On 12.09.19 01:36, Dexuan Cui wrote: > When hibernation is enabled, we must ignore the balloon up/down and > hot-add requests from the host, if any. > > Fow now, if people want to test hibernation, please blacklist hv_balloon > or do not enable Dynamic Memory and Memory Resizing. See the comment in > balloon_probe() for more info. >
Why do you even care about supporting hibernation? Can't you just pause the VM in the hypervisor and continue to live a happy life? :) > Signed-off-by: Dexuan Cui <[email protected]> > --- > > This patch is basically a pure Hyper-V specific change and it has a > build dependency on the commit 271b2224d42f ("Drivers: hv: vmbus: Implement > suspend/resume for VSC drivers for hibernation"), which is on Sasha Levin's > Hyper-V tree's hyperv-next branch: > https://git.kernel.org/pub/scm/linux/kernel/git/hyperv/linux.git/log/?h=hyperv-next > > I request this patch should go through Sasha's tree rather than the > other tree(s). > > drivers/hv/hv_balloon.c | 101 > +++++++++++++++++++++++++++++++++++++++++++++++- > 1 file changed, 99 insertions(+), 2 deletions(-) > > diff --git a/drivers/hv/hv_balloon.c b/drivers/hv/hv_balloon.c > index 34bd735..7df0f67 100644 > --- a/drivers/hv/hv_balloon.c > +++ b/drivers/hv/hv_balloon.c > @@ -24,6 +24,8 @@ > > #include <linux/hyperv.h> > > +#include <asm/mshyperv.h> > + > #define CREATE_TRACE_POINTS > #include "hv_trace_balloon.h" > > @@ -457,6 +459,7 @@ struct hot_add_wrk { > struct work_struct wrk; > }; > > +static bool allow_hibernation; > static bool hot_add = true; > static bool do_hot_add; > /* > @@ -1053,8 +1056,12 @@ static void hot_add_req(struct work_struct *dummy) > else > resp.result = 0; > > - if (!do_hot_add || (resp.page_count == 0)) > - pr_err("Memory hot add failed\n"); > + if (!do_hot_add || resp.page_count == 0) { > + if (!allow_hibernation) > + pr_err("Memory hot add failed\n"); > + else > + pr_info("Ignore hot-add request!\n"); > + } > > dm->state = DM_INITIALIZED; > resp.hdr.trans_id = atomic_inc_return(&trans_id); > @@ -1509,6 +1516,11 @@ static void balloon_onchannelcallback(void *context) > break; > > case DM_BALLOON_REQUEST: > + if (allow_hibernation) { > + pr_info("Ignore balloon-up request!\n"); > + break; > + } > + > if (dm->state == DM_BALLOON_UP) > pr_warn("Currently ballooning\n"); > bal_msg = (struct dm_balloon *)recv_buffer; > @@ -1518,6 +1530,11 @@ static void balloon_onchannelcallback(void *context) > break; > > case DM_UNBALLOON_REQUEST: > + if (allow_hibernation) { > + pr_info("Ignore balloon-down request!\n"); > + break; > + } > + > dm->state = DM_BALLOON_DOWN; > balloon_down(dm, > (struct dm_unballoon_request *)recv_buffer); > