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>
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>
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>
vmptrld_vmexit_handler() has a same code snippet with
vmclear_vmexit_handler(). Wrap the same code snippet as a static
function clear_vmcs02().
There is only a small logic change that add
nested->current_vmcs12_ptr = INVALID_GPA
in vmptrld_vmexit_handler() for the old VMCS. That's reasonable.
Tracked-On: #5923
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
generate_shadow_ept_entry() didn't verify the correctness of the requested
guest EPT mapping. That might leak host memory access to L2 VM.
To simplify the implementation of the guest EPT audit, hide capabilities
'map 2-Mbyte page' and 'map 1-Gbyte page' from L1 VM. In addition,
minimize the attribute bits of EPT entry when create a shadow EPT entry.
Also, for invalid requested mapping address, reflect the EPT_VIOLATION to
L1 VM.
Here, we have some TODOs:
1) Enable large page support in generate_shadow_ept_entry()
2) Evaluate if need to emulate the invalid GPA access of L2 in HV directly.
3) Minimize EPT entry attributes.
Tracked-On: #5923
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Reviewed-by: Jason Chen CJ <jason.cj.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
* Hide 5 level EPT capability, let L1 guest stick to 4 level EPT.
* Access/Dirty bits are not support currently, hide corresponding EPT
capability bits.
* "Mode-based execute control for EPT" is also not support well
currently, hide its capability bit from MSR_IA32_VMX_PROCBASED_CTLS2.
Tracked-On: #5923
Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Reviewed-by: Jason Chen CJ <jason.cj.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
'struct nept_desc' is used to associate guest EPTP with a shadow EPTP.
It's created in the first reference and be freed while no reference.
The life cycle seems like,
While guest VMCS VMX_EPT_POINTER_FULL is changed, the 'struct nept_desc'
of the new guest EPTP is referenced; the 'struct nept_desc' of the old
guest EPTP is dereferenced.
While guest VMCS be cleared(by VMCLEAR in L1 VM), the 'struct nept_desc'
of the old guest EPTP is dereferenced.
While a new guest VMCS be loaded(by VMPTRLD in L1 VM), the 'struct
nept_desc' of the new guest EPTP is referenced. The 'struct nept_desc'
of the old guest EPTP is dereferenced.
Tracked-On: #5923
Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Reviewed-by: Jason Chen CJ <jason.cj.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Shadow EPT uses lots of pages to construct the shadow page table. To
utilize the memory more efficient, a page poll sept_page_pool is
introduced.
For simplicity, total platform RAM size is considered to calculate the
memory needed for shadow page tables. This is not an accurate upper
bound. This can satisfy typical use-cases where there is not a lot
of overcommitment and sharing of memory between L2 VMs.
Memory of the pool is marked as reserved from E820 table in early stage.
Tracked-On: #5923
Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
Signed-off-by: Shuo A Liu <shuo.a.liu@intel.com>
Reviewed-by: Jason Chen CJ <jason.cj.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Nested VM exits happen when vCPU is in guest mode (VMCS02 is current).
Initially we reflect all nested VM exits to L1 hypervisor. To prepare
the environment to run L1 guest:
- restore some VMCS fields to the value as what L1 hypervisor programmed.
- VMCLEAR VMCS02, VMPTRLD VMCS01 and enable VMCS shadowing.
- load the non-shadowing host states from VMCS12 to VMCS01 guest states.
- VMRESUME to L1 guest with this modified VMCS01.
Tracked-On: #5923
Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
Signed-off-by: Alexander Merritt <alex.merritt@intel.com>
invvpid and invept instructions cause VM exits unconditionally.
For initial support, we pass all the instruction operands as is
to the pCPU.
Tracked-On: #5923
Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
Implement the VMLAUNCH and VMRESUME instructions, allowing a L1
hypervisor to run nested guests.
- merge VMCS control fields and VMCS guest fields to VMCS02
- clear shadow VMCS indicator on VMCS02 and load VMCS02 as current
- set VMCS12 launch state to "launched" in VMLAUNCH handler
Tracked-On: #5923
Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
Signed-off-by: Alex Merritt <alex.merritt@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
This patch implements the VMREAD and VMWRITE instructions.
