In very large number of VM extis, the VM-exit instruction length could be
zero, and it's no need to update VMX_GUEST_RIP.
Some examples:
- all external interrupt VM exits in non LAPIC passthru setup.
- for all the nested VM-exits that are reflecting to L1 hypervisor.
Tracked-On: #6289
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
- wrap a new function exec_vmentry() to reduce code duplication.
- remove exec_vmread(VMX_GUEST_RSP) since ACRN doesn't need to know
guest RSP in run time.
Tracked-On: #6289
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Change "uint64_t vmcs_hva" to "void *vmcs_hva" in the input argument,
list, so that no type casting is needed when calling them from pointers.
Tracked-On: #6289
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
update board name from nuc7i7dnb to nuc11tnbi5 in makefile because
we have removed the nuc7i7dnb board folder, and also update the
scenario name from industry to shared to fix "make all" build issue.
Tracked-On: #6315
Signed-off-by: Kunhui-Li <kunhuix.li@intel.com>
In current design, when pass-thru dev,
for the PIO bar, need to ensure the guest PIO start address
equals to host PIO start address.
But malicious guest may reprogram the PIO bar,
then hv will pass-thru the reprogramed PIO address to guest.
This isn't safe behavior.
When guest tries to reprogram pass-thru dev PIO bar,
inject #GP to guest directly.
Tracked-On: #6508
Signed-off-by: Liu,Junming <junming.liu@intel.com>
Reviewed-by: Zhao Yakui <yakui.zhao@intel.com>
Reviewed-by: Fei Li <fei1.li@intel.com>
In current design, when pass-thru dev,
for the PIO bar, need to ensure the guest PIO start address
equals to host PIO start address.
Then set the VMCS io bitmap to pass-thru the corresponding
port io to guest for performance.
ACRN-DM and acrn-config should ensure the identical mapping of PIO bar.
If ACRN-DM or acrn-config failed to achieve this,
we should deny the launch of VM
Tracked-On: #6508
Signed-off-by: Liu,Junming <junming.liu@intel.com>
Reviewed-by: Zhao Yakui <yakui.zhao@intel.com>
Reviewed-by: Fei Li <fei1.li@intel.com>
In the commit of 4e1deab3d9, we changed the
init sequence that init paging first and then init e820 because we worried
about the efi memory map could be beyond 4GB space on some platform.
After we double checked multiboot2 spec, when system boot from multiboot2
protocol, the efi memory map info will be embedded in multiboot info so it
is guaranteed that the efi memory map must be under 4GB space. Consider that
the page table will be allocated in free memory space in future, we have
to change the init sequence back that init e820 first and then init paging.
If we need to support other boot protocol in future that the efi memory map
might be put beyond 4GB, we could have below options:
1. Request bootloader put efi memory map below 4GB;
2. Call EFI_BOOT_SERVICES.GetMemoryMap() before ExitBootServices();
3. Enable a early 64bit page table to get the efi memory map only;
Tracked-On: #5626
Signed-off-by: Victor Sun <victor.sun@intel.com>
This patch changes the size of vvmcs[] array from 1 to
PER_VCPU_ACTIVE_VVMCS_NUM, and actually enables multiple active VMCS12
support in ACRN. The basic operations:
- if L1 VMPTRLDs a VMCS12 without previously VMCLEAR the current
VMCS12, ACRN no longer unconditionally flushes the current VMCS12
back to L1. Instead, it tries to keep both the current and the newly
loaded VMCS12 in the nested->vvmcs[] array, unless:
- if there is no more available vvmcs[] entry, ACRN flushes one active
VMCS12 to make room for this new VMCS12.
Tracked-On: #6289
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Some processors don't support VMX_PROCBASED_CTLS_TERTIARY bit
and VMX_PROCBASED_CTLS2_UWAIT_PAUSE bit in MSRs
(IA32_VMX_PROCBASED_CTLS & IA32_VMX_PROCBASED_CTLS2),
HV will output error log which will cause confusion,
change the log level from pr_err to pr_info.
Tracked-On: #6397
Signed-off-by: Mingqiang Chi <mingqiang.chi@intel.com>
This patch adds a new priority based scheduler to support
vCPU scheduling based on their pre-configured priorities.
