d/freebsd-dev
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

xen: implement the privcmd user-space device

Browse Source 
This device is only attached to priviledged domains, and allows the
toolstack to interact with Xen. The two functions of the privcmd
interface is to allow the execution of hypercalls from user-space, and
the mapping of foreign domain memory.

Sponsored by: Citrix Systems R&D

i386/include/xen/hypercall.h:
amd64/include/xen/hypercall.h:
 - Introduce a function to make generic hypercalls into Xen.

xen/interface/xen.h:
xen/interface/memory.h:
 - Import the new hypercall XENMEM_add_to_physmap_range used by
   auto-translated guests to map memory from foreign domains.

dev/xen/privcmd/privcmd.c:
 - This device has the following functions:
   - Allow user-space applications to make hypercalls into Xen.
   - Allow user-space applications to map memory from foreign domains,
     this is accomplished using the newly introduced hypercall
     (XENMEM_add_to_physmap_range).

xen/privcmd.h:
 - Public ioctl interface for the privcmd device.

x86/xen/hvm.c:
 - Remove declaration of hypercall_page, now it's declared in
   hypercall.h.

conf/files:
 - Add the privcmd device to the build process.
This commit is contained in:
Roger Pau Monné 2014-10-22 17:07:20 +00:00
parent 317db2799e
commit bf7313e3b7
Notes: svn2git 2020-12-20 02:59:44 +00:00 
svn path=/head/; revision=273476
8 changed files with 549 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

22
sys/amd64/include/xen/hypercall.h
View File

@ -45,6 +45,8 @@
# error "please don't include this file directly"
#endif
extern char *hypercall_page;
#define __STR(x) #x
#define STR(x) __STR(x)
#define ENOXENSYS 38
@ -134,6 +136,26 @@
__res; \
})
static inline int
privcmd_hypercall(long op, long a1, long a2, long a3, long a4, long a5)
{
int __res;
long __ign1, __ign2, __ign3;
register long __arg4 __asm__("r10") = (long)(a4);
register long __arg5 __asm__("r8") = (long)(a5);
long __call = (long)&hypercall_page + (op * 32);
__asm__ volatile (
"call *%[call]"
: "=a" (__res), "=D" (__ign1), "=S" (__ign2),
"=d" (__ign3), "+r" (__arg4), "+r" (__arg5)
: "1" ((long)(a1)), "2" ((long)(a2)),
"3" ((long)(a3)), [call] "a" (__call)
: "memory" );
return (__res);
}
static inline int __must_check
HYPERVISOR_set_trap_table(
const trap_info_t *table)

1
sys/conf/files
View File

@ -2648,6 +2648,7 @@ dev/xen/xenstore/xenstore.c optional xen | xenhvm
dev/xen/xenstore/xenstore_dev.c optional xen | xenhvm
dev/xen/xenstore/xenstored_dev.c optional xen | xenhvm
dev/xen/evtchn/evtchn_dev.c optional xen | xenhvm
dev/xen/privcmd/privcmd.c optional xen | xenhvm
dev/xl/if_xl.c optional xl pci
dev/xl/xlphy.c optional xl pci
fs/autofs/autofs.c optional autofs

