xen/arm: dump guest stack even if not the current VCPU

If show_guest_stack was called from Xen context (for instance hitting
'0' key on Xen console) get_page_from_gva was not able to get the
page returning NULL.
Detecting different domain and changing VTTBR register make
get_page_from_gva works for different domains.

Signed-off-by: Frediano Ziglio <frediano.ziglio@huawei.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>

diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index 7b08f16d03cb461cb5c8049f610e10a9e2203feb..8809f5a297912eee57d5f2a154b9a64f49a596ed 100644 (file)
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -1157,13 +1157,29 @@ struct page_info *get_page_from_gva(struct domain *d, vaddr_t va,
 {
     struct p2m_domain *p2m = &d->arch.p2m;
     struct page_info *page = NULL;
-    paddr_t maddr;
-
-    ASSERT(d == current->domain);
+    paddr_t maddr = 0;
+    int rc;
 
     spin_lock(&p2m->lock);
 
-    if ( gvirt_to_maddr(va, &maddr, flags) )
+    if ( unlikely(d != current->domain) )
+    {
+        unsigned long irq_flags;
+
+        local_irq_save(irq_flags);
+        p2m_load_VTTBR(d);
+
+        rc = gvirt_to_maddr(va, &maddr, flags);
+
+        p2m_load_VTTBR(current->domain);
+        local_irq_restore(irq_flags);
+    }
+    else
+    {
+        rc = gvirt_to_maddr(va, &maddr, flags);
+    }
+
+    if ( rc )
         goto err;
 
     if ( !mfn_valid(maddr >> PAGE_SHIFT) )

diff --git a/xen/arch/arm/traps.c b/xen/arch/arm/traps.c
index f6fc8f8e1ec161fea7cc53c8af55e69af2d974e1..4c932503a7efbe8203e076b21833738e7529b518 100644 (file)
--- a/xen/arch/arm/traps.c
+++ b/xen/arch/arm/traps.c
@@ -892,7 +892,7 @@ static void show_guest_stack(struct vcpu *v, struct cpu_user_regs *regs)
         return;
     }
 
-    page = get_page_from_gva(current->domain, sp, GV2M_READ);
+    page = get_page_from_gva(v->domain, sp, GV2M_READ);
     if ( page == NULL )
     {
         printk("Failed to convert stack to physical address\n");