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>
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>
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>