414
sys/dev/xen/privcmd/privcmd.c Normal file
View File

@ -0,0 +1,414 @@
/*
* Copyright (c) 2014 Roger Pau Monné <roger.pau@citrix.com>
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*/
#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/uio.h>
#include <sys/bus.h>
#include <sys/malloc.h>
#include <sys/kernel.h>
#include <sys/lock.h>
#include <sys/mutex.h>
#include <sys/rwlock.h>
#include <sys/selinfo.h>
#include <sys/poll.h>
#include <sys/conf.h>
#include <sys/fcntl.h>
#include <sys/ioccom.h>
#include <sys/rman.h>
#include <sys/tree.h>
#include <sys/module.h>
#include <sys/proc.h>
#include <vm/vm.h>
#include <vm/vm_param.h>
#include <vm/vm_extern.h>
#include <vm/vm_kern.h>
#include <vm/vm_page.h>
#include <vm/vm_map.h>
#include <vm/vm_object.h>
#include <vm/vm_pager.h>
#include <vm/vm_phys.h>
#include <machine/md_var.h>
#include <xen/xen-os.h>
#include <xen/hypervisor.h>
#include <xen/privcmd.h>
#include <xen/error.h>
MALLOC_DEFINE(M_PRIVCMD, "privcmd_dev", "Xen privcmd user-space device");
struct privcmd_map {
vm_object_t mem;
vm_size_t size;
struct resource *pseudo_phys_res;
int pseudo_phys_res_id;
vm_paddr_t phys_base_addr;
boolean_t mapped;
int *errs;
};
static d_ioctl_t privcmd_ioctl;
static d_mmap_single_t privcmd_mmap_single;
static struct cdevsw privcmd_devsw = {
.d_version = D_VERSION,
.d_ioctl = privcmd_ioctl,
.d_mmap_single = privcmd_mmap_single,
.d_name = "privcmd",
};
static int privcmd_pg_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
vm_ooffset_t foff, struct ucred *cred, u_short *color);
static void privcmd_pg_dtor(void *handle);
static int privcmd_pg_fault(vm_object_t object, vm_ooffset_t offset,
int prot, vm_page_t *mres);
static struct cdev_pager_ops privcmd_pg_ops = {
.cdev_pg_fault = privcmd_pg_fault,
.cdev_pg_ctor = privcmd_pg_ctor,
.cdev_pg_dtor = privcmd_pg_dtor,
};
static device_t privcmd_dev = NULL;
/*------------------------- Privcmd Pager functions --------------------------*/
static int
privcmd_pg_ctor(void *handle, vm_ooffset_t size, vm_prot_t prot,
vm_ooffset_t foff, struct ucred *cred, u_short *color)
{
return (0);
}
static void
privcmd_pg_dtor(void *handle)
{
struct xen_remove_from_physmap rm = { .domid = DOMID_SELF };
struct privcmd_map *map = handle;
int error;
vm_size_t i;
vm_page_t m;
/*
* Remove the mappings from the used pages. This will remove the
* underlying p2m bindings in Xen second stage translation.
*/
if (map->mapped == true) {
VM_OBJECT_WLOCK(map->mem);
retry:
for (i = 0; i < map->size; i++) {
m = vm_page_lookup(map->mem, i);
if (m == NULL)
continue;
if (vm_page_sleep_if_busy(m, "pcmdum"))
goto retry;
cdev_pager_free_page(map->mem, m);
}
VM_OBJECT_WUNLOCK(map->mem);
for (i = 0; i < map->size; i++) {
rm.gpfn = atop(map->phys_base_addr) + i;
HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &rm);
}
free(map->errs, M_PRIVCMD);
}
vm_phys_fictitious_unreg_range(map->phys_base_addr,
map->phys_base_addr + map->size * PAGE_SIZE);
error = bus_release_resource(privcmd_dev, SYS_RES_MEMORY,
map->pseudo_phys_res_id, map->pseudo_phys_res);
KASSERT(error == 0, ("Unable to release memory resource: %d", error));
free(map, M_PRIVCMD);
}
static int
privcmd_pg_fault(vm_object_t object, vm_ooffset_t offset,
int prot, vm_page_t *mres)
{
struct privcmd_map *map = object->handle;
vm_pindex_t pidx;
vm_page_t page, oldm;
if (map->mapped != true)
return (VM_PAGER_FAIL);
pidx = OFF_TO_IDX(offset);
if (pidx >= map->size || map->errs[pidx] != 0)
return (VM_PAGER_FAIL);
page = PHYS_TO_VM_PAGE(map->phys_base_addr + offset);
if (page == NULL)
return (VM_PAGER_FAIL);
KASSERT((page->flags & PG_FICTITIOUS) != 0,
("not fictitious %p", page));
KASSERT(page->wire_count == 1, ("wire_count not 1 %p", page));
KASSERT(vm_page_busied(page) == 0, ("page %p is busy", page));
if (*mres != NULL) {
oldm = *mres;
vm_page_lock(oldm);
vm_page_free(oldm);
vm_page_unlock(oldm);
*mres = NULL;
}
vm_page_insert(page, object, pidx);
page->valid = VM_PAGE_BITS_ALL;
vm_page_xbusy(page);
*mres = page;
return (VM_PAGER_OK);
}
/*----------------------- Privcmd char device methods ------------------------*/
static int
privcmd_mmap_single(struct cdev *cdev, vm_ooffset_t *offset, vm_size_t size,
vm_object_t *object, int nprot)
{
struct privcmd_map *map;
int error;
map = malloc(sizeof(*map), M_PRIVCMD, M_WAITOK | M_ZERO);
map->size = OFF_TO_IDX(size);
map->pseudo_phys_res_id = 0;
map->pseudo_phys_res = bus_alloc_resource(privcmd_dev, SYS_RES_MEMORY,
