From: Igor Mammedov <[email protected]> Reading QEMU_CLOCK_VIRTUAL is thread-safe, write access is NOP.
This makes possible to boot Windows with large vCPUs count when hv-time is not used. Reproducer: -M q35,hpet=off -cpu host -enable-kvm -smp 240,sockets=4 -m 8G WS2025.img fails to boot within 30min. With this fix it boots within 2-1min. Signed-off-by: Igor Mammedov <[email protected]> Reviewed-by: Peter Xu <[email protected]> Acked-by: Michael S. Tsirkin <[email protected]> Link: https://lore.kernel.org/r/[email protected] Signed-off-by: Paolo Bonzini <[email protected]> --- hw/acpi/core.c | 1 + 1 file changed, 1 insertion(+) diff --git a/hw/acpi/core.c b/hw/acpi/core.c index 58f8964e130..ff165828033 100644 --- a/hw/acpi/core.c +++ b/hw/acpi/core.c @@ -547,6 +547,7 @@ void acpi_pm_tmr_init(ACPIREGS *ar, acpi_update_sci_fn update_sci, ar->tmr.timer = timer_new_ns(QEMU_CLOCK_VIRTUAL, acpi_pm_tmr_timer, ar); memory_region_init_io(&ar->tmr.io, memory_region_owner(parent), &acpi_pm_tmr_ops, ar, "acpi-tmr", 4); + memory_region_enable_lockless_io(&ar->tmr.io); memory_region_add_subregion(parent, 8, &ar->tmr.io); } -- 2.51.0
