[Xen-devel] xsd_kva mmap

[Chris Wright <chrisw@xxxxxxxxxxxx>]

Hi Keir,

I did an almost identical patch to yours for xsd_kva mmap.  You'll find
it below.  I just saw the conflict when updating, and think that we
may want to merge approaches.  Main difference is in populating the
ops, and making xsd_kva rdwr.  The first is just cleanup, the second I
don't believe is functional in your version.  Can't open rdwr and mmap
PROT_READ|PROT_WRITE and 0400 file.  Also, I just drop the read interface
entirely, as it's no longer needed.  I'll follow this up with the actual
diff between the two.

thanks,
-chris
--

Make xsd_kva provide its own mmap interface.  Eliminates reliance on
/dev/kmem which is not installed by default in some distros.

Signed-off-by: Chris Wright <chrisw@xxxxxxxxxxxx>
---

 linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_probe.c |   28 
+++++++++-------- tools/xenstore/xenstored_domain.c                      |   23 
+++----------
 2 files changed, 21 insertions(+), 30 deletions(-)

diff -r 1c46091df7ce linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_probe.c
--- a/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_probe.c    Fri Mar  3 
19:06:50 2006 +0100
+++ b/linux-2.6-xen-sparse/drivers/xen/xenbus/xenbus_probe.c    Sat Mar  4 
17:31:03 2006 -0800
@@ -951,18 +951,22 @@
 }
 
 
+static int xsd_kva_mmap (struct file *filp, struct vm_area_struct *vma)
+{
+       unsigned long size = vma->vm_end - vma->vm_start;
+       unsigned long pfn = mfn_to_pfn(xen_start_info->store_mfn);
+
+       if (vma->vm_pgoff || size > PAGE_SIZE)
+               return -EINVAL;
+
+       return remap_pfn_range(vma, vma->vm_start, pfn , size, 
vma->vm_page_prot);
+}
+
+static struct file_operations xsd_kva_fops = {
+       .mmap   = xsd_kva_mmap,
+};
 static struct proc_dir_entry *xsd_kva_intf;
 static struct proc_dir_entry *xsd_port_intf;
-
-
-static int xsd_kva_read(char *page, char **start, off_t off,
-                        int count, int *eof, void *data)
-{
-       int len;
-       len  = sprintf(page, "0x%p", mfn_to_virt(xen_start_info->store_mfn));
-       *eof = 1;
-       return len;
-}
 
 static int xsd_port_read(char *page, char **start, off_t off,
                         int count, int *eof, void *data)
@@ -1027,8 +1031,8 @@
                xen_start_info->store_evtchn = op.u.alloc_unbound.port;
 
                /* And finally publish the above info in /proc/xen */
-               if((xsd_kva_intf = create_xen_proc_entry("xsd_kva", 0400)))
-                       xsd_kva_intf->read_proc = xsd_kva_read;
+               if((xsd_kva_intf = create_xen_proc_entry("xsd_kva", 0600)))
+                       xsd_kva_intf->proc_fops = &xsd_kva_fops;
                if((xsd_port_intf = create_xen_proc_entry("xsd_port", 0400)))
                        xsd_port_intf->read_proc = xsd_port_read;
        }
diff -r 1c46091df7ce tools/xenstore/xenstored_domain.c
--- a/tools/xenstore/xenstored_domain.c Fri Mar  3 19:06:50 2006 +0100
+++ b/tools/xenstore/xenstored_domain.c Sat Mar  4 17:31:03 2006 -0800
@@ -466,21 +466,8 @@
 { 
        int rc, fd;
        evtchn_port_t port; 
-       unsigned long kva; 
        char str[20]; 
        struct domain *dom0; 
-
-       fd = open(XENSTORED_PROC_KVA, O_RDONLY); 
-       if (fd == -1)
-               return -1;
-
-       rc = read(fd, str, sizeof(str)); 
-       if (rc == -1)
-               goto outfd;
-       str[rc] = '\0'; 
-       kva = strtoul(str, NULL, 0); 
-
-       close(fd); 
 
        fd = open(XENSTORED_PROC_PORT, O_RDONLY); 
        if (fd == -1)
@@ -494,14 +481,14 @@
 
        close(fd); 
 
-       dom0 = new_domain(NULL, 0, port); 
-
-       fd = open(_PATH_KMEM, O_RDWR);
+       fd = open(XENSTORED_PROC_KVA, O_RDWR); 
        if (fd == -1)
                return -1;
 
-       dom0->interface = mmap(NULL, getpagesize(), PROT_READ|PROT_WRITE,
-                              MAP_SHARED, fd, kva);
+       dom0 = new_domain(NULL, 0, port); 
+
+       dom0->interface = mmap(NULL, getpagesize(), PROT_READ|PROT_WRITE, 
MAP_SHARED,
+                               fd, 0);
        if (dom0->interface == MAP_FAILED)
                goto outfd;
 

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxxxxxxxx
http://lists.xensource.com/xen-devel