Commit-ID: 999696752db1099aba595aac4f8d881f8c7cf4e6 Gitweb: https://git.kernel.org/tip/999696752db1099aba595aac4f8d881f8c7cf4e6 Author: Juergen Gross <jgross@xxxxxxxx> AuthorDate: Wed, 12 Sep 2018 19:41:22 +0200 Committer: Ingo Molnar <mingo@xxxxxxxxxx> CommitDate: Wed, 12 Sep 2018 21:15:02 +0200 x86/xen: Disable CPU0 hotplug for Xen PV Xen PV guests don't allow CPU0 hotplug, so disable it. Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx> Cc: Peter Zijlstra <peterz@xxxxxxxxxxxxx> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx> Cc: boris.ostrovsky@xxxxxxxxxx Cc: xen-devel@xxxxxxxxxxxxxxxxxxxx Link: http://lkml.kernel.org/r/20180912174122.24282-1-jgross@xxxxxxxx Signed-off-by: Ingo Molnar <mingo@xxxxxxxxxx> --- arch/x86/kernel/topology.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/topology.c b/arch/x86/kernel/topology.c index 12cbe2b88c0f..738bf42b0218 100644 --- a/arch/x86/kernel/topology.c +++ b/arch/x86/kernel/topology.c @@ -111,8 +111,10 @@ int arch_register_cpu(int num) /* * Currently CPU0 is only hotpluggable on Intel platforms. Other * vendors can add hotplug support later. + * Xen PV guests don't support CPU0 hotplug at all. */ - if (c->x86_vendor != X86_VENDOR_INTEL) + if (c->x86_vendor != X86_VENDOR_INTEL || + boot_cpu_has(X86_FEATURE_XENPV)) cpu0_hotpluggable = 0; /*
|