Commit 1c599472 authored by Paul Durrant's avatar Paul Durrant Committed by Stefano Stabellini
Browse files

xen: use libxendevice model to restrict operations 



This patch adds a command-line option (-xen-domid-restrict) which will
use the new libxendevicemodel API to restrict devicemodel [1] operations
to the specified domid. (Such operations are not applicable to the xenpv
machine type).

This patch also adds a tracepoint to allow successful enabling of the
restriction to be monitored.

[1] I.e. operations issued by libxendevicemodel. Operation issued by other
    xen libraries (e.g. libxenforeignmemory) are currently still unrestricted
    but this will be rectified by subsequent patches.

Signed-off-by: default avatarPaul Durrant <paul.durrant@citrix.com>
Reviewed-by: default avatarStefano Stabellini <sstabellini@kernel.org>
parent f1167ee6

hw/xen/trace-events

+1 −0
Original line number Diff line number Diff line
@@ -11,3 +11,4 @@ xen_map_portio_range(uint32_t id, uint64_t start_addr, uint64_t end_addr) "id: % 
xen_unmap_portio_range(uint32_t id, uint64_t start_addr, uint64_t end_addr) "id: %u start: %#"PRIx64" end: %#"PRIx64

xen_map_pcidev(uint32_t id, uint8_t bus, uint8_t dev, uint8_t func) "id: %u bdf: %02x.%02x.%02x"

xen_unmap_pcidev(uint32_t id, uint8_t bus, uint8_t dev, uint8_t func) "id: %u bdf: %02x.%02x.%02x"

xen_domid_restrict(int err) "err: %u"

include/hw/xen/xen.h

+1 −0
Original line number Diff line number Diff line
@@ -21,6 +21,7 @@ enum xen_mode { 


extern uint32_t xen_domid;

extern enum xen_mode xen_mode;

extern bool xen_domid_restrict;



extern bool xen_allowed;

include/hw/xen/xen_common.h

+20 −0
Original line number Diff line number Diff line
@@ -151,6 +151,13 @@ static inline int xendevicemodel_set_mem_type( 
    return xc_hvm_set_mem_type(dmod, domid, mem_type, first_pfn, nr);

}



static inline int xendevicemodel_restrict(

    xendevicemodel_handle *dmod, domid_t domid)

{

    errno = ENOTTY;

    return -1;

}



#else /* CONFIG_XEN_CTRL_INTERFACE_VERSION >= 40900 */



#undef XC_WANT_COMPAT_DEVICEMODEL_API
@@ -206,6 +213,19 @@ static inline int xen_modified_memory(domid_t domid, uint64_t first_pfn, 
    return xendevicemodel_modified_memory(xen_dmod, domid, first_pfn, nr);

}



static inline int xen_restrict(domid_t domid)

{

    int rc = xendevicemodel_restrict(xen_dmod, domid);



    trace_xen_domid_restrict(errno);



    if (errno == ENOTTY) {

        return 0;

    }



    return rc;

}



/* Xen 4.2 through 4.6 */

#if CONFIG_XEN_CTRL_INTERFACE_VERSION < 40701

qemu-options.hx

+7 −0
Original line number Diff line number Diff line
@@ -3354,6 +3354,11 @@ DEF("xen-attach", 0, QEMU_OPTION_xen_attach, 
    "-xen-attach     attach to existing xen domain\n"

    "                xend will use this when starting QEMU\n",

    QEMU_ARCH_ALL)

DEF("xen-domid-restrict", 0, QEMU_OPTION_xen_domid_restrict,

    "-xen-domid-restrict     restrict set of available xen operations\n"

    "                        to specified domain id. (Does not affect\n"

    "                        xenpv machine type).\n",

    QEMU_ARCH_ALL)

STEXI

@item -xen-domid @var{id}

@findex -xen-domid
@@ -3366,6 +3371,8 @@ Warning: should not be used when xend is in use (XEN only). 
@findex -xen-attach

Attach to existing xen domain.

xend will use this when starting QEMU (XEN only).

@findex -xen-domid-restrict

Restrict set of available xen operations to specified domain id (XEN only).

ETEXI



DEF("no-reboot", 0, QEMU_OPTION_no_reboot, \

vl.c

+8 −0
Original line number Diff line number Diff line
@@ -205,6 +205,7 @@ static NotifierList machine_init_done_notifiers = 
bool xen_allowed;

uint32_t xen_domid;

enum xen_mode xen_mode = XEN_EMULATE;

bool xen_domid_restrict;



static int has_defaults = 1;

static int default_serial = 1;
@@ -3933,6 +3934,13 @@ int main(int argc, char **argv, char **envp) 
                }

                xen_mode = XEN_ATTACH;

                break;

            case QEMU_OPTION_xen_domid_restrict:

                if (!(xen_available())) {

                    error_report("Option not supported for this target");

                    exit(1);

                }

                xen_domid_restrict = true;

                break;

            case QEMU_OPTION_trace:

                g_free(trace_file);

                trace_file = trace_opt_parse(optarg);