diff options
Diffstat (limited to 'drivers/xen/privcmd.c')
| -rw-r--r-- | drivers/xen/privcmd.c | 139 |
1 files changed, 139 insertions, 0 deletions
diff --git a/drivers/xen/privcmd.c b/drivers/xen/privcmd.c index 5e5c7aef0c9f..1a6f1860e008 100644 --- a/drivers/xen/privcmd.c +++ b/drivers/xen/privcmd.c @@ -22,6 +22,7 @@ #include <linux/pagemap.h> #include <linux/seq_file.h> #include <linux/miscdevice.h> +#include <linux/moduleparam.h> #include <asm/pgalloc.h> #include <asm/pgtable.h> @@ -32,6 +33,7 @@ #include <xen/xen.h> #include <xen/privcmd.h> #include <xen/interface/xen.h> +#include <xen/interface/hvm/dm_op.h> #include <xen/features.h> #include <xen/page.h> #include <xen/xen-ops.h> @@ -43,6 +45,17 @@ MODULE_LICENSE("GPL"); #define PRIV_VMA_LOCKED ((void *)1) +static unsigned int privcmd_dm_op_max_num = 16; +module_param_named(dm_op_max_nr_bufs, privcmd_dm_op_max_num, uint, 0644); +MODULE_PARM_DESC(dm_op_max_nr_bufs, + "Maximum number of buffers per dm_op hypercall"); + +static unsigned int privcmd_dm_op_buf_max_size = 4096; +module_param_named(dm_op_buf_max_size, privcmd_dm_op_buf_max_size, uint, + 0644); +MODULE_PARM_DESC(dm_op_buf_max_size, + "Maximum size of a dm_op hypercall buffer"); + static int privcmd_vma_range_is_mapped( struct vm_area_struct *vma, unsigned long addr, @@ -548,6 +561,128 @@ out_unlock: goto out; } +static int lock_pages( + struct privcmd_dm_op_buf kbufs[], unsigned int num, + struct page *pages[], unsigned int nr_pages) +{ + unsigned int i; + + for (i = 0; i < num; i++) { + unsigned int requested; + int pinned; + + requested = DIV_ROUND_UP( + offset_in_page(kbufs[i].uptr) + kbufs[i].size, + PAGE_SIZE); + if (requested > nr_pages) + return -ENOSPC; + + pinned = get_user_pages_fast( + (unsigned long) kbufs[i].uptr, + requested, FOLL_WRITE, pages); + if (pinned < 0) + return pinned; + + nr_pages -= pinned; + pages += pinned; + } + + return 0; +} + +static void unlock_pages(struct page *pages[], unsigned int nr_pages) +{ + unsigned int i; + + if (!pages) + return; + + for (i = 0; i < nr_pages; i++) { + if (pages[i]) + put_page(pages[i]); + } +} + +static long privcmd_ioctl_dm_op(void __user *udata) +{ + struct privcmd_dm_op kdata; + struct privcmd_dm_op_buf *kbufs; + unsigned int nr_pages = 0; + struct page **pages = NULL; + struct xen_dm_op_buf *xbufs = NULL; + unsigned int i; + long rc; + + if (copy_from_user(&kdata, udata, sizeof(kdata))) + return -EFAULT; + + if (kdata.num == 0) + return 0; + + if (kdata.num > privcmd_dm_op_max_num) + return -E2BIG; + + kbufs = kcalloc(kdata.num, sizeof(*kbufs), GFP_KERNEL); + if (!kbufs) + return -ENOMEM; + + if (copy_from_user(kbufs, kdata.ubufs, + sizeof(*kbufs) * kdata.num)) { + rc = -EFAULT; + goto out; + } + + for (i = 0; i < kdata.num; i++) { + if (kbufs[i].size > privcmd_dm_op_buf_max_size) { + rc = -E2BIG; + goto out; + } + + if (!access_ok(VERIFY_WRITE, kbufs[i].uptr, + kbufs[i].size)) { + rc = -EFAULT; + goto out; + } + + nr_pages += DIV_ROUND_UP( + offset_in_page(kbufs[i].uptr) + kbufs[i].size, + PAGE_SIZE); + } + + pages = kcalloc(nr_pages, sizeof(*pages), GFP_KERNEL); + if (!pages) { + rc = -ENOMEM; + goto out; + } + + xbufs = kcalloc(kdata.num, sizeof(*xbufs), GFP_KERNEL); + if (!xbufs) { + rc = -ENOMEM; + goto out; + } + + rc = lock_pages(kbufs, kdata.num, pages, nr_pages); + if (rc) + goto out; + + for (i = 0; i < kdata.num; i++) { + set_xen_guest_handle(xbufs[i].h, kbufs[i].uptr); + xbufs[i].size = kbufs[i].size; + } + + xen_preemptible_hcall_begin(); + rc = HYPERVISOR_dm_op(kdata.dom, kdata.num, xbufs); + xen_preemptible_hcall_end(); + +out: + unlock_pages(pages, nr_pages); + kfree(xbufs); + kfree(pages); + kfree(kbufs); + + return rc; +} + static long privcmd_ioctl(struct file *file, unsigned int cmd, unsigned long data) { @@ -571,6 +706,10 @@ static long privcmd_ioctl(struct file *file, ret = privcmd_ioctl_mmap_batch(udata, 2); break; + case IOCTL_PRIVCMD_DM_OP: + ret = privcmd_ioctl_dm_op(udata); + break; + default: break; } |