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

[Binbin Wu]

On 3/16/2024 1:26 AM, Sean Christopherson wrote:
> On Mon, Feb 26, 2024, isaku.yamahata@xxxxxxxxx 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();
> > +}
> > +