[2/2] tools/libs/gnttab: decouple more from mini-os

Commit Message

Jürgen Groß Jan. 7, 2022, 10:35 a.m. UTC

libgnttab is using implementation details of Mini-OS. Change that by
letting libgnttab use the new get_file_from_fd() function and the
generic dev pointer of struct file from Mini-OS.

Signed-off-by: Juergen Gross <[e-mail]>
---
 tools/libs/gnttab/minios.c | 48 ++++++++++++++++++++++++++------------
 1 file changed, 33 insertions(+), 15 deletions(-)

Comments

Andrew Cooper Jan. 10, 2022, 6:56 p.m. UTC | #1

On 07/01/2022 10:35, Juergen Gross wrote:
> @@ -54,8 +70,11 @@ int osdep_gnttab_close(xengnttab_handle *xgt)
>  
>  void minios_gnttab_close_fd(int fd)
>  {
> -    gntmap_fini(&files[fd].gntmap);
> -    files[fd].type = FTYPE_NONE;
> +    struct file *file = get_file_from_fd(fd);
> +
> +    gntmap_fini(file->dev);
> +    free(file->dev);

file->dev = NULL ?

Particularly as this is a pointer in a global files[] array.

Otherwise, LGTM.

~Andrew

Jürgen Groß Jan. 11, 2022, 6:10 a.m. UTC | #2

On 10.01.22 19:56, Andrew Cooper wrote:
> On 07/01/2022 10:35, Juergen Gross wrote:
>> @@ -54,8 +70,11 @@ int osdep_gnttab_close(xengnttab_handle *xgt)
>>   
>>   void minios_gnttab_close_fd(int fd)
>>   {
>> -    gntmap_fini(&files[fd].gntmap);
>> -    files[fd].type = FTYPE_NONE;
>> +    struct file *file = get_file_from_fd(fd);
>> +
>> +    gntmap_fini(file->dev);
>> +    free(file->dev);
> 
> file->dev = NULL ?
> 
> Particularly as this is a pointer in a global files[] array.

I'll reset all the struct file contents in close() for all file types.


Juergen

Patch

diff --git a/tools/libs/gnttab/minios.c b/tools/libs/gnttab/minios.c
index f78caadd30..64601db085 100644
--- a/tools/libs/gnttab/minios.c
+++ b/tools/libs/gnttab/minios.c
@@ -28,6 +28,7 @@ 
 #include <sys/mman.h>
 
 #include <errno.h>
+#include <malloc.h>
 #include <unistd.h>
 
 #include "private.h"
@@ -36,10 +37,25 @@  void minios_gnttab_close_fd(int fd);
 
 int osdep_gnttab_open(xengnttab_handle *xgt)
 {
-    int fd = alloc_fd(FTYPE_GNTMAP);
-    if ( fd == -1 )
+    int fd;
+    struct file *file;
+    struct gntmap *gntmap;
+
+    gntmap = malloc(sizeof(*gntmap));
+    if ( !gntmap )
         return -1;
-    gntmap_init(&files[fd].gntmap);
+
+    fd = alloc_fd(FTYPE_GNTMAP);
+    file = get_file_from_fd(fd);
+
+    if ( !file )
+    {
+        free(gntmap);
+        return -1;
+    }
+
+    file->dev = gntmap;
+    gntmap_init(gntmap);
     xgt->fd = fd;
     return 0;
 }
@@ -54,8 +70,11 @@  int osdep_gnttab_close(xengnttab_handle *xgt)
 
 void minios_gnttab_close_fd(int fd)
 {
-    gntmap_fini(&files[fd].gntmap);
-    files[fd].type = FTYPE_NONE;
+    struct file *file = get_file_from_fd(fd);
+
+    gntmap_fini(file->dev);
+    free(file->dev);
+    file->type = FTYPE_NONE;
 }
 
 void *osdep_gnttab_grant_map(xengnttab_handle *xgt,
@@ -64,16 +83,16 @@  void *osdep_gnttab_grant_map(xengnttab_handle *xgt,
                              uint32_t notify_offset,
                              evtchn_port_t notify_port)
 {
-    int fd = xgt->fd;
+    struct file *file = get_file_from_fd(xgt->fd);
     int stride = 1;
+
     if (flags & XENGNTTAB_GRANT_MAP_SINGLE_DOMAIN)
         stride = 0;
     if (notify_offset != -1 || notify_port != -1) {
         errno = ENOSYS;
         return NULL;
     }
-    return gntmap_map_grant_refs(&files[fd].gntmap,
-                                 count, domids, stride,
+    return gntmap_map_grant_refs(file->dev, count, domids, stride,
                                  refs, prot & PROT_WRITE);
 }
 
@@ -81,11 +100,10 @@  int osdep_gnttab_unmap(xengnttab_handle *xgt,
                        void *start_address,
                        uint32_t count)
 {
-    int fd = xgt->fd;
+    struct file *file = get_file_from_fd(xgt->fd);
     int ret;
-    ret = gntmap_munmap(&files[fd].gntmap,
-                        (unsigned long) start_address,
-                        count);
+
+    ret = gntmap_munmap(file->dev, (unsigned long) start_address, count);
     if (ret < 0) {
         errno = -ret;
         return -1;
@@ -95,10 +113,10 @@  int osdep_gnttab_unmap(xengnttab_handle *xgt,
 
 int osdep_gnttab_set_max_grants(xengnttab_handle *xgt, uint32_t count)
 {
-    int fd = xgt->fd;
+    struct file *file = get_file_from_fd(xgt->fd);
     int ret;
-    ret = gntmap_set_max_grants(&files[fd].gntmap,
-                                count);
+
+    ret = gntmap_set_max_grants(file->dev, count);
     if (ret < 0) {
         errno = -ret;
         return -1;