RTVM (with lapic PT) boots hang when maxcpus is
assigned a value less than the CPU number configured
in hypervisor.
In this case, vlapic_state(per VM) is left in TRANSITION
state after BSP boot, which blocks interupts to be injected
to this UOS.
Tracked-On: #4803
Signed-off-by: Yonghua Huang <yonghua.huang@intel.com>
Reviewed-by: Li, Fei <fei1.li@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
remove unnecessary state check and
add pre-condition for vcpu APIs.
Tracked-On: #4320
Signed-off-by: Mingqiang Chi <mingqiang.chi@intel.com>
Reviewed-by: Jason Chen CJ <jason.cj.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Currently vlapic_build_id() uses vcpu_id to retrieve the lapic_id
per_cpu variable:
vlapic_id = per_cpu(lapic_id, vcpu->vcpu_id);
SOS vcpu_id may not equal to pcpu_id, and in that case it runs into
problems. For example, if any pre-launched VMs are launched on PCPUs
whose IDs are smaller than any PCPU IDs that are used by SOS.
This patch fixes the issue and simplify the code to create or get
vapic_id by:
- assign vapic_id in create_vlapic(), which now takes pcpu_id as input
argument, and save it in the new field: vlapic->vapic_id, which will
never be changed.
- simplify vlapic_get_apicid() by returning te saved vapid_id directly.
- remove vlapic_build_id().
- vlapic_init() is only called once, merge it into vlapic_create().
Tracked-On: #4268
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Maintain a per-pCPU array of vCPUs (struct acrn_vcpu *vcpu_array[CONFIG_MAX_VM_NUM]),
one VM cannot have multiple vCPUs share one pcpu, so we can utilize this property
and use the containing VM's vm_id as the index to the vCPU array:
In create_vcpu(), we simply do:
per_cpu(vcpu_array, pcpu_id)[vm->vm_id] = vcpu;
In offline_vcpu():
per_cpu(vcpu_array, pcpuid_from_vcpu(vcpu))[vcpu->vm->vm_id] = NULL;
so basically we use the containing VM's vm_id as the index to the vCPU array,
as well as the index of posted interrupt IRQ/vector pair that are assigned
to this vCPU:
0: first vCPU and first posted interrupt IRQs/vector pair
(POSTED_INTR_IRQ/POSTED_INTR_VECTOR)
...
CONFIG_MAX_VM_NUM-1: last vCPU and last posted interrupt IRQs/vector pair
((POSTED_INTR_IRQ + CONFIG_MAX_VM_NUM - 1U)/(POSTED_INTR_VECTOR + CONFIG_MAX_VM_NUM - 1U)
In the posted interrupt handler, it will do the following:
Translate the IRQ into a zero based index of where the vCPU
is located in the vCPU list for current pCPU. Once the
vCPU is found, we wake up the waiting thread and record
this request as ACRN_REQUEST_EVENT
Tracked-On: #4506
Signed-off-by: dongshen <dongsheng.x.zhang@intel.com>
Reviewed-by: Eddie Dong <eddie.dong@Intel.com>
Signed-off-by: dongshen <dongsheng.x.zhang@intel.com>
This is a preparation patch for adding support for VT-d PI
related vCPU scheduling.
ACRN does not support vCPU migration, one vCPU always runs on
the same pCPU, so PI's ndst is never changed after startup.
VCPUs of a VM won’t share same pCPU. So the maximum possible number
of VCPUs that can run on a pCPU is CONFIG_MAX_VM_NUM.
Allocate unique Activation Notification Vectors (ANV) for each vCPU
that belongs to the same pCPU, the ANVs need only be unique within each
pCPU, not across all vCPUs. This reduces # of pre-allocated ANVs for
posted interrupts to CONFIG_MAX_VM_NUM, and enables ACRN to avoid
switching between active and wake-up vector values in the posted
interrupt descriptor on vCPU scheduling state changes.
A total of CONFIG_MAX_VM_NUM consecutive IRQs/vectors are reserved
for posted interrupts use.
The code first initializes vcpu->arch.pid.control.bits.nv dynamically
(will be added in subsequent patch), the other code shall use
vcpu->arch.pid.control.bits.nv instead of the hard-coded notification vectors.
Rename some functions:
apicv_post_intr --> apicv_trigger_pi_anv
posted_intr_notification --> handle_pi_notification
setup_posted_intr_notification --> setup_pi_notification
Tracked-On: #4506
Signed-off-by: dongshen <dongsheng.x.zhang@intel.com>
Reviewed-by: Eddie Dong <eddie.dong@Intel.com>
This function casts a member of a structure out to the containing structure.
