Re: [PATCH v19 098/130] KVM: TDX: Add a place holder to handle TDX VM exit

[Binbin Wu]

On 2/26/2024 4:26 PM, isaku.yamahata@xxxxxxxxx wrote:
> From: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
>
> Wire up handle_exit and handle_exit_irqoff methods

This patch also wires up get_exit_info.

>   and add a place holder
> to handle VM exit.  Add helper functions to get exit info, exit
> qualification, etc.
>
> Signed-off-by: Isaku Yamahata <isaku.yamahata@xxxxxxxxx>
> Reviewed-by: Paolo Bonzini <pbonzini@xxxxxxxxxx>
> ---
>   arch/x86/kvm/vmx/main.c    |  37 ++++++++++++-
>   arch/x86/kvm/vmx/tdx.c     | 110 +++++++++++++++++++++++++++++++++++++
>   arch/x86/kvm/vmx/x86_ops.h |  10 ++++
>   3 files changed, 154 insertions(+), 3 deletions(-)
[...]
> @@ -562,7 +593,7 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
>   
>   	.vcpu_pre_run = vt_vcpu_pre_run,
>   	.vcpu_run = vt_vcpu_run,
> -	.handle_exit = vmx_handle_exit,
> +	.handle_exit = vt_handle_exit,
>   	.skip_emulated_instruction = vmx_skip_emulated_instruction,
>   	.update_emulated_instruction = vmx_update_emulated_instruction,
>   	.set_interrupt_shadow = vt_set_interrupt_shadow,
> @@ -597,7 +628,7 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
>   	.set_identity_map_addr = vmx_set_identity_map_addr,
>   	.get_mt_mask = vt_get_mt_mask,
>   
> -	.get_exit_info = vmx_get_exit_info,
> +	.get_exit_info = vt_get_exit_info,
>   
>   	.vcpu_after_set_cpuid = vmx_vcpu_after_set_cpuid,
>   
> @@ -611,7 +642,7 @@ struct kvm_x86_ops vt_x86_ops __initdata = {
>   	.load_mmu_pgd = vt_load_mmu_pgd,
>   
>   	.check_intercept = vmx_check_intercept,
> -	.handle_exit_irqoff = vmx_handle_exit_irqoff,
> +	.handle_exit_irqoff = vt_handle_exit_irqoff,
>   
>   	.request_immediate_exit = vt_request_immediate_exit,
>   
[...]
>   
> +int tdx_handle_exit(struct kvm_vcpu *vcpu, fastpath_t fastpath)
> +{
> +	union tdx_exit_reason exit_reason = to_tdx(vcpu)->exit_reason;
> +
> +	/* See the comment of tdh_sept_seamcall(). */

Should be tdx_seamcall_sept().

> +	if (unlikely(exit_reason.full == (TDX_OPERAND_BUSY | TDX_OPERAND_ID_SEPT)))

Can use "TDX_ERROR_SEPT_BUSY" instead.

> +		return 1;
> +
> +	/*
> +	 * TDH.VP.ENTRY

"TDH.VP.ENTRY" -> "TDH.VP.ENTER"

>   checks TD EPOCH which contend with TDH.MEM.TRACK and
> +	 * vcpu TDH.VP.ENTER.
Do you mean TDH.VP.ENTER on one vcpu can contend with TDH.MEM.TRACK and 
TDH.VP.ENTER on another vcpu?

> +	 */