XSM/Flask: split the .iomem_mapping() hook

It's used twice in entirely different situations. The use in do_domctl()
wants to become an ordinary XSM_DM_PRIV invocation, while the one in vPCI
code need to remain XSM_HOOK (it may plausibly become XSM_TARGET). For
Flask, the same backing function will continue to be used for the time
being.

This is part of XSA-492.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Daniel P. Smith <dpsmith@apertussolutions.com>
(cherry picked from commit 6bb83b1aa0)

xen/drivers/vpci/header.c

@@ -67,7 +67,7 @@ static int cf_check map_range(
             return -EPERM;
         }
 
-        rc = xsm_iomem_mapping(XSM_HOOK, map->d, map_mfn, m_end, map->map);
+        rc = xsm_iomem_mapping_vpci(XSM_HOOK, map->d, map_mfn, m_end, map->map);
         if ( rc )
         {
             printk(XENLOG_G_WARNING

xen/include/xsm/dummy.h

@@ -579,6 +579,13 @@ static XSM_INLINE int cf_check xsm_iomem_mapping(
     return xsm_default_action(action, current->domain, d);
 }
 
+static XSM_INLINE int cf_check xsm_iomem_mapping_vpci(
+    XSM_DEFAULT_ARG struct domain *d, uint64_t s, uint64_t e, uint8_t allow)
+{
+    XSM_ASSERT_ACTION(XSM_HOOK);
+    return xsm_default_action(action, current->domain, d);
+}
+
 static XSM_INLINE int cf_check xsm_pci_config_permission(
     XSM_DEFAULT_ARG struct domain *d, uint32_t machine_bdf, uint16_t start,
     uint16_t end, uint8_t access)

xen/include/xsm/xsm.h

@@ -117,6 +117,8 @@ struct xsm_ops {
                             uint8_t allow);
     int (*iomem_mapping)(struct domain *d, uint64_t s, uint64_t e,
                          uint8_t allow);
+    int (*iomem_mapping_vpci)(struct domain *d, uint64_t s, uint64_t e,
+                              uint8_t allow);
     int (*pci_config_permission)(struct domain *d, uint32_t machine_bdf,
                                  uint16_t start, uint16_t end, uint8_t access);
 
@@ -504,6 +506,12 @@ static inline int xsm_iomem_mapping(
     return alternative_call(xsm_ops.iomem_mapping, d, s, e, allow);
 }
 
+static inline int xsm_iomem_mapping_vpci(
+    xsm_default_t def, struct domain *d, uint64_t s, uint64_t e, uint8_t allow)
+{
+    return alternative_call(xsm_ops.iomem_mapping_vpci, d, s, e, allow);
+}
+
 static inline int xsm_pci_config_permission(
     xsm_default_t def, struct domain *d, uint32_t machine_bdf, uint16_t start,
     uint16_t end, uint8_t access)

xen/xsm/dummy.c

@@ -72,6 +72,7 @@ static const struct xsm_ops __initconst_cf_clobber dummy_ops = {
     .irq_permission                = xsm_irq_permission,
     .iomem_permission              = xsm_iomem_permission,
     .iomem_mapping                 = xsm_iomem_mapping,
+    .iomem_mapping_vpci            = xsm_iomem_mapping_vpci,
     .pci_config_permission         = xsm_pci_config_permission,
     .get_vnumainfo                 = xsm_get_vnumainfo,
 

xen/xsm/flask/hooks.c

@@ -1921,6 +1921,7 @@ static const struct xsm_ops __initconst_cf_clobber flask_ops = {
     .irq_permission = flask_irq_permission,
     .iomem_permission = flask_iomem_permission,
     .iomem_mapping = flask_iomem_mapping,
+    .iomem_mapping_vpci = flask_iomem_mapping,
     .pci_config_permission = flask_pci_config_permission,
 
     .resource_plug_core = flask_resource_plug_core,