[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH mini-os enhancements for vtpm 7/8] add floating point and sse to mini-os
Ian Campbell, le Tue 18 Sep 2012 08:38:23 +0100, a écrit : > On Tue, 2012-09-18 at 08:31 +0100, Samuel Thibault wrote: > > Ian Campbell, le Tue 18 Sep 2012 08:21:18 +0100, a écrit : > > > On Mon, 2012-09-17 at 23:04 +0100, Matthew Fioravante wrote: > > > > This patch adds floating point and sse support to mini-os by > > > > initializing the floating point unit and the see unit during domain > > > > boot up. > > > > > > > > > > > > Signed of by: Matthew Fioravante matthew.fioravante@xxxxxxxxxx > > > > > > > > diff --git a/extras/mini-os/arch/x86/setup.c > > > > b/extras/mini-os/arch/x86/setup.c > > > > --- a/extras/mini-os/arch/x86/setup.c > > > > +++ b/extras/mini-os/arch/x86/setup.c > > > > @@ -74,9 +74,28 @@ shared_info_t *map_shared_info(unsigned long pa) > > > > return (shared_info_t *)shared_info; > > > > } > > > > > > > > +static inline void fpu_init(void) { > > > > + asm volatile("fninit"); > > > > +} > > > > + > > > > +#ifdef __SSE__ > > > > > > How and when is this symbol defined? > > > > This is defined by the compiler if some -msse is enabled. This is the > > default on i686/x86_64 at least. > > Do we support processors/compilers without SSE or conversely do we > require SSE support? > > It sounds like either we need a runtime test or the compile time test is > unnecessary. If the code is compiled with -msse (and thus __SSE__ defined), the compiler itself can emit sse code, so a runtime test will not be enough to avoid a crash on a non-sse machine. The compile test is however not strictly needed since the code is provided in assembly. And it might be useful to enable sse anyway in case some -msse code gets pulled. IIRC we only support SSE machines, but I'm not 100% sure. Samuel _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx http://lists.xen.org/xen-devel
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