diff mbox series

[v2,5/9] x86/shadow: L2H shadow type is PV32-only

Message ID af8ca228-473a-6777-4a4c-a474a5faec1f@suse.com (mailing list archive)
State Superseded
Headers show
Series x86/shadow: misc tidying | expand

Commit Message

Jan Beulich Jan. 11, 2023, 1:54 p.m. UTC 
Like for the various HVM-only types, save a little bit of code by suitably
"masking" this type out when !PV32.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
---
I wasn't really sure whether it would be worthwhile to also update the
"#else" part of shadow_size(). Doing so would be a little tricky, as the
type to return 0 for has no name right now; I'd need to move down the
#undef to allow for that. Thoughts?
---
v2: Merely comment out the sh_type_to_size[] entry.

Comments

Andrew Cooper Jan. 17, 2023, 7:06 p.m. UTC | #1 
On 11/01/2023 1:54 pm, Jan Beulich wrote:
> Like for the various HVM-only types, save a little bit of code by suitably
> "masking" this type out when !PV32.
>
> Signed-off-by: Jan Beulich <jbeulich@suse.com>

Acked-by: Andrew Cooper <andrew.cooper3@citrix.com>
diff mbox series

Patch

--- a/xen/arch/x86/mm/shadow/common.c
+++ b/xen/arch/x86/mm/shadow/common.c
@@ -1740,9 +1740,11 @@  void sh_destroy_shadow(struct domain *d,
     case SH_type_fl1_64_shadow:
         SHADOW_INTERNAL_NAME(sh_destroy_l1_shadow, 4)(d, smfn);
         break;
+#ifdef CONFIG_PV32
     case SH_type_l2h_64_shadow:
         ASSERT(is_pv_32bit_domain(d));
         /* Fall through... */
+#endif
     case SH_type_l2_64_shadow:
         SHADOW_INTERNAL_NAME(sh_destroy_l2_shadow, 4)(d, smfn);
         break;
@@ -2095,7 +2097,9 @@  static int sh_remove_shadow_via_pointer(
 #endif
     case SH_type_l1_64_shadow:
     case SH_type_l2_64_shadow:
+#ifdef CONFIG_PV32
     case SH_type_l2h_64_shadow:
+#endif
     case SH_type_l3_64_shadow:
     case SH_type_l4_64_shadow:
         SHADOW_INTERNAL_NAME(sh_clear_shadow_entry, 4)(d, vaddr, pmfn);
@@ -2133,7 +2137,9 @@  void sh_remove_shadows(struct domain *d,
         [SH_type_l2_pae_shadow] = SHADOW_INTERNAL_NAME(sh_remove_l1_shadow, 3),
 #endif
         [SH_type_l2_64_shadow] = SHADOW_INTERNAL_NAME(sh_remove_l1_shadow, 4),
+#ifdef CONFIG_PV32
         [SH_type_l2h_64_shadow] = SHADOW_INTERNAL_NAME(sh_remove_l1_shadow, 4),
+#endif
         [SH_type_l3_64_shadow] = SHADOW_INTERNAL_NAME(sh_remove_l2_shadow, 4),
         [SH_type_l4_64_shadow] = SHADOW_INTERNAL_NAME(sh_remove_l3_shadow, 4),
     };
@@ -2146,7 +2152,9 @@  void sh_remove_shadows(struct domain *d,
 #endif
         [SH_type_l1_64_shadow] = SHF_L2H_64 | SHF_L2_64,
         [SH_type_l2_64_shadow] = SHF_L3_64,
+#ifdef CONFIG_PV32
         [SH_type_l2h_64_shadow] = SHF_L3_64,
+#endif
         [SH_type_l3_64_shadow] = SHF_L4_64,
     };
 
@@ -2210,7 +2218,9 @@  void sh_remove_shadows(struct domain *d,
 #endif
     DO_UNSHADOW(SH_type_l4_64_shadow);
     DO_UNSHADOW(SH_type_l3_64_shadow);
+#ifdef CONFIG_PV32
     DO_UNSHADOW(SH_type_l2h_64_shadow);
+#endif
     DO_UNSHADOW(SH_type_l2_64_shadow);
     DO_UNSHADOW(SH_type_l1_64_shadow);
 
