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authorAndy Lutomirski <luto@kernel.org>2017-06-29 17:53:21 +0200
committerIngo Molnar <mingo@kernel.org>2017-07-05 10:52:58 +0200
commit660da7c9228f685b2ebe664f9fd69aaddcc420b5 (patch)
tree363dd4d5cc99b8d78cf66d8f6c3973a1d852dcb5 /arch/x86/xen/enlighten_pv.c
parentx86/mm: Add the 'nopcid' boot option to turn off PCID (diff)
downloadlinux-660da7c9228f685b2ebe664f9fd69aaddcc420b5.tar.xz
linux-660da7c9228f685b2ebe664f9fd69aaddcc420b5.zip
x86/mm: Enable CR4.PCIDE on supported systems
We can use PCID if the CPU has PCID and PGE and we're not on Xen. By itself, this has no effect. A followup patch will start using PCID. Signed-off-by: Andy Lutomirski <luto@kernel.org> Reviewed-by: Nadav Amit <nadav.amit@gmail.com> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Arjan van de Ven <arjan@linux.intel.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dave Hansen <dave.hansen@intel.com> Cc: Juergen Gross <jgross@suse.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Mel Gorman <mgorman@suse.de> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Rik van Riel <riel@redhat.com> Cc: linux-mm@kvack.org Link: http://lkml.kernel.org/r/6327ecd907b32f79d5aa0d466f04503bbec5df88.1498751203.git.luto@kernel.org Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/xen/enlighten_pv.c')
-rw-r--r--arch/x86/xen/enlighten_pv.c6
1 files changed, 6 insertions, 0 deletions
diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index f33eef4ebd12..a136aac543c3 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -295,6 +295,12 @@ static void __init xen_init_capabilities(void)
setup_clear_cpu_cap(X86_FEATURE_ACC);
setup_clear_cpu_cap(X86_FEATURE_X2APIC);
+ /*
+ * Xen PV would need some work to support PCID: CR3 handling as well
+ * as xen_flush_tlb_others() would need updating.
+ */
+ setup_clear_cpu_cap(X86_FEATURE_PCID);
+
if (!xen_initial_domain())
setup_clear_cpu_cap(X86_FEATURE_ACPI);