Dan Magenheimer
2009-Oct-20 15:05 UTC
[Xen-devel] [PATCH] Enable TSC_RELIABLE for AMD servers
(Mark, please ack)
Enable TSC_RELIABLE for AMD servers
Except for a published BIOS errata on family 11h processors,
all AMD servers that have the Invariant TSC bit set have
a reliable TSC so Xen should not write to the TSC.
Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com>
diff -r d7d7f978d704 xen/arch/x86/cpu/amd.c
--- a/xen/arch/x86/cpu/amd.c Tue Oct 20 14:36:01 2009 +0100
+++ b/xen/arch/x86/cpu/amd.c Tue Oct 20 08:55:53 2009 -0600
@@ -465,6 +465,8 @@ static void __devinit init_amd(struct cp
if (c->x86_power & (1<<8)) {
set_bit(X86_FEATURE_CONSTANT_TSC, c->x86_capability);
set_bit(X86_FEATURE_NONSTOP_TSC, c->x86_capability);
+ if (c->x86 != 0x11)
+ set_bit(X86_FEATURE_TSC_RELIABLE, c->x86_capability);
}
}
_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xensource.com
http://lists.xensource.com/xen-devel
Langsdorf, Mark
2009-Oct-22 14:56 UTC
RE: [Xen-devel] [PATCH] Enable TSC_RELIABLE for AMD servers
The TSC on AMD processors with the invariant TSC bit is reliable per Xen''s definition of the term. Acked-by: Mark Langsdorf <mark.langsdorf@amd.com> -Mark Langsdorf Operating System Research Center AMD> -----Original Message----- > From: xen-devel-bounces@lists.xensource.com > [mailto:xen-devel-bounces@lists.xensource.com] On Behalf Of > Dan Magenheimer > Sent: Tuesday, October 20, 2009 10:05 AM > To: Xen-Devel (E-mail) > Cc: Langsdorf, Mark; Keir Fraser > Subject: [Xen-devel] [PATCH] Enable TSC_RELIABLE for AMD servers > > (Mark, please ack) > > Enable TSC_RELIABLE for AMD servers > > Except for a published BIOS errata on family 11h processors, > all AMD servers that have the Invariant TSC bit set have > a reliable TSC so Xen should not write to the TSC. > > Signed-off-by: Dan Magenheimer <dan.magenheimer@oracle.com> > > > diff -r d7d7f978d704 xen/arch/x86/cpu/amd.c > --- a/xen/arch/x86/cpu/amd.c Tue Oct 20 14:36:01 2009 +0100 > +++ b/xen/arch/x86/cpu/amd.c Tue Oct 20 08:55:53 2009 -0600 > @@ -465,6 +465,8 @@ static void __devinit init_amd(struct cp > if (c->x86_power & (1<<8)) { > set_bit(X86_FEATURE_CONSTANT_TSC, > c->x86_capability); > set_bit(X86_FEATURE_NONSTOP_TSC, > c->x86_capability); > + if (c->x86 != 0x11) > + > set_bit(X86_FEATURE_TSC_RELIABLE, c->x86_capability); > } > } > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xensource.com > http://lists.xensource.com/xen-devel > >_______________________________________________ Xen-devel mailing list Xen-devel@lists.xensource.com http://lists.xensource.com/xen-devel