A vCPU can be running only if there is no higher priority
vCPU running on the same pCPU.
Tracked-On: #6571
Signed-off-by: Jie Deng <jie.deng@intel.com>
The current config.mk uses the variable BOARD_FILE as the path to the board
XML when generating an unmodified copy of configuration files for
comparison, which is incorrect. The right variable is HV_BOARD_XML which is
the path to the copy of board XML that is actually used for the build.
This patch corrects the bug above.
In addition, this patch also skips binary files (which are not meant to be
edited manually) when calculating the differences.
Tracked-On: #6592
Signed-off-by: Junjie Mao <junjie.mao@intel.com>
For local APIC passthrough case, EOI would not trigger VM-exit. So virtual
'Remote IRR' would not be updated. Needs to read physical IOxAPIC RTE to
update virtual 'Remote IRR' field each time when guest wants to read I/O
REDIRECTION TABLE REGISTERS
Tracked-On: #5923
Signed-off-by: Fei Li <fei1.li@intel.com>
In local APIC passthrough case, when devices triggered a INTx interrupt, this
interrupt would be delivered to vCPU directly. For this case, need to set the
virtual vector in
the 'Interrupt Vector' field of physical IOxAPIC I/O REDIRECTION TABLE REGISTER
(bits 7:0) and 'Vector' field of vt-d Interrupt Remapping Table Entry (IRTE)
for Remapped Interrupts.
Assumption:
(a) IOAPIC pins won't be shared between LAPIC PT guest and other guests;
(b) The guest would not trigger this IRQ before it switched to x2 APIC mode.
Tracked-On: #5923
Signed-off-by: Zide Chen <zide.chen@intel.com>
check some essential vmx capablility,
will panic if processor doesn't support it.
Tracked-On: #6584
Signed-off-by: Mingqiang Chi <mingqiang.chi@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
In current RDT code, if CDP is configured, L2/L3 resources' num_closids calculation
is wrong:
res_cap_info[res].num_closids = (uint16_t)((edx & 0xffffU) >> 1U) + 1U;
Should be:
res_cap_info[res].num_closids = (uint16_t)((edx & 0xffffU) >> 1U + 1) >> 1U;
Aslo, in order to enable CDP system-wide, need to enable the CDP bit (bit 0) on all pcpus,
not just on pcpu 0.
Tracked-On: #5917
Signed-off-by: dongshen <dongsheng.x.zhang@intel.com>
Rename the clos_max field in struct rdt_info to num_closids
Rename variable valid_clos_num to common_num_closids and make it static
Tracked-On: #5917
Signed-off-by: dongshen <dongsheng.x.zhang@intel.com>
Normalize hypervisor help command output format, remove the 10 lines
limit for one screen, fix the misspelled words.
Tracked-On: #5112
Signed-off-by: Liu Long <long.liu@intel.com>
Reviewed-by: VanCutsem, Geoffroy <geoffroy.vancutsem@intel.com>
These dirty flags are supposed to be per VMCS12, so move them from the
per vCPU acrn_nested struct to the newly added acrn_vvmcs struct.
Tracked-On: #6289
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
This variable represents the L1 GPA of the current VMCS12. But it's
no longer needed in the multiple active VMCS12 case, which uses the
following variables for this purpose.
- nested->current_vvmcs refers to the vvmcs[] entry which contains the
cached current VMCS12, its associated VMCS02, and other context info.
- nested->current_vvmcs->vmcs12_gpa refers to the L1 GPA of this
current VMCS12.
Tracked-On: #6289
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Add an array of struct acrn_vvmcs to struct acrn_nested, so it is
possible to cache multiple active VMCS12s.
This patch declares the size of this array to 1, meaning that there is
only one active VMCS12. This is to minimize the logical code changes.
Add pointer current_vvmcs to struct acrn_nested, which refers to the
current vvmcs[] entry. In this patch, if any VMCS12 is active, it
always points to vvmcs[0].
Tracked-On: #6289
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
No any logical changes, this patch is preparing for multiple active
VMCS12 support.
- currently it's easy to get the vmcs12 pointer from the vcpu pointer.
