[PATCH v2 04/14] x86: restrict PHYSDEVOP_* when PV=n

[Jan Beulich <jbeulich@suse.com>]

hvm_physdev_op() permits through only a subset of sub-ops. The code
handling other sub-ops is therefore unreachable when PV=n, violating MISRA
C:2012 rule 2.1. With that the XSM .apic() hook also becomes unreachable /
dead when PV=n.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
---
At least for the sub-ops using xsm_apic() IS_ENABLED() cannot be used.
Therefore #ifdef is used throughout.
---
v2: Re-base over re-ordering of series.

--- a/xen/arch/x86/physdev.c
+++ b/xen/arch/x86/physdev.c
@@ -233,6 +233,8 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_H
         break;
     }
 
+#ifdef CONFIG_PV
+
     case PHYSDEVOP_pirq_eoi_gmfn_v2:
     case PHYSDEVOP_pirq_eoi_gmfn_v1: {
         struct physdev_pirq_eoi_gmfn info;
@@ -281,6 +283,8 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_H
         break;
     }
 
+#endif /* CONFIG_PV */
+
     case PHYSDEVOP_irq_status_query: {
         struct physdev_irq_status_query irq_status_query;
         ret = -EFAULT;
@@ -379,6 +383,8 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_H
         break;
     }
 
+#ifdef CONFIG_PV
+
     case PHYSDEVOP_apic_read: {
         struct physdev_apic apic;
         ret = -EFAULT;
@@ -526,6 +532,8 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_H
         break;
     }
 
+#endif /* CONFIG_PV */
+
     case PHYSDEVOP_pci_mmcfg_reserved: {
         struct physdev_pci_mmcfg_reserved info;
 
@@ -560,6 +568,8 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_H
         break;
     }
 
+#ifdef CONFIG_PV
+
     case PHYSDEVOP_restore_msi: {
         struct physdev_restore_msi restore_msi;
         struct pci_dev *pdev;
@@ -591,6 +601,8 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_H
         break;
     }
 
+#endif /* CONFIG_PV */
+
     case PHYSDEVOP_setup_gsi: {
         struct physdev_setup_gsi setup_gsi;
 
@@ -610,6 +622,7 @@ ret_t do_physdev_op(int cmd, XEN_GUEST_H
                               setup_gsi.polarity);
         break; 
     }
+
     case PHYSDEVOP_get_free_pirq: {
         struct physdev_get_free_pirq out;
 
--- a/xen/include/xsm/dummy.h
+++ b/xen/include/xsm/dummy.h
@@ -644,13 +644,6 @@ static XSM_INLINE int xsm_mem_sharing_op
     return xsm_default_action(action, current->domain, cd);
 }
 
-static XSM_INLINE int xsm_apic(
-    XSM_DEFAULT_ARG struct domain *d, int cmd)
-{
-    XSM_ASSERT_ACTION(XSM_PRIV);
-    return xsm_default_action(action, d, NULL);
-}
-
 static XSM_INLINE int xsm_machine_memory_map(XSM_DEFAULT_VOID)
 {
     XSM_ASSERT_ACTION(XSM_PRIV);
@@ -666,6 +659,13 @@ static XSM_INLINE int xsm_domain_memory_
 
 #ifdef CONFIG_PV
 
+static XSM_INLINE int xsm_apic(
+    XSM_DEFAULT_ARG struct domain *d, int cmd)
+{
+    XSM_ASSERT_ACTION(XSM_PRIV);
+    return xsm_default_action(action, d, NULL);
+}
+
 static XSM_INLINE int xsm_do_mca(XSM_DEFAULT_VOID)
 {
     XSM_ASSERT_ACTION(XSM_PRIV);
--- a/xen/include/xsm/hooks.h
+++ b/xen/include/xsm/hooks.h
@@ -131,10 +131,10 @@ XSM_HOOK(int, mem_sharing_op, struct dom
 XSM_HOOK(int, platform_op, uint32_t)
 
 #ifdef CONFIG_X86
-XSM_HOOK(int, apic, struct domain *, int)
 XSM_HOOK(int, machine_memory_map)
 XSM_HOOK(int, domain_memory_map, struct domain *)
 #ifdef CONFIG_PV
+XSM_HOOK(int, apic, struct domain *, int)
 XSM_HOOK(int, do_mca)
 XSM_HOOK(int, mmu_update, struct domain *, struct domain *, struct domain *,
                           uint32_t)
--- a/xen/xsm/flask/hooks.c
+++ b/xen/xsm/flask/hooks.c
@@ -1750,6 +1750,19 @@ static int cf_check flask_mem_sharing_op
 }
 #endif
 
+static int cf_check flask_machine_memory_map(void)
+{
+    return avc_current_has_perm(SECINITSID_XEN, SECCLASS_MMU, MMU__MEMORYMAP,
+                                NULL);
+}
+
+static int cf_check flask_domain_memory_map(struct domain *d)
+{
+    return current_has_perm(d, SECCLASS_MMU, MMU__MEMORYMAP);
+}
+
+#ifdef CONFIG_PV
+
 static int cf_check flask_apic(struct domain *d, int cmd)
 {
     uint32_t perm;
@@ -1770,18 +1783,6 @@ static int cf_check flask_apic(struct do
     return domain_has_xen(d, perm);
 }
 
-static int cf_check flask_machine_memory_map(void)
-{
-    return avc_current_has_perm(SECINITSID_XEN, SECCLASS_MMU, MMU__MEMORYMAP, NULL);
-}
-
-static int cf_check flask_domain_memory_map(struct domain *d)
-{
-    return current_has_perm(d, SECCLASS_MMU, MMU__MEMORYMAP);
-}
-
-#ifdef CONFIG_PV
-
 static int cf_check flask_do_mca(void)
 {
     return domain_has_xen(current->domain, XEN__MCA_OP);