[PATCH v3 2/3] xen/oprofile: use set_nmi_continuation() for sending virq to guest

[Juergen Gross <jgross@xxxxxxxx>]

Instead of calling send_guest_vcpu_virq() from NMI context use the
NMI continuation framework for that purpose. This avoids taking locks
in NMI mode.

Signed-off-by: Juergen Gross <jgross@xxxxxxxx>
---
 xen/arch/x86/oprofile/nmi_int.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/xen/arch/x86/oprofile/nmi_int.c b/xen/arch/x86/oprofile/nmi_int.c
index 0f103d80a6..825f0aeef0 100644
--- a/xen/arch/x86/oprofile/nmi_int.c
+++ b/xen/arch/x86/oprofile/nmi_int.c
@@ -83,6 +83,13 @@ void passive_domain_destroy(struct vcpu *v)
                model->free_msr(v);
 }
 
+static void nmi_oprofile_send_virq(void *arg)
+{
+       struct vcpu *v = arg;
+
+       send_guest_vcpu_virq(v, VIRQ_XENOPROF);
+}
+
 static int nmi_callback(const struct cpu_user_regs *regs, int cpu)
 {
        int xen_mode, ovf;
@@ -90,7 +97,7 @@ static int nmi_callback(const struct cpu_user_regs *regs, int 
cpu)
        ovf = model->check_ctrs(cpu, &cpu_msrs[cpu], regs);
        xen_mode = ring_0(regs);
        if ( ovf && is_active(current->domain) && !xen_mode )
-               send_guest_vcpu_virq(current, VIRQ_XENOPROF);
+               set_nmi_continuation(nmi_oprofile_send_virq, current);
 
        if ( ovf == 2 )
                current->arch.nmi_pending = true;
-- 
2.26.2