[PATCH v4 13/42] xen/riscv: introduce vintc_ctxt_switch_{from,to}()

[Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>]

Virtual interrupt controller state must be preserved across vCPU context
switches.

Introduce vintc_ctxt_switch_{from,to}() wrappers around new
ctxt_switch_{from,to}() hooks in struct vintc_ops, and call them from the
context switch path, so that this state can be saved/restored without
knowing which vINTC variant a domain uses.

No vINTC variant implements the hooks yet: the vAPLIC implementation is
added separately.

Signed-off-by: Oleksii Kurochko <oleksii.kurochko@xxxxxxxxx>
Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Baptiste Le Duc <baptiste.le-duc@xxxxxxxxxx>
---
Changes in v4:
 - Add Reviewed-by: Baptiste Le Duc <baptiste.le-duc@xxxxxxxxxx>.
---
Changes in v3:
 - s/v/{p,n} for vintc_ctxt_switch_{from,to}() arguments and also for
   hook prototypes.
 - Add Acked-by: Jan Beulich <jbeulich@xxxxxxxx>.
---
Changes in v2:
 - Update the commit message.
 - s/vintc_state_{save,restore}/vintc_ctxt_switch_{to,from}.
 - s/{re}store_state/ctxt_switch_{to,from} for vintc_ops.
 - s/vcpu/v for vintc_ctxt_switch_{to,from}() arguments.
---
---
 xen/arch/riscv/domain.c           |  4 ++++
 xen/arch/riscv/include/asm/intc.h |  9 +++++++++
 xen/arch/riscv/intc.c             | 14 ++++++++++++++
 3 files changed, 27 insertions(+)

diff --git a/xen/arch/riscv/domain.c b/xen/arch/riscv/domain.c
index 089d968ace27..a65de57e486f 100644
--- a/xen/arch/riscv/domain.c
+++ b/xen/arch/riscv/domain.c
@@ -412,6 +412,8 @@ static void ctxt_switch_from(struct vcpu *p)
 
     vtimer_ctxt_switch_from(p);
 
+    vintc_ctxt_switch_from(p);
+
     csrs_ctxt_switch_from(p);
 }
 
@@ -427,6 +429,8 @@ static void ctxt_switch_to(struct vcpu *n)
 
     csrs_ctxt_switch_to(n);
 
+    vintc_ctxt_switch_to(n);
+
     vtimer_ctxt_switch_to(n);
 
     p2m_ctxt_switch_to(n);
diff --git a/xen/arch/riscv/include/asm/intc.h 
b/xen/arch/riscv/include/asm/intc.h
index 7a31c6a298a0..58196927aab2 100644
--- a/xen/arch/riscv/include/asm/intc.h
+++ b/xen/arch/riscv/include/asm/intc.h
@@ -64,6 +64,12 @@ struct vintc_ops {
 
     /* Deinitialize some vINTC-related stuff for a vCPU */
     void (*vcpu_deinit)(struct vcpu *v);
+
+    /* Save vINTC state of the vCPU being switched out */
+    void (*ctxt_switch_from)(struct vcpu *p);
+
+    /* Restore vINTC state of the vCPU being switched in */
+    void (*ctxt_switch_to)(struct vcpu *n);
 };
 
 struct vintc {
@@ -94,4 +100,7 @@ void domain_vintc_deinit(struct domain *d);
 
 int vintc_reserve_virq(const struct domain *d, unsigned int virq);
 
+void vintc_ctxt_switch_from(struct vcpu *p);
+void vintc_ctxt_switch_to(struct vcpu *n);
+
 #endif /* RISCV_INTC_H */
diff --git a/xen/arch/riscv/intc.c b/xen/arch/riscv/intc.c
index cdbc039d0258..70dfe6cd6f34 100644
--- a/xen/arch/riscv/intc.c
+++ b/xen/arch/riscv/intc.c
@@ -190,3 +190,17 @@ int __overlay_init vintc_reserve_virq(const struct domain 
*d,
 
     return test_and_set_bit(virq, d->arch.vintc->used_irqs) ? -EEXIST : 0;
 }
+
+void vintc_ctxt_switch_from(struct vcpu *p)
+{
+    const struct vintc_ops *ops = p->domain->arch.vintc->ops;
+
+    ops->ctxt_switch_from(p);
+}
+
+void vintc_ctxt_switch_to(struct vcpu *n)
+{
+    const struct vintc_ops *ops = n->domain->arch.vintc->ops;
+
+    ops->ctxt_switch_to(n);
+}
-- 
2.56.1