xen: set cpu capabilities from xen_start_kernel()

BugLink: https://bugs.launchpad.net/bugs/1791080

Upstream commit: 0808e80c ("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@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Srivatsa S. Bhat <srivatsa@csail.mit.edu>
Reviewed-by: Matt Helsley (VMware) <matt.helsley@gmail.com>
Reviewed-by: Alexey Makhalov <amakhalov@vmware.com>
Reviewed-by: Bo Gan <ganb@vmware.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

arch/x86/xen/enlighten.c

@@ -461,6 +461,14 @@ static void __init xen_init_cpuid_mask(void)
 		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);
@@ -1588,6 +1596,7 @@ asmlinkage __visible void __init xen_start_kernel(void)
 
 	xen_init_irq_ops();
 	xen_init_cpuid_mask();
+	xen_init_capabilities();
 
 #ifdef CONFIG_X86_LOCAL_APIC
 	/*
@@ -1884,14 +1893,6 @@ 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,
@@ -1899,7 +1900,6 @@ const struct hypervisor_x86 x86_hyper_xen = {
 	.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);