| Message ID | 1460030246-30153-5-git-send-email-andrew.cooper3@citrix.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Thu, Apr 07, 2016 at 12:57:09PM +0100, Andrew Cooper wrote: > When clearing a cpu cap, clear all dependent features. This avoids having a > featureset with intermediate features disabled, but leaf features enabled. > > Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com> > Reviewed-by: Jan Beulich <JBeulich@suse.com> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> > --- > v3: > * Style fixes. Use __test_and_set_bit() > --- > xen/arch/x86/cpu/common.c | 16 +++++++++++++++- > 1 file changed, 15 insertions(+), 1 deletion(-) > > diff --git a/xen/arch/x86/cpu/common.c b/xen/arch/x86/cpu/common.c > index d302272..0942b44 100644 > --- a/xen/arch/x86/cpu/common.c > +++ b/xen/arch/x86/cpu/common.c > @@ -53,8 +53,22 @@ static unsigned int cleared_caps[NCAPINTS]; > > void __init setup_clear_cpu_cap(unsigned int cap) > { > + const uint32_t *dfs; > + unsigned int i; > + > + if (__test_and_set_bit(cap, cleared_caps)) > + return; > + > __clear_bit(cap, boot_cpu_data.x86_capability); > - __set_bit(cap, cleared_caps); > + dfs = lookup_deep_deps(cap); > + > + if (!dfs) > + return; > + > + for (i = 0; i < FSCAPINTS; ++i) { > + cleared_caps[i] |= dfs[i]; > + boot_cpu_data.x86_capability[i] &= ~dfs[i]; > + } > } > > static void default_init(struct cpuinfo_x86 * c) > -- > 2.1.4 > > > _______________________________________________ > Xen-devel mailing list > Xen-devel@lists.xen.org > http://lists.xen.org/xen-devel
diff --git a/xen/arch/x86/cpu/common.c b/xen/arch/x86/cpu/common.c index d302272..0942b44 100644 --- a/xen/arch/x86/cpu/common.c +++ b/xen/arch/x86/cpu/common.c @@ -53,8 +53,22 @@ static unsigned int cleared_caps[NCAPINTS]; void __init setup_clear_cpu_cap(unsigned int cap) { + const uint32_t *dfs; + unsigned int i; + + if (__test_and_set_bit(cap, cleared_caps)) + return; + __clear_bit(cap, boot_cpu_data.x86_capability); - __set_bit(cap, cleared_caps); + dfs = lookup_deep_deps(cap); + + if (!dfs) + return; + + for (i = 0; i < FSCAPINTS; ++i) { + cleared_caps[i] |= dfs[i]; + boot_cpu_data.x86_capability[i] &= ~dfs[i]; + } } static void default_init(struct cpuinfo_x86 * c)