So rename to container_of is more readable.
Tracked-On: #4550
Signed-off-by: Li Fei1 <fei1.li@intel.com>
For CPU side posted interrupts, it only uses bit 0 (ON) of the PI's 64-bit control
, other bits are don't care. This is not the case for VT-d posted
interrupts, define more bit fields for the PI's 64-bit control.
Use bitmap functions to manipulate the bit fields atomically.
Some MISRA-C violation and coding style fixes
Tracked-On: #4506
Signed-off-by: dongshen <dongsheng.x.zhang@intel.com>
Reviewed-by: Eddie Dong <eddie.dong@Intel.com>
Current code avoid the rule 88 S in MISRA-C, so move xsaves and xrstors
assembler to individual functions.
Tracked-On: #4436
Signed-off-by: Conghui Chen <conghui.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
The init value for XCR0 and XSS should be the same with spec:
In SDM Vol1 13.3:
XCR0[0] is associated with x87 state (see Section 13.5.1). XCR0[0] is
always 1. The other bits in XCR0 are all 0 coming out of RESET.
The IA32_XSS MSR (with MSR index DA0H) is zero coming out of RESET.
The previous code try to fix the xsave area leak to other VMs during init
phase, but bring the error to linux. Besides, it cannot avoid the
possible leak in running phase. Need find a better solution.
Tracked-On: #4430
Signed-off-by: Conghui Chen <conghui.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
On UEFI UP2 board, APs might execute HLT before SOS kernel INIT them.
After SOS kernel take over and will re-init the APs directly. The flows
from HV perspective is like:
HLT trap:
wait_event(VCPU_EVENT_VIRTUAL_INTERRUPT) -> sleep_thread
SOS kernel INIT, SIPI APs:
pause_vcpu(ZOMBIE) -> sleep_thread
-> reset_vcpu
-> launch_vcpu -> wake_vcpu
However, the last wake_vcpu will fail because the cpu event
VCPU_EVENT_VIRTUAL_INTERRUPT had not got signaled.
This patch will reset all vcpu events in reset_vcpu. If the thread was
previously waiting for a event, its waiting status will be cleared and
launch_vcpu will wake it to running.
Tracked-On: #4402
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Introduce two kinds of events for each vcpu,
VCPU_EVENT_IOREQ: for vcpu waiting for IO request completion
VCPU_EVENT_VIRTUAL_INTERRUPT: for vcpu waiting for virtual interrupts events
vcpu can wait for such events, and resume to run when the
event get signalled.
This patch also change IO request waiting/notifying to this way.
Tracked-On: #4329
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Per SDM 10.12.5.1 vol.3, local APIC should keep LAPIC state after receiving
INIT. The local APIC ID register should also be preserved.
Tracked-On: #4267
Signed-off-by: Victor Sun <victor.sun@intel.com>
Reviewed-by: Jason Chen CJ <jason.cj.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
The patch abstract a vcpu_reset_internal() api for internal usage, the
function would not touch any vcpu state transition and just do vcpu reset
processing. It will be called by create_vcpu() and reset_vcpu().
The reset_vcpu() will act as a public api and should be called
only when vcpu receive INIT or vm reset/resume from S3. It should not be
called when do shutdown_vm() or hcall_sos_offline_cpu(), so the patch remove
reset_vcpu() in shutdown_vm() and hcall_sos_offline_cpu().
The patch also introduced reset_mode enum so that vcpu and vlapic could do
different context operation according to different reset mode;
Tracked-On: #4267
Signed-off-by: Victor Sun <victor.sun@intel.com>
Reviewed-by: Jason Chen CJ <jason.cj.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
In current architecutre, the maximum vCPUs number per VM could not
exceed the pCPUs number. Given the MAX_PCPU_NUM macro is provided
in board configurations, so remove the MAX_VCPUS_PER_VM from Kconfig
and add a macro of MAX_VCPUS_PER_VM to reference MAX_PCPU_NUM directly.
Tracked-On: #4230
Signed-off-by: Victor Sun <victor.sun@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
It's meaningless to sleep a non-running vcpu. Add a state check before
sleep the thread object of the vcpu.
Tracked-On: #4178
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
With cpu-sharing enabled, there are more than 1 vcpu on 1 pcpu, so the
smp_call handler should switch the vmcs to the target vcpu's vmcs. Then
get the info.
dump_vcpu_reg and dump_guest_mem should run on certain vmcs, otherwise,
there will be #GP error.