&map->pseudo_phys_res_id, 0, ~0, size, RF_ACTIVE);
if (map->pseudo_phys_res == NULL) {
free(map, M_PRIVCMD);
return (ENOMEM);
}
map->phys_base_addr = rman_get_start(map->pseudo_phys_res);
error = vm_phys_fictitious_reg_range(map->phys_base_addr,
map->phys_base_addr + size, VM_MEMATTR_DEFAULT);
if (error) {
bus_release_resource(privcmd_dev, SYS_RES_MEMORY,
map->pseudo_phys_res_id, map->pseudo_phys_res);
free(map, M_PRIVCMD);
return (error);
}
map->mem = cdev_pager_allocate(map, OBJT_MGTDEVICE, &privcmd_pg_ops,
size, nprot, *offset, NULL);
if (map->mem == NULL) {
bus_release_resource(privcmd_dev, SYS_RES_MEMORY,
map->pseudo_phys_res_id, map->pseudo_phys_res);
free(map, M_PRIVCMD);
return (ENOMEM);
}
*object = map->mem;
return (0);
}
static int
privcmd_ioctl(struct cdev *dev, unsigned long cmd, caddr_t arg,
int mode, struct thread *td)
{
int error, i;
switch (cmd) {
case IOCTL_PRIVCMD_HYPERCALL: {
struct ioctl_privcmd_hypercall *hcall;
hcall = (struct ioctl_privcmd_hypercall *)arg;
error = privcmd_hypercall(hcall->op, hcall->arg[0],
hcall->arg[1], hcall->arg[2], hcall->arg[3], hcall->arg[4]);
if (error >= 0) {
hcall->retval = error;
error = 0;
} else {
error = xen_translate_error(error);
hcall->retval = 0;
}
break;
}
case IOCTL_PRIVCMD_MMAPBATCH: {
struct ioctl_privcmd_mmapbatch *mmap;
vm_map_t map;
vm_map_entry_t entry;
vm_object_t mem;
vm_pindex_t index;
vm_prot_t prot;
boolean_t wired;
struct xen_add_to_physmap_range add;
xen_ulong_t *idxs;
xen_pfn_t *gpfns;
int *errs;
struct privcmd_map *umap;
mmap = (struct ioctl_privcmd_mmapbatch *)arg;
if ((mmap->num == 0) ||
((mmap->addr & PAGE_MASK) != 0)) {
error = EINVAL;
break;
}
map = &td->td_proc->p_vmspace->vm_map;
error = vm_map_lookup(&map, mmap->addr, VM_PROT_NONE, &entry,
&mem, &index, &prot, &wired);
if (error != KERN_SUCCESS) {
error = EINVAL;
break;
}
if ((entry->start != mmap->addr) ||
(entry->end != mmap->addr + (mmap->num * PAGE_SIZE))) {
vm_map_lookup_done(map, entry);
error = EINVAL;
break;
}
vm_map_lookup_done(map, entry);
if ((mem->type != OBJT_MGTDEVICE) ||
(mem->un_pager.devp.ops != &privcmd_pg_ops)) {
error = EINVAL;
break;
}
umap = mem->handle;
add.domid = DOMID_SELF;
add.space = XENMAPSPACE_gmfn_foreign;
add.size = mmap->num;
add.foreign_domid = mmap->dom;
idxs = malloc(sizeof(*idxs) * mmap->num, M_PRIVCMD,
M_WAITOK | M_ZERO);
gpfns = malloc(sizeof(*gpfns) * mmap->num, M_PRIVCMD,
M_WAITOK | M_ZERO);
errs = malloc(sizeof(*errs) * mmap->num, M_PRIVCMD,
M_WAITOK | M_ZERO);
set_xen_guest_handle(add.idxs, idxs);
set_xen_guest_handle(add.gpfns, gpfns);
set_xen_guest_handle(add.errs, errs);
error = copyin(&mmap->arr[0], idxs,
sizeof(idxs[0]) * mmap->num);
if (error != 0)
goto mmap_out;
for (i = 0; i < mmap->num; i++)
gpfns[i] = atop(umap->phys_base_addr + i * PAGE_SIZE);
error = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &add);
if (error) {
error = xen_translate_error(error);
goto mmap_out;
}
for (i = 0; i < mmap->num; i++) {
if (errs[i] != 0)
errs[i] = xen_translate_error(errs[i]);
}
/*
* Save errs, so we know which pages have been
* successfully mapped.
*/
umap->errs = errs;
umap->mapped = true;
error = copyout(errs, &mmap->err[0],
sizeof(errs[0]) * mmap->num);
mmap_out:
free(idxs, M_PRIVCMD);
free(gpfns, M_PRIVCMD);
if (!umap->mapped)
free(errs, M_PRIVCMD);
break;
}
default:
error = ENOSYS;
break;
}
return (error);
}
/*------------------ Private Device Attachment Functions --------------------*/
static void
privcmd_identify(driver_t *driver, device_t parent)
{
KASSERT(xen_domain(),
("Trying to attach privcmd device on non Xen domain"));
if (BUS_ADD_CHILD(parent, 0, "privcmd", 0) == NULL)
panic("unable to attach privcmd user-space device");
}
static int
privcmd_probe(device_t dev)
{
privcmd_dev = dev;
device_set_desc(dev, "Xen privileged interface user-space device");
return (BUS_PROBE_NOWILDCARD);
}
static int
privcmd_attach(device_t dev)
{
make_dev_credf(MAKEDEV_ETERNAL, &privcmd_devsw, 0, NULL, UID_ROOT,
GID_WHEEL, 0600, "xen/privcmd");
return (0);
}
/*-------------------- Private Device Attachment Data -----------------------*/
static device_method_t privcmd_methods[] = {
DEVMETHOD(device_identify, privcmd_identify),
DEVMETHOD(device_probe, privcmd_probe),
DEVMETHOD(device_attach, privcmd_attach),
DEVMETHOD_END
};
static driver_t privcmd_driver = {
"privcmd",
privcmd_methods,
0,
};
devclass_t privcmd_devclass;
DRIVER_MODULE(privcmd, xenpv, privcmd_driver, privcmd_devclass, 0, 0);
MODULE_DEPEND(privcmd, xenpv, 1, 1, 1);

