[PATCH v2 2/4] xen/arm: Handle cases when hardware_domain is NULL

[Luca Fancellu <luca.fancellu@arm.com>]

The function is_hardware_domain() returns true if the
hardware_domain and the passed domain is NULL, here we
add a check to return false if there is no hardware_domain.

Among the common and arm codebase there are few cases where
the hardware_domain variable is checked to see if the current
domain is equal to the hardware_domain, change this cases to
use is_hardware_domain() function instead.

Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
---
 xen/arch/arm/irq.c                       | 2 +-
 xen/common/domain.c                      | 4 ++--
 xen/drivers/passthrough/arm/ipmmu-vmsa.c | 2 +-
 xen/drivers/passthrough/arm/smmu-v3.c    | 2 +-
 xen/drivers/passthrough/arm/smmu.c       | 2 +-
 xen/include/asm-arm/domain.h             | 2 +-
 xen/include/xen/sched.h                  | 2 +-
 7 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/xen/arch/arm/irq.c b/xen/arch/arm/irq.c
index b71b099e6f..b761d90c40 100644
--- a/xen/arch/arm/irq.c
+++ b/xen/arch/arm/irq.c
@@ -412,7 +412,7 @@ bool is_assignable_irq(unsigned int irq)
  */
 bool irq_type_set_by_domain(const struct domain *d)
 {
-    return (d == hardware_domain);
+    return is_hardware_domain(d);
 }
 
 /*
diff --git a/xen/common/domain.c b/xen/common/domain.c
index d85984638a..e8ec3ba445 100644
--- a/xen/common/domain.c
+++ b/xen/common/domain.c
@@ -308,7 +308,7 @@ static int late_hwdom_init(struct domain *d)
     struct domain *dom0;
     int rv;
 
-    if ( d != hardware_domain || d->domain_id == 0 )
+    if ( !is_hardware_domain(d) || d->domain_id == 0 )
         return 0;
 
     rv = xsm_init_hardware_domain(XSM_HOOK, d);
@@ -705,7 +705,7 @@ struct domain *domain_create(domid_t domid,
     err = err ?: -EILSEQ; /* Release build safety. */
 
     d->is_dying = DOMDYING_dead;
-    if ( hardware_domain == d )
+    if ( is_hardware_domain(d) )
         hardware_domain = old_hwdom;
     atomic_set(&d->refcnt, DOMAIN_DESTROYED);
 
diff --git a/xen/drivers/passthrough/arm/ipmmu-vmsa.c b/xen/drivers/passthrough/arm/ipmmu-vmsa.c
index aef358d880..8b8e3a00ba 100644
--- a/xen/drivers/passthrough/arm/ipmmu-vmsa.c
+++ b/xen/drivers/passthrough/arm/ipmmu-vmsa.c
@@ -1168,7 +1168,7 @@ static int ipmmu_reassign_device(struct domain *s, struct domain *t,
     int ret = 0;
 
     /* Don't allow remapping on other domain than hwdom */
-    if ( t && t != hardware_domain )
+    if ( t && !is_hardware_domain(t) )
         return -EPERM;
 
     if ( t == s )
diff --git a/xen/drivers/passthrough/arm/smmu-v3.c b/xen/drivers/passthrough/arm/smmu-v3.c
index 53d150cdb6..d115df7320 100644
--- a/xen/drivers/passthrough/arm/smmu-v3.c
+++ b/xen/drivers/passthrough/arm/smmu-v3.c
@@ -3366,7 +3366,7 @@ static int arm_smmu_reassign_dev(struct domain *s, struct domain *t,
 	int ret = 0;
 
 	/* Don't allow remapping on other domain than hwdom */
-	if (t && t != hardware_domain)
+	if ( t && !is_hardware_domain(t) )
 		return -EPERM;
 
 	if (t == s)
diff --git a/xen/drivers/passthrough/arm/smmu.c b/xen/drivers/passthrough/arm/smmu.c
index 3e8aa37866..932fdfd6dd 100644
--- a/xen/drivers/passthrough/arm/smmu.c
+++ b/xen/drivers/passthrough/arm/smmu.c
@@ -2670,7 +2670,7 @@ static int arm_smmu_reassign_dev(struct domain *s, struct domain *t,
 	int ret = 0;
 
 	/* Don't allow remapping on other domain than hwdom */
-	if (t && t != hardware_domain)
+	if ( t && !is_hardware_domain(t) )
 		return -EPERM;
 
 	if (t == s)
diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
index 1da90f207d..738bda5ef3 100644
--- a/xen/include/asm-arm/domain.h
+++ b/xen/include/asm-arm/domain.h
@@ -30,7 +30,7 @@ enum domain_type {
 #endif
 
 /* The hardware domain has always its memory direct mapped. */
-#define is_domain_direct_mapped(d) ((d) == hardware_domain)
+#define is_domain_direct_mapped(d) (is_hardware_domain(d))
 
 struct vtimer {
     struct vcpu *v;
diff --git a/xen/include/xen/sched.h b/xen/include/xen/sched.h
index 5485d08afb..bfc9d2577c 100644
--- a/xen/include/xen/sched.h
+++ b/xen/include/xen/sched.h
@@ -1022,7 +1022,7 @@ static always_inline bool is_hardware_domain(const struct domain *d)
     if ( IS_ENABLED(CONFIG_PV_SHIM_EXCLUSIVE) )
         return false;
 
-    return evaluate_nospec(d == hardware_domain);
+    return evaluate_nospec((hardware_domain != NULL) && (d == hardware_domain));
 }
 
 /* This check is for functionality specific to a control domain */
-- 
2.17.1