[PATCH 4.4 046/107] xen: set cpu capabilities from xen_start_kernel()

From: Greg Kroah-Hartman
Date: Mon Jul 23 2018 - 08:44:53 EST


4.4-stable review patch. If anyone has any objections, please let me know.

------------------

From: Juergen Gross <jgross@xxxxxxxx>

Upstream commit: 0808e80cb760de2733c0527d2090ed2205a1eef8 ("xen: set
cpu capabilities from xen_start_kernel()")

There is no need to set the same capabilities for each cpu
individually. This can easily be done for all cpus when starting the
kernel.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
Signed-off-by: Srivatsa S. Bhat <srivatsa@xxxxxxxxxxxxx>
Reviewed-by: Matt Helsley (VMware) <matt.helsley@xxxxxxxxx>
Reviewed-by: Alexey Makhalov <amakhalov@xxxxxxxxxx>
Reviewed-by: Bo Gan <ganb@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---

arch/x86/xen/enlighten.c | 18 +++++++++---------
1 file changed, 9 insertions(+), 9 deletions(-)

--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -460,6 +460,14 @@ static void __init xen_init_cpuid_mask(v
cpuid_leaf1_ecx_set_mask = (1 << (X86_FEATURE_MWAIT % 32));
}

+static void __init xen_init_capabilities(void)
+{
+ if (xen_pv_domain()) {
+ setup_clear_cpu_cap(X86_BUG_SYSRET_SS_ATTRS);
+ setup_force_cpu_cap(X86_FEATURE_XENPV);
+ }
+}
+
static void xen_set_debugreg(int reg, unsigned long val)
{
HYPERVISOR_set_debugreg(reg, val);
@@ -1587,6 +1595,7 @@ asmlinkage __visible void __init xen_sta

xen_init_irq_ops();
xen_init_cpuid_mask();
+ xen_init_capabilities();

#ifdef CONFIG_X86_LOCAL_APIC
/*
@@ -1883,14 +1892,6 @@ bool xen_hvm_need_lapic(void)
}
EXPORT_SYMBOL_GPL(xen_hvm_need_lapic);

-static void xen_set_cpu_features(struct cpuinfo_x86 *c)
-{
- if (xen_pv_domain()) {
- clear_cpu_bug(c, X86_BUG_SYSRET_SS_ATTRS);
- set_cpu_cap(c, X86_FEATURE_XENPV);
- }
-}
-
const struct hypervisor_x86 x86_hyper_xen = {
.name = "Xen",
.detect = xen_platform,
@@ -1898,7 +1899,6 @@ const struct hypervisor_x86 x86_hyper_xe
.init_platform = xen_hvm_guest_init,
#endif
.x2apic_available = xen_x2apic_para_available,
- .set_cpu_features = xen_set_cpu_features,
};
EXPORT_SYMBOL(x86_hyper_xen);