On Tue, Feb 12, 2019 at 05:09:29PM +0530, P J P wrote: > From: Prasad J Pandit <p...@fedoraproject.org> > > On ppc hosts, hypervisor shares following system attributes > > - /proc/device-tree/system-id > - /proc/device-tree/model > > with a guest. This could lead to information leakage and misuse.[*] > Add machine attributes to control such system information exposure > to a guest. > > [*] https://wiki.openstack.org/wiki/OSSN/OSSN-0028 > > Reported-by: Daniel P. Berrangé <berra...@redhat.com> > Fix-suggested-by: Daniel P. Berrangé <berra...@redhat.com> > Signed-off-by: Prasad J Pandit <p...@fedoraproject.org> > --- > hw/core/machine.c | 46 +++++++++++++++++++++++++++++++++++++++++++++ > hw/ppc/spapr.c | 36 +++++++++++++++++++++++++++++------ > include/hw/boards.h | 2 ++ > qemu-options.hx | 10 +++++++++- > util/qemu-config.c | 8 ++++++++ > 5 files changed, 95 insertions(+), 7 deletions(-) > > Update v2: add backward compatible properties > -> https://lists.gnu.org/archive/html/qemu-devel/2019-02/msg00593.html > > diff --git a/hw/core/machine.c b/hw/core/machine.c > index 2629515363..2d5a52476a 100644 > --- a/hw/core/machine.c > +++ b/hw/core/machine.c > @@ -476,6 +476,38 @@ static void machine_set_memory_encryption(Object *obj, > const char *value, > ms->memory_encryption = g_strdup(value); > } > > +static char *machine_get_host_serial(Object *obj, Error **errp) > +{ > + MachineState *ms = MACHINE(obj); > + > + return g_strdup(ms->host_serial); > +} > + > +static void machine_set_host_serial(Object *obj, const char *value, > + Error **errp) > +{ > + MachineState *ms = MACHINE(obj); > + > + g_free(ms->host_serial); > + ms->host_serial = g_strdup(value); > +} > + > +static char *machine_get_host_model(Object *obj, Error **errp) > +{ > + MachineState *ms = MACHINE(obj); > + > + return g_strdup(ms->host_model); > +} > + > +static void machine_set_host_model(Object *obj, const char *value, > + Error **errp) > +{ > + MachineState *ms = MACHINE(obj); > + > + g_free(ms->host_model); > + ms->host_model = g_strdup(value); > +} > + > void machine_class_allow_dynamic_sysbus_dev(MachineClass *mc, const char > *type) > { > strList *item = g_new0(strList, 1); > @@ -760,6 +792,18 @@ static void machine_class_init(ObjectClass *oc, void > *data) > &error_abort); > object_class_property_set_description(oc, "memory-encryption", > "Set memory encryption object to use", &error_abort); > + > + object_class_property_add_str(oc, "host-serial", > + machine_get_host_serial, machine_set_host_serial, > + &error_abort); > + object_class_property_set_description(oc, "host-serial", > + "Set host's system-id to use", &error_abort); > + > + object_class_property_add_str(oc, "host-model", > + machine_get_host_model, machine_set_host_model, > + &error_abort); > + object_class_property_set_description(oc, "host-model", > + "Set host's model-id to use", &error_abort);
You're adding properties to *all* machines, for something that's only
used on the PAPR machine. That doesn't seem right.
> }
>
> static void machine_class_base_init(ObjectClass *oc, void *data)
> @@ -785,6 +829,8 @@ static void machine_initfn(Object *obj)
> ms->dump_guest_core = true;
> ms->mem_merge = true;
> ms->enable_graphics = true;
> + ms->host_serial = NULL;
> + ms->host_model = NULL;
>
> /* Register notifier when init is done for sysbus sanity checks */
> ms->sysbus_notifier.notify = machine_init_notify;
> diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c
> index 0942f35bf8..a70667d72d 100644
> --- a/hw/ppc/spapr.c
> +++ b/hw/ppc/spapr.c
> @@ -1249,13 +1249,31 @@ static void *spapr_build_fdt(sPAPRMachineState *spapr,
> * Add info to guest to indentify which host is it being run on
> * and what is the uuid of the guest
> */
> - if (kvmppc_get_host_model(&buf)) {
> - _FDT(fdt_setprop_string(fdt, 0, "host-model", buf));
> - g_free(buf);
> + if (machine->host_model && !g_str_equal(machine->host_model, "none")) {
> + if (g_str_equal(machine->host_model, "passthrough")) {
> + /* -M host-model=passthrough */
> + if (kvmppc_get_host_model(&buf)) {
> + _FDT(fdt_setprop_string(fdt, 0, "host-model", buf));
> + g_free(buf);
> + }
> + } else {
> + /* -M host-model=<user-string> */