Renaming:
vcpu_dumpreg -> dump_vcpu_reg
switch_vmcs -> load_vmcs
Tracked-On: #4178
Signed-off-by: Conghui Chen <conghui.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
xsave area:
legacy region: 512 bytes
xsave header: 64 bytes
extended region: < 3k bytes
So, pre-allocate 4k area for xsave. Use certain instruction to save or
restore the area according to hardware xsave feature set.
Tracked-On: #4166
Signed-off-by: Conghui Chen <conghui.chen@intel.com>
Reviewed-by: Anthony Xu <anthony.xu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
We should use INIT signal to notify the vcpu threads when
powering off the hard RTVM. To achive this, we should set
the vcpu->thread_obj.notify_mode as SCHED_NOTIFY_INIT.
Patch (27163df9 hv: sched: add sleep/wake for thread object)
tries to set the notify_mode according `is_lapic_pt_enabled(vcpu)`
in function prepare_vcpu. But at this point, the is_lapic_pt_enabled(vcpu)
will always return false. Consequently, it will set notify_mode
as SCHED_NOTIFY_IPI. Then leads to the failure of powering off
hard RTVM.
This patch fixes it by:
- Initialize the notify_mode as SCHED_NOTIFY_IPI in prepare_vcpu.
- Set notify_mode as SCHED_NOTIFY_INIT after guest is trying to
enable x2apic mode of passthru lapic.
Tracked-On: #3975
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Reviewed-by: Yan, Like <like.yan@intel.com>
Signed-off-by: Kaige Fu <kaige.fu@intel.com>
kick means to notify one thread_object. If the target thread object is
running, send a IPI to notify it; if the target thread object is
runnable, make reschedule on it.
Also add kick_vcpu API in vcpu layer to notify vcpu.
Tracked-On: #3813
Signed-off-by: Jason Chen CJ <jason.cj.chen@intel.com>
Signed-off-by: Yu Wang <yu1.wang@intel.com>
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
This patch decouple some scheduling logic and abstract into a scheduler.
Then we have scheduler, schedule framework. From modulization
perspective, schedule framework provides some APIs for other layers to
use, also interact with scheduler through scheduler interaces.
Tracked-On: #3813
Signed-off-by: Jason Chen CJ <jason.cj.chen@intel.com>
Signed-off-by: Yu Wang <yu1.wang@intel.com>
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Let init thread end with run_idle_thread(), then idle thread take over and
start to do scheduling.
Change enter_guest_mode() to init_guest_mode() as run_idle_thread() is removed
out of it. Also add run_thread() in schedule module to run
thread_object's thread loop directly.
rename: switch_to_idle -> run_idle_thread
Tracked-On: #3813
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
sleep one thread_object means to prevent it from being scheduled.
wake one thread_object is an opposite operation of sleep.
This patch also add notify_mode in thread_object to indicate how to
deliver the request.
Tracked-On: #3813
Signed-off-by: Jason Chen CJ <jason.cj.chen@intel.com>
Signed-off-by: Yu Wang <yu1.wang@intel.com>
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
To support cpu sharing, multiple vcpu can run on same pcpu. We need do
necessary vcpu context switch. This patch add below actions in context
switch.
1) fxsave/fxrstor;
2) save/restore MSRs: MSR_IA32_STAR, MSR_IA32_LSTAR,
MSR_IA32_FMASK, MSR_IA32_KERNEL_GS_BASE;
3) switch vmcs.
Tracked-On: #3813
Signed-off-by: Jason Chen CJ <jason.cj.chen@intel.com>
Signed-off-by: Yu Wang <yu1.wang@intel.com>
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
With cpu sharing enabled, per_cpu vcpu cannot work properly as we might
has multiple vcpus running on one pcpu.
Add a schedule API sched_get_current to get current thread_object on
specific pcpu, also add a vcpu API get_running_vcpu to get corresponding
vcpu of the thread_object.
Tracked-On: #3813
Signed-off-by: Jason Chen CJ <jason.cj.chen@intel.com>
Signed-off-by: Yu Wang <yu1.wang@intel.com>
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
With cpu sharing enabled, we will map acrn_vcpu to thread_object
in scheduling. From modulization perspective, we'd better hide the
pcpu_id in acrn_vcpu and move it to thread_object.
Tracked-On: #3813
Signed-off-by: Jason Chen CJ <jason.cj.chen@intel.com>
Signed-off-by: Yu Wang <yu1.wang@intel.com>
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
vcpu thread's stack shouldn't follow reset_vcpu to reset.