When L1 guest is running with an active VMCS12, the “VMCS shadowing”
VM-execution control is always set to 1 in VMCS01. Thus the possible
behavior of VMREAD or VMWRITE from L1 could be:
- It causes a VM exit to L0 if the bit corresponds to the target VMCS
field in the VMREAD bitmap or VMWRITE bitmap is set to 1.
- It accesses the VMCS referenced by VMCS01 link pointer (VMCS02 in
our case) if the above mentioned bit is set to 0.
This patch handles the VMREAD and VMWRITE VM exits in this way:
- on VMWRITE, it writes the desired VMCS value to the respective field
in the cached VMCS12. For VMCS fields that need to be synced to VMCS02,
sets the corresponding dirty flag.
- on VMREAD, it reads the desired VMCS value from the cached VMCS12.
Tracked-On: #5923
Signed-off-by: Alex Merritt <alex.merritt@intel.com>
Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@Intel.com>
This patch is to emulate VMCLEAR instruction.
L1 hypervisor issues VMCLEAR on a VMCS12 whose state could be any of
these: active and current, active but not current, not yet VMPTRLDed.
To emulate the VMCLEAR instruction, ACRN sets the VMCS12 launch state to
"clear", and if L0 already cached this VMCS12, need to sync it back to
guest memory:
- sync shadow fields from shadow VMCS VMCS to cache VMCS12
- copy cache VMCS12 to L1 guest memory
Tracked-On: #5923
Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
Enable VMCS shadowing for most of the VMCS fields, so that execution of
the VMREAD or VMWRITE on these shadow VMCS fields from L1 hypervisor
won't cause VM exits, but read from or write to the shadow VMCS.
Tracked-On: #5923
Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: Alexander Merritt <alex.merritt@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
Software layout of VMCS12 data is a contract between L1 guest and L0
hypervisor to run a L2 guest.
ACRN hypervisor caches the VMCS12 which is passed down from L1 hypervisor
by the VMPTRLD instructin. At the time of VMCLEAR, ACRN syncs the cached
VMCS12 back to L1 guest memory.
Tracked-On: #5923
Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@Intel.com>
This patch emulates the VMPTRLD instruction. L0 hypervisor (ACRN) caches
the VMCS12 that is passed down from the VMPTRLD instruction, and merges it
with VMCS01 to create VMCS02 to run the nested VM.
- Currently ACRN can't cache multiple VMCS12 on one vCPU, so it needs to
flushes active but not current VMCS12s to L1 guest.
- ACRN creates VMCS02 to run nested VM based on VMCS12:
1) copy VMCS12 from guest memory to the per vCPU cache VMCS12
2) initialize VMCS02 revision ID and host-state area
3) load shadow fields from cache VMCS12 to VMCS02
4) enable VMCS shadowing before L1 Vm entry
Tracked-On: #5923
Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
This patch implements the VMXOFF instruction. By issuing VMXOFF,
L1 guest Leaves VMX Operation.
- cleanup VCPU nested virtualization context states in VMXOFF handler.
- implement check_vmx_permission() to check permission for VMX operation
for VMXOFF and other VMX instructions.
Tracked-On: #5923
Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@Intel.com>
According to VMXON Instruction Reference, do the following checks in the
virtual hardware environment: vCPU CPL, guest CR0, CR4, revision ID
in VMXON region, etc.
Currently ACRN doesn't support 32-bit L1 hypervisor, and injects an #UD
exception if L1 hypervisor is not running in 64-bit mode.
Tracked-On: #5923
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@Intel.com>
This patch emulates VMXON instruction. Basically checks some
prerequisites to enable VMX operation on L1 guest (next patch), and
prepares some virtual hardware environment in L0.
Tracked-On: #5923
Signed-off-by: Sainath Grandhi <sainath.grandhi@intel.com>
Signed-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@Intel.com>
Define LIST_OF_VMX_MSRS which includes a list of MSRs that are visible to
L1 guests if nested virtualization is enabled.
- If CONFIG_NVMX_ENABLED is set, these MSRs are included in
emulated_guest_msrs[].
- otherwise, they are included in unsupported_msrs[].
In this way we can take advantage of the existing infrastructure to
emulate these MSRs.
Tracked-On: #5923
Spick igned-off-by: Zide Chen <zide.chen@intel.com>
Acked-by: Eddie Dong <eddie.dong@intel.com>
