WARNING - OLD ARCHIVES

This is an archived copy of the Xen.org mailing list, which we have preserved to ensure that existing links to archives are not broken. The live archive, which contains the latest emails, can be found at http://lists.xen.org/
   
 
 
Xen 
 
Home Products Support Community News
 
   
 

xen-devel

Re: [Xen-devel] Fwd: Fwd: [Xen-users] Shared memory between Dom0 and Dom

To: Pasi Kärkkäinen <pasik@xxxxxx>
Subject: Re: [Xen-devel] Fwd: Fwd: [Xen-users] Shared memory between Dom0 and DomU
From: Ian Campbell <Ian.Campbell@xxxxxxxxxx>
Date: Wed, 16 Mar 2011 08:03:02 +0000
Cc: "xen-users@xxxxxxxxxxxxxxxxxxx" <xen-users@xxxxxxxxxxxxxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>, MAYAP christine <christine.mayapkamga@xxxxxxxxxxx>, Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Delivery-date: Wed, 16 Mar 2011 01:05:23 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <20110316075847.GS32595@xxxxxxxxxxx>
List-help: <mailto:xen-devel-request@lists.xensource.com?subject=help>
List-id: Xen developer discussion <xen-devel.lists.xensource.com>
List-post: <mailto:xen-devel@lists.xensource.com>
List-subscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=subscribe>
List-unsubscribe: <http://lists.xensource.com/mailman/listinfo/xen-devel>, <mailto:xen-devel-request@lists.xensource.com?subject=unsubscribe>
Organization: Citrix Systems, Inc.
References: <4D78A1ED.8040403@xxxxxxxxxxx> <20110316031714.GB7905@xxxxxxxxxxxx> <20110316075847.GS32595@xxxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
On Wed, 2011-03-16 at 07:58 +0000, Pasi Kärkkäinen wrote:
> On Tue, Mar 15, 2011 at 11:17:14PM -0400, Konrad Rzeszutek Wilk wrote:
> > On Thu, Mar 10, 2011 at 11:03:25AM +0100, MAYAP christine wrote:
> > > Hello,
> > >
> > > I'm still reading document about inter-VM communication via shared memory.
> > > I found many reference about IVC.
> >
> > The IVC on I think is the XCP source code. Google for XCP source code
> > and you should find it.
> >
> 
> There's also V4V in Citrix XenClient.. sources available in the source iso.
> It includes xen patches, linux kernel patches, and user space libraries 
> providing a socket-like API (for linux and windows).

I wasn't aware of an IVC mechanisms in XCP so I suspect this is what
Konrad was thinking of.

Ian.

