Re: [Xen-devel] [PATCH 5/6] xen/pvh: balloon and grant changes.

[Stefano Stabellini <stefano.stabellini@xxxxxxxxxxxxx>]

On Sat, 20 Oct 2012, Konrad Rzeszutek Wilk wrote:
> From: Mukesh Rathor <mukesh.rathor@xxxxxxxxxx>
> 
> For balloon changes we skip setting of local P2M as it's updated
> in Xen. For grant, the shared grant frame is the pfn and not mfn,
> hence its mapped via the same code path as HVM.
> 
> Signed-off-by: Mukesh Rathor <mukesh.rathor@xxxxxxxxxx>
> Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
> ---
>  drivers/xen/balloon.c     |   15 +++++++++------
>  drivers/xen/gntdev.c      |    3 ++-
>  drivers/xen/grant-table.c |   26 ++++++++++++++++++++++----
>  3 files changed, 33 insertions(+), 11 deletions(-)
> 
> diff --git a/drivers/xen/balloon.c b/drivers/xen/balloon.c
> index 31ab82f..c825b63 100644
> --- a/drivers/xen/balloon.c
> +++ b/drivers/xen/balloon.c
> @@ -361,7 +361,9 @@ static enum bp_state increase_reservation(unsigned long 
> nr_pages)
>               set_phys_to_machine(pfn, frame_list[i]);
>  
>               /* Link back into the page tables if not highmem. */
> -             if (xen_pv_domain() && !PageHighMem(page)) {
> +             if (xen_pv_domain() && !PageHighMem(page) &&
> +                 !xen_feature(XENFEAT_auto_translated_physmap)) {
> +
>                       int ret;
>                       ret = HYPERVISOR_update_va_mapping(
>                               (unsigned long)__va(pfn << PAGE_SHIFT),
> @@ -418,12 +420,13 @@ static enum bp_state decrease_reservation(unsigned long 
> nr_pages, gfp_t gfp)
>               scrub_page(page);
>  
>               if (xen_pv_domain() && !PageHighMem(page)) {
> -                     ret = HYPERVISOR_update_va_mapping(
> -                             (unsigned long)__va(pfn << PAGE_SHIFT),
> -                             __pte_ma(0), 0);
> -                     BUG_ON(ret);
> +                     if (!xen_feature(XENFEAT_auto_translated_physmap)) {
> +                             ret = HYPERVISOR_update_va_mapping(
> +                                     (unsigned long)__va(pfn << PAGE_SHIFT),
> +                                     __pte_ma(0), 0);
> +                             BUG_ON(ret);
> +                     }
>               }

this change, unlike the one before, actually makes things different for
traditional pv domains in case PageHighMem(page).

The rest looks good.

>       }
>  
>       /* Ensure that ballooned highmem pages don't have kmaps. */
> diff --git a/drivers/xen/gntdev.c b/drivers/xen/gntdev.c
> index 610bfc6..d39d54e 100644
> --- a/drivers/xen/gntdev.c
> +++ b/drivers/xen/gntdev.c
> @@ -803,7 +803,8 @@ static int __init gntdev_init(void)
>       if (!xen_domain())
>               return -ENODEV;
>  
> -     use_ptemod = xen_pv_domain();
> +     use_ptemod = xen_pv_domain() &&
> +                  !xen_feature(XENFEAT_auto_translated_physmap);
>  
>       err = misc_register(&gntdev_miscdev);
>       if (err != 0) {
> diff --git a/drivers/xen/grant-table.c b/drivers/xen/grant-table.c
> index b2b0a37..9c0019d 100644
> --- a/drivers/xen/grant-table.c
> +++ b/drivers/xen/grant-table.c
> @@ -1029,14 +1029,19 @@ static void gnttab_unmap_frames_v2(void)
>  static int gnttab_map(unsigned int start_idx, unsigned int end_idx)
>  {
>       struct gnttab_setup_table setup;
> -     unsigned long *frames;
> +     unsigned long *frames, start_gpfn;
>       unsigned int nr_gframes = end_idx + 1;
>       int rc;
>  
> -     if (xen_hvm_domain()) {
> +     if (xen_hvm_domain() || xen_feature(XENFEAT_auto_translated_physmap)) {
>               struct xen_add_to_physmap xatp;
>               unsigned int i = end_idx;
>               rc = 0;
> +
> +             if (xen_hvm_domain())
> +                     start_gpfn = xen_hvm_resume_frames >> PAGE_SHIFT;
> +             else
> +                     start_gpfn = virt_to_pfn(gnttab_shared.addr);
>               /*
>                * Loop backwards, so that the first hypercall has the largest
>                * index, ensuring that the table will grow only once.
> @@ -1045,7 +1050,7 @@ static int gnttab_map(unsigned int start_idx, unsigned 
> int end_idx)
>                       xatp.domid = DOMID_SELF;
>                       xatp.idx = i;
>                       xatp.space = XENMAPSPACE_grant_table;
> -                     xatp.gpfn = (xen_hvm_resume_frames >> PAGE_SHIFT) + i;
> +                     xatp.gpfn = start_gpfn + i;
>                       rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap, &xatp);
>                       if (rc != 0) {
>                               printk(KERN_WARNING
> @@ -1108,7 +1113,7 @@ static void gnttab_request_version(void)
>       int rc;
>       struct gnttab_set_version gsv;
>  
> -     if (xen_hvm_domain())
> +     if (xen_hvm_domain() || xen_feature(XENFEAT_auto_translated_physmap))
>               gsv.version = 1;
>       else
>               gsv.version = 2;
> @@ -1136,12 +1141,25 @@ static void gnttab_request_version(void)
>  int gnttab_resume(void)
>  {
>       unsigned int max_nr_gframes;
> +     char *kmsg = "Failed to kmalloc pages for pv in hvm grant frames\n";
>  
>       gnttab_request_version();
>       max_nr_gframes = gnttab_max_grant_frames();
>       if (max_nr_gframes < nr_grant_frames)
>               return -ENOSYS;
>  
> +     /* PVH note: xen will free existing kmalloc'd mfn in
> +      * XENMEM_add_to_physmap. TBD/FIXME: use xen ballooning instead of
> +      * kmalloc(). */
> +     if (xen_pv_domain() && xen_feature(XENFEAT_auto_translated_physmap) &&
> +         !gnttab_shared.addr) {
> +             gnttab_shared.addr =
> +                     kmalloc(max_nr_gframes * PAGE_SIZE, GFP_KERNEL);
> +             if (!gnttab_shared.addr) {
> +                     pr_warn("%s", kmsg);
> +                     return -ENOMEM;
> +             }
> +     }
>       if (xen_pv_domain())
>               return gnttab_map(0, nr_grant_frames - 1);
>  
> -- 
> 1.7.7.6
> 

_______________________________________________
Xen-devel mailing list
Xen-devel@xxxxxxxxxxxxx
http://lists.xen.org/xen-devel