Re: [Xen-devel] [PATCH V2 7/7]: PVH: privcmd changes.

From: Ian Campbell
Date: Fri Oct 12 2012 - 05:11:18 EST


> @@ -260,15 +268,24 @@ struct mmap_batch_state {
> xen_pfn_t __user *user_mfn;
> };
>
> +/* auto translated dom0 note: if domU being created is PV, then mfn is
> + * mfn(addr on bus). If it's auto xlated, then mfn is pfn (input to HAP).
> + */
> static int mmap_batch_fn(void *data, void *state)
> {
> xen_pfn_t *mfnp = data;
> struct mmap_batch_state *st = state;
> + struct vm_area_struct *vma = st->vma;
> + struct page **pages = vma->vm_private_data;
> + struct page *cur_page = NULL;
> int ret;
>
> + if (xen_feature(XENFEAT_auto_translated_physmap))
> + cur_page = pages[st->index++];

Shame we can't pass the batchiness of mmap_batch_fn through to
remap_domain_mfn_range. Perhaps one for future work.

> +
> ret = xen_remap_domain_mfn_range(st->vma, st->va & PAGE_MASK, *mfnp, 1,
> st->vma->vm_page_prot, st->domain,
> - NULL);
> + &cur_page);
>
> /* Store error code for second pass. */
> *(st->err++) = ret;
> @@ -439,6 +490,20 @@ static long privcmd_ioctl(struct file *file,
> return ret;
> }
>
> +static void privcmd_close(struct vm_area_struct *vma)
> +{
> + struct page **pages = vma ? vma->vm_private_data : NULL;
> + int numpgs = (vma->vm_end - vma->vm_start) >> PAGE_SHIFT;
> +
> + if (!pages || !numpgs || !xen_feature(XENFEAT_auto_translated_physmap))
> + return;
> +
> + xen_unmap_domain_mfn_range(vma);
> + while (numpgs--)
> + free_xenballooned_pages(1, &pages[numpgs]);

Does free_xenballooned_pages(numpgs, pages) not do what I expect?

> + kfree(pages);
> +}
> +
> static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
> {
> printk(KERN_DEBUG "privcmd_fault: vma=%p %lx-%lx, pgoff=%lx, uv=%p\n",
> @@ -449,6 +514,7 @@ static int privcmd_fault(struct vm_area_struct *vma, struct vm_fault *vmf)
> }
>
> static struct vm_operations_struct privcmd_vm_ops = {
> + .close = privcmd_close,
> .fault = privcmd_fault
> };
>
> @@ -465,7 +531,7 @@ static int privcmd_mmap(struct file *file, struct vm_area_struct *vma)
>
> static int privcmd_enforce_singleshot_mapping(struct vm_area_struct *vma)
> {
> - return (xchg(&vma->vm_private_data, (void *)1) == NULL);
> + return !cmpxchg(&vma->vm_private_data, NULL, PRIV_VMA_LOCKED);

Looks good, thanks.

> }
>
> const struct file_operations xen_privcmd_fops = {


--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/