There is also a bug here:
while vcpu B thread set vcpu->running to false, other vcpu A thread
will treat the vcpu B is paused while it has not been switch out
completely, then reset_vcpu will reset the vcpu B thread's stack and
corrupt its running context.
This patch will remove the vcpu thread's stack reset from reset_vcpu.
With the change, we need do init_vmcs between vcpu startup address be
settled and scheduled in. And switch_to_idle() is not needed anymore
as S3 thread's stack will not be reset.
Tracked-On: #3813
Signed-off-by: Fengwei Yin <fengwei.yin@intel.com>
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Currently we are using a 1:1 mapping logic for pcpu:vcpu. So don't need
a runqueue for it. Removing it as preparation work to abstract scheduler
framework.
Tracked-On: #3813
Signed-off-by: Jason Chen CJ <jason.cj.chen@intel.com>
Signed-off-by: Yu Wang <yu1.wang@intel.com>
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
--remove unnecessary includes
--remove unnecssary forward-declaration for 'struct vhm_request'
Tracked-On: #861
Signed-off-by: Mingqiang Chi <mingqiang.chi@intel.com>
As we introduced vcpu_affinity[] to assign vcpus to different pcpus, the
old policy and functions are not needed. Remove them.
Tracked-On: #3663
Signed-off-by: Conghui Chen <conghui.chen@intel.com>
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Now the structures(run_context & ext_context) are defined
in vcpu.h,and they are used in the lower-layer modules(wakeup.S),
this patch move down the structures from vcpu.h to cpu.h
to avoid reversed dependency.
Tracked-On: #1842
Signed-off-by: Mingqiang Chi <mingqiang.chi@intel.com>
Reviewed-by: Jason Chen CJ <jason.cj.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Currently, the clos id of the cpu cores in vmx root mode is the same as non-root mode.
For RTVM, if hypervisor share the same clos id with non-root mode, the cacheline may
be polluted due to the hypervisor code execution when vmexit.
The patch adds hv_clos in vm_configurations.c
Hypervisor initializes clos setting according to hv_clos during physical cpu cores initialization.
For RTVM, MSR auto load/store areas are used to switch different settings for VMX root/non-root
mode for RTVM.
Tracked-On: #2462
Signed-off-by: Binbin Wu <binbin.wu@intel.com>
Reviewed-by: Eddie Dong <eddie.dong@intel.com>
-- remove some unnecessary includes
-- fix a typo
-- remove unnecessary void before launch_vms
Tracked-On: #1842
Signed-off-by: Mingqiang Chi <mingqiang.chi@intel.com>
Now, we use native gdt saved in boot context for guest and assume
it could be put to same address of guest. But it may not be true
after the pre-launched VM is introduced. The gdt for guest could
be overwritten by guest images.
This patch make 32bit protect mode boot not use saved boot context.
Insteadly, we use predefined vcpu_regs value for protect guest to
initialize the guest bsp registers and copy pre-defined gdt table
to a safe place of guest memory to avoid gdt table overwritten by
guest images.
Tracked-On: #3532
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Reviewed-by: Jason Chen CJ <jason.cj.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
fix violations touched below:
1.Cast operation on a constant value
2.signed/unsigned implicity conversion
3.return value unused.
V1->V2:
1.bitmap api will return boolean type, not need to check "!= 0", deleted.
2.The behaves ~(uint32_t)X and (uint32_t)~X are not defined in ACRN hypervisor Coding Guidelines,
removed the change of it.
Tracked-On: #861
Signed-off-by: Huihuang Shi <huihuang.shi@intel.com>
Reviewed-by: Junjie Mao <junjie.mao@intel.com>
After "commit f0e1c5e init vcpu host stack when reset vcpu", SOS resume form S3
wants to schedule to vcpu_thread not the point where SOS enter S3. So we should
schedule to idel first then reschedule to execute vcpu_thread.
Tracked-On: #3387
Signed-off-by: Li, Fei1 <fei1.li@intel.com>
Otherwise, the previous local variables in host stack is not reset.
Tracked-On: #3387
Signed-off-by: Yin Fengwei <fengwei.yin@intel.com>
Acked-by: Anthony Xu <anthony.xu@intel.com>
This commit adds ops to vlapic structure, and add an *ops parameter to vlapic_reset().
At vlapic reset, the ops is set to the global apicv_ops, and may be assigned
to other ops later.
Tracked-On: #3227
Signed-off-by: Yan, Like <like.yan@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
vCPU schedule state change is under schedule lock protection. So there's no need
to be atomic.
