Currently CPU frequency control is hidden to guests, and controlled
by hypervisor. While it is sufficient in most cases, some guest OS may
still need CPU performance info to make multi-core scheduling decisions.
This is seen on Linux kernel, which uses HWP highest performance level
as CPU core's priority in multi-core scheduling (CONFIG_SCHED_MC_PRIO).
Enabling this kernel feature could improve performance as single thread
workloads are scheduled on the highest performance cores. This is
significantly useful for guests with hybrid cores.
The concept is to expose performance interface to guest who exclusively
owns pCPU assigned to it. So that Linux guest can load intel_pstate
driver which will then provide the kernel with each core's schedule
priority.
Intel_pstate driver also relies on CONFIG_ACPI_CPPC_LIB to implement
this mechanic, this means we also need to provide ACPI _CPC in DM.
This patch sets up a guest flag GUEST_FLAG_VHWP to indicate whether
the guest can have VHWP feature.
Tracked-On: #8414
Signed-off-by: Wu Zhou <wu.zhou@intel.com>
Reviewed-by: Junjie Mao <junjie.mao@intel.com>
The design of ACRN CPU performance management is to let hardware
do the autonomous frequency selection(or set to a fixed value),
and remove guest's ability to control CPU frequency.
This patch is to implement the CPU frequency initializer, which will
setup CPU frequency base on the performance policy type.
Two performance policy types are provided for user to choose from:
- 'Performance': CPU runs at its CPU runs at its maximum frequency.
Enable hardware autonomous frequency selection if HWP is presented.
- 'Nominal': CPU runs at its guaranteed frequency.
The policy type is passed to hypervisor through boot parameter, as
either 'cpu_perf_policy=Nominal' or 'cpu_perf_policy=Performance'.
The default type is 'Performance'.
Both HWP and ACPI p-state are supported. HWP is the first choice, for
it provides hardware autonomous frequency selection, while keeps
frequency transaction time low.
Two functions are added to the hypervisor to call:
- init_frequency_policy(): called by BSP at start up time. It processes
the boot parameters, and enables HWP if it is presented.
- apply_frequency_policy(): called after init_frequency_policy().
It applies initial CPU frequency policy setting for each core. It
uses a set of frequency limits data struct to quickly decide what the
highest/nominal frequency is. The frequency limits are generated by
config-tools.
The hypervisor will not be governing CPU frequency after initial policy
is applied.
Cores running RTVMs are fixed to nominal/guaranteed frequency, to get
more certainty in latency. This is done by setting the core's frequency
limits to highest=lowest=nominal in config-tools.
Tracked-On: #8168
Signed-off-by: Wu Zhou <wu.zhou@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
For an IO request, hv will check if it was registered in asyncio desc
list. If yes, put the corresponding fd to the shared buffer. If the
shared buffer is full, yield the vcpu and try again later.
Tracked-On: #8209
Signed-off-by: Conghui <conghui.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Add hypercall to add/remove asyncio request info. Hv will record the
info in a list, and when a new ioreq is come, hv will check if it is
in the asyncio list, if yes, queue the fd to asyncio buffer.
Tracked-On: #8209
Signed-off-by: Conghui <conghui.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Current IO emulation is synchronous. The user VM need to wait for the
completion of the the I/O request before return. But Virtio Spec
introduces introduces asynchronous IO with a new register in MMIO/PIO
space named NOTIFY, to be used for FE driver to notify BE driver, ACRN
hypervisor can emulate this register by sending a notification to vCPU
in Service VM side. This way, FE side can resume to work without waiting
for the full completion of BE side response.
Tracked-On: #8209
Signed-off-by: Conghui <conghui.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Extend sbuf hypercall to support other kinds of share buffer.
Tracked-On: #8209
Signed-off-by: Conghui <conghui.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
sbuf is now only used for debug purpose, but later, it will be used as a
common interfaces. So, move the sbuf related code out of the debug directory.
