On Tue, 21 Mar 2017, Paul Durrant wrote: > Fixing list address... > > > -----Original Message----- > > From: Stefano Stabellini [mailto:sstabell...@kernel.org] > > Sent: 20 March 2017 22:05 > > To: Paul Durrant <paul.durr...@citrix.com> > > Cc: qemu-de...@lists.xenproject.org; Stefano Stabellini > > <sstabell...@kernel.org>; Anthony Perard <anthony.per...@citrix.com>; > > Paolo Bonzini <pbonz...@redhat.com> > > Subject: Re: [PATCH v2] xen: use libxendevice model to restrict operations > > > > On Mon, 20 Mar 2017, Paul Durrant wrote: > > > This patch adds a command-line option (-xen-domid-restrict) which will > > > use the new libxendevicemodel API to restrict devicemodel operations to > > > the specified domid. > > > > > > This patch also adds a tracepoint to allow successful enabling of the > > > restriction to be monitored. > > > > > > Signed-off-by: Paul Durrant <paul.durr...@citrix.com> > > > --- > > > Cc: Stefano Stabellini <sstabell...@kernel.org> > > > Cc: Anthony Perard <anthony.per...@citrix.com> > > > Cc: Paolo Bonzini <pbonz...@redhat.com> > > > > > > NOTE: This is already re-based on Juergen Gross's patch "xen: use 5 digit > > > xen versions" and so should not be applied until after that patch > > > has been applied. > > > > > > v2: > > > - Log errno in tracepoint > > > --- > > > hw/xen/trace-events | 1 + > > > include/hw/xen/xen.h | 1 + > > > include/hw/xen/xen_common.h | 20 ++++++++++++++++++++ > > > qemu-options.hx | 6 ++++++ > > > vl.c | 8 ++++++++ > > > xen-hvm.c | 8 ++++++++ > > > 6 files changed, 44 insertions(+) > > > > > > diff --git a/hw/xen/trace-events b/hw/xen/trace-events > > > index c4fb6f1..5615dce 100644 > > > --- a/hw/xen/trace-events > > > +++ b/hw/xen/trace-events > > > @@ -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" > > > diff --git a/include/hw/xen/xen.h b/include/hw/xen/xen.h > > > index 2b1733b..7efcdaa 100644 > > > --- a/include/hw/xen/xen.h > > > +++ b/include/hw/xen/xen.h > > > @@ -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; > > > > > > diff --git a/include/hw/xen/xen_common.h > > b/include/hw/xen/xen_common.h > > > index df098c7..4f3bd35 100644 > > > --- a/include/hw/xen/xen_common.h > > > +++ b/include/hw/xen/xen_common.h > > > @@ -152,6 +152,13 @@ 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 */ > > > > > > #include <xendevicemodel.h> > > > @@ -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 > > > > > > diff --git a/qemu-options.hx b/qemu-options.hx > > > index 99af8ed..4aab077 100644 > > > --- a/qemu-options.hx > > > +++ b/qemu-options.hx > > > @@ -3354,6 +3354,10 @@ 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\n", > > > + QEMU_ARCH_ALL) > > > > Please make a note that the QEMU xenpv machine (backend provider for PV > > guests) is completely unaffected. > > Sure. > > > > > Also, does this xendevicemodel_restrict operation restrict any of the > > xenstore accesses? > > > > Not yet. The intention is that it will (which is why I am not specific in the > usage comment) but that facility is not available as yet. The other > restriction that is also not yet implemented is foreign memory mapping, which > will require a new call to be added to libxenforeignmemory.
That's something worth documenting. If it's all already written in a Xen doc, then please add a link to it, otherwise, please add few words on what this restriction does here. > > > > > STEXI > > > @item -xen-domid @var{id} > > > @findex -xen-domid > > > @@ -3366,6 +3370,8 @@ 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, \ > > > diff --git a/vl.c b/vl.c > > > index 0b4ed52..f46e070 100644 > > > --- a/vl.c > > > +++ b/vl.c > > > @@ -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); > > > diff --git a/xen-hvm.c b/xen-hvm.c > > > index 4b928cf..335e263 100644 > > > --- a/xen-hvm.c > > > +++ b/xen-hvm.c > > > @@ -1226,6 +1226,14 @@ void xen_hvm_init(PCMachineState *pcms, > > MemoryRegion **ram_memory) > > > goto err; > > > } > > > > > > + if (xen_domid_restrict) { > > > + rc = xen_restrict(xen_domid); > > > + if (rc < 0) { > > > + error_report("failed to restrict: error %d", errno); > > > + goto err; > > > + } > > > + } > > > + > > > xen_create_ioreq_server(xen_domid, &state->ioservid); > > > > > > state->exit.notify = xen_exit_notifier; > > > -- > > > 2.1.4 > > > >