On 15/07/2022 09:18, Jane Malalane wrote:
On 14/07/2022 00:27, Boris Ostrovsky wrote:And others.
Yes, specifically for the check in libxl__domain_pvcontrol_available.xen_hvm_smp_init();What are you trying to make the toolstack aware of? That we have *a*
WARN_ON(xen_cpuhp_setup(xen_cpu_up_prepare_hvm, xen_cpu_dead_hvm));
diff --git a/arch/x86/xen/suspend_hvm.c b/arch/x86/xen/suspend_hvm.c
index 9d548b0c772f..be66e027ef28 100644
--- a/arch/x86/xen/suspend_hvm.c
+++ b/arch/x86/xen/suspend_hvm.c
@@ -5,6 +5,7 @@
#include <xen/hvm.h>
#include <xen/features.h>
#include <xen/interface/features.h>
+#include <xen/events.h>
#include "xen-ops.h"
@@ -14,6 +15,23 @@ void xen_hvm_post_suspend(int suspend_cancelled)
xen_hvm_init_shared_info();
xen_vcpu_restore();
}
- xen_setup_callback_vector();
+ if (xen_ack_upcall) {
+ unsigned int cpu;
+
+ for_each_online_cpu(cpu) {
+ xen_hvm_evtchn_upcall_vector_t op = {
+ .vector = HYPERVISOR_CALLBACK_VECTOR,
+ .vcpu = per_cpu(xen_vcpu_id, cpu),
+ };
+
+ BUG_ON(HYPERVISOR_hvm_op(HVMOP_set_evtchn_upcall_vector,
+ &op));
+ /* Trick toolstack to think we are enlightened. */
+ if (!cpu)
+ BUG_ON(xen_set_callback_via(1));
callback (either global or percpu)?
This is all a giant bodge, but basically a lot of tooling uses the
non-zero-ness of the CALLBACK_VIA param to determine whether the VM has
Xen-aware drivers loaded or not.
The value 1 is a CALLBACK_VIA value which encodes GSI 1, and the only
reason this doesn't explode everywhere is because the
evtchn_upcall_vector registration takes priority over GSI delivery.
This is decades of tech debt piled on top of tech debt.