[PATCH 2/4] domctl: Provide appropriate error code when PIRQs are not supported

[Milan Djokic <milan_djokic@xxxxxxxx>]

When PIRQs are not supported (e.g. for arm), XEN_DOMCTL_irq_permission
command is not handled.
This results with default (-ENOSYS) error code returned to control domain.
Update command handling to return -EOPNOTSUPP if control domain
invokes it by mistake when PIRQs are not supported.
Also exclude xsm_irq_permission hooks from compilation when
PIRQs are not supported.

Signed-off-by: Milan Djokic <milan_djokic@xxxxxxxx>
---
 xen/common/domctl.c     | 6 ++++--
 xen/include/xsm/dummy.h | 4 ++--
 xen/include/xsm/xsm.h   | 6 ++++--
 xen/xsm/dummy.c         | 2 ++
 xen/xsm/flask/hooks.c   | 5 ++++-
 5 files changed, 16 insertions(+), 7 deletions(-)

diff --git a/xen/common/domctl.c b/xen/common/domctl.c
index 29a7726d32..159864bc99 100644
--- a/xen/common/domctl.c
+++ b/xen/common/domctl.c
@@ -638,9 +638,9 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) 
u_domctl)
         }
         break;
 
-#ifdef CONFIG_HAS_PIRQ
     case XEN_DOMCTL_irq_permission:
     {
+#ifdef CONFIG_HAS_PIRQ
         unsigned int pirq = op->u.irq_permission.pirq, irq;
         int allow = op->u.irq_permission.allow_access;
 
@@ -656,9 +656,11 @@ long do_domctl(XEN_GUEST_HANDLE_PARAM(xen_domctl_t) 
u_domctl)
             ret = irq_permit_access(d, irq);
         else
             ret = irq_deny_access(d, irq);
+#else
+        ret = -EOPNOTSUPP;
+#endif
         break;
     }
-#endif
 
     case XEN_DOMCTL_iomem_permission:
     {
diff --git a/xen/include/xsm/dummy.h b/xen/include/xsm/dummy.h
index e801dbcdba..6f6de161f9 100644
--- a/xen/include/xsm/dummy.h
+++ b/xen/include/xsm/dummy.h
@@ -555,14 +555,14 @@ static XSM_INLINE int cf_check xsm_unmap_domain_irq(
     XSM_ASSERT_ACTION(XSM_HOOK);
     return xsm_default_action(action, current->domain, d);
 }
-
+#ifdef CONFIG_HAS_PIRQ
 static XSM_INLINE int cf_check xsm_irq_permission(
     XSM_DEFAULT_ARG struct domain *d, int pirq, uint8_t allow)
 {
     XSM_ASSERT_ACTION(XSM_HOOK);
     return xsm_default_action(action, current->domain, d);
 }
-
+#endif
 static XSM_INLINE int cf_check xsm_iomem_permission(
     XSM_DEFAULT_ARG struct domain *d, uint64_t s, uint64_t e, uint8_t allow)
 {
diff --git a/xen/include/xsm/xsm.h b/xen/include/xsm/xsm.h
index 2d831d7745..b85cf9933a 100644
--- a/xen/include/xsm/xsm.h
+++ b/xen/include/xsm/xsm.h
@@ -113,7 +113,9 @@ struct xsm_ops {
     int (*unmap_domain_irq)(struct domain *d, int irq, const void *data);
     int (*bind_pt_irq)(struct domain *d, struct xen_domctl_bind_pt_irq *bind);
     int (*unbind_pt_irq)(struct domain *d, struct xen_domctl_bind_pt_irq 
*bind);
+#ifdef CONFIG_HAS_PIRQ
     int (*irq_permission)(struct domain *d, int pirq, uint8_t allow);
+#endif
     int (*iomem_permission)(struct domain *d, uint64_t s, uint64_t e,
                             uint8_t allow);
     int (*iomem_mapping)(struct domain *d, uint64_t s, uint64_t e,
@@ -504,13 +506,13 @@ static inline int xsm_unbind_pt_irq(
 {
     return alternative_call(xsm_ops.unbind_pt_irq, d, bind);
 }
-
+#ifdef CONFIG_HAS_PIRQ
 static inline int xsm_irq_permission(
     xsm_default_t def, struct domain *d, int pirq, uint8_t allow)
 {
     return alternative_call(xsm_ops.irq_permission, d, pirq, allow);
 }
-
+#endif
 static inline int xsm_iomem_permission(
     xsm_default_t def, struct domain *d, uint64_t s, uint64_t e, uint8_t allow)
 {
diff --git a/xen/xsm/dummy.c b/xen/xsm/dummy.c
index 96dc82ac2e..28ef4a0beb 100644
--- a/xen/xsm/dummy.c
+++ b/xen/xsm/dummy.c
@@ -73,7 +73,9 @@ static const struct xsm_ops __initconst_cf_clobber dummy_ops 
= {
     .unmap_domain_irq              = xsm_unmap_domain_irq,
     .bind_pt_irq                   = xsm_bind_pt_irq,
     .unbind_pt_irq                 = xsm_unbind_pt_irq,
+#ifdef CONFIG_HAS_PIRQ
     .irq_permission                = xsm_irq_permission,
+#endif
     .iomem_permission              = xsm_iomem_permission,
     .iomem_mapping                 = xsm_iomem_mapping,
     .pci_config_permission         = xsm_pci_config_permission,
diff --git a/xen/xsm/flask/hooks.c b/xen/xsm/flask/hooks.c
index 9f3915617c..63e4b4c353 100644
--- a/xen/xsm/flask/hooks.c
+++ b/xen/xsm/flask/hooks.c
@@ -1110,13 +1110,14 @@ static int cf_check flask_unbind_pt_irq(
 {
     return current_has_perm(d, SECCLASS_RESOURCE, RESOURCE__REMOVE);
 }
-
+#ifdef CONFIG_HAS_PIRQ
 static int cf_check flask_irq_permission(
     struct domain *d, int pirq, uint8_t access)
 {
     /* the PIRQ number is not useful; real IRQ is checked during mapping */
     return current_has_perm(d, SECCLASS_RESOURCE, resource_to_perm(access));
 }
+#endif
 
 struct iomem_has_perm_data {
     uint32_t ssid;
@@ -1943,7 +1944,9 @@ static const struct xsm_ops __initconst_cf_clobber 
flask_ops = {
     .unmap_domain_irq = flask_unmap_domain_irq,
     .bind_pt_irq = flask_bind_pt_irq,
     .unbind_pt_irq = flask_unbind_pt_irq,
+#ifdef CONFIG_HAS_PIRQ
     .irq_permission = flask_irq_permission,
+#endif
     .iomem_permission = flask_iomem_permission,
     .iomem_mapping = flask_iomem_mapping,
     .pci_config_permission = flask_pci_config_permission,
-- 
2.43.0