> 
> -- Pasi
> 
> > > Is it already present in Xen? How can i use them?
> >
> > You could also look at gntalloc driver.
> > Look in git://git.kernel.org/pub/scm/linux/kernel/git/konrad/xen.git 
> > #master tree.
> >
> >
> > I think it pretty much does what you want. Here is test code that
> > you can use to communicate between domains using mmap-ed memory.
> >
> >
> > Courtesy of Daniel De Graaf.
> >
> > #include <errno.h>
> > #include <fcntl.h>
> > #include <unistd.h>
> > #include <stdio.h>
> > #include <string.h>
> > #include <stdint.h>
> > #include <sys/ioctl.h>
> > #include <sys/mman.h>
> >
> > struct ioctl_gntdev_grant_ref {
> >       /* The domain ID of the grant to be mapped. */
> >       uint32_t domid;
> >       /* The grant reference of the grant to be mapped. */
> >       uint32_t ref;
> > };
> >
> > /*
> >  * Allocates a new page and creates a new grant reference.
> >  */
> > #define IOCTL_GNTALLOC_ALLOC_GREF \
> > _IOC(_IOC_NONE, 'G', 5, sizeof(struct ioctl_gntalloc_alloc_gref))
> > struct ioctl_gntalloc_alloc_gref {
> >       /* IN parameters */
> >       /* The ID of the domain to be given access to the grants. */
> >       uint16_t domid;
> >       /* Flags for this mapping */
> >       uint16_t flags;
> >       /* Number of pages to map */
> >       uint32_t count;
> >       /* OUT parameters */
> >       /* The offset to be used on a subsequent call to mmap(). */
> >       uint64_t index;
> >       /* The grant references of the newly created grant, one per page */
> >       /* Variable size, depending on count */
> >       uint32_t gref_ids[1];
> > };
> >
> > #define GNTALLOC_FLAG_WRITABLE 1
> >
> > /*
> >  * Deallocates the grant reference, allowing the associated page to be 
> > freed if
> >  * no other domains are using it.
> >  */
> > #define IOCTL_GNTALLOC_DEALLOC_GREF \
> > _IOC(_IOC_NONE, 'G', 6, sizeof(struct ioctl_gntalloc_dealloc_gref))
> > struct ioctl_gntalloc_dealloc_gref {
> >       /* IN parameters */
> >       /* The offset returned in the map operation */
> >       uint64_t index;
> >       /* Number of references to unmap */
> >       uint32_t count;
> > };
> >
> > #define IOCTL_GNTDEV_MAP_GRANT_REF \
> > _IOC(_IOC_NONE, 'G', 0, sizeof(struct ioctl_gntdev_map_grant_ref))
> > struct ioctl_gntdev_map_grant_ref {
> >     /* IN parameters */
> >     /* The number of grants to be mapped. */
> >     uint32_t count;
> >     uint32_t pad;
> >     /* OUT parameters */
> >     /* The offset to be used on a subsequent call to mmap(). */
> >     uint64_t index;
> >     /* Variable IN parameter. */
> >     /* Array of grant references, of size @count. */
> >     struct ioctl_gntdev_grant_ref refs[1];
> > };
> > #define GNTDEV_MAP_WRITABLE 0x1
> >
> > #define IOCTL_GNTDEV_UNMAP_GRANT_REF \
> > _IOC(_IOC_NONE, 'G', 1, sizeof(struct ioctl_gntdev_unmap_grant_ref))
> > struct ioctl_gntdev_unmap_grant_ref {
> >     /* IN parameters */
> >     /* The offset was returned by the corresponding map operation. */
> >     uint64_t index;
> >     /* The number of pages to be unmapped. */
> >     uint32_t count;
> >     uint32_t pad;
> > };
> >
> > /*
> >  * Sets up an unmap notification within the page, so that the other side 
> > can do
> >  * cleanup if this side crashes. Required to implement cross-domain robust
> >  * mutexes or close notification on communication channels.
> >  *
> >  * Each mapped page only supports one notification; multiple calls 
> > referring to
> >  * the same page overwrite the previous notification. You must clear the
> >  * notification prior to the IOCTL_GNTALLOC_DEALLOC_GREF if you do not want 
> > it
> >  * to occur.
> >  */
> > #define IOCTL_GNTDEV_SET_UNMAP_NOTIFY \
> > _IOC(_IOC_NONE, 'G', 7, sizeof(struct ioctl_gntdev_unmap_notify))