20
sys/i386/include/xen/hypercall.h
View File

@ -34,6 +34,8 @@
#include <xen/interface/xen.h>
#include <xen/interface/sched.h>
extern char *hypercall_page;
#define __STR(x) #x
#define STR(x) __STR(x)
#define ENOXENSYS 38
@ -115,6 +117,24 @@
(type)__res; \
})
static inline long
privcmd_hypercall(long op, long a1, long a2, long a3, long a4, long a5)
{
long __res, __ign1, __ign2, __ign3, __ign4, __ign5, __call;
__call = (long)&hypercall_page + (op * 32);
__asm__ volatile (
"call *%[call]"
: "=a" (__res), "=b" (__ign1), "=c" (__ign2),
"=d" (__ign3), "=S" (__ign4), "=D" (__ign5)
: "1" ((long)(a1)), "2" ((long)(a2)),
"3" ((long)(a3)), "4" ((long)(a4)),
"5" ((long)(a5)), [call] "a" (__call)
: "memory" );
return __res;
}
static inline int
HYPERVISOR_set_trap_table(
trap_info_t *table)

2
sys/x86/xen/hvm.c
View File

@ -97,8 +97,6 @@ DPCPU_DEFINE(struct vcpu_info, vcpu_local_info);
DPCPU_DEFINE(struct vcpu_info *, vcpu_info);
/*------------------ Hypervisor Access Shared Memory Regions -----------------*/
/** Hypercall table accessed via HYPERVISOR_*_op() methods. */
extern char *hypercall_page;
shared_info_t *HYPERVISOR_shared_info;
start_info_t *HYPERVISOR_start_info;