> + _FDT(fdt_setprop_string(fdt, 0, "host-model",
> machine->host_model));
> + }
> }
> - if (kvmppc_get_host_serial(&buf)) {
> - _FDT(fdt_setprop_string(fdt, 0, "host-serial", buf));
> - g_free(buf);
> +
> + if (machine->host_serial && !g_str_equal(machine->host_serial, "none")) {
> + if (g_str_equal(machine->host_serial, "passthrough")) {
> + /* -M host-serial=passthrough */
> + if (kvmppc_get_host_serial(&buf)) {
> + _FDT(fdt_setprop_string(fdt, 0, "host-serial", buf));
> + g_free(buf);
> + }
> + } else {
> + /* -M host-serial=<user-string> */
> + _FDT(fdt_setprop_string(fdt, 0,
> + "host-serial", machine->host_serial));
> + }
> }
>
> buf = qemu_uuid_unparse_strdup(&qemu_uuid);
> @@ -4080,9 +4098,15 @@ DEFINE_SPAPR_MACHINE(4_0, "4.0", true);
> static void spapr_machine_3_1_class_options(MachineClass *mc)
> {
> sPAPRMachineClass *smc = SPAPR_MACHINE_CLASS(mc);
> + static GlobalProperty compat[] = {
> + { TYPE_SPAPR_MACHINE, "host-model", "passthrough" },
> + { TYPE_SPAPR_MACHINE, "host-serial", "passthrough" },
> + };
>
> spapr_machine_4_0_class_options(mc);
> compat_props_add(mc->compat_props, hw_compat_3_1, hw_compat_3_1_len);
> + compat_props_add(mc->compat_props, compat, G_N_ELEMENTS(compat));
I'm still not convinced maintaining super-strict backwards compat at
the expense of security is a good tradeoff here, but since the code's
already written, let's run with it.
> +
> mc->default_cpu_type = POWERPC_CPU_TYPE_NAME("power8_v2.0");
> smc->update_dt_enabled = false;
> }
> diff --git a/include/hw/boards.h b/include/hw/boards.h
> index 02f114085f..3e63dc4501 100644
> --- a/include/hw/boards.h
> +++ b/include/hw/boards.h
> @@ -257,6 +257,8 @@ struct MachineState {
> bool enforce_config_section;
> bool enable_graphics;
> char *memory_encryption;
> + char *host_serial;
> + char *host_model;
> DeviceMemoryState *device_memory;
>
> ram_addr_t ram_size;
> diff --git a/qemu-options.hx b/qemu-options.hx
> index 521511ec13..67ac1a9959 100644
> --- a/qemu-options.hx
> +++ b/qemu-options.hx
> @@ -43,7 +43,9 @@ DEF("machine", HAS_ARG, QEMU_OPTION_machine, \
> " suppress-vmdesc=on|off disables self-describing
> migration (default=off)\n"
> " nvdimm=on|off controls NVDIMM support (default=off)\n"
> " enforce-config-section=on|off enforce configuration
> section migration (default=off)\n"
> - " memory-encryption=@var{} memory encryption object to
> use (default=none)\n",
> + " memory-encryption=@var{} memory encryption object to
> use (default=none)\n"
> + " host-serial=none|passthrough|string controls host
> systemd-id (default=passthrough)\n"
> + " host-model=none|passthrough|string controls host
> model-id (default=passthrough)\n",
> QEMU_ARCH_ALL)
> STEXI
> @item -machine [type=]@var{name}[,prop=@var{value}[,...]]
> @@ -103,6 +105,12 @@ NOTE: this parameter is deprecated. Please use
> @option{-global}
> @option{migration.send-configuration}=@var{on|off} instead.
> @item memory-encryption=@var{}
> Memory encryption object to use. The default is none.
> +@item host-serial=none|passthrough|string
> +Pass 'system-id' parameter from host's device-tree to a guest. A user may
> +disable it with 'none' or define a custom string for a guest.
> +@item host-model=none|passthrough|string
> +Pass 'model' paramter from host's device-tree to a guest. A user may disable
> +it with 'none' or define a custom string for a guest.
> @end table
> ETEXI
>
> diff --git a/util/qemu-config.c b/util/qemu-config.c
> index 9d2e278e29..86483ded34 100644
> --- a/util/qemu-config.c
> +++ b/util/qemu-config.c
> @@ -238,6 +238,14 @@ static QemuOptsList machine_opts = {
> .help = "Up to 8 chars in set of [A-Za-z0-9. ](lower case chars"
> " converted to upper case) to pass to machine"
> " loader, boot manager, and guest kernel",
> + },{
> + .name = "host-serial",
> + .type = QEMU_OPT_STRING,
> + .help = "host's system-id seen by guest",
> + },{
> + .name = "host-model",
> + .type = QEMU_OPT_STRING,
> + .help = "host's model-id seen by guest",
> },
> { /* End of list */ }
> }
--
David Gibson | I'll have my music baroque, and my code
david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_
| _way_ _around_!
http://www.ozlabs.org/~dgibson
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