> > struct ioctl_gntdev_unmap_notify {
> >       /* IN parameters */
> >       /* Index of a byte in the page */
> >       uint64_t index;
> >       /* Action(s) to take on unmap */
> >       uint32_t action;
> >       /* Event channel to notify */
> >       uint32_t event_channel_port;
> > };
> >
> > /* Clear (set to zero) the byte specified by index */
> > #define UNMAP_NOTIFY_CLEAR_BYTE 0x1
> > /* Send an interrupt on the indicated event channel */
> > #define UNMAP_NOTIFY_SEND_EVENT 0x2
> >
> > /*
> >  * Sets up an unmap notification within the page, so that the other side 
> > can do
> >  * cleanup if this side crashes. Required to implement cross-domain robust
> >  * mutexes or close notification on communication channels.
> >  *
> >  * Each mapped page only supports one notification; multiple calls 
> > referring to
> >  * the same page overwrite the previous notification. You must clear the
> >  * notification prior to the IOCTL_GNTALLOC_DEALLOC_GREF if you do not want 
> > it
> >  * to occur.
> >  */
> > #define IOCTL_GNTALLOC_SET_UNMAP_NOTIFY \
> > _IOC(_IOC_NONE, 'G', 7, sizeof(struct ioctl_gntalloc_unmap_notify))
> > struct ioctl_gntalloc_unmap_notify {
> >       /* IN parameters */
> >       /* Index of a byte in the page */
> >       uint64_t index;
> >       /* Action(s) to take on unmap */
> >       uint32_t action;
> >       /* Event channel to notify */
> >       uint32_t event_channel_port;
> > };
> >
> > /* Clear (set to zero) the byte specified by index */
> > #define UNMAP_NOTIFY_CLEAR_BYTE 0x1
> > /* Send an interrupt on the indicated event channel */
> > #define UNMAP_NOTIFY_SEND_EVENT 0x2
> >
> > #ifndef offsetof
> > #define offsetof(TYPE, MEMBER) ((size_t) &((TYPE *)0)->MEMBER)
> > #endif
> >
> >
> > int a_fd;
> > int d_fd;
> >
> > struct shr_page {
> >       uint64_t id;
> >       char buffer[64];
> >       uint8_t notifies[8];
> > };
> >
> > struct data {
> >       struct shr_page* mem;
> >       int handle;
> > } items[128];
> >
> > void sa(int id)
> > {
> >       struct ioctl_gntalloc_alloc_gref arg = {
> >               .domid = id,
> >               .flags = GNTALLOC_FLAG_WRITABLE,
> >               .count = 1
> >       };
> >       int rv = ioctl(a_fd, IOCTL_GNTALLOC_ALLOC_GREF, &arg);
> >       if (rv) {
> >               printf("src-add error: %s (rv=%d)\n", strerror(errno), rv);
> >               return;
> >       }
> >       int i=0;
> >       while (items[i].mem) i++;
> >       items[i].mem = mmap(0, 4096, PROT_READ|PROT_WRITE, MAP_SHARED, a_fd, 
> > arg.index);
> >       if (items[i].mem == MAP_FAILED) {
> >               items[i].mem = 0;
> >               printf("mmap failed: SHOULD NOT HAPPEN\n");
> >               return;
> >       }
> >       items[i].handle = arg.index;
> >       printf("Created shared page with domain %d, grant #%d. Mapped locally 
> > at %d=%p\n",
> >               id, arg.gref_ids[0], arg.index, items[i].mem);
> >
> >       items[i].mem->id = rand() | ((long)(getpid()) << 32);
> >       items[i].mem->notifies[0] = 1;
> >       struct ioctl_gntalloc_unmap_notify uarg = {
> >               .index = arg.index + offsetof(struct shr_page, notifies[0]),
> >               .action = UNMAP_NOTIFY_CLEAR_BYTE
> >       };
> >       rv = ioctl(a_fd, IOCTL_GNTALLOC_SET_UNMAP_NOTIFY, &uarg);
> >       if (rv)
> >               printf("gntalloc unmap notify error: %s (rv=%d)\n", 
> > strerror(errno), rv);
> > }
> >
> > void sd(int ref) {
> >       struct ioctl_gntalloc_dealloc_gref arg = {
> >               .index = ref,
> >               .count = 1
> >       };
> >
> >       int rv = ioctl(a_fd, IOCTL_GNTALLOC_DEALLOC_GREF, &arg);
> >       if (rv)
> >               printf("src-del error: %s (rv=%d)\n", strerror(errno), rv);
