kvm: nVMX: Introduce KVM_CAP_NESTED_STATE

For nested virtualization L0 KVM is managing a bit of state for L2 guests,
this state can not be captured through the currently available IOCTLs. In
fact the state captured through all of these IOCTLs is usually a mix of L1
and L2 state. It is also dependent on whether the L2 guest was running at
the moment when the process was interrupted to save its state.

With this capability, there are two new vcpu ioctls: KVM_GET_NESTED_STATE
and KVM_SET_NESTED_STATE. These can be used for saving and restoring a VM
that is in VMX operation.

Cc: Paolo Bonzini <[email protected]>
Cc: Radim Krčmář <[email protected]>
Cc: Thomas Gleixner <[email protected]>
Cc: Ingo Molnar <[email protected]>
Cc: H. Peter Anvin <[email protected]>
Cc: [email protected]
Cc: [email protected]
Cc: [email protected]
Signed-off-by: Jim Mattson <[email protected]>
[karahmed@ - rename structs and functions and make them ready for AMD and
             address previous comments.
           - handle nested.smm state.
           - rebase & a bit of refactoring.
           - Merge 7/8 and 8/8 into one patch. ]
Signed-off-by: KarimAllah Ahmed <[email protected]>
Signed-off-by: Paolo Bonzini <[email protected]>
This commit is contained in:
Jim Mattson 2018-07-10 11:27:20 +02:00 • committed by Paolo Bonzini
commit 8fcc4b5923
6 changed files with 330 additions and 2 deletions

View file

@ -3561,6 +3561,62 @@ Returns: 0 on success,
-ENOENT on deassign if the conn_id isn't registered
-EEXIST on assign if the conn_id is already registered
4.114 KVM_GET_NESTED_STATE
Capability: KVM_CAP_NESTED_STATE
Architectures: x86
Type: vcpu ioctl
Parameters: struct kvm_nested_state (in/out)
Returns: 0 on success, -1 on error
Errors:
E2BIG: the total state size (including the fixed-size part of struct
kvm_nested_state) exceeds the value of 'size' specified by
the user; the size required will be written into size.
struct kvm_nested_state {
__u16 flags;
__u16 format;
__u32 size;
union {
struct kvm_vmx_nested_state vmx;
struct kvm_svm_nested_state svm;
__u8 pad[120];
};
__u8 data[0];
};
#define KVM_STATE_NESTED_GUEST_MODE 0x00000001
#define KVM_STATE_NESTED_RUN_PENDING 0x00000002
#define KVM_STATE_NESTED_SMM_GUEST_MODE 0x00000001
#define KVM_STATE_NESTED_SMM_VMXON 0x00000002
struct kvm_vmx_nested_state {
__u64 vmxon_pa;
__u64 vmcs_pa;
struct {
__u16 flags;
} smm;
};
This ioctl copies the vcpu's nested virtualization state from the kernel to
userspace.
The maximum size of the state, including the fixed-size part of struct
kvm_nested_state, can be retrieved by passing KVM_CAP_NESTED_STATE to
the KVM_CHECK_EXTENSION ioctl().
4.115 KVM_SET_NESTED_STATE
Capability: KVM_CAP_NESTED_STATE
Architectures: x86
Type: vcpu ioctl
Parameters: struct kvm_nested_state (in)
Returns: 0 on success, -1 on error
This copies the vcpu's kvm_nested_state struct from userspace to the kernel. For
the definition of struct kvm_nested_state, see KVM_GET_NESTED_STATE.
5. The kvm_run structure
------------------------