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] [PATCH 1/5] xen/netback: Use xenballooned pages for comm

To: David Vrabel <david.vrabel@xxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH 1/5] xen/netback: Use xenballooned pages for comms
From: Ian Campbell <Ian.Campbell@xxxxxxxxxx>
Date: Wed, 19 Oct 2011 16:12:45 +0100
Cc: Daniel De Graaf <dgdegra@xxxxxxxxxxxxx>, "xen-devel@xxxxxxxxxxxxxxxxxxx" <xen-devel@xxxxxxxxxxxxxxxxxxx>, Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Delivery-date: Wed, 19 Oct 2011 08:16:31 -0700
Envelope-to: www-data@xxxxxxxxxxxxxxxxxxx
In-reply-to: <4E9EA8D9.5060708@xxxxxxxxxx>
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: <1318969583-23902-1-git-send-email-dgdegra@xxxxxxxxxxxxx> <1318969583-23902-2-git-send-email-dgdegra@xxxxxxxxxxxxx> <1319015064.3385.80.camel@xxxxxxxxxxxxxxxxxxxxxx> <4E9EA8D9.5060708@xxxxxxxxxx>
Sender: xen-devel-bounces@xxxxxxxxxxxxxxxxxxx
On Wed, 2011-10-19 at 11:39 +0100, David Vrabel wrote:
> On 19/10/11 10:04, Ian Campbell wrote:
> > On Tue, 2011-10-18 at 21:26 +0100, Daniel De Graaf wrote:
> >> For proper grant mappings, HVM guests require pages allocated using
> >> alloc_xenballooned_pages instead of alloc_vm_area.
> >>
> >> Signed-off-by: Daniel De Graaf <dgdegra@xxxxxxxxxxxxx>
> >> ---
> >>  drivers/net/xen-netback/common.h  |    4 ++--
> >>  drivers/net/xen-netback/netback.c |   34 
> >> ++++++++++++++++++++--------------
> >>  2 files changed, 22 insertions(+), 16 deletions(-)
> >>
> >> diff --git a/drivers/net/xen-netback/common.h 
> >> b/drivers/net/xen-netback/common.h
> >> index 161f207..d5ee9d1 100644
> >> --- a/drivers/net/xen-netback/common.h
> >> +++ b/drivers/net/xen-netback/common.h
> >> @@ -70,8 +70,8 @@ struct xenvif {
> >>    /* The shared rings and indexes. */
> >>    struct xen_netif_tx_back_ring tx;
> >>    struct xen_netif_rx_back_ring rx;
> >> -  struct vm_struct *tx_comms_area;
> >> -  struct vm_struct *rx_comms_area;
> >> +  struct page *tx_comms_page;
> >> +  struct page *rx_comms_page;
> > 
> > This will conflict with David Vrabel's patch "net: xen-netback: use API
> > provided by xenbus module to map rings", which I've just noticed hasn't
> > been committed anywhere.
> > 
> > I suspect that building on David's patches (that series does something
> > similar to blkback too) will greatly simplify this one since you can
> > just patch xenbus_map_ring_valloc and friends.
> > 
> > Could you also explain where the requirement to use xenballooned pages
> > and not alloc_vm_area comes from in your commit message.
> > 
> > David, I guess you should resend your series now that everyone is happy
> > with it. If you cc the netback one to netdev@ with my Ack then Dave
> > Miller will pick it up into his tree (it stands alone, right?). The
> > blkback and grant-table ones go via Konrad I think. I suspect the last
> > one needs to go via akpm, or at least with his Ack.
> 
> I thought Konrad had picked them all up -- they were on his stuff queued
> for 3.2 list.

Perhaps, git://oss.oracle.com doesn't seem to be responding so I can't
tell. In any case the netback stuff ought to go via David Miller.

Ian.