In multiple active vmcs12 case, we need to explicitly add "struct
acrn_vmcs12 *vmcs12" to certain APIs' input argument list, in order to
get the desired vmcs12 pointer.
- merge flush_current_vmcs12() into clear_vmcs02() for multiple reasons:
a) it's called only once; b) we don't wrap the opposite operation
(loading vmcs12) in an API; c) this API has simple and clear logic.
Tracked-On: #6289
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
By changing the way to assign L1 VPID from bottom-up to top-down,
the possibilities for VPID conflicts between L1 and L2 guests are
small.
Then we can flush VPID just in case of conflicting.
Tracked-On: #6289
Signed-off-by: Anthony Xu <anthony.xu@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Before checking whether a PCI device is a Multi-Function Device or not, we need
make sure this PCI device is a valid PCI device. For a valid PCI device, the
'Header Layout' field in Header Type Register must be 000 0000b (Type 0 PCI device)
or 000 0001b (Type 1 PCI device).
So for a valid PCI device, the Header Type can't be 0xff.
Tracked-On: #4134
Signed-off-by: Fei Li <fei1.li@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
In run time, it's rare for L1 to write to the intercepted non host-state
VMCS fields, and using multiple dirty flags is not necessary.
This patch uses one single dirty flag to manage all non host-state VMCS
fields. This helps to simplify current code and in the future we may
not need to declare new dirty flags when we intercept more VMCS fields.
Tracked-On: #5923
Signed-off-by: Zide Chen <zide.chen@intel.com>
Currently vmptrld_vmexit_handler() doesn't sync VMX_EPT_POINTER_FULL
from vmcs12 to vmcs02, instead it sets gpa_field_dirty and relies on
nested_vmentry() to sync EPTP in next nested VMentry.
This creates readability issue since all other intercepted VMCS fields
are synced in sync_vmcs12_to_vmcs02(). Another issue is that other
VMCS fields managed by gpa_field_dirty are repeatedly synced in both
vmptrld and nested vmentry handler.
This patch moves get_nept_desc() ahead of sync_vmcs12_to_vmcs02(), such
that shadow_eptp is allocated before sync_vmcs12_to_vmcs02() which
can sync EPTP properly.
BTW, in nested_vmexit_handler(), don't need to read from VMCS to get
the exit reason, since vcpu->arch.exit_reason has it already.
Tracked-On: #5923
Signed-off-by: Zide Chen <zide.chen@intel.com>
Add a couple of missing dependencies in the ACRN Makefiles:
1. 'acrn.bin' is required before the hypervisor can be installed
2. The 'acrn_mngr.h' needs to be installed ('tools-install') in
the build folder.
Tracked-On: #6360
Signed-off-by: Geoffroy Van Cutsem <geoffroy.vancutsem@intel.com>
While we have default values of configuration entries stated in the schema
of scenario XMLs, today we still require user-given scenario XMLs to
contain literally ALL XML nodes. Missing of a single node will cause schema
validation errors even though we can use its default value defined in the
schema.
This patch allows user-given scenario XMLs to ignore nodes with default
values. It is done by adding the missing nodes, all containing the defined
default values, to the input scenario XML when copying it to the build
directory. This approach imposes no changes to either the schema or
subsequent scripts in the build system.
Tracked-On: #6292
Signed-off-by: Junjie Mao <junjie.mao@intel.com>
Previously it is (falsely) assumed that the major_ver of 32-bit SMBIOS
entry point structure (which is called SMBIOS 2.1 in spec, or SMBIOS2 in code)
will have a value of 2 and major_ver of 64-bit SMBIOS (which is called SMBIOS
3.0 in spec, and SMBIOS3 in code) will have a value of 3. This turned out to be
wrong. This major_ver refers to the implemented doc revision, and 32-bit SMBIOS2
can have its major_ver to be 3 (current most recent implementation).
This patch removes the use of major_ver to distinguish between
SMBIOS2/3, and use a doc-defined anchor string instead.
Tracked-On: #6528
Signed-off-by: Yifan Liu <yifan1.liu@intel.com>
The locked btr instruction is expensive. This patch changes the
logic to ensure that the bitmap is non-zero before executing
bitmap_test_and_clear_lock().