33
sys/xen/interface/memory.h
View File

@ -198,6 +198,14 @@ struct xen_machphys_mapping {
typedef struct xen_machphys_mapping xen_machphys_mapping_t;
DEFINE_XEN_GUEST_HANDLE(xen_machphys_mapping_t);
#define XENMAPSPACE_shared_info 0 /* shared info page */
#define XENMAPSPACE_grant_table 1 /* grant table page */
#define XENMAPSPACE_gmfn 2 /* GMFN */
#define XENMAPSPACE_gmfn_range 3 /* GMFN range, XENMEM_add_to_physmap only. */
#define XENMAPSPACE_gmfn_foreign 4 /* GMFN from another dom,
* XENMEM_add_to_physmap_range only.
*/
/*
* Sets the GPFN at which a particular page appears in the specified guest's
* pseudophysical address space.
@ -248,6 +256,31 @@ DEFINE_XEN_GUEST_HANDLE(xen_remove_from_physmap_t);
/*** REMOVED ***/
/*#define XENMEM_translate_gpfn_list 8*/
#define XENMEM_add_to_physmap_range 23
struct xen_add_to_physmap_range {
/* IN */
/* Which domain to change the mapping for. */
domid_t domid;
uint16_t space; /* => enum phys_map_space */
/* Number of pages to go through */
uint16_t size;
domid_t foreign_domid; /* IFF gmfn_foreign */
/* Indexes into space being mapped. */
XEN_GUEST_HANDLE(xen_ulong_t) idxs;
/* GPFN in domid where the source mapping page should appear. */
XEN_GUEST_HANDLE(xen_pfn_t) gpfns;
/* OUT */
/* Per index error code. */
XEN_GUEST_HANDLE(int) errs;
};
typedef struct xen_add_to_physmap_range xen_add_to_physmap_range_t;
DEFINE_XEN_GUEST_HANDLE(xen_add_to_physmap_range_t);
/*
* Returns the pseudo-physical memory map as it was when the domain
* was started (specified by XENMEM_set_memory_map).

1
sys/xen/interface/xen.h
View File

@ -51,6 +51,7 @@ DEFINE_XEN_GUEST_HANDLE(void);
DEFINE_XEN_GUEST_HANDLE(uint64_t);
DEFINE_XEN_GUEST_HANDLE(xen_pfn_t);
DEFINE_XEN_GUEST_HANDLE(xen_ulong_t);
#endif
/*

58
sys/xen/privcmd.h Normal file
View File

@ -0,0 +1,58 @@
/******************************************************************************
* privcmd.h
*
* Interface to /proc/xen/privcmd.
*
* Copyright (c) 2003-2005, K A Fraser
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License version 2
* as published by the Free Software Foundation; or, when distributed
* separately from the Linux kernel or incorporated into other
* software packages, subject to the following license:
*
* Permission is hereby granted, free of charge, to any person obtaining a copy
* of this source file (the "Software"), to deal in the Software without
* restriction, including without limitation the rights to use, copy, modify,
* merge, publish, distribute, sublicense, and/or sell copies of the Software,
* and to permit persons to whom the Software is furnished to do so, subject to
* the following conditions:
*
* The above copyright notice and this permission notice shall be included in
* all copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
* FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
* AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
* LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
* FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS
* IN THE SOFTWARE.
*
* $FreeBSD$
*/
#ifndef __XEN_PRIVCMD_H__
#define __XEN_PRIVCMD_H__
struct ioctl_privcmd_hypercall
{
unsigned long op; /* hypercall number */
unsigned long arg[5]; /* arguments */
long retval; /* return value */
};
struct ioctl_privcmd_mmapbatch {
int num; /* number of pages to populate */
domid_t dom; /* target domain */
unsigned long addr; /* virtual address */
const xen_pfn_t *arr; /* array of mfns */
int *err; /* array of error codes */
};
#define IOCTL_PRIVCMD_HYPERCALL \
_IOWR('E', 0, struct ioctl_privcmd_hypercall)
#define IOCTL_PRIVCMD_MMAPBATCH \
_IOWR('E', 1, struct ioctl_privcmd_mmapbatch)
#endif /* !__XEN_PRIVCMD_H__ */