Tracked-On: #8209
Signed-off-by: Conghui <conghui.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Modified the copyright year range in code, and corrected "int32_tel"
into "Intel" in two "hypervisor/include/debug/profiling.h" and
"hypervisor/include/debug/profiling_internal.h".
Tracked-On: #7559
Signed-off-by: Ziheng Li <ziheng.li@intel.com>
Many of the license and Intel copyright headers include the "All rights
reserved" string. It is not relevant in the context of the BSD-3-Clause
license that the code is released under. This patch removes those strings
throughout the code (hypervisor, devicemodel and misc).
Tracked-On: #7254
Signed-off-by: Geoffroy Van Cutsem <geoffroy.vancutsem@intel.com>
Add a flag: GUEST_FLAG_PMU_PASSTHROUGH to indicate if
PMU (Performance Monitor Unit) is passthrough to guest VM.
Tracked-On: #6966
Acked-by: Anthony Xu <anthony.xu@intel.com>
Signed-off-by: Minggui Cao <minggui.cao@intel.com>
HC_GET_PLATFORM_INFO hypercall is not supported anymore,
hence to remove related function and data structure definition.
Tracked-On: #6690
Signed-off-by: Yonghua Huang <yonghua.huang@intel.com>
This patch adds the x86_tee hypercall interfaces.
- HC_TEE_VCPU_BOOT_DONE
This hypercall is used to notify the hypervisor that the TEE VCPU Boot
is done, so that we can sleep the corresponding TEE VCPU. REE will be
started at the last time this hypercall is called by TEE.
- HC_SWITCH_EE
For REE VM, it uses this hypercall to request TEE service.
For TEE VM, it uses this hypercall to switch back to REE
when it completes the REE service.
Tracked-On: #6571
Signed-off-by: Jie Deng <jie.deng@intel.com>
Reviewed-by: Wang, Yu1 <yu1.wang@intel.com>
Acked-by: Eddie Dong <eddie.dong@Intel.com>
Add two VM flags for x86_tee. GUEST_FLAG_TEE for TEE VM,
GUEST_FLAG_REE for normal rich VM.
Tracked-On: #6571
Signed-off-by: Jie Deng <jie.deng@intel.com>
Reviewed-by: Wang, Yu1 <yu1.wang@intel.com>
Since the UUID is not a *must* set parameter for the standard post-launched
VM which doesn't depend on any static VM configuration. We can remove
the KATA related code from hypervisor as it belongs to such VM type.
v2-->v3:
separate the struce acrn_platform_info change of devicemodel
v1-->v2:
update the subject and commit msg
Tracked-On:#6685
Signed-off-by: Chenli Wei <chenli.wei@intel.com>
Reviewed-by: Wang, Yu1 <yu1.wang@intel.com>
With current arch design the UUID is used to identify ACRN VMs,
all VM configurations must be deployed with given UUIDs at build time.
For post-launched VMs, end user must use UUID as acrn-dm parameter
to launch specified user VM. This is not friendly for end users
that they have to look up the pre-configured UUID before launching VM,
and then can only launch the VM which its UUID in the pre-configured UUID
list,otherwise the launch will fail.Another side, VM name is much straight
forward for end user to identify VMs, whereas the VM name defined
in launch script has not been passed to hypervisor VM configuration
so it is not consistent with the VM name when user list VM
in hypervisor shell, this would confuse user a lot.
This patch will resolve these issues by removing UUID as VM identifier
and use VM name instead:
1. Hypervisor will check the VM name duplication during VM creation time
to make sure the VM name is unique.
2. If the VM name passed from acrn-dm matches one of pre-configured
VM configurations, the corresponding VM will be launched,
we call it static configured VM.
If there is no matching found, hypervisor will try to allocate one
unused VM configuration slot for this VM with given VM name and get it
run if VM number does not reach CONFIG_MAX_VM_NUM,
we will call it dynamic configured VM.
