[libvirt] [PATCH] tools/virt-host-validate: Fix IOMMU check on s390x

[Boris Fiuczynski]

Besides the minor required change below
Reviewed-by: Boris Fiuczynski <fiuczy at linux.ibm.com>

Thanks for catching this

On 2/26/19 12:02 PM, Thomas Huth wrote:
> When running virt-host-validate on an s390x host, the tool currently
> warns that it is "Unknown if this platform has IOMMU support".
> We can use the common check for entries in sys/kernel/iommu_groups here,
> too, but it only makes sense to check it if there are also PCI devices
> available. It's also common on s390x that there are no PCI devices
> assigned to the LPAR, and in that case there is no need for the
> PCI-related IOMMU, so without PCI devices we should simply skip this
> test.
> 
> Signed-off-by: Thomas Huth <thuth at redhat.com>
> ---
>   tools/virt-host-validate-common.c | 11 +++++++++--
>   1 file changed, 9 insertions(+), 2 deletions(-)
> 
> diff --git a/tools/virt-host-validate-common.c b/tools/virt-host-validate-common.c
> index 73e3bdb..75c7cfc 100644
> --- a/tools/virt-host-validate-common.c
> +++ b/tools/virt-host-validate-common.c
> @@ -337,7 +337,7 @@ int virHostValidateIOMMU(const char *hvname,
>       virBitmapPtr flags;
>       struct stat sb;
>       const char *bootarg = NULL;
> -    bool isAMD = false, isIntel = false, isPPC = false;
> +    bool isAMD = false, isIntel = false, isPPC, isS390;
>       flags = virHostValidateGetCPUFlags();
>   
>       if (flags && virBitmapIsBitSet(flags, VIR_HOST_VALIDATE_CPU_FLAG_VMX))
> @@ -348,6 +348,7 @@ int virHostValidateIOMMU(const char *hvname,
>       virBitmapFree(flags);
>   
>       isPPC = ARCH_IS_PPC64(virArchFromHost());
> +    isS390 = ARCH_IS_S390(virArchFromHost());
>   
>       if (isIntel) {
>           virHostMsgCheck(hvname, "%s", _("for device assignment IOMMU support"));
> @@ -375,6 +376,12 @@ int virHostValidateIOMMU(const char *hvname,
>           }
>       } else if (isPPC) {
>           /* Empty Block */
> +    } else if (isS390) {
> +	/* On s390x, we skip the IOMMU check if there are no PCI devices
> +	 * (which is quite usual on s390x) */
TAB_in_indentation
../tools/virt-host-validate-common.c:380:       /* On s390x, we skip the 
IOMMU check if there are no PCI devices
../tools/virt-host-validate-common.c:381:        * (which is quite usual 
on s390x) */
maint.mk: indent with space, not TAB, in C, sh, html, py, syms and RNG 
schemas
make: *** [../cfg.mk:501: sc_TAB_in_indentation] Error 1



> +        if (stat("/sys/bus/pci/devices", &sb) < 0 || !S_ISDIR(sb.st_mode) ||
> +            sb.st_nlink <= 2)
> +            return 0;
>       } else {
>           virHostMsgFail(level,
>                          "Unknown if this platform has IOMMU support");
> @@ -391,7 +398,7 @@ int virHostValidateIOMMU(const char *hvname,
>   
>       virHostMsgCheck(hvname, "%s", _("if IOMMU is enabled by kernel"));
>       if (sb.st_nlink <= 2) {
> -        if (!isPPC)
> +        if (bootarg)
>               virHostMsgFail(level,
>                              "IOMMU appears to be disabled in kernel. "
>                              "Add %s to kernel cmdline arguments", bootarg);
> 


-- 
Mit freundlichen Grüßen/Kind regards
    Boris Fiuczynski

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