The VMX transition time gets significant improvement. SOS running
on TGL, the CPUID roundtrip reduces from ~2400 cycles to ~2000 cycles.
Tracked-On: #6289
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Currently ACRN assumes firmware setup IA32_PAT correctly. This patch
explicitly initializes host IA32_PAT MSR according to ISDM Table 11-12.
Memory Type Setting of PAT Entries Following a Power-up or Reset.
ACRN creates host page tables based on PAT0 (WB) and PAT3 (UC).
Tracked-On: #6289
Signed-off-by: Zide Chen <zide.chen@intel.com>
is_lapic_pt_enabled() is called at least twice in one loop of the vCPU
thread, and it's called in vmexit_handler() frequently if LAPIC is not
pass-through. Thus the efficiency of this function has direct
impact to the system performance.
Since the LAPIC mode is not changed in run time, we don't have to
calculate it on the fly in is_lapic_pt_enabled().
BTW, removed the unused lapic_mask from struct acrn_vcpu_arch.
Tracked-On: #6289
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
For platforms that do not support XSAVES/XRSTORS instructions, like QEMU,
executing these instructions causes #UD.
This patch adds the check before the execution of XSAVES/XRSTORS instructions.
It also refines the logic inside rstore_xsave_area for the following reason:
If XSAVES/XRSTORS instructions are supported, restore XSAVE area if any of the
following conditions is met:
1. "vcpu->launched" is false (state initialization for guest)
2. "vcpu->arch.xsave_enabled" is true (state restoring for guest)
* Before vCPU is launched, condition 1 is satisfied.
* After vCPU is launched, condition 2 is satisfied because
is_valid_xsave_combination() guarantees that "vcpu->arch.xsave_enabled"
is consistent with pcpu_has_cap(X86_FEATURE_XSAVES).
Therefore, the check against "vcpu->launched" and "vcpu->arch.xsave_enabled"
can be eliminated here.
Tracked-On: #6481
Signed-off-by: Shiqing Gao <shiqing.gao@intel.com>
Acked-by: Eddie Dong <eddie.dong@Intel.com>
Use an unused MSR on host to save ACRN pcpu ID and avoid saving and
restoring TSC AUX MSR on VMX transitions.
Tracked-On: #6289
Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
Reviewed-by: Eddie Dong <eddie.dong@intel.com>
This feature is guarded under config CONFIG_SECURITY_VM_FIXUP, which
by default should be disabled.
This patch passthrough native SMBIOS information to prelaunched VM.
SMBIOS table contains a small entry point structure and a table, of which
the entry point structure will be put in 0xf0000-0xfffff region in guest
address space, and the table will be put in the ACPI_NVS region in guest
address space.
v2 -> v3:
uuid_is_equal moved to util.h as inline API
result -> pVendortable, in function efi_search_guid
recalc_checksum -> generate_checksum
efi_search_smbios -> efi_search_smbios_eps
scan_smbios_eps -> mem_search_smbios_eps
EFI GUID definition kept
Tracked-On: #6320
Signed-off-by: Yifan Liu <yifan1.liu@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>
In ACRN RT VM if the lapic is passthrough to the guest, the ipi can't
trigger VM_EXIT and the vNMI is just for notification, it can't handle
the smp_call function. Modify vcpu_dumpreg function prompt user switch
to vLAPIC mode for vCPU register dump.
Tracked-On: #6473
Signed-off-by: Liu Long <long.liu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
- remove vcpu->arch.nrexits which is useless.
- record full 32 bits of exit_reason to TRACE_2L(). Make the code simpler.
Tracked-On: #6289
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
GSI of hcall_set_irqline should be checked against target_vm's
total GSI count instead of SOS's total GSI count.
Tracked-On: #6357
Signed-off-by: Jian Jun Chen <jian.jun.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
This helps to improve performance:
- Don't need to execute VMREAD in vcpu_get_efer(), which is frequently
called.
- VMX_EXIT_CTLS_SAVE_EFER can be removed from VM-Exit Controls.
- If the value of IA32_EFER MSR is identical between the host and guest
(highly likely), adjust the VMX controls not to load IA32_EFER on
VMExit and VMEntry.