> >       else
> >               printf("Stopped offering grant at offset %d\n", ref);
> > }
> >
> > void mm(int domid, int refid) {
> >       struct ioctl_gntdev_map_grant_ref arg = {
> >               .count = 1,
> >               .refs[0].domid = domid,
> >               .refs[0].ref = refid,
> >       };
> >       int rv = ioctl(d_fd, IOCTL_GNTDEV_MAP_GRANT_REF, &arg);
> >       if (rv) {
> >               printf("Could not map grant %d.%d: %s (rv=%d)\n", domid, 
> > refid, strerror(errno), rv);
> >               return;
> >       }
> >       int i=0,j=1;
> >       while (items[i].mem) i++;
> >       items[i].mem = mmap(0, 4096, PROT_READ|PROT_WRITE, MAP_SHARED, d_fd, 
> > arg.index);
> >       if (items[i].mem == MAP_FAILED) {
> >               items[i].mem = 0;
> >               printf("Could not map grant %d.%d: %s (map failed)\n", domid, 
> > refid, strerror(errno), rv);
> >               return;
> >       }
> >       items[i].handle = arg.index;
> >       printf("Mapped grant %d.%d as %d=%p\n", domid, refid, arg.index, 
> > items[i].mem);
> >
> >       while (items[i].mem->notifies[j]) j++;
> >       items[i].mem->notifies[j] = 1;
> >       struct ioctl_gntalloc_unmap_notify uarg = {
> >               .index = arg.index + offsetof(struct shr_page, notifies[j]),
> >               .action = UNMAP_NOTIFY_CLEAR_BYTE
> >       };
> >       rv = ioctl(d_fd, IOCTL_GNTDEV_SET_UNMAP_NOTIFY, &uarg);
> >       if (rv)
> >               printf("gntdev unmap notify error: %s (rv=%d)\n", 
> > strerror(errno), rv);
> > }
> >
> > void gu(int index) {
> >       struct ioctl_gntdev_unmap_grant_ref arg = {
> >               .index = index,
> >               .count = 1,
> >       };
> >       int rv = ioctl(d_fd, IOCTL_GNTDEV_UNMAP_GRANT_REF, &arg);
> >       if (rv)
> >               printf("gu error: %s (rv=%d)\n", strerror(errno), rv);
> >       else
> >               printf("Unhooked mapped grant at offset %d\n", index);
> > }
> >
> > void mu(void* addr) {
> >       int i = 0;
> >       munmap(addr, 4096);
> >       while (i < 128)
> >       {
> >               if (items[i].mem == addr)
> >                       items[i].mem = 0;
> >               i++;
> >       }
> >       printf("Unmapped page at %p\n", addr);
> > }
> >
> > void show(char* word) {
> >       int i;
> >       int wlen = strlen(word);
> >       for(i=0; i < 128; i++) {
> >               if (!items[i].mem)
> >                       continue;
> >               memmove(items[i].mem->buffer + wlen, items[i].mem->buffer, 63 
> > - wlen);
> >               memcpy(items[i].mem->buffer, word, wlen);
> >               printf("%02d(%ld,%d): id %16lx n=%d%d%d%d%d%d%d%d b=%s\n",
> >                       i, items[i].mem, items[i].handle, items[i].mem->id,
> >                       items[i].mem->notifies[0], items[i].mem->notifies[1], 
> > items[i].mem->notifies[2], items[i].mem->notifies[3],
> >                       items[i].mem->notifies[4], items[i].mem->notifies[5], 
> > items[i].mem->notifies[6], items[i].mem->notifies[7],
> >                       items[i].mem->buffer);
> >       }
> >       printf("END\n");
> > }
> >
> > int main(int argc, char** argv) {
> >       a_fd = open("/dev/xen/gntalloc", O_RDWR);
> >       d_fd = open("/dev/xen/gntdev", O_RDWR);
> >       printf(
> >               "add <domid>           return gntref, address\n"
> >               "map <domid> <ref>     return index, address\n"
> >               "adel <gntref>         delete <add> internal\n"
> >               "ddel <index>          delete <map> internal\n"
> >               "unmap <address>       unmap memory\n"
> >               "show                  show all pages\n"
> >               "<word>                append word to all mapped pages, 
