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.
>
> /* 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;
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