[PATCH v2 08/11] x86/xen: use capabilities instead of fake cpuid values for x2apic

From	Juergen Gross <jgross@suse.com>
Newsgroups	linux.kernel
Subject	[PATCH v2 08/11] x86/xen: use capabilities instead of fake cpuid values for x2apic
Date	2017-04-13 12:20 +0200
Message-ID	<tvK13-1zL-3@gated-at.bofh.it> (permalink)
References	<tvK13-1zL-5@gated-at.bofh.it>
Organization	linux.* mail to news gateway

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When running as pv domain xen_cpuid() is being used instead of
native_cpuid(). In xen_cpuid() the x2apic feature is indicated as not
being present by special casing the related cpuid leaf.

Instead of delivering fake cpuid values clear the cpu capability bit
for x2apic instead.

Signed-off-by: Juergen Gross <jgross@suse.com>
---
 arch/x86/xen/enlighten_pv.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/arch/x86/xen/enlighten_pv.c b/arch/x86/xen/enlighten_pv.c
index d43382284ada..38dec28a8e6d 100644
--- a/arch/x86/xen/enlighten_pv.c
+++ b/arch/x86/xen/enlighten_pv.c
@@ -286,8 +286,6 @@ static void __init xen_init_cpuid_mask(void)
 	unsigned int ax, bx, cx, dx;
 	unsigned int xsave_mask;
 
-	cpuid_leaf1_ecx_mask &= ~(1 << (X86_FEATURE_X2APIC % 32));
-
 	ax = 1;
 	cx = 0;
 	cpuid(1, &ax, &bx, &cx, &dx);
@@ -309,6 +307,7 @@ static void __init xen_init_capabilities(void)
 	setup_clear_cpu_cap(X86_FEATURE_APERFMPERF);
 	setup_clear_cpu_cap(X86_FEATURE_MTRR);
 	setup_clear_cpu_cap(X86_FEATURE_ACC);
+	setup_clear_cpu_cap(X86_FEATURE_X2APIC);
 
 	if (!xen_initial_domain())
 		setup_clear_cpu_cap(X86_FEATURE_ACPI);
-- 
2.12.0

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[PATCH v2 08/11] x86/xen: use capabilities instead of fake cpuid values for x2apic Juergen Gross <jgross@suse.com> - 2017-04-13 12:20 +0200

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