> 
> > 
> >>  
> >>    /* Frontend feature information. */
> >>    u8 can_sg:1;
> >> diff --git a/drivers/net/xen-netback/netback.c 
> >> b/drivers/net/xen-netback/netback.c
> >> index fd00f25..f35e07c 100644
> >> --- a/drivers/net/xen-netback/netback.c
> >> +++ b/drivers/net/xen-netback/netback.c
> >> @@ -42,6 +42,7 @@
> >>  
> >>  #include <xen/events.h>
> >>  #include <xen/interface/memory.h>
> >> +#include <xen/balloon.h>
> >>  
> >>  #include <asm/xen/hypercall.h>
> >>  #include <asm/xen/page.h>
> >> @@ -1578,9 +1579,11 @@ static int xen_netbk_kthread(void *data)
> >>  void xen_netbk_unmap_frontend_rings(struct xenvif *vif)
> >>  {
> >>    struct gnttab_unmap_grant_ref op;
> >> +  void *addr;
> >>  
> >>    if (vif->tx.sring) {
> >> -          gnttab_set_unmap_op(&op, (unsigned 
> >> long)vif->tx_comms_area->addr,
> >> +          addr = pfn_to_kaddr(page_to_pfn(vif->tx_comms_page));
> >> +          gnttab_set_unmap_op(&op, (unsigned long)addr,
> >>                                GNTMAP_host_map, vif->tx_shmem_handle);
> >>  
> >>            if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1))
> >> @@ -1588,16 +1591,17 @@ void xen_netbk_unmap_frontend_rings(struct xenvif 
> >> *vif)
> >>    }
> >>  
> >>    if (vif->rx.sring) {
> >> -          gnttab_set_unmap_op(&op, (unsigned 
> >> long)vif->rx_comms_area->addr,
> >> +          addr = pfn_to_kaddr(page_to_pfn(vif->rx_comms_page));
> >> +          gnttab_set_unmap_op(&op, (unsigned long)addr,
> >>                                GNTMAP_host_map, vif->rx_shmem_handle);
> >>  
> >>            if (HYPERVISOR_grant_table_op(GNTTABOP_unmap_grant_ref, &op, 1))
> >>                    BUG();
> >>    }
> >> -  if (vif->rx_comms_area)
> >> -          free_vm_area(vif->rx_comms_area);
> >> -  if (vif->tx_comms_area)
> >> -          free_vm_area(vif->tx_comms_area);
> >> +  if (vif->rx_comms_page)
> >> +          free_xenballooned_pages(1, &vif->rx_comms_page);
> >> +  if (vif->tx_comms_page)
> >> +          free_xenballooned_pages(1, &vif->tx_comms_page);
> >>  }
> >>  
> >>  int xen_netbk_map_frontend_rings(struct xenvif *vif,
> >> @@ -1610,15 +1614,19 @@ int xen_netbk_map_frontend_rings(struct xenvif 
> >> *vif,
> >>  
> >>    int err = -ENOMEM;
> >>  
> >> -  vif->tx_comms_area = alloc_vm_area(PAGE_SIZE);
> >> -  if (vif->tx_comms_area == NULL)
> >> +  if (alloc_xenballooned_pages(1, &vif->tx_comms_page))
> >>            goto err;
> >>  
> >> -  vif->rx_comms_area = alloc_vm_area(PAGE_SIZE);
> >> -  if (vif->rx_comms_area == NULL)
> >> +  txs = (struct xen_netif_tx_sring *)pfn_to_kaddr(page_to_pfn(
> >> +                  vif->tx_comms_page));
> >> +
> >> +  if (alloc_xenballooned_pages(1, &vif->rx_comms_page))
> >>            goto err;
> >>  
> >> -  gnttab_set_map_op(&op, (unsigned long)vif->tx_comms_area->addr,
> >> +  rxs = (struct xen_netif_rx_sring *)pfn_to_kaddr(page_to_pfn(
> >> +                  vif->rx_comms_page));
> >> +
> >> +  gnttab_set_map_op(&op, (unsigned long)txs,
> >>                      GNTMAP_host_map, tx_ring_ref, vif->domid);
> >>  
> >>    if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
> >> @@ -1635,10 +1643,9 @@ int xen_netbk_map_frontend_rings(struct xenvif *vif,
> >>    vif->tx_shmem_ref    = tx_ring_ref;
> >>    vif->tx_shmem_handle = op.handle;
> >>  
> >> -  txs = (struct xen_netif_tx_sring *)vif->tx_comms_area->addr;
> >>    BACK_RING_INIT(&vif->tx, txs, PAGE_SIZE);
> >>  
> >> -  gnttab_set_map_op(&op, (unsigned long)vif->rx_comms_area->addr,
> >> +  gnttab_set_map_op(&op, (unsigned long)rxs,
> >>                      GNTMAP_host_map, rx_ring_ref, vif->domid);
> >>  
> >>    if (HYPERVISOR_grant_table_op(GNTTABOP_map_grant_ref, &op, 1))
> >> @@ -1656,7 +1663,6 @@ int xen_netbk_map_frontend_rings(struct xenvif *vif,
> >>    vif->rx_shmem_handle  = op.handle;
> >>    vif->rx_req_cons_peek = 0;
> >>  
> >> -  rxs = (struct xen_netif_rx_sring *)vif->rx_comms_area->addr;
> >>    BACK_RING_INIT(&vif->rx, rxs, PAGE_SIZE);
> >>  
> >>    return 0;
> > 
> > 
> 



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

<Prev in Thread] Current Thread [Next in Thread>