Re: [PATCH 2/2] x86/vmware: VMware support for TDX userspace hypercalls

[Kirill A . Shutemov]

On Wed, Jul 03, 2024 at 11:36:01PM +0000, Tim Merrifield wrote:
> @@ -539,6 +547,24 @@ unsigned long vmware_tdx_hypercall(unsigned long cmd,
>  	return args.r12;
>  }
>  EXPORT_SYMBOL_GPL(vmware_tdx_hypercall);
> +
> +static bool vmware_tdx_user_hcall(struct pt_regs *regs)
> +{
> +	struct tdx_module_args args;

Zero the struct to not leak data to VMM.

> +
> +	vmware_init_tdx_args(&args, true, regs->cx, regs->bx,
> +			     regs->dx, regs->si, regs->di, regs->bp);
> +	__tdx_hypercall(&args);
> +	regs->ax = args.r12;
> +	regs->bx = args.rbx;
> +	regs->cx = args.r13;
> +	regs->dx = args.rdx;
> +	regs->si = args.rsi;
> +	regs->di = args.rdi;
> +	regs->bp = args.r14;
> +
> +	return true;
> +}
>  #endif
>  
>  #ifdef CONFIG_AMD_MEM_ENCRYPT
> @@ -586,4 +612,7 @@ const __initconst struct hypervisor_x86 x86_hyper_vmware = {
>  	.runtime.sev_es_hcall_prepare	= vmware_sev_es_hcall_prepare,
>  	.runtime.sev_es_hcall_finish	= vmware_sev_es_hcall_finish,
>  #endif
> +#ifdef CONFIG_INTEL_TDX_GUEST
> +	.runtime.tdx_hcall              = vmware_tdx_user_hcall,
> +#endif
>  };
> -- 
> 2.40.1
> 

-- 
  Kiryl Shutsemau / Kirill A. Shutemov