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authorAnkur Arora <ankur.a.arora@oracle.com>2017-06-02 17:05:58 -0700
committerJuergen Gross <jgross@suse.com>2017-06-13 16:05:14 +0200
commitad73fd595c2ab168fdd01a266cbe6e4df95f8db0 (patch)
tree59d5195bd08008ea036af15648e17683aabd049f /arch/x86/xen/enlighten.c
parentc48f64ab472389df6f48171899c9d337adfadc5b (diff)
downloadlinux-ad73fd595c2ab168fdd01a266cbe6e4df95f8db0.tar.bz2
xen/vcpu: Simplify xen_vcpu related code
Largely mechanical changes to aid unification of xen_vcpu_restore() logic for PV, PVH and PVHVM. xen_vcpu_setup(): the only change in logic is that clamp_max_cpus() is now handled inside the "if (!xen_have_vcpu_info_placement)" block. xen_vcpu_restore(): code movement from enlighten_pv.c to enlighten.c. xen_vcpu_info_reset(): pulls together all the code where xen_vcpu is set to default. Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> Signed-off-by: Ankur Arora <ankur.a.arora@oracle.com> Signed-off-by: Juergen Gross <jgross@suse.com>
Diffstat (limited to 'arch/x86/xen/enlighten.c')
-rw-r--r--arch/x86/xen/enlighten.c101
1 files changed, 73 insertions, 28 deletions
diff --git a/arch/x86/xen/enlighten.c b/arch/x86/xen/enlighten.c
index a5ffcbb20cc0..96b745e3f56c 100644
--- a/arch/x86/xen/enlighten.c
+++ b/arch/x86/xen/enlighten.c
@@ -106,6 +106,35 @@ int xen_cpuhp_setup(int (*cpu_up_prepare_cb)(unsigned int),
return rc >= 0 ? 0 : rc;
}
+/*
+ * On restore, set the vcpu placement up again.
+ * If it fails, then we're in a bad state, since
+ * we can't back out from using it...
+ */
+void xen_vcpu_restore(void)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ bool other_cpu = (cpu != smp_processor_id());
+ bool is_up = HYPERVISOR_vcpu_op(VCPUOP_is_up, xen_vcpu_nr(cpu),
+ NULL);
+
+ if (other_cpu && is_up &&
+ HYPERVISOR_vcpu_op(VCPUOP_down, xen_vcpu_nr(cpu), NULL))
+ BUG();
+
+ xen_setup_runstate_info(cpu);
+
+ if (xen_have_vcpu_info_placement)
+ xen_vcpu_setup(cpu);
+
+ if (other_cpu && is_up &&
+ HYPERVISOR_vcpu_op(VCPUOP_up, xen_vcpu_nr(cpu), NULL))
+ BUG();
+ }
+}
+
static void clamp_max_cpus(void)
{
#ifdef CONFIG_SMP
@@ -114,6 +143,17 @@ static void clamp_max_cpus(void)
#endif
}
+void xen_vcpu_info_reset(int cpu)
+{
+ if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS) {
+ per_cpu(xen_vcpu, cpu) =
+ &HYPERVISOR_shared_info->vcpu_info[xen_vcpu_nr(cpu)];
+ } else {
+ /* Set to NULL so that if somebody accesses it we get an OOPS */
+ per_cpu(xen_vcpu, cpu) = NULL;
+ }
+}
+
void xen_vcpu_setup(int cpu)
{
struct vcpu_register_vcpu_info info;
@@ -137,40 +177,45 @@ void xen_vcpu_setup(int cpu)
if (per_cpu(xen_vcpu, cpu) == &per_cpu(xen_vcpu_info, cpu))
return;
}
- if (xen_vcpu_nr(cpu) < MAX_VIRT_CPUS)
- per_cpu(xen_vcpu, cpu) =
- &HYPERVISOR_shared_info->vcpu_info[xen_vcpu_nr(cpu)];
+
+ xen_vcpu_info_reset(cpu);
+
+ if (xen_have_vcpu_info_placement) {
+ vcpup = &per_cpu(xen_vcpu_info, cpu);
+ info.mfn = arbitrary_virt_to_mfn(vcpup);
+ info.offset = offset_in_page(vcpup);
+
+ /*
+ * Check to see if the hypervisor will put the vcpu_info
+ * structure where we want it, which allows direct access via
+ * a percpu-variable.
+ * N.B. This hypercall can _only_ be called once per CPU.
+ * Subsequent calls will error out with -EINVAL. This is due to
+ * the fact that hypervisor has no unregister variant and this
+ * hypercall does not allow to over-write info.mfn and
+ * info.offset.
+ */
+ err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info,
+ xen_vcpu_nr(cpu), &info);
+
+ if (err) {
+ pr_warn_once("register_vcpu_info failed: cpu=%d err=%d\n",
+ cpu, err);
+ xen_have_vcpu_info_placement = 0;
+ } else {
+ /*
+ * This cpu is using the registered vcpu info, even if
+ * later ones fail to.
+ */
+ per_cpu(xen_vcpu, cpu) = vcpup;
+ }
+ }
if (!xen_have_vcpu_info_placement) {
if (cpu >= MAX_VIRT_CPUS)
clamp_max_cpus();
return;
}
-
- vcpup = &per_cpu(xen_vcpu_info, cpu);
- info.mfn = arbitrary_virt_to_mfn(vcpup);
- info.offset = offset_in_page(vcpup);
-
- /* Check to see if the hypervisor will put the vcpu_info
- structure where we want it, which allows direct access via
- a percpu-variable.
- N.B. This hypercall can _only_ be called once per CPU. Subsequent
- calls will error out with -EINVAL. This is due to the fact that
- hypervisor has no unregister variant and this hypercall does not
- allow to over-write info.mfn and info.offset.
- */
- err = HYPERVISOR_vcpu_op(VCPUOP_register_vcpu_info, xen_vcpu_nr(cpu),
- &info);
-
- if (err) {
- printk(KERN_DEBUG "register_vcpu_info failed: err=%d\n", err);
- xen_have_vcpu_info_placement = 0;
- clamp_max_cpus();
- } else {
- /* This cpu is using the registered vcpu info, even if
- later ones fail to. */
- per_cpu(xen_vcpu, cpu) = vcpup;
- }
}
void xen_reboot(int reason)