Messages in this thread | | | Subject | Re: [PATCH 1/3] xen: check required Xen features | From | Juergen Gross <> | Date | Thu, 22 Apr 2021 17:32:32 +0200 |
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On 22.04.21 17:26, Stefano Stabellini wrote: > On Thu, 22 Apr 2021, Juergen Gross wrote: >> Linux kernel is not supported to run on Xen versions older than 4.0. >> >> Add tests for required Xen features always being present in Xen 4.0 >> and newer. >> >> Signed-off-by: Juergen Gross <jgross@suse.com> >> --- >> drivers/xen/features.c | 18 ++++++++++++++++++ >> 1 file changed, 18 insertions(+) >> >> diff --git a/drivers/xen/features.c b/drivers/xen/features.c >> index 25c053b09605..60503299c9bc 100644 >> --- a/drivers/xen/features.c >> +++ b/drivers/xen/features.c >> @@ -9,13 +9,26 @@ >> #include <linux/types.h> >> #include <linux/cache.h> >> #include <linux/export.h> >> +#include <linux/printk.h> >> >> #include <asm/xen/hypercall.h> >> >> +#include <xen/xen.h> >> #include <xen/interface/xen.h> >> #include <xen/interface/version.h> >> #include <xen/features.h> >> >> +/* >> + * Linux kernel expects at least Xen 4.0. >> + * >> + * Assume some features to be available for that reason (depending on guest >> + * mode, of course). >> + */ >> +#define chk_feature(f) { \ >> + if (!xen_feature(f)) \ >> + pr_err("Xen: feature %s not available!\n", #f); \ >> + } > > I think this could be done as a static inline function in > include/xen/features.h. That way it would be available everywhere. Also, > static inlines are better than macro when it is possible to use them in > terms of code safety.
It is a macro in order to have only one parameter.
And being a local macro is rendering the code safety reasoning moot.
Additionally I don't want this testing to be scattered all over the code base. It should be done in one place only.
Juergen [unhandled content-type:application/pgp-keys][unhandled content-type:application/pgp-signature] | |