On 2/3/26 5:43 PM, Jan Beulich wrote:
On 22.01.2026 17:47, Oleksii Kurochko wrote:
Introduce vtimer_ctx_switch_from() and vtimer_ctx_switch_to() to handle
virtual timer state across vCPU context switches.
At present, vtimer_ctx_switch_from() is a no-op because the RISC-V SSTC
extension, which provides a virtualization-aware timer, is not yet
supported. Xen therefore relies the virtual (SBI-based) timer.
The virtual timer uses Xen's internal timer infrastructure and must be
associated with the pCPU on which the vCPU is currently running so that
timer events can be delivered efficiently. As a result, vtimer_ctx_switch_to()
migrates the timer to the target pCPU when a vCPU is scheduled in.
Signed-off-by: Oleksii Kurochko <[email protected]>
Acked-by: Jan Beulich <[email protected]>
Thanks.
However, ...
--- a/xen/arch/riscv/include/asm/vtimer.h
+++ b/xen/arch/riscv/include/asm/vtimer.h
@@ -17,4 +17,7 @@ void vcpu_timer_destroy(struct vcpu *v);
void vtimer_set_timer(struct vtimer *t, uint64_t ticks);
+void vtimer_ctx_switch_from(struct vcpu *p);
+void vtimer_ctx_switch_to(struct vcpu *n);
... may I ask that you reconsider naming here? Both Arm and x86 have functions
where the prefix / infix is "ctxt", not just "ctx". Being able to find all by
grep-ing for e.g. ctxt_switch_from might be quite nice.
Sure, I will do that, it makes sense.
~ Oleksii
