[v4,1/6] x86/p2m: move and rename paging_max_paddr_bits()

Commit Message

Roger Pau Monné Dec. 20, 2023, 1:43 p.m. UTC

The function also supports non-paging domains, and hence it being placed in
p2m.h and named with the paging_ prefix is misleading.

Move to x86 domain.c and rename to domain_max_paddr_bits().  Moving to a
different header is non trivial, as the function depends on helpers declared in
p2m.h.  There's no performance reason for the function being inline.

Note the function is safe to use against PV or system domains, as it does check
whether the domain is using external paging, and if not the returned physical
address width is the host (native) value.

No functional change intended.

Signed-off-by: Roger Pau Monné <[e-mail]>
Reviewed-by: Jan Beulich <[e-mail]>
---
Changes since v3:
 - Expand changelog.

Changes since v2:
 - New in this version.
---
 xen/arch/x86/cpu-policy.c         |  2 +-
 xen/arch/x86/domain.c             | 21 +++++++++++++++++++++
 xen/arch/x86/include/asm/domain.h |  3 +++
 xen/arch/x86/include/asm/paging.h | 22 ----------------------
 4 files changed, 25 insertions(+), 23 deletions(-)

Patch

diff --git a/xen/arch/x86/cpu-policy.c b/xen/arch/x86/cpu-policy.c
index 423932bc13d6..76efb050edf7 100644
--- a/xen/arch/x86/cpu-policy.c
+++ b/xen/arch/x86/cpu-policy.c
@@ -864,7 +864,7 @@  void recalculate_cpuid_policy(struct domain *d)
 
     p->extd.maxphysaddr = min(p->extd.maxphysaddr, max->extd.maxphysaddr);
     p->extd.maxphysaddr = min_t(uint8_t, p->extd.maxphysaddr,
-                                paging_max_paddr_bits(d));
+                                domain_max_paddr_bits(d));
     p->extd.maxphysaddr = max_t(uint8_t, p->extd.maxphysaddr,
                                 (p->basic.pae || p->basic.pse36) ? 36 : 32);
 
diff --git a/xen/arch/x86/domain.c b/xen/arch/x86/domain.c
index 3712e36df930..8a31d18f6967 100644
--- a/xen/arch/x86/domain.c
+++ b/xen/arch/x86/domain.c
@@ -2552,6 +2552,27 @@  static int __init cf_check init_vcpu_kick_softirq(void)
 }
 __initcall(init_vcpu_kick_softirq);
 
+unsigned int domain_max_paddr_bits(const struct domain *d)
+{
+    unsigned int bits = paging_mode_hap(d) ? hap_paddr_bits : paddr_bits;
+
+    if ( paging_mode_external(d) )
+    {
+        if ( !IS_ENABLED(CONFIG_BIGMEM) && paging_mode_shadow(d) )
+        {
+            /* Shadowed superpages store GFNs in 32-bit page_info fields. */
+            bits = min(bits, 32U + PAGE_SHIFT);
+        }
+        else
+        {
+            /* Both p2m-ept and p2m-pt only support 4-level page tables. */
+            bits = min(bits, 48U);
+        }
+    }
+
+    return bits;
+}
+
 /*
  * Local variables:
  * mode: C
diff --git a/xen/arch/x86/include/asm/domain.h b/xen/arch/x86/include/asm/domain.h
index 4b6b7ceab1ed..622d22bef255 100644
--- a/xen/arch/x86/include/asm/domain.h
+++ b/xen/arch/x86/include/asm/domain.h
@@ -777,6 +777,9 @@  static inline void pv_inject_sw_interrupt(unsigned int vector)
 struct arch_vcpu_io {
 };
 
+/* Maxphysaddr supportable by the paging infrastructure. */
+unsigned int domain_max_paddr_bits(const struct domain *d);
+
 #endif /* __ASM_DOMAIN_H__ */
 
 /*
diff --git a/xen/arch/x86/include/asm/paging.h b/xen/arch/x86/include/asm/paging.h
index 76162a9429ce..8a2a0af40874 100644
--- a/xen/arch/x86/include/asm/paging.h
+++ b/xen/arch/x86/include/asm/paging.h
@@ -336,28 +336,6 @@  static inline bool gfn_valid(const struct domain *d, gfn_t gfn)
     return !(gfn_x(gfn) >> (d->arch.cpuid->extd.maxphysaddr - PAGE_SHIFT));
 }
 
-/* Maxphysaddr supportable by the paging infrastructure. */
-static always_inline unsigned int paging_max_paddr_bits(const struct domain *d)
-{
-    unsigned int bits = paging_mode_hap(d) ? hap_paddr_bits : paddr_bits;
-
-    if ( paging_mode_external(d) )
-    {
-        if ( !IS_ENABLED(CONFIG_BIGMEM) && paging_mode_shadow(d) )
-        {
-            /* Shadowed superpages store GFNs in 32-bit page_info fields. */
-            bits = min(bits, 32U + PAGE_SHIFT);
-        }
-        else
-        {
-            /* Both p2m-ept and p2m-pt only support 4-level page tables. */
-            bits = min(bits, 48U);
-        }
-    }
-
-    return bits;
-}
-
 #endif /* XEN_PAGING_H */
 
 /*