xen/pvhvm: run xen_vcpu_setup() for the boot CPU

Historically we didn't call VCPUOP_register_vcpu_info for CPU0 for
PVHVM guests (while we had it for PV and ARM guests). This is usually
fine as we can use vcpu info in the shared_info page but when we try
booting on a vCPU with Xen's vCPU id > 31 (e.g. when we try to kdump
after crashing on this CPU) we're not able to boot.

Switch to always doing VCPUOP_register_vcpu_info for the boot CPU.

Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>

3 files changed, 9 insertions, 1 deletions

diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index 5ca92e600a69..85ef4c0442e0 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -184,7 +184,7 @@ static void clamp_max_cpus(void)
 #endif
 }
 
-static void xen_vcpu_setup(int cpu)
+void xen_vcpu_setup(int cpu)
 {
         struct vcpu_register_vcpu_info info;
         int err;
diff --git a/arch/x86/xen/smp.c b/arch/x86/xen/smp.c
index a3118f250416..0b4d04c8ab4d 100644
--- a/arch/x86/xen/smp.c
+++ b/arch/x86/xen/smp.c
@@ -322,6 +322,13 @@ static void __init xen_smp_prepare_boot_cpu(void)
                 xen_filter_cpu_maps();
                 xen_setup_vcpu_info_placement();
         }
+
+        /*
+         * Setup vcpu_info for boot CPU.
+         */
+        if (xen_hvm_domain())
+                xen_vcpu_setup(0);
+
         /*
          * The alternative logic (which patches the unlock/lock) runs before
          * the smp bootup up code is activated. Hence we need to set this up
diff --git a/arch/x86/xen/xen-ops.h b/arch/x86/xen/xen-ops.h
index 4140b070f2e9..3cbce3b085e7 100644
--- a/arch/x86/xen/xen-ops.h
+++ b/arch/x86/xen/xen-ops.h
@@ -76,6 +76,7 @@ irqreturn_t xen_debug_interrupt(int irq, void *dev_id);
 
 bool xen_vcpu_stolen(int vcpu);
 
+void xen_vcpu_setup(int cpu);
 void xen_setup_vcpu_info_placement(void);
 
 #ifdef CONFIG_SMP