn_to_paddr(initrd_mfn);
         }
         else
+#endif
         {
             while ( count-- )
                 if ( assign_pages(mfn_to_page(_mfn(mfn++)), 1, d, 0) )
diff --git a/xen/arch/x86/pv/domain.c b/xen/arch/x86/pv/domain.c
index 11db6a6d8396..d58e4e213e5c 100644
--- a/xen/arch/x86/pv/domain.c
+++ b/xen/arch/x86/pv/domain.c
@@ -255,7 +255,7 @@ int switch_compat(struct domain *d)
     }
 
     if ( MACH2PHYS_COMPAT_NR_ENTRIES(d) < max_page )
-        d->arch.physaddr_bitsize =
+        d->arch.pv.physaddr_bitsize =
             /* 2^n entries can be contained in guest's p2m mapping space */
             fls(MACH2PHYS_COMPAT_NR_ENTRIES(d)) - 1 + PAGE_SHIFT;
 
diff --git a/xen/arch/x86/x86_64/mm.c b/xen/arch/x86/x86_64/mm.c
index 42fd4fe4e9b5..8eadab7933d0 100644
--- a/xen/arch/x86/x86_64/mm.c
+++ b/xen/arch/x86/x86_64/mm.c
@@ -1119,13 +1119,6 @@ int handle_memadd_fault(unsigned long addr, struct cpu_user_regs *regs)
     return ret;
 }
 
-unsigned int domain_clamp_alloc_bitsize(struct domain *d, unsigned int bits)
-{
-    if ( (d == NULL) || (d->arch.physaddr_bitsize == 0) )
-        return bits;
-    return min(d->arch.physaddr_bitsize, bits);
-}
-
 static int transfer_pages_to_heap(struct mem_hotadd_info *info)
 {
     unsigned long i;