@@ -3175,7 +3185,9 @@  void shadow_audit_tables(struct vcpu *v)
         [SH_type_l1_64_shadow] = SHADOW_INTERNAL_NAME(sh_audit_l1_table, 4),
         [SH_type_fl1_64_shadow] = SHADOW_INTERNAL_NAME(sh_audit_fl1_table, 4),
         [SH_type_l2_64_shadow] = SHADOW_INTERNAL_NAME(sh_audit_l2_table, 4),
+# ifdef CONFIG_PV32
         [SH_type_l2h_64_shadow] = SHADOW_INTERNAL_NAME(sh_audit_l2_table, 4),
+# endif
         [SH_type_l3_64_shadow] = SHADOW_INTERNAL_NAME(sh_audit_l3_table, 4),
         [SH_type_l4_64_shadow] = SHADOW_INTERNAL_NAME(sh_audit_l4_table, 4),
 #endif
--- a/xen/arch/x86/mm/shadow/hvm.c
+++ b/xen/arch/x86/mm/shadow/hvm.c
@@ -56,7 +56,7 @@  const uint8_t sh_type_to_size[] = {
     [SH_type_l1_64_shadow]   = 1,
     [SH_type_fl1_64_shadow]  = 1,
     [SH_type_l2_64_shadow]   = 1,
-    [SH_type_l2h_64_shadow]  = 1,
+/*  [SH_type_l2h_64_shadow]  = 1,  PV32-only */
     [SH_type_l3_64_shadow]   = 1,
     [SH_type_l4_64_shadow]   = 1,
     [SH_type_p2m_table]      = 1,
--- a/xen/arch/x86/mm/shadow/multi.c
+++ b/xen/arch/x86/mm/shadow/multi.c
@@ -97,6 +97,13 @@  static void sh_flush_local(const struct
     flush_local(guest_flush_tlb_flags(d));
 }
 
+#if GUEST_PAGING_LEVELS >= 4 && defined(CONFIG_PV32)
+#define ASSERT_VALID_L2(t) \
+    ASSERT((t) == SH_type_l2_shadow || (t) == SH_type_l2h_shadow)
+#else
+#define ASSERT_VALID_L2(t) ASSERT((t) == SH_type_l2_shadow)
+#endif
+
 /**************************************************************************/
 /* Hash table mapping from guest pagetables to shadows
  *
@@ -337,7 +344,7 @@  static void sh_audit_gw(struct vcpu *v,
         if ( mfn_valid((smfn = get_shadow_status(d, gw->l2mfn,
                                                  SH_type_l2_shadow))) )
             sh_audit_l2_table(d, smfn, INVALID_MFN);
-#if GUEST_PAGING_LEVELS >= 4 /* 32-bit PV only */
+#if GUEST_PAGING_LEVELS >= 4 && defined(CONFIG_PV32)
         if ( mfn_valid((smfn = get_shadow_status(d, gw->l2mfn,
                                                  SH_type_l2h_shadow))) )
             sh_audit_l2_table(d, smfn, INVALID_MFN);
@@ -859,13 +866,12 @@  do {
     int _i;                                                                 \
     int _xen = !shadow_mode_external(_dom);                                 \
     shadow_l2e_t *_sp = map_domain_page((_sl2mfn));                         \
-    ASSERT(mfn_to_page(_sl2mfn)->u.sh.type == SH_type_l2_64_shadow ||\
-           mfn_to_page(_sl2mfn)->u.sh.type == SH_type_l2h_64_shadow);\
+    ASSERT_VALID_L2(mfn_to_page(_sl2mfn)->u.sh.type);                       \
     for ( _i = 0; _i < SHADOW_L2_PAGETABLE_ENTRIES; _i++ )                  \
     {                                                                       \
         if ( (!(_xen))                                                      \
              || !is_pv_32bit_domain(_dom)                                   \
-             || mfn_to_page(_sl2mfn)->u.sh.type != SH_type_l2h_64_shadow    \
+             || mfn_to_page(_sl2mfn)->u.sh.type == SH_type_l2_64_shadow     \
              || (_i < COMPAT_L2_PAGETABLE_FIRST_XEN_SLOT(_dom)) )           \
         {                                                                   \
             (_sl2e) = _sp + _i;                                             \
@@ -992,6 +998,7 @@  sh_make_shadow(struct vcpu *v, mfn_t gmf
         }
         break;
 
+#ifdef CONFIG_PV32
         case SH_type_l2h_shadow:
             BUILD_BUG_ON(sizeof(l2_pgentry_t) != sizeof(shadow_l2e_t));
             if ( is_pv_32bit_domain(d) )
@@ -1002,6 +1009,8 @@  sh_make_shadow(struct vcpu *v, mfn_t gmf
                 unmap_domain_page(l2t);
             }
             break;
+#endif
+
         default: /* Do nothing */ break;
         }
     }
@@ -1123,11 +1132,13 @@  static shadow_l2e_t * shadow_get_and_cre
         shadow_l3e_t new_sl3e;
         unsigned int t = SH_type_l2_shadow;
 