3. For dynamic configured VMs, we need a guest flag to identify them
because the VM configuration need to be destroyed
when it is shutdown or creation failed.
v7->v8:
-- rename is_static_vm_configured to is_static_configured_vm
-- only set DM owned guest_flags in hcall_create_vm
-- add check dynamic flag in get_unused_vmid
v6->v7:
-- refine get_vmid_by_name, return the first matching vm_id
-- the GUEST_FLAG_STATIC_VM is added to identify the static or
dynamic VM, the offline tool will set this flag for
all the pre-defined VMs.
-- only clear name field for dynamic VM instead of clear entire
vm_config
Tracked-On: #6685
Signed-off-by: Mingqiang Chi <mingqiang.chi@intel.com>
Reviewed-by: Zhao Yakui <yakui.zhao@intel.com>
Reviewed-by: Victor Sun<victor.sun@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
The coding guideline rule C-TY-12 requires that 'all type conversions shall
be explicit'. Especially implicit cases on the signedness of variables
shall be avoided.
This patch either adds explicit type casts or adjust local variable types
to make sure that Booleans, signed and unsigned integers are not used
mixedly.
This patch has no semantic changes.
Tracked-On: #6776
Signed-off-by: Junjie Mao <junjie.mao@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Rename SOS_VM type to SERVICE_VM
rename UOS to User VM in XML description
rename uos_thread_pid to user_vm_thread_pid
rename devname_uos to devname_user_vm
rename uosid to user_vmid
rename UOS_ACK to USER_VM_ACK
rename SOS_VM_CONFIG_CPU_AFFINITY to SERVICE_VM_CONFIG_CPU_AFFINITY
rename SOS_COM to SERVICE_VM_COM
rename SOS_UART1_VALID_NUM" to SERVICE_VM_UART1_VALID_NUM
rename SOS_BOOTARGS_DIFF to SERVICE_VM_BOOTARGS_DIFF
rename uos to user_vm in launch script and xml
Tracked-On: #6744
Signed-off-by: Liu Long <long.liu@linux.intel.com>
Reviewed-by: Geoffroy Van Cutsem <geoffroy.vancutsem@intel.com>
Rename gpa_uos to gpa_user_vm
rename base_gpa_in_uos to base_gpa_in_user_vm
rename UOS_VIRT_PCI_MMCFG_BASE to USER_VM_VIRT_PCI_MMCFG_BASE
rename UOS_VIRT_PCI_MMCFG_START_BUS to USER_VM_VIRT_PCI_MMCFG_START_BUS
rename UOS_VIRT_PCI_MMCFG_END_BUS to USER_VM_VIRT_PCI_MMCFG_END_BUS
rename UOS_VIRT_PCI_MEMBASE32 to USER_VM_VIRT_PCI_MEMBASE32
rename UOS_VIRT_PCI_MEMLIMIT32 to USER_VM_VIRT_PCI_MEMLIMIT32
rename UOS_VIRT_PCI_MEMBASE64 to USER_VM_VIRT_PCI_MEMBASE64
rename UOS_VIRT_PCI_MEMLIMIT64 to USER_VM_VIRT_PCI_MEMLIMIT64
rename UOS in comments message to User VM.
Tracked-On: #6744
Signed-off-by: Liu Long <long.liu@linux.intel.com>
Reviewed-by: Geoffroy Van Cutsem <geoffroy.vancutsem@intel.com>
Rename sos_vm to service_vm.
rename sos_vmid to service_vmid.
rename sos_vm_ptr to service_vm_ptr.
rename get_sos_vm to get_service_vm.
rename sos_vm_gpa to service_vm_gpa.
rename sos_vm_e820 to service_vm_e820.
rename sos_efi_info to service_vm_efi_info.
rename sos_vm_config to service_vm_config.
rename sos_vm_hpa2gpa to service_vm_hpa2gpa.
rename vdev_in_sos to vdev_in_service_vm.
rename create_sos_vm_e820 to create_service_vm_e820.
rename sos_high64_max_ram to service_vm_high64_max_ram.
rename prepare_sos_vm_memmap to prepare_service_vm_memmap.
rename post_uos_sworld_memory to post_user_vm_sworld_memory
rename hcall_sos_offline_cpu to hcall_service_vm_offline_cpu.
rename filter_mem_from_sos_e820 to filter_mem_from_service_vm_e820.
rename create_sos_vm_efi_mmap_desc to create_service_vm_efi_mmap_desc.
rename HC_SOS_OFFLINE_CPU to HC_SERVICE_VM_OFFLINE_CPU.
rename SOS to Service VM in comments message.
