[Xen-devel] [PATCH v4 31/39] arm/altp2m: Introduce altp2m_switch_vcpu_altp2m_by_id

[Sergej Proskurin <proskurin@xxxxxxxxxxxxx>]

This commit adds the function "altp2m_switch_vcpu_altp2m_by_id" that is
executed after checking whether the vcpu should be switched to a different
altp2m within the function "altp2m_check".

Signed-off-by: Sergej Proskurin <proskurin@xxxxxxxxxxxxx>
---
Cc: Stefano Stabellini <sstabellini@xxxxxxxxxx>
Cc: Julien Grall <julien.grall@xxxxxxx>
---
v3: This commit has been moved out of the commit "arm/p2m: Add altp2m
    paging mechanism".

    Moved the function "p2m_altp2m_check" from p2m.c to altp2m.c and
    renamed it to "altp2m_check". This change required the adoption of
    the complementary function in the x86 architecture.

v4: Moved code renaming and movement of ARM and x86 related code out of
    this commit.

    While parts of this commit have been Acked-by Razvan Cojocaru and
    George Dunlap in v3, we have removed the Acks as the previous patch
    has been distributed across multiple smaller patches and now needs
    to be reviewed again.
---
 xen/arch/arm/altp2m.c        | 32 ++++++++++++++++++++++++++++++++
 xen/include/asm-arm/altp2m.h |  6 +-----
 2 files changed, 33 insertions(+), 5 deletions(-)

diff --git a/xen/arch/arm/altp2m.c b/xen/arch/arm/altp2m.c
index 4883b1323b..9c9876c932 100644
--- a/xen/arch/arm/altp2m.c
+++ b/xen/arch/arm/altp2m.c
@@ -32,6 +32,38 @@ struct p2m_domain *altp2m_get_altp2m(struct vcpu *v)
     return v->domain->arch.altp2m_p2m[idx];
 }
 
+static bool altp2m_switch_vcpu_altp2m_by_id(struct vcpu *v, unsigned int idx)
+{
+    struct domain *d = v->domain;
+    bool rc = false;
+
+    if ( unlikely(idx >= MAX_ALTP2M) )
+        return rc;
+
+    altp2m_lock(d);
+
+    if ( d->arch.altp2m_p2m[idx] != NULL )
+    {
+        if ( idx != v->arch.ap2m_idx )
+        {
+            atomic_dec(&altp2m_get_altp2m(v)->active_vcpus);
+            v->arch.ap2m_idx = idx;
+            atomic_inc(&altp2m_get_altp2m(v)->active_vcpus);
+        }
+        rc = true;
+    }
+
+    altp2m_unlock(d);
+
+    return rc;
+}
+
+void altp2m_check(struct vcpu *v, uint16_t idx)
+{
+    if ( altp2m_active(v->domain) )
+        altp2m_switch_vcpu_altp2m_by_id(v, idx);
+}
+
 int altp2m_switch_domain_altp2m_by_id(struct domain *d, unsigned int idx)
 {
     struct vcpu *v;
diff --git a/xen/include/asm-arm/altp2m.h b/xen/include/asm-arm/altp2m.h
index 5a2444e8f8..f9e14ab1dc 100644
--- a/xen/include/asm-arm/altp2m.h
+++ b/xen/include/asm-arm/altp2m.h
@@ -50,11 +50,7 @@ void altp2m_vcpu_destroy(struct vcpu *v);
 struct p2m_domain *altp2m_get_altp2m(struct vcpu *v);
 
 /* Check to see if vcpu should be switched to a different p2m. */
-static inline
-void altp2m_check(struct vcpu *v, uint16_t idx)
-{
-    /* Not supported on ARM. */
-}
+void altp2m_check(struct vcpu *v, uint16_t idx);
 
 /* Switch alternate p2m for entire domain */
 int altp2m_switch_domain_altp2m_by_id(struct domain *d,
-- 
2.13.3


_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
https://lists.xen.org/xen-devel