xen: additionally restrict xenforeignmemory operations

Commit f0f272baf3a7 "xen: use libxendevice model to restrict operations"
added a command-line option (-xen-domid-restrict) to limit operations
using the libxendevicemodel API to a specified domid. The commit also
noted that the restriction would be extended to cover operations issued
via other xen libraries by subsequent patches.

My recent Xen patch [1] added a call to the xenforeignmemory API to allow
it to be restricted. This patch now makes use of that new call when the
-xen-domid-restrict option is passed.

[1] http://xenbits.xen.org/gitweb/?p=xen.git;a=commit;h=5823d6eb

Signed-off-by: Paul Durrant <paul.durrant@citrix.com>
Signed-off-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
This commit is contained in:
Paul Durrant 2017-03-28 16:54:55 +01:00 committed by Stefano Stabellini
parent 1c599472b0
commit 14d015b6fc
1 changed files with 78 additions and 56 deletions

View File

@ -26,6 +26,58 @@ extern xc_interface *xen_xc;
* We don't support Xen prior to 4.2.0.
*/
/* Xen 4.2 through 4.6 */
#if CONFIG_XEN_CTRL_INTERFACE_VERSION < 40701
typedef xc_interface xenforeignmemory_handle;
typedef xc_evtchn xenevtchn_handle;
typedef xc_gnttab xengnttab_handle;
#define xenevtchn_open(l, f) xc_evtchn_open(l, f);
#define xenevtchn_close(h) xc_evtchn_close(h)
#define xenevtchn_fd(h) xc_evtchn_fd(h)
#define xenevtchn_pending(h) xc_evtchn_pending(h)
#define xenevtchn_notify(h, p) xc_evtchn_notify(h, p)
#define xenevtchn_bind_interdomain(h, d, p) xc_evtchn_bind_interdomain(h, d, p)
#define xenevtchn_unmask(h, p) xc_evtchn_unmask(h, p)
#define xenevtchn_unbind(h, p) xc_evtchn_unbind(h, p)
#define xengnttab_open(l, f) xc_gnttab_open(l, f)
#define xengnttab_close(h) xc_gnttab_close(h)
#define xengnttab_set_max_grants(h, n) xc_gnttab_set_max_grants(h, n)
#define xengnttab_map_grant_ref(h, d, r, p) xc_gnttab_map_grant_ref(h, d, r, p)
#define xengnttab_unmap(h, a, n) xc_gnttab_munmap(h, a, n)
#define xengnttab_map_grant_refs(h, c, d, r, p) \
xc_gnttab_map_grant_refs(h, c, d, r, p)
#define xengnttab_map_domain_grant_refs(h, c, d, r, p) \
xc_gnttab_map_domain_grant_refs(h, c, d, r, p)
#define xenforeignmemory_open(l, f) xen_xc
#define xenforeignmemory_close(h)
static inline void *xenforeignmemory_map(xc_interface *h, uint32_t dom,
int prot, size_t pages,
const xen_pfn_t arr[/*pages*/],
int err[/*pages*/])
{
if (err)
return xc_map_foreign_bulk(h, dom, prot, arr, err, pages);
else
return xc_map_foreign_pages(h, dom, prot, arr, pages);
}
#define xenforeignmemory_unmap(h, p, s) munmap(p, s * XC_PAGE_SIZE)
#else /* CONFIG_XEN_CTRL_INTERFACE_VERSION >= 40701 */
#include <xenevtchn.h>
#include <xengnttab.h>
#include <xenforeignmemory.h>
#endif
extern xenforeignmemory_handle *xen_fmem;
#if CONFIG_XEN_CTRL_INTERFACE_VERSION < 40900
typedef xc_interface xendevicemodel_handle;
@ -158,6 +210,13 @@ static inline int xendevicemodel_restrict(
return -1;
}
static inline int xenforeignmemory_restrict(
xenforeignmemory_handle *fmem, domid_t domid)
{
errno = ENOTTY;
return -1;
}
#else /* CONFIG_XEN_CTRL_INTERFACE_VERSION >= 40900 */
#undef XC_WANT_COMPAT_DEVICEMODEL_API
@ -215,69 +274,32 @@ static inline int xen_modified_memory(domid_t domid, uint64_t first_pfn,
static inline int xen_restrict(domid_t domid)
{
int rc = xendevicemodel_restrict(xen_dmod, domid);
int rc;
trace_xen_domid_restrict(errno);
/* Attempt to restrict devicemodel operations */
rc = xendevicemodel_restrict(xen_dmod, domid);
trace_xen_domid_restrict(rc ? errno : 0);
if (errno == ENOTTY) {
return 0;
if (rc < 0) {
/*
* If errno is ENOTTY then restriction is not implemented so
* there's no point in trying to restrict other types of
* operation, but it should not be treated as a failure.
*/
if (errno == ENOTTY) {
return 0;
}
return rc;
}
/* Restrict foreignmemory operations */
rc = xenforeignmemory_restrict(xen_fmem, domid);
trace_xen_domid_restrict(rc ? errno : 0);
return rc;
}
/* Xen 4.2 through 4.6 */
#if CONFIG_XEN_CTRL_INTERFACE_VERSION < 40701
typedef xc_interface xenforeignmemory_handle;
typedef xc_evtchn xenevtchn_handle;
typedef xc_gnttab xengnttab_handle;
#define xenevtchn_open(l, f) xc_evtchn_open(l, f);
#define xenevtchn_close(h) xc_evtchn_close(h)
#define xenevtchn_fd(h) xc_evtchn_fd(h)
#define xenevtchn_pending(h) xc_evtchn_pending(h)
#define xenevtchn_notify(h, p) xc_evtchn_notify(h, p)
#define xenevtchn_bind_interdomain(h, d, p) xc_evtchn_bind_interdomain(h, d, p)
#define xenevtchn_unmask(h, p) xc_evtchn_unmask(h, p)
#define xenevtchn_unbind(h, p) xc_evtchn_unbind(h, p)
#define xengnttab_open(l, f) xc_gnttab_open(l, f)
#define xengnttab_close(h) xc_gnttab_close(h)
#define xengnttab_set_max_grants(h, n) xc_gnttab_set_max_grants(h, n)
#define xengnttab_map_grant_ref(h, d, r, p) xc_gnttab_map_grant_ref(h, d, r, p)
#define xengnttab_unmap(h, a, n) xc_gnttab_munmap(h, a, n)
#define xengnttab_map_grant_refs(h, c, d, r, p) \
xc_gnttab_map_grant_refs(h, c, d, r, p)
#define xengnttab_map_domain_grant_refs(h, c, d, r, p) \
xc_gnttab_map_domain_grant_refs(h, c, d, r, p)
#define xenforeignmemory_open(l, f) xen_xc
#define xenforeignmemory_close(h)
static inline void *xenforeignmemory_map(xc_interface *h, uint32_t dom,
int prot, size_t pages,
const xen_pfn_t arr[/*pages*/],
int err[/*pages*/])
{
if (err)
return xc_map_foreign_bulk(h, dom, prot, arr, err, pages);
else
return xc_map_foreign_pages(h, dom, prot, arr, pages);
}
#define xenforeignmemory_unmap(h, p, s) munmap(p, s * XC_PAGE_SIZE)
#else /* CONFIG_XEN_CTRL_INTERFACE_VERSION >= 40701 */
#include <xenevtchn.h>
#include <xengnttab.h>
#include <xenforeignmemory.h>
#endif
extern xenforeignmemory_handle *xen_fmem;
void destroy_hvm_domain(bool reboot);
/* shutdown/destroy current domain because of an error */