Tracked-On: #6744
Signed-off-by: Liu Long <long.liu@linux.intel.com>
Reviewed-by: Geoffroy Van Cutsem <geoffroy.vancutsem@intel.com>
Add the VCAT_ENABLED element to RDTType so that user can enable/disable vCAT globally
Add the GUEST_FLAG_VCAT_ENABLED guest flag to enable/disable vCAT per-VM.
Currently we have the following per-VM clos element in scenario file for RDT use:
<clos>
<vcpu_clos>0</vcpu_clos>
<vcpu_clos>0</vcpu_clos>
</clos>
When the GUEST_FLAG_VCAT_ENABLED guest flag is not specified, clos is for RDT use,
vcpu_clos is per-CPU and it configures each CPU in VMs to a desired CLOS ID.
When the GUEST_FLAG_VCAT_ENABLED guest flag is specified, vCAT is enabled for this VM,
clos is for vCAT use, vcpu_clos is not per-CPU anymore in this case, just a list of
physical CLOSIDs (minimum 2) that are assigned to VMs for vCAT use. Each vcpu_clos
will be mapped to a virtual CLOSID, the first vcpu_clos is mapped to virtual CLOSID
0 and the second is mapped to virtual CLOSID 1, etc
Add xs:assert to prevent any problems with invalid configuration data for vCAT:
If any GUEST_FLAG_VCAT_ENABLED guest flag is specified, both RDT_ENABLED and VCAT_ENABLED
must be 'y'
If VCAT_ENABLED is 'y', RDT_ENABLED must be 'y' and CDP_ENABLED must be 'n'
For a vCAT VM, vcpu_clos cannot be set to CLOSID 0, CLOSID 0 is reserved to be used by hypervisor
For a vCAT VM, number of clos/vcpu_clos elements must be greater than 1
For a vCAT VM, each clos/vcpu_clos must be less than L2/L3 COS_MAX
For a vCAT VM, its clos/vcpu_clos elements cannot contain duplicate values
There should not be any CLOS IDs overlap between a vCAT VM and any other VMs
Tracked-On: #5917
Signed-off-by: dongshen <dongsheng.x.zhang@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
PR #6283 updated code and docs to the new kernel HSM driver. Fix
some references to VHM missed in the doxygen comments. Also fixed some
misspellings while in these files.
Tracked-On: #6282
Signed-off-by: David B. Kinder <david.b.kinder@intel.com>
This patch renames the GUEST_FLAG_TPM2_FIXUP to
GUEST_FLAG_SECURITY_VM.
v2 -> v3:
The "FIXUP" suffix is removed.
Tracked-On: #6320
Signed-off-by: Yifan Liu <yifan1.liu@intel.com>
ACRN used to prepare the vTPM2 ACPI Table for pre-launched VM at the build stage
using config tools. This is OK if the TPM2 ACPI Table never changes. However,
TPM2 ACPI Table may be changed in some conditions: change BIOS configuration or
update BIOS.
This patch do TPM2 fixup to update the vTPM2 ACPI Table and TPM2 MMIO resource
configuration according to the physical TPM2 ACPI Table.
Tracked-On: #6366
Signed-off-by: Tao Yuhong <yuhong.tao@intel.com>
Signed-off-by: Fei Li <fei1.li@intel.com>
1. add a name field to indicate what the MMIO Device is.
2. add two more MMIO resource to the acrn_mmiodev data structure.
Tracked-On: #6366
Signed-off-by: Tao Yuhong <yuhong.tao@intel.com>
Signed-off-by: Fei Li <fei1.li@intel.com>
Common structures are used by DM, kernel, HV. Aligned attribute might
caused structures size mismatch between DM/HV and kernel, as kernel uses
default GCC alignment.
