=back
+=item B<rdm="RDM_RESERVATION_STRING">
+
+(HVM/x86 only) Specifies information about Reserved Device Memory (RDM),
+which is necessary to enable robust device passthrough. One example of RDM
+is reported through ACPI Reserved Memory Region Reporting (RMRR) structure
+on x86 platform.
+
+B<RDM_RESERVE_STRING> has the form C<[KEY=VALUE,KEY=VALUE,...> where:
+
+=over 4
+
+=item B<KEY=VALUE>
+
+Possible B<KEY>s are:
+
+=over 4
+
+=item B<strategy="STRING">
+
+Currently there is only one valid type:
+
+"host" means all reserved device memory on this platform should be checked to
+reserve regions in this VM's guest address space. This global rdm parameter
+allows user to specify reserved regions explicitly, and using "host" includes
+all reserved regions reported on this platform, which is useful when doing
+hotplug.
+
+By default this isn't set so we don't check all rdms. Instead, we just check
+rdm specific to a given device if you're assigning this kind of device. Note
+this option is not recommended unless you can make sure any conflict does exist.
+
+For example, you're trying to set "memory = 2800" to allocate memory to one
+given VM but the platform owns two RDM regions like,
+
+Device A [sbdf_A]: RMRR region_A: base_addr ac6d3000 end_address ac6e6fff
+Device B [sbdf_B]: RMRR region_B: base_addr ad800000 end_address afffffff
+
+In this conflict case,
+
+#1. If B<strategy> is set to "host", for example,
+
+rdm = "strategy=host,policy=strict" or rdm = "strategy=host,policy=relaxed"
+
+It means all conflicts will be handled according to the policy
+introduced by B<policy> as described below.
+
+#2. If B<strategy> is not set at all, but
+
+pci = [ 'sbdf_A, rdm_policy=xxxxx' ]
+
+It means only one conflict of region_A will be handled according to the policy
+introduced by B<rdm_policy="STRING"> as described inside pci options.
+
+=item B<policy="STRING">
+
+Specifies how to deal with conflicts when reserving reserved device
+memory in guest address space.
+
+When that conflict is unsolved,
+
+"strict" means VM can't be created, or the associated device can't be
+attached in the case of hotplug.
+
+"relaxed" allows VM to be created but may cause VM to crash if
+pass-through device accesses RDM. For exampl,e Windows IGD GFX driver
+always accessed RDM regions so it leads to VM crash.
+
+Note this may be overridden by rdm_policy option in PCI device configuration.
+
+=back
+
+=back
+
=item B<pci=[ "PCI_SPEC_STRING", "PCI_SPEC_STRING", ... ]>
Specifies the host PCI devices to passthrough to this guest. Each B<PCI_SPEC_STRING>
D0-D3hot power management states for the PCI device. False (0) by
default.
+=item B<rdm_policy="STRING">
+
+(HVM/x86 only) This is same as policy option inside the rdm option but
+just specific to a given device. Therefore the default is "relaxed" as
+same as policy option as well.
+
+Note this would override global B<rdm> option.
+
=back
=back
To override for a specific device:
pci = [ '01:00.0,msitranslate=0', '03:00.0' ]
+RDM, 'reserved device memory', for PCI Device Passthrough
+---------------------------------------------------------
+
+There are some devices the BIOS controls, for e.g. USB devices to perform
+PS2 emulation. The regions of memory used for these devices are marked
+reserved in the e820 map. When we turn on DMA translation, DMA to those
+regions will fail. Hence BIOS uses RMRR to specify these regions along with
+devices that need to access these regions. OS is expected to setup
+identity mappings for these regions for these devices to access these regions.
+
+While creating a VM we should reserve them in advance, and avoid any conflicts.
+So we introduce user configurable parameters to specify RDM resource and
+according policies,
+
+To enable this globally, add "rdm" in the config file:
+
+ rdm = "strategy=host, policy=relaxed" (default policy is "relaxed")
+
+Or just for a specific device:
+
+ pci = [ '01:00.0,rdm_policy=relaxed', '03:00.0,rdm_policy=strict' ]
+
+For all the options available to RDM, see xl.cfg(5).
