On 4/1/2026 10:24 PM, Michael Kelley wrote:
From: Naman Jain <[email protected]> Sent: Monday, March 16, 2026
5:13 AM
Nit: For the patch "Subject", the most common prefix for the file
arch/arm64/kernel/smp.c is "arm64: smp:". I'd suggest using that
prefix for historical consistency.
Acked. Will change in v2.
mshv_vtl_main.c calls smp_send_reschedule() which expands to
arch_smp_send_reschedule(). When CONFIG_MSHV_VTL=m, the module cannot
access this symbol since it is not exported on arm64.
smp_send_reschedule() is used in mshv_vtl_cancel() to interrupt a vCPU
thread running on another CPU. When a vCPU is looping in
mshv_vtl_ioctl_return_to_lower_vtl(), it checks a per-CPU cancel flag
before each VTL0 entry. Setting cancel=1 alone is not enough if the
target CPU thread is sleeping - the IPI from smp_send_reschedule() kicks
the remote CPU out of idle/sleep so it re-checks the cancel flag and
exits the loop promptly.
Other architectures (riscv, loongarch, powerpc) already export this
symbol. Add the same EXPORT_SYMBOL_GPL for arm64. This is required
for adding arm64 support in MSHV_VTL.
Signed-off-by: Naman Jain <[email protected]>
---
arch/arm64/kernel/smp.c | 1 +
1 file changed, 1 insertion(+)
diff --git a/arch/arm64/kernel/smp.c b/arch/arm64/kernel/smp.c
index 1aa324104afb..26b1a4456ceb 100644
--- a/arch/arm64/kernel/smp.c
+++ b/arch/arm64/kernel/smp.c
@@ -1152,6 +1152,7 @@ void arch_smp_send_reschedule(int cpu)
{
smp_cross_call(cpumask_of(cpu), IPI_RESCHEDULE);
}
+EXPORT_SYMBOL_GPL(arch_smp_send_reschedule);
#ifdef CONFIG_ARM64_ACPI_PARKING_PROTOCOL
void arch_send_wakeup_ipi(unsigned int cpu)
--
2.43.0
The "Subject" nit notwithstanding,
Reviewed-by: Michael Kelley <[email protected]>
Thanks,
Naman