So, make DM/HV also use the default GCC alignment.
Tracked-On: #6282
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
IC_ADD_HV_VDEV -> ACRN_IOCTL_CREATE_VDEV
IC_REMOVE_HV_VDEV -> ACRN_IOCTL_DESTROY_VDEV
struct acrn_emul_dev -> struct acrn_vdev
Also, move struct acrn_vdev to acrn_common.h as this structure is used
by both DM and HV.
Tracked-On: #6282
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
IC_ASSIGN_MMIODEV -> ACRN_IOCTL_ASSIGN_MMIODEV
IC_DEASSIGN_MMIODEV -> ACRN_IOCTL_DEASSIGN_MMIODEV
struct acrn_mmiodev has slight change. Move struct acrn_mmiodev into
acrn_common.h because it is used by both DM and HV.
Tracked-On: #6282
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
IC_ASSIGN_PCIDEV -> ACRN_IOCTL_ASSIGN_PCIDEV
IC_DEASSIGN_PCIDEV -> ACRN_IOCTL_DEASSIGN_PCIDEV
QUIRK_PTDEV -> ACRN_PTDEV_QUIRK_ASSIGN
struct acrn_assign_pcidev -> struct acrn_pcidev
Move struct acrn_pcidev into acrn_common.h because it is used by both
DM and HV.
Tracked-On: #6282
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
struct hc_platform_info -> struct acrn_platform_info
MAX_PLATFORM_LAPIC_IDS -> ACRN_PLATFORM_LAPIC_IDS_MAX
A layout change to the struct hc_platform_info is that move
max_kata_containers to back of vm_config_size,
uint16_t max_vcpus_per_vm;
uint16_t max_vms;
uint32_t vm_config_size;
uint64_t max_kata_containers;
Then, they are nature 64-bits aligned.
Tracked-On: #6282
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
It seems important that passthru device's max payload settings match
the settings on the native device otherwise passthru device may not work.
So we have to set vrp's max payload capacity as native root port
otherwise we may accidentally change passthru device's max payload
since during guest OS's pci device enumeration, pass-thru device will
renegotiate its max payload's setting with vrp.
Tracked-On: #5915
Signed-off-by: Rong Liu <rong.l.liu@intel.com>
Reviewed-by: Jason Chen CJ <jason.cj.chen@intel.com>
So that DM can retrieve physical APIC IDs and use them to fill in the ACPI MADT table for
post-launched VMs.
Note:
1. DM needs to use the same logic as hypervisor to calculate vLAPIC IDs based on physical APIC IDs
and CPU affinity setting
2. Using reserved0[] in struct hc_platform_info to pass physical APIC IDs means we can only support at
most 116 cores. And it assumes LAPIC ID is 8bits (X2APIC mode supports 32 bits).
Cat IDs shift will be used by DM RTCT V2
Tracked-On: #6020
Reviewed-by: Wang, Yu1 <yu1.wang@intel.com>
Signed-off-by: dongshen <dongsheng.x.zhang@intel.com>
If PTM can be enabled on passthru device, a virtual root port
is added to vm to act as ptm root. And the passthru device is
connected to the virtual root port instead of the virtual host bridge.
Tracked-On: #5915
Signed-off-by: Rong Liu <rong.l.liu@intel.com>
Acked-by: Yu Wang <yu1.wang@intel.com>
NVMX_ENABLED: ACRN is built to support nested virtualization if set.
GUEST_FLAG_NVMX_ENABLED: indicates that the VMX capability can be present
in this guest to run nested VMs.
Tracked-On: #5923
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Currently, ACRN only support shutdown when triple fault happens, because ACRN
doesn't present/emulate a virtual HW, i.e. port IO, to support shutdown. This
patch emulate a virtual shutdown component, and the vACPI method for guest OS
to use.