+
Caveat on Conventional PCI Device Passthrough
---------------------------------------------
return 0;
}
+void libxl__rdm_setdefault(libxl__gc *gc, libxl_domain_build_info *b_info)
+{
+ if (b_info->u.hvm.rdm.policy == LIBXL_RDM_RESERVE_POLICY_INVALID)
+ b_info->u.hvm.rdm.policy = LIBXL_RDM_RESERVE_POLICY_RELAXED;
+}
+
int libxl__domain_build_info_setdefault(libxl__gc *gc,
libxl_domain_build_info *b_info)
{
libxl_defbool_setdefault(&b_info->u.hvm.gfx_passthru, false);
+ libxl__rdm_setdefault(gc, b_info);
break;
case LIBXL_DOMAIN_TYPE_PV:
libxl_defbool_setdefault(&b_info->u.pv.e820_host, false);
_hidden int libxl__device_vfb_setdefault(libxl__gc *gc, libxl_device_vfb *vfb);
_hidden int libxl__device_vkb_setdefault(libxl__gc *gc, libxl_device_vkb *vkb);
_hidden int libxl__device_pci_setdefault(libxl__gc *gc, libxl_device_pci *pci);
+_hidden void libxl__rdm_setdefault(libxl__gc *gc,
+ libxl_domain_build_info *b_info);
_hidden const char *libxl__device_nic_devname(libxl__gc *gc,
uint32_t domid,
out:
if (!libxl_is_stubdom(ctx, domid, NULL)) {
+ if (pcidev->rdm_policy == LIBXL_RDM_RESERVE_POLICY_STRICT) {
+ flag &= ~XEN_DOMCTL_DEV_RDM_RELAXED;
+ } else if (pcidev->rdm_policy != LIBXL_RDM_RESERVE_POLICY_RELAXED) {
+ LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "unknown rdm check flag.");
+ return ERROR_FAIL;
+ }
rc = xc_assign_device(ctx->xch, domid, pcidev_encode_bdf(pcidev), flag);
if (rc < 0 && (hvm || errno != ENOSYS)) {
LIBXL__LOG_ERRNO(ctx, LIBXL__LOG_ERROR, "xc_assign_device failed");
int libxl__device_pci_setdefault(libxl__gc *gc, libxl_device_pci *pci)
{
+ /* We'd like to force reserve rdm specific to a device by default.*/
+ if (pci->rdm_policy == LIBXL_RDM_RESERVE_POLICY_INVALID)
+ pci->rdm_policy = LIBXL_RDM_RESERVE_POLICY_STRICT;
return 0;
}
(2, "PV"),
], init_val = "LIBXL_DOMAIN_TYPE_INVALID")
+libxl_rdm_reserve_strategy = Enumeration("rdm_reserve_strategy", [
+ (0, "ignore"),
+ (1, "host"),
+ ])
+
+libxl_rdm_reserve_policy = Enumeration("rdm_reserve_policy", [
+ (-1, "invalid"),
+ (0, "strict"),
+ (1, "relaxed"),
+ ], init_val = "LIBXL_RDM_RESERVE_POLICY_INVALID")
+
libxl_channel_connection = Enumeration("channel_connection", [
(0, "UNKNOWN"),
(1, "PTY"),
(0x30, "v3")
], init_val = "LIBXL_GIC_VERSION_DEFAULT")
+libxl_rdm_reserve = Struct("rdm_reserve", [
+ ("strategy", libxl_rdm_reserve_strategy),
+ ("policy", libxl_rdm_reserve_policy),
+ ])
+
libxl_domain_build_info = Struct("domain_build_info",[
("max_vcpus", integer),
("avail_vcpus", libxl_bitmap),
# See libxl_ms_vm_genid_generate()
("ms_vm_genid", libxl_ms_vm_genid),
("serial_list", libxl_string_list),
+ ("rdm", libxl_rdm_reserve),
])),
("pv", Struct(None, [("kernel", string),
("slack_memkb", MemKB),
("power_mgmt", bool),
("permissive", bool),
("seize", bool),
+ ("rdm_policy", libxl_rdm_reserve_policy),
])
libxl_device_dtdev = Struct("device_dtdev", [
projects / xen.git / commitdiff