# HG changeset patch
# User yamahata@xxxxxxxxxxxxx
# Date 1164685924 -32400
# Node ID ec4428278e416371c6ddfaaa3bcc10419e55dff2
# Parent  84c0f49de1b1e241a4b409a48192c110b01788a0
[XENOPROFILE] fix shared_xenoprof_page_with_guest() and clean up.
- share_xenoprof_page_with_guest() must check page reference count manually
  and clear the page owner in order to keep page_info consistency.
  free_domheap_pages() called by put_page() doesn't clear page owner.
  It's intentional. On the other hand, share_xen_page_with_guest() checks
  whether the page owner is already a requested one at first. If so,
  it simply returns doing nothing because share_xen_page_with_guest() expects
  freshly allocated pages or already shared one and doesn't expect
  put_page()-and-free_domheap_pages() pages or pages shared with
  another domains.
- clean up
  remove unsed argument gmaddr of alloc_xenoprof_buf(), alloc_xenoprof_struct()
PATCHNAME: xenoprof_common_allocation

Signed-off-by: Isaku Yamahata <yamahata@xxxxxxxxxxxxx>

diff -r 84c0f49de1b1 -r ec4428278e41 xen/common/xenoprof.c
--- a/xen/common/xenoprof.c	Mon Nov 27 10:06:41 2006 +0000
+++ b/xen/common/xenoprof.c	Tue Nov 28 12:52:04 2006 +0900
@@ -92,13 +92,42 @@ static void xenoprof_reset_buf(struct do
     }
 }
 
-static void
+static int
 share_xenoprof_page_with_guest(struct domain* d, unsigned long mfn, int npages)
 {
     int i;
     
+    /*
+     * kludge.
+     * free_domheap_pages() called by put_page() doesn't clear
+     * page owner. It's intentional.
+     * On the other hand, share_xen_page_with_guest() checks whether
+     * the page owner is already a requested one at first.
+     * If so, it simply returns doing nothing because
+     * share_xen_page_with_guest() expects freshly allocated pages or
+     * already shared one and doesn't expect
+     * put_page()-and-free_domheap_pages() pages or pages shared with
+     * another domains.
+     * we have to check it manually and clear the page owner in order 
+     * to keep page_info consistency.
+     */
+    for ( i = 0; i < npages; i++ )
+    {
+        struct page_info* page = mfn_to_page(mfn + i);
+        if ( (page->count_info & (PGC_allocated|PGC_count_mask)) != 0 )
+        {
+            gdprintk(XENLOG_INFO, "%s: mfn 0x%lx page->count_info 0x%x\n",
+                     __func__, mfn + i, page->count_info);
+            return -EBUSY;
+        }
+
+        page_set_owner(page, NULL);
+    }
+
+    /* Share pages so that kernel can map it */
     for ( i = 0; i < npages; i++ )
         share_xen_page_with_guest(mfn_to_page(mfn + i), d, XENSHARE_writable);
+    return 0;
 }
 
 static void
@@ -128,7 +157,7 @@ xenoprof_shared_gmfn_with_guest(
     }
 }
 
-static char *alloc_xenoprof_buf(struct domain *d, int npages, uint64_t gmaddr)
+static char *alloc_xenoprof_buf(struct domain *d, int npages)
 {
     char *rawbuf;
     int order;
@@ -146,7 +175,7 @@ static char *alloc_xenoprof_buf(struct d
 }
 
 static int alloc_xenoprof_struct(
-    struct domain *d, int max_samples, int is_passive, uint64_t gmaddr)
+    struct domain *d, int max_samples, int is_passive)
 {
     struct vcpu *v;
     int nvcpu, npages, bufsize, max_bufsize;
@@ -179,8 +208,7 @@ static int alloc_xenoprof_struct(
         (max_samples - 1) * sizeof(struct event_log);
     npages = (nvcpu * bufsize - 1) / PAGE_SIZE + 1;
     
-    d->xenoprof->rawbuf = alloc_xenoprof_buf(is_passive ? dom0 : d, npages,
-                                             gmaddr);
+    d->xenoprof->rawbuf = alloc_xenoprof_buf(is_passive ? dom0 : d, npages);
 
     if ( d->xenoprof->rawbuf == NULL )
     {
@@ -368,8 +396,7 @@ static int add_passive_list(XEN_GUEST_HA
 
     if ( d->xenoprof == NULL )
     {
-        ret = alloc_xenoprof_struct(
-            d, passive.max_samples, 1, passive.buf_gmaddr);
+        ret = alloc_xenoprof_struct(d, passive.max_samples, 1);
         if ( ret < 0 )
         {
             put_domain(d);
@@ -377,9 +404,14 @@ static int add_passive_list(XEN_GUEST_HA
         }
     }
 
-    share_xenoprof_page_with_guest(
+    ret = share_xenoprof_page_with_guest(
         current->domain, virt_to_mfn(d->xenoprof->rawbuf),
         d->xenoprof->npages);
+    if ( ret < 0 )
+    {
+        put_domain(d);
+        return ret;
+    }
 
     d->xenoprof->domain_type = XENOPROF_DOMAIN_PASSIVE;
     passive.nbuf = d->xenoprof->nbuf;
@@ -509,15 +541,15 @@ static int xenoprof_op_get_buffer(XEN_GU
      */
     if ( d->xenoprof == NULL )
     {
-        ret = alloc_xenoprof_struct(
-            d, xenoprof_get_buffer.max_samples, 0,
-            xenoprof_get_buffer.buf_gmaddr);
+        ret = alloc_xenoprof_struct(d, xenoprof_get_buffer.max_samples, 0);
         if ( ret < 0 )
             return ret;
     }
 
-    share_xenoprof_page_with_guest(
+    ret = share_xenoprof_page_with_guest(
         d, virt_to_mfn(d->xenoprof->rawbuf), d->xenoprof->npages);
+    if ( ret < 0 )
+        return ret;
 
     xenoprof_reset_buf(d);