Re: [RFC v2 6/8] tools/arm: Introduce force_assign_without_iommu option to xl.cfg

From: Jan Beulich <jbeulich@suse.com>
To: Oleksii Moisieiev <Oleksii_Moisieiev@epam.com>
Cc: Wei Liu <wl@xen.org>, Andrew Cooper <andrew.cooper3@citrix.com>,
	"xen-devel@lists.xenproject.org" <xen-devel@lists.xenproject.org>,
	George Dunlap <george.dunlap@citrix.com>,
	Julien Grall <julien@xen.org>,
	Stefano Stabellini <sstabellini@kernel.org>,
	Nick Rosbrook <rosbrookn@ainfosec.com>,
	Anthony PERARD <anthony.perard@citrix.com>,
	Juergen Gross <jgross@suse.com>, Paul Durrant <paul@xen.org>
Subject: Re: [RFC v2 6/8] tools/arm: Introduce force_assign_without_iommu option to xl.cfg
Date: Fri, 3 Jun 2022 15:43:55 +0200	[thread overview]
Message-ID: <a5590d8c-2255-6dbb-6823-2db0ff714da6@suse.com> (raw)
In-Reply-To: <d333126d12f2281f8df92e66cfba1c9eb2425dca.1644341635.git.oleksii_moisieiev@epam.com>

On 08.02.2022 19:00, Oleksii Moisieiev wrote:
> --- a/xen/common/domain.c
> +++ b/xen/common/domain.c
> @@ -512,7 +512,7 @@ static int sanitise_domain_config(struct xen_domctl_createdomain *config)
>  
>      if ( iommu )
>      {
> -        if ( config->iommu_opts & ~XEN_DOMCTL_IOMMU_no_sharept )
> +        if ( config->iommu_opts >> XEN_DOMCTL_IOMMU_MAX )
>          {
>              dprintk(XENLOG_INFO, "Unknown IOMMU options %#x\n",
>                      config->iommu_opts);

While in common code this is perhaps okay, the new bit wants rejecting
(or also implementing) for x86.

> @@ -534,6 +536,7 @@ int iommu_do_domctl(
>  {
>      int ret = -ENODEV;
>  
> +
>      if ( !is_iommu_enabled(d) )
>          return -EOPNOTSUPP;

Please don't.

> @@ -542,7 +545,7 @@ int iommu_do_domctl(
>  #endif
>  
>  #ifdef CONFIG_HAS_DEVICE_TREE
> -    if ( ret == -ENODEV )
> +    if ( ret == -ENOSYS )
>          ret = iommu_do_dt_domctl(domctl, d, u_domctl);
>  #endif

Why?

Jan