It's convenient to continue use the exiting vcpu_s/get_efer() APIs,
other than the common vcpu_s/get_guest_msr().
Tracked-On: #6289
Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
MAXIMUM_PA_WIDTH will be calculated from board information.
Tracked-On: #6357
Signed-off-by: Liang Yi <yi.liang@intel.com>
Signed-off-by: Junjie Mao <junjie.mao@intel.com>
Mask off support of 57-bit linear addresses and five-level paging.
ICX-D has LA57 but ACRN doesn't support 5-level paging yet.
Tracked-On: #6357
Signed-off-by: Liang Yi <yi.liang@intel.com>
Signed-off-by: Li, Fei1 <fei1.li@intel.com>
It is used to specify the maximum number of EFI memmap entries.
On some platforms, like Tiger Lake, the number of EFI memmap entries
becomes 268 when the BIOS settings are changed.
The current value of MAX_EFI_MMAP_ENTRIES (256) defined in hypervisor
is not big enough to cover such cases.
As the number of EFI memmap entries depends on the platforms and the
BIOS settings, this patch introduces a new entry MAX_EFI_MMAP_ENTRIES
in configurations so that it can be adjusted for different cases.
Tracked-On: #6442
Signed-off-by: Shiqing Gao <shiqing.gao@intel.com>
If SOS is using kernel 5.4, hypervisor got panic with #GP.
Here is an example on KBL showing how the panic occurs when kernel 5.4 is used:
Notes:
* Physical MSR_IA32_XSS[bit 8] is 1 when physical CPU boots up.
* vcpu_get_guest_msr(vcpu, MSR_IA32_XSS)[bit 8] is initialized to 0.
Following thread switches would happen at run time:
1. idle thread -> vcpu thread
context_switch_in happens and rstore_xsave_area is called.
At this moment, vcpu->arch.xsave_enabled is false as vcpu is not launched yet
and init_vmcs is not called yet (where xsave_enabled is set to true).
Thus, physical MSR_IA32_XSS is not updated with the value of guest MSR_IA32_XSS.
States at this point:
* Physical MSR_IA32_XSS[bit 8] is 1.
* vcpu_get_guest_msr(vcpu, MSR_IA32_XSS)[bit 8] is 0.
2. vcpu thread -> idle thread
context_switch_out happens and save_xsave_area is called.
At this moment, vcpu->arch.xsave_enabled is true. Processor state is saved
to memory with XSAVES instruction. As physical MSR_IA32_XSS[bit 8] is 1,
ectx->xs_area.xsave_hdr.hdr.xcomp_bv[bit 8] is set to 1 after the execution
of XSAVES instruction.
States at this point:
* Physical MSR_IA32_XSS[bit 8] is 1.
* vcpu_get_guest_msr(vcpu, MSR_IA32_XSS)[bit 8] is 0.
* ectx->xs_area.xsave_hdr.hdr.xcomp_bv[bit 8] is 1.
3. idle thread -> vcpu thread
context_switch_in happens and rstore_xsave_area is called.
At this moment, vcpu->arch.xsave_enabled is true. Physical MSR_IA32_XSS is
updated with the value of guest MSR_IA32_XSS, which is 0.
States at this point:
* Physical MSR_IA32_XSS[bit 8] is 0.
* vcpu_get_guest_msr(vcpu, MSR_IA32_XSS)[bit 8] is 0.
* ectx->xs_area.xsave_hdr.hdr.xcomp_bv[bit 8] is 1.
Processor state is restored from memory with XRSTORS instruction afterwards.
According to SDM Vol1 13.12 OPERATION OF XRSTORS, a #GP occurs if XCOMP_BV
sets a bit in the range 62:0 that is not set in XCR0 | IA32_XSS.
So, #GP occurs once XRSTORS instruction is executed.
Such issue does not happen with kernel 5.10. Because kernel 5.10 writes to
MSR_IA32_XSS during initialization, while kernel 5.4 does not do such write.
Once guest writes to MSR_IA32_XSS, it would be trapped to hypervisor, then,
physical MSR_IA32_XSS and the value of MSR_IA32_XSS in vcpu->arch.guest_msrs
are updated with the value specified by guest. So, in the point 2 above,
correct processor state is saved. And #GP would not happen in the point 3.