Pre-launched VM uses ACPI reduced HW mode, intercept the virtual sleep control/status
registers for pre-launched VMs shutdown
Tracked-On: #5411
Signed-off-by: dongshen <dongsheng.x.zhang@intel.com>
Add HC_CREATE_VDEV and HC_DESTROY_VDEV two hypercalls that are used to
create and destroy an emulated device(PCI device or legacy device) in hypervisor
v3: 1) change HC_CREATE_DEVICE and HC_DESTROY_DEVICE to HC_CREATE_VDEV
and HC_DESTROY_VDEV
2) refine code style
v4: 1) remove unnecessary parameter
2) add VM state check for HC_CREATE_VDEV and HC_DESTROY hypercalls
Tracked-On: #4853
Reviewed-by: Wang, Yu1 <yu1.wang@intel.com>
Signed-off-by: Yuan Liu <yuan1.liu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
-- use an array to fast locate the hypercall handler
to replace switch case.
-- uniform hypercall handler as below:
int32_t (*handler)(sos_vm, target_vm, param1, param2)
Tracked-On: #4958
Signed-off-by: Mingqiang Chi <mingqiang.chi@intel.com>
Reviewed-by: Jason Chen CJ <jason.cj.chen@intel.com>
Reviewed-by: Eddie Dong <eddie.dong@intel.com>
Add two hypercalls to support MMIO device pass through for post-launched VM.
And when we support MMIO pass through for pre-launched VM, we could re-use
the code in mmio_dev.c
Tracked-On: #5053
Signed-off-by: Li Fei1 <fei1.li@intel.com>
- add a new member cpu_affinity to struct acrn_create_vm, so that acrn-dm
is able to assign CPU affinity through HC_CREATE_VM hypercall.
- if vm_create.cpu_affinity is zero, hypervisor launches the VM with the
statically configured CPU affinity.
Tracked-On: #4616
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Hypervisor reports VM configuration information to SOS which can be used to
dynamically allocate VCPU affinity.
Servise OS can get the vm_configs in this order:
1. call platform_info HC (set vm_configs_addr with 0) to get max_vms and
vm_config_entry_size.
2. allocate memory for acrn_vm_config array based on the number of VMs
and entry size that just got in step 1.
3. call platform_info HC again to collect VM configurations.
Tracked-On: #4616
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
There're some PCI devices need special handler for vendor-specical feature or
capability CFG access. The Intel GPU is one of them. In order to keep the ACRN-HV
clean, we want to throw the qurik part of PCI CFG asccess to DM to handle.
To achieve this, we implement per-device policy base on whether it needs quirk handler
for a VM: each device could configure as "quirk pass through device" or not. For a
"quirk pass through device", we will handle the general part in HV and the quirk part
in DM. For a non "quirk pass through device", we will handle all the part in HV.
Tracked-On: #4371
Signed-off-by: Li Fei1 <fei1.li@intel.com>
Now we split passthrough PCI device from DM to HV, we could remove all the passthrough
PCI device unused code.
Tracked-On: #4371
Signed-off-by: Li Fei1 <fei1.li@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Add assign/deassign PCI device hypercall APIs to assign a PCI device from SOS to
post-launched VM or deassign a PCI device from post-launched VM to SOS. This patch
is prepared for spliting passthrough PCI device from DM to HV.
The old assign/deassign ptdev APIs will be discarded.
Tracked-On: #4371
Signed-off-by: Li Fei1 <fei1.li@intel.com>
In platforms that support CAT, when it is enabled by ACRN, i.e.
IA32_resourceType_MASK_n registers are programmed with customized values,
it has impacts to the whole system.
The per guest flag GUEST_FLAG_CLOS_REQUIRED suggests that CAT may be
enabled in some guests, but not in others who don't have this flag,
which is conceptually incorrect.
This patch removes GUEST_FLAG_CLOS_REQUIRED, and adds a new Kconfig
entry CAT_ENABLED for CAT enabling. When it's enabled, platform_clos_array[]
defines a set of system-wide Class of Service (COS, or CLOS), and the
per guest vm_configs[].clos associates the guest with particular CLOS.
Tracked-On: #2462
Signed-off-by: Zide Chen <zide.chen@intel.com>