Tracked-On: #1842
Signed-off-by: Li, Fei1 <fei1.li@intel.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
For pre-launched VMs and SOS, vCPUs are created on BSP one by one; For post-launched VMs,
vCPUs are created under vmm_hypercall_lock protection. So vcpu_create is called sequentially.
Operation in vcpu_create don't need to be atomic.
Tracked-On: #1842
Signed-off-by: Li, Fei1 <fei1.li@intel.com>
For per-vCPU, EOI exit bitmap is a global parameter which should set or clear
atomically since there's no lock to protect this critical variable.
Tracked-On: #1842
Signed-off-by: Li, Fei1 <fei1.li@intel.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
Now sched_object and sched_context are protected by scheduler_lock. There's no
chance to use runqueue_lock to protect schedule runqueue if we have no plan to
support schedule migration.
Signed-off-by: Li, Fei1 <fei1.li@intel.com>
Reviewed-by: Yin Fengwei <fengwei.yin@intel.com>
cancel_event_injection is not need any more if we do 'scheudle' prior to
acrn_handle_pending_request. Commit "921288a6672: hv: fix interrupt
lost when do acrn_handle_pending_request twice" bring 'schedule'
forward, so remove cancel_event_injection related stuff.
Tracked-On: #3374
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Reviewed-by: Jason Chen CJ <jason.cj.chen@intel.com>
Microarchitectural Data Sampling (MDS) is a hardware vulnerability
which allows unprivileged speculative access to data which is available
in various CPU internal buffers.
1. Mitigation on ACRN:
1) Microcode update is required.
2) Clear CPU internal buffers (store buffer, load buffer and
load port) if current CPU is affected by MDS, when VM entry
to avoid any information leakage to guest thru above buffers.
3) Mitigation is not needed if ARCH_CAP_MDS_NO bit (bit5)
is set in IA32_ARCH_CAPABILITIES MSR (10AH), in this case,
current processor is no affected by MDS vulnerability, in other
cases mitigation for MDS is required.
2. Methods to clear CPU buffers (microcode update is required):
1) L1D cache flush
2) VERW instruction
Either of above operations will trigger clearing all
CPU internal buffers if this CPU is affected by MDS.
Above mechnism is enumerated by:
CPUID.(EAX=7H, ECX=0):EDX[MD_CLEAR=10].
3. Mitigation details on ACRN:
if (processor is affected by MDS)
if (processor is not affected by L1TF OR
L1D flush is not launched on VM Entry)
execute VERW instruction when VM entry.
endif
endif
4. Referrence:
Deep Dive: Intel Analysis of Microarchitectural Data Sampling
https://software.intel.com/security-software-guidance/insights/
deep-dive-intel-analysis-microarchitectural-data-sampling
Deep Dive: CPUID Enumeration and Architectural MSRs
https://software.intel.com/security-software-guidance/insights/
deep-dive-cpuid-enumeration-and-architectural-msrs
Tracked-On: #3317
Signed-off-by: Yonghua Huang <yonghua.huang@intel.com>
Reviewed-by: Anthony Xu <anthony.xu@intel.com>
Reviewed-by: Jason CJ Chen <jason.cj.chen@intel.com>
ACRN coding guideline requires function shall have only one return entry.
Fix it.
Tracked-On: #861
Signed-off-by: Huihuang Shi <huihuang.shi@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
vcpu is never scan because of scan tool will be crashed!
After modulization, the vcpu can be scaned by the scan tool.
Clean up the violations in vcpu.c.
Fix the violations:
1.No brackets to then/else.
2.Function return value not checked.
3.Signed/unsigned coversion without cast.
V1->V2:
change the type of "vcpu->arch.irq_window_enabled" to bool.
V2->V3:
add "void *" prefix on the 1st parameter of memset.
Tracked-On: #861
Signed-off-by: Huihuang Shi <huihuang.shi@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
The sbuf is allocated for each pcpu by hypercall from SOS. Before launch
Guest OS, the script will offline cpus, which will trigger vcpu reset and
then reset sbuf pointer. But sbuf only initiate once by SOS, so these
cpus for Guest OS has no sbuf to use. Thus, when run 'acrntrace' on SOS,
there is no trace data for Guest OS.
To fix the issue, only reset the sbuf for SOS.
Tracked-On: #3335
Signed-off-by: Conghui Chen <conghui.chen@intel.com>
Reviewed-by: Eddie Dong <eddie.dong@intel.com>
Reviewed-by: Yan, Like <like.yan@intel.com>
