[PATCH 1/4] x86/hvm: stop passing explicit domid to hvm_create_ioreq_server()

[Paul Durrant <paul.durrant@citrix.com>]

There are only two call-sites for this function:

- The 'default' call site, which sets the is_default argument to true
  and passes the value of HVM_PARAM_DM_DOMAIN as domid.
- The 'dm op' call site, which sets the is_default argument to false
  and passes current->domain->domain_id as domid.

Clearly the correct value of domid can be discerned from the is_default
argument so this patch modifies hvm_create_ioreq_server() to do that
internally, negating the need for the domid argument.

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
---
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
---
 xen/arch/x86/hvm/dm.c           |  5 ++---
 xen/arch/x86/hvm/hvm.c          |  4 +---
 xen/arch/x86/hvm/ioreq.c        | 17 +++++++++--------
 xen/include/asm-x86/hvm/ioreq.h |  5 ++---
 4 files changed, 14 insertions(+), 17 deletions(-)

diff --git a/xen/arch/x86/hvm/dm.c b/xen/arch/x86/hvm/dm.c
index 7788577a73..96b0d13f2f 100644
--- a/xen/arch/x86/hvm/dm.c
+++ b/xen/arch/x86/hvm/dm.c
@@ -402,7 +402,6 @@ static int dm_op(const struct dmop_args *op_args)
     {
     case XEN_DMOP_create_ioreq_server:
     {
-        struct domain *curr_d = current->domain;
         struct xen_dm_op_create_ioreq_server *data =
             &op.u.create_ioreq_server;
 
@@ -412,8 +411,8 @@ static int dm_op(const struct dmop_args *op_args)
         if ( data->pad[0] || data->pad[1] || data->pad[2] )
             break;
 
-        rc = hvm_create_ioreq_server(d, curr_d->domain_id, false,
-                                     data->handle_bufioreq, &data->id);
+        rc = hvm_create_ioreq_server(d, false, data->handle_bufioreq,
+                                     &data->id);
         break;
     }
 
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 91bc3e8b27..42a294a6cc 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -4443,9 +4443,7 @@ static int hvmop_get_param(
          */
         if ( !d->creation_finished )
         {
-            domid_t domid = d->arch.hvm_domain.params[HVM_PARAM_DM_DOMAIN];
-
-            rc = hvm_create_ioreq_server(d, domid, true,
+            rc = hvm_create_ioreq_server(d, true,
                                          HVM_IOREQSRV_BUFIOREQ_LEGACY, NULL);
             if ( rc != 0 && rc != -EEXIST )
                 goto out;
diff --git a/xen/arch/x86/hvm/ioreq.c b/xen/arch/x86/hvm/ioreq.c
index 7e66965bcd..ee5f47de65 100644
--- a/xen/arch/x86/hvm/ioreq.c
+++ b/xen/arch/x86/hvm/ioreq.c
@@ -599,16 +599,18 @@ static void hvm_ioreq_server_disable(struct hvm_ioreq_server *s,
 }
 
 static int hvm_ioreq_server_init(struct hvm_ioreq_server *s,
-                                 struct domain *d, domid_t domid,
-                                 bool is_default, int bufioreq_handling,
-                                 ioservid_t id)
+                                 struct domain *d, bool is_default,
+                                 int bufioreq_handling, ioservid_t id)
 {
     struct vcpu *v;
     int rc;
 
     s->id = id;
     s->domain = d;
-    s->domid = domid;
+
+    s->domid = is_default ?
+        d->arch.hvm_domain.params[HVM_PARAM_DM_DOMAIN] :
+        current->domain->domain_id;
 
     spin_lock_init(&s->lock);
     INIT_LIST_HEAD(&s->ioreq_vcpu_list);
@@ -680,9 +682,8 @@ static ioservid_t next_ioservid(struct domain *d)
     return id;
 }
 
-int hvm_create_ioreq_server(struct domain *d, domid_t domid,
-                            bool is_default, int bufioreq_handling,
-                            ioservid_t *id)
+int hvm_create_ioreq_server(struct domain *d, bool is_default,
+                            int bufioreq_handling, ioservid_t *id)
 {
     struct hvm_ioreq_server *s;
     int rc;
@@ -702,7 +703,7 @@ int hvm_create_ioreq_server(struct domain *d, domid_t domid,
     if ( is_default && d->arch.hvm_domain.default_ioreq_server != NULL )
         goto fail2;
 
-    rc = hvm_ioreq_server_init(s, d, domid, is_default, bufioreq_handling,
+    rc = hvm_ioreq_server_init(s, d, is_default, bufioreq_handling,
                                next_ioservid(d));
     if ( rc )
         goto fail3;
diff --git a/xen/include/asm-x86/hvm/ioreq.h b/xen/include/asm-x86/hvm/ioreq.h
index 1829fcf43e..0048a7c41c 100644
--- a/xen/include/asm-x86/hvm/ioreq.h
+++ b/xen/include/asm-x86/hvm/ioreq.h
@@ -23,9 +23,8 @@ bool hvm_io_pending(struct vcpu *v);
 bool handle_hvm_io_completion(struct vcpu *v);
 bool is_ioreq_server_page(struct domain *d, const struct page_info *page);
 
-int hvm_create_ioreq_server(struct domain *d, domid_t domid,
-                            bool is_default, int bufioreq_handling,
-                            ioservid_t *id);
+int hvm_create_ioreq_server(struct domain *d, bool is_default,
+                            int bufioreq_handling, ioservid_t *id);
 int hvm_destroy_ioreq_server(struct domain *d, ioservid_t id);
 int hvm_get_ioreq_server_info(struct domain *d, ioservid_t id,
                               unsigned long *ioreq_gfn,
-- 
2.11.0


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