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authorDavid Woodhouse <dwmw@amazon.co.uk>2021-01-06 18:39:58 +0300
committerJuergen Gross <jgross@suse.com>2021-01-13 18:12:09 +0300
commit3d7746bea92530e8695258a3cf3ddec7a135edd6 (patch)
tree0f4e7c71c0a47b70342589c701b3b3e44772fa2d /arch
parent4621dc6a5bf1235249e92231db30c96dfd1a18b9 (diff)
downloadlinux-3d7746bea92530e8695258a3cf3ddec7a135edd6.tar.xz
x86/xen: Fix xen_hvm_smp_init() when vector callback not available
Only the IPI-related functions in the smp_ops should be conditional on the vector callback being available. The rest should still happen: • xen_hvm_smp_prepare_boot_cpu() This function does two things, both of which should still happen if there is no vector callback support. The call to xen_vcpu_setup() for vCPU0 should still happen as it just sets up the vcpu_info for CPU0. That does happen for the secondary vCPUs too, from xen_cpu_up_prepare_hvm(). The second thing it does is call xen_init_spinlocks(), which perhaps counter-intuitively should *also* still be happening in the case without vector callbacks, so that it can clear its local xen_pvspin flag and disable the virt_spin_lock_key accordingly. Checking xen_have_vector_callback in xen_init_spinlocks() itself would affect PV guests, so set the global nopvspin flag in xen_hvm_smp_init() instead, when vector callbacks aren't available. • xen_hvm_smp_prepare_cpus() This does some IPI-related setup by calling xen_smp_intr_init() and xen_init_lock_cpu(), which can be made conditional. And it sets the xen_vcpu_id to XEN_VCPU_ID_INVALID for all possible CPUS, which does need to happen. • xen_smp_cpus_done() This offlines any vCPUs which doesn't fit in the global shared_info page, if separate vcpu_info placement isn't available. That part also needs to happen regardless of vector callback support. • xen_hvm_cpu_die() This doesn't actually do anything other than commin_cpu_die() right right now in the !vector_callback case; all three teardown functions it calls should be no-ops. But to guard against future regressions it's useful to call it anyway, and for it to explicitly check for xen_have_vector_callback before calling those additional functions. Signed-off-by: David Woodhouse <dwmw@amazon.co.uk> Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Link: https://lore.kernel.org/r/20210106153958.584169-6-dwmw2@infradead.org Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/xen/smp_hvm.c27
1 files changed, 17 insertions, 10 deletions
diff --git a/arch/x86/xen/smp_hvm.c b/arch/x86/xen/smp_hvm.c
index f5e7db4f82ab..056430a1080b 100644
--- a/arch/x86/xen/smp_hvm.c
+++ b/arch/x86/xen/smp_hvm.c
@@ -33,9 +33,11 @@ static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
int cpu;
native_smp_prepare_cpus(max_cpus);
- WARN_ON(xen_smp_intr_init(0));
- xen_init_lock_cpu(0);
+ if (xen_have_vector_callback) {
+ WARN_ON(xen_smp_intr_init(0));
+ xen_init_lock_cpu(0);
+ }
for_each_possible_cpu(cpu) {
if (cpu == 0)
@@ -50,9 +52,11 @@ static void __init xen_hvm_smp_prepare_cpus(unsigned int max_cpus)
static void xen_hvm_cpu_die(unsigned int cpu)
{
if (common_cpu_die(cpu) == 0) {
- xen_smp_intr_free(cpu);
- xen_uninit_lock_cpu(cpu);
- xen_teardown_timer(cpu);
+ if (xen_have_vector_callback) {
+ xen_smp_intr_free(cpu);
+ xen_uninit_lock_cpu(cpu);
+ xen_teardown_timer(cpu);
+ }
}
}
#else
@@ -64,14 +68,17 @@ static void xen_hvm_cpu_die(unsigned int cpu)
void __init xen_hvm_smp_init(void)
{
- if (!xen_have_vector_callback)
+ smp_ops.smp_prepare_boot_cpu = xen_hvm_smp_prepare_boot_cpu;
+ smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
+ smp_ops.smp_cpus_done = xen_smp_cpus_done;
+ smp_ops.cpu_die = xen_hvm_cpu_die;
+
+ if (!xen_have_vector_callback) {
+ nopvspin = true;
return;
+ }
- smp_ops.smp_prepare_cpus = xen_hvm_smp_prepare_cpus;
smp_ops.smp_send_reschedule = xen_smp_send_reschedule;
- smp_ops.cpu_die = xen_hvm_cpu_die;
smp_ops.send_call_func_ipi = xen_smp_send_call_function_ipi;
smp_ops.send_call_func_single_ipi = xen_smp_send_call_function_single_ipi;
- smp_ops.smp_prepare_boot_cpu = xen_hvm_smp_prepare_boot_cpu;
- smp_ops.smp_cpus_done = xen_smp_cpus_done;
}