On 1/23/2024 7:52 AM, isaku.yamahata@xxxxxxxxx wrote:
From: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
KVM accesses Virtual Machine Control Structure (VMCS) with VMX instructions
to operate on VM. TDX doesn't allow VMM to operate VMCS directly.
Instead, TDX has its own data structures, and TDX SEAMCALL APIs for VMM to
indirectly operate those data structures. This means we must have a TDX
version of kvm_x86_ops.
The existing global struct kvm_x86_ops already defines an interface which
fits with TDX. But kvm_x86_ops is system-wide, not per-VM structure. To
allow VMX to coexist with TDs, the kvm_x86_ops callbacks will have wrappers
"if (tdx) tdx_op() else vmx_op()" to switch VMX or TDX at run time.
To split the runtime switch, the VMX implementation, and the TDX
implementation, add main.c, and move out the vmx_x86_ops hooks in
preparation for adding TDX, which can coexist with VMX, i.e. KVM can run
both VMs and TDs. Use 'vt' for the naming scheme as a nod to VT-x and as a
concatenation of VmxTdx.
The current code looks as follows.
In vmx.c
static vmx_op() { ... }
static struct kvm_x86_ops vmx_x86_ops = {
.op = vmx_op,
initialization code
The eventually converted code will look like
In vmx.c, keep the VMX operations.
vmx_op() { ... }
VMX initialization
In tdx.c, define the TDX operations.
tdx_op() { ... }
TDX initialization
In x86_ops.h, declare the VMX and TDX operations.
vmx_op();
tdx_op();
In main.c, define common wrappers for VMX and TDX.
static vt_ops() { if (tdx) tdx_ops() else vmx_ops() }
static struct kvm_x86_ops vt_x86_ops = {
.op = vt_op,
initialization to call VMX and TDX initialization
Opportunistically, fix the name inconsistency from vmx_create_vcpu() and
vmx_free_vcpu() to vmx_vcpu_create() and vmx_vcpu_free().
Co-developed-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
Signed-off-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
Signed-off-by: Sean Christopherson <sean.j.christopherson@xxxxxxxxx>
Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
Reviewed-by: Binbin Wu <binbin.wu@xxxxxxxxxxxxxxx>
Reviewed-by: Xiaoyao Li <xiaoyao.li@xxxxxxxxx>