+#ifdef CONFIG_PV32
         /* Tag compat L2 containing hypervisor (m2p) mappings */
         if ( is_pv_32bit_domain(d) &&
              guest_l4_table_offset(gw->va) == 0 &&
              guest_l3_table_offset(gw->va) == 3 )
             t = SH_type_l2h_shadow;
+#endif
 
         /* No l2 shadow installed: find and install it. */
         *sl2mfn = get_shadow_status(d, gw->l2mfn, t);
@@ -1337,11 +1348,7 @@  void sh_destroy_l2_shadow(struct domain
 
     SHADOW_DEBUG(DESTROY_SHADOW, "%"PRI_mfn"\n", mfn_x(smfn));
 
-#if GUEST_PAGING_LEVELS >= 4
-    ASSERT(t == SH_type_l2_shadow || t == SH_type_l2h_shadow);
-#else
-    ASSERT(t == SH_type_l2_shadow);
-#endif
+    ASSERT_VALID_L2(t);
     ASSERT(sp->u.sh.head);
 
     /* Record that the guest page isn't shadowed any more (in this type) */
@@ -1865,7 +1872,7 @@  int
 sh_map_and_validate_gl2he(struct vcpu *v, mfn_t gl2mfn,
                            void *new_gl2p, u32 size)
 {
-#if GUEST_PAGING_LEVELS >= 4
+#if GUEST_PAGING_LEVELS >= 4 && defined(CONFIG_PV32)
     return sh_map_and_validate(v, gl2mfn, new_gl2p, size,
                                 SH_type_l2h_shadow,
                                 shadow_l2_index,
@@ -3674,7 +3681,7 @@  void sh_clear_shadow_entry(struct domain
         shadow_set_l1e(d, ep, shadow_l1e_empty(), p2m_invalid, smfn);
         break;
     case SH_type_l2_shadow:
-#if GUEST_PAGING_LEVELS >= 4
+#if GUEST_PAGING_LEVELS >= 4 && defined(CONFIG_PV32)
     case SH_type_l2h_shadow:
 #endif
         shadow_set_l2e(d, ep, shadow_l2e_empty(), smfn);
@@ -4124,14 +4131,16 @@  int cf_check sh_audit_l3_table(struct do
 
         if ( SHADOW_AUDIT & SHADOW_AUDIT_ENTRIES_MFNS )
         {
+            unsigned int t = SH_type_l2_shadow;
+
             gfn = guest_l3e_get_gfn(*gl3e);
             mfn = shadow_l3e_get_mfn(*sl3e);
-            gmfn = get_shadow_status(d, get_gfn_query_unlocked(
-                                        d, gfn_x(gfn), &p2mt),
-                                     (is_pv_32bit_domain(d) &&
-                                      guest_index(gl3e) == 3)
-                                     ? SH_type_l2h_shadow
-                                     : SH_type_l2_shadow);
+#ifdef CONFIG_PV32
+            if ( guest_index(gl3e) == 3 && is_pv_32bit_domain(d) )
+                t = SH_type_l2h_shadow;
+#endif
+            gmfn = get_shadow_status(
+                       d, get_gfn_query_unlocked(d, gfn_x(gfn), &p2mt), t);
             if ( !mfn_eq(gmfn, mfn) )
                 AUDIT_FAIL(3, "bad translation: gfn %" SH_PRI_gfn
                            " --> %" PRI_mfn " != mfn %" PRI_mfn,
--- a/xen/arch/x86/mm/shadow/private.h
+++ b/xen/arch/x86/mm/shadow/private.h
@@ -209,6 +209,10 @@  extern void shadow_audit_tables(struct v
 #define SH_type_unused        10U
 #endif
 
+#ifndef CONFIG_PV32 /* Unused (but uglier to #ifdef above): */
+#undef SH_type_l2h_64_shadow
+#endif
+
 /*
  * What counts as a pinnable shadow?
  */
@@ -286,7 +290,11 @@  static inline void sh_terminate_list(str
 #define SHF_L1_64   (1u << SH_type_l1_64_shadow)
 #define SHF_FL1_64  (1u << SH_type_fl1_64_shadow)
 #define SHF_L2_64   (1u << SH_type_l2_64_shadow)
+#ifdef CONFIG_PV32
 #define SHF_L2H_64  (1u << SH_type_l2h_64_shadow)
+#else
+#define SHF_L2H_64  0
+#endif
 #define SHF_L3_64   (1u << SH_type_l3_64_shadow)
 #define SHF_L4_64   (1u << SH_type_l4_64_shadow)