Re: [PATCH v2] xen/arm: check on domain type against hardware support

[Ian Campbell <Ian.Campbell@citrix.com>]

On Fri, 2014-09-26 at 11:28 +0530, vijay.kilari@gmail.com wrote:
> From: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>
> 
> Some arm64 platforms implement only aarch64 mode. So allow
> domains that are only 64-bit
> 
> Signed-off-by: Vijaya Kumar K <Vijaya.Kumar@caviumnetworks.com>

Acked-by: Ian Campbell <ian.campbell@citrix.com>

I think this is a bug fix so we should take it for 4.5.

Ian.

> ---
> v2:-Fixed coding style comments
>    -Make cpu_has_aarch32 check for both A32 and T32
>    -Updated aarch32 capabilities info print
> ---
>  xen/arch/arm/arm64/domctl.c      |    3 +++
>  xen/arch/arm/domain_build.c      |    7 +++++++
>  xen/arch/arm/setup.c             |   10 +++++++---
>  xen/include/asm-arm/cpufeature.h |    3 ++-
>  4 files changed, 19 insertions(+), 4 deletions(-)
> 
> diff --git a/xen/arch/arm/arm64/domctl.c b/xen/arch/arm/arm64/domctl.c
> index 41e2562..c0ff248 100644
> --- a/xen/arch/arm/arm64/domctl.c
> +++ b/xen/arch/arm/arm64/domctl.c
> @@ -11,6 +11,7 @@
>  #include <xen/sched.h>
>  #include <xen/hypercall.h>
>  #include <public/domctl.h>
> +#include <asm/cpufeature.h>
>  
>  static long switch_mode(struct domain *d, enum domain_type type)
>  {
> @@ -35,6 +36,8 @@ long subarch_do_domctl(struct xen_domctl *domctl, struct domain *d,
>          switch ( domctl->u.address_size.size )
>          {
>          case 32:
> +            if ( !cpu_has_el1_32 )
> +                return -EINVAL;
>              return switch_mode(d, DOMAIN_32BIT);
>          case 64:
>              return switch_mode(d, DOMAIN_64BIT);
> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
> index 90abc3a..138ca89 100644
> --- a/xen/arch/arm/domain_build.c
> +++ b/xen/arch/arm/domain_build.c
> @@ -17,6 +17,7 @@
>  #include <asm/platform.h>
>  #include <asm/psci.h>
>  #include <asm/setup.h>
> +#include <asm/cpufeature.h>
>  
>  #include <asm/gic.h>
>  #include <xen/irq.h>
> @@ -1274,6 +1275,12 @@ int construct_dom0(struct domain *d)
>          return rc;
>  
>  #ifdef CONFIG_ARM_64
> +    /* if aarch32 mode is not supported at EL1 do not allow 32-bit domain */
> +    if ( !(cpu_has_el1_32) && kinfo.type == DOMAIN_32BIT )
> +    {
> +        printk("Platform does not support 32-bit domain\n");
> +        return -EINVAL;
> +    }
>      d->arch.type = kinfo.type;
>  #endif
>  
> diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
> index 446de8a..ceb5af8 100644
> --- a/xen/arch/arm/setup.c
> +++ b/xen/arch/arm/setup.c
> @@ -127,8 +127,9 @@ static void __init processor_id(void)
>          printk("32-bit Execution:\n");
>          printk("  Processor Features: %08"PRIx32":%08"PRIx32"\n",
>                 boot_cpu_data.pfr32.bits[0], boot_cpu_data.pfr32.bits[1]);
> -        printk("    Instruction Sets:%s%s%s%s%s\n",
> +        printk("    Instruction Sets:%s%s%s%s%s%s\n",
>                 cpu_has_aarch32 ? " AArch32" : "",
> +               cpu_has_a32 ? " A32" : "",
>                 cpu_has_thumb ? " Thumb" : "",
>                 cpu_has_thumb2 ? " Thumb-2" : "",
>                 cpu_has_thumbee ? " ThumbEE" : "",
> @@ -851,8 +852,11 @@ void arch_get_xen_caps(xen_capabilities_info_t *info)
>      snprintf(s, sizeof(s), "xen-%d.%d-aarch64 ", major, minor);
>      safe_strcat(*info, s);
>  #endif
> -    snprintf(s, sizeof(s), "xen-%d.%d-armv7l ", major, minor);
> -    safe_strcat(*info, s);
> +    if ( cpu_has_aarch32 )
> +    {
> +        snprintf(s, sizeof(s), "xen-%d.%d-armv7l ", major, minor);
> +        safe_strcat(*info, s);
> +    }
>  }
>  
>  /*
> diff --git a/xen/include/asm-arm/cpufeature.h b/xen/include/asm-arm/cpufeature.h
> index 7a6d3de..e605bf5 100644
> --- a/xen/include/asm-arm/cpufeature.h
> +++ b/xen/include/asm-arm/cpufeature.h
> @@ -21,11 +21,12 @@
>  #define cpu_feature32(c, feat)         ((c)->pfr32.feat)
>  #define boot_cpu_feature32(feat)       (boot_cpu_data.pfr32.feat)
>  
> -#define cpu_has_aarch32   (boot_cpu_feature32(arm) == 1)
> +#define cpu_has_a32       (boot_cpu_feature32(arm) == 1)
>  #define cpu_has_thumb     (boot_cpu_feature32(thumb) >= 1)
>  #define cpu_has_thumb2    (boot_cpu_feature32(thumb) >= 3)
>  #define cpu_has_jazelle   (boot_cpu_feature32(jazelle) >= 0)
>  #define cpu_has_thumbee   (boot_cpu_feature32(thumbee) == 1)
> +#define cpu_has_aarch32   (cpu_has_a32 || cpu_has_thumb)
>  
>  #ifdef CONFIG_ARM_32
>  #define cpu_has_gentimer  (boot_cpu_feature32(gentimer) == 1)