This patch initializes the XSAVE related processor state for guest.
If vcpu is not launched yet, the processor state is initialized according to
the initial value of vcpu_get_guest_msr(vcpu, MSR_IA32_XSS), ectx->xcr0,
and ectx->xs_area. With this approach, the physical processor state is
consistent with the one presented to guest.
Tracked-On: #6434
Signed-off-by: Shiqing Gao <shiqing.gao@intel.com>
Reviewed-by: Li Fei1 <fei1.li@intel.com>
Currently init_vmx_msrs() emulates same value for the IA32_VMX_xxx_CTLS
and IA32_VMX_TRUE_xxx_CTLS MSRs.
But the value of physical MSRs could be different between the pair,
and we need to adjust the emulated value accordingly.
Tracked-On: #6289
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
check_vmx_permission() is called in vmresume_vmexit_handler() and
vmlaunch_vmexit_handler() already.
Tracked-On: #6289
Signed-off-by: Zide Chen <zide.chen@intel.com>
Currently the sched event handling may encounter data race problem, and
as a result some vcpus might be stalled forever.
One example can be wbinvd handling where more than 1 vcpus are doing
wbinvd concurrently. The following is a possible execution of 3 vcpus:
-------
0 1 2
req [Note: 0]
req bit0 set [Note: 1]
IPI -> 0
req bit2 set
IPI -> 2
VMExit
req bit2 cleared
wait
vcpu2 descheduled
VMExit
req bit0 cleared
wait
vcpu0 descheduled
signal 0
event0->set=true
wake 0
signal 2
event2->set=true [Note: 3]
wake 2
vcpu2 scheduled
event2->set=false
resume
req
req bit0 set
IPI -> 0
req bit1 set
IPI -> 1
(doesn't matter)
vcpu0 scheduled [Note: 4]
signal 0
event0->set=true
(no wake) [Note: 2]
event0->set=false (the rest doesn't matter)
resume
Any VMExit
req bit0 cleared
wait
idle running
(blocked forever)
Notes:
0: req: vcpu_make_request(vcpu, ACRN_REQUEST_WAIT_WBINVD).
1: req bit: Bit in pending_req_bits. Bit0 stands for bit for vcpu0.
2: In function signal_event, At this time the event->waiting_thread
is not NULL, so wake_thread will not execute
3: eventX: struct sched_event of vcpuX.
4: In function wait_event, the lock does not strictly cover the execution between
schedule() and event->set=false, so other threads may kick in.
-----
As shown in above example, before the last random VMExit, vcpu0 ended up
with request bit set but event->set==false, so blocked forever.
This patch proposes to change event->set from a boolean variable to an
integer. The semantic is very similar to a semaphore. The wait_event
will add 1 to this value, and block when this value is > 0, whereas signal_event
will decrease this value by 1.
It may happen that this value was decreased to a negative number but that
is OK. As long as the wait_event and signal_event are paired and
program order is observed (that is, wait_event always happens-before signal_event
on a single vcpu), this value will eventually be 0.
Tracked-On: #6405
Signed-off-by: Yifan Liu <yifan1.liu@intel.com>
This is a simply implement for the 32bit and 64bit elf loader.
The loading function first reads the image header, and finds the program
entries that are marked as PT_LOAD, then loads segments from elf file to
guest ram. After that, it finds the bss section in the elf section entries, and
clear the ram area it points to.
Limitations:
1. The e_type of the elf image must be ET_EXEC(executable). Relocatable or
dynamic code is not supported.
2. The loader only copies program segments that has a p_type of
PT_LOAD(loadable segment). Other segments are ignored.
3. The loader doesn’t support Sections that are relocatable
(sh_type is SHT_REL or SHT_RELA)
4. The 64bit elf’s entry address must below 4G.
5. The elf is assumed to be able to put segments to valid guest memory.
Tracked-On: #6323
Signed-off-by: Zhou, Wu <wu.zhou@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
This patch adds a function elf_loader() to load elf image.
It checks the elf header, get its 32/64 bit type, then calls
the corresponding loading routines, which are empty, and
will be realized later.
Tracked-On: #6323
Signed-off-by: Zhou, Wu <wu.zhou@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
