Re: [PATCH v19 078/130] KVM: TDX: Implement TDX vcpu enter/exit path

Binbin Wu
2024-04-07T01:42:29Z

On 3/16/2024 1:26 AM, Sean Christopherson wrote:
> On Mon, Feb 26, 2024, isaku.yamahata@intel.com wrote:
>> + */
>> + struct kvm_vcpu *vcpu = &tdx->vcpu;
>> +
>> + guest_state_enter_irqoff();
>> +
>> + /*
>> + * TODO: optimization:
>> + * - Eliminate copy between args and vcpu->arch.regs.
>> + * - copyin/copyout registers only if (tdx->tdvmvall.regs_mask != 0)
>> + * which means TDG.VP.VMCALL.
>> + */
>> + args = (struct tdx_module_args) {
>> + .rcx = tdx->tdvpr_pa,
>> +#define REG(reg, REG) .reg = vcpu->arch.regs[VCPU_REGS_ ## REG]
> Organizing tdx_module_args's registers by volatile vs. non-volatile is asinine.
> This code should not need to exist.

Did you suggest to align the tdx_module_args with enum kvm_reg for GP
registers, so it can be done by a simple mem copy?

>
>> + WARN_ON_ONCE(!kvm_rebooting &&
>> + (tdx->exit_reason.full & TDX_SW_ERROR) == TDX_SW_ERROR);
>> +
>> + guest_state_exit_irqoff();
>> +}
>> +
>>