> > show\n"
> >               " PID %x\n", getpid()
> >       );
> >       while (1) {
> >               char line[80];
> >               char word[80];
> >               long a, b;
> >               printf("\n> ");
> >               fflush(stdout);
> >               fgets(line, 80, stdin);
> >               sscanf(line, "%s %ld %ld", word, &a, &b);
> >               if (!strcmp(word, "add")) {
> >                       sa(a);
> >               } else if (!strcmp(word, "map")) {
> >                       mm(a, b);
> >               } else if (!strcmp(word, "adel")) {
> >                       sd(a);
> >               } else if (!strcmp(word, "ddel")) {
> >                       gu(a);
> >               } else if (!strcmp(word, "unmap")) {
> >                       mu((void*)a);
> >               } else if (!strcmp(word, "show")) {
> >                       show("");
> >               } else {
> >                       show(word);
> >               }
> >       }
> > }
> > >
> > > I really need some explanations .
> > > Thanks!
> > >
> > >
> > >
> > > -------- Message original --------
> > > Sujet:      Fwd: [Xen-users] Shared memory between Dom0 and DomU
> > > Date :      Wed, 09 Mar 2011 15:12:06 +0100
> > > De :        MAYAP christine <christine.mayapkamga@xxxxxxxxxxx>
> > > Pour :      xen-devel@xxxxxxxxxxxxxxxxxxx, xen-users@xxxxxxxxxxxxxxxxxxx
> > >
> > >
> > >
> > > Hello
> > >
> > > While waiting for some help, i continued to google about this topic.
> > > In fact, i want two distinct process (one on the Dom0 and the second
> > > one on the DomU) to be able the read or write in a share memory.
> > >
> > > Many post are talking about granting permissions or grant table.
> > >
> > > I'm sorry if my question is a bit stupid. Where would i start to be
> > > able the test those grant permission?
> > > Should i need to write an external program or should i modify some
> > > Xen source codes?
> > >
> > > I really have no idea about where to start.
> > > I'll sincerely appreciate any idea. Even one stating where to start.
> > >
> > > Thanks in advance!
> > >
> > > -------- Message original --------
> > > Sujet:      [Xen-users] Shared memory between Dom0 and DomU
> > > Date :      Wed, 09 Mar 2011 13:07:19 +0100
> > > De :        MAYAP christine <christine.mayapkamga@xxxxxxxxxxx>
> > > Pour :      xen-devel@xxxxxxxxxxxxxxxxxxx, xen-users@xxxxxxxxxxxxxxxxxxx
> > >
> > >
> > >
> > > HI,
> > >
> > > I'm a newbie in using shared memory with Xen. I was usually unsing it
> > > between process on a same Computer.
> > >
> > > Please, can i have some usefull links abour sharing memoru betwen Dom0
> > > and DomU first and between DomU.
> > >
> > > I'm able to give more informations if needed!
> > >
> > > Cheers!
> > >
> > > --
> > > MAYAP Christine
> > > IRIT/ENSEEIHT
> > > 2 rue Charles Camichel - BP 7122
> > > 31071 Toulouse cedex  7
> > >
> > >
> > > _______________________________________________
> > > Xen-users mailing list
> > > Xen-users@xxxxxxxxxxxxxxxxxxx
> > > http://lists.xensource.com/xen-users
> > >
> >
> > > _______________________________________________
> > > Xen-users mailing list
> > > Xen-users@xxxxxxxxxxxxxxxxxxx
> > > http://lists.xensource.com/xen-users
> >
> > > _______________________________________________
> > > Xen-devel mailing list
> > > Xen-devel@xxxxxxxxxxxxxxxxxxx
> > > http://lists.xensource.com/xen-devel
> >
> >
> > _______________________________________________
> > Xen-devel mailing list
> > Xen-devel@xxxxxxxxxxxxxxxxxxx
> > http://lists.xensource.com/xen-devel
> 
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxxxxxxxx
> http://lists.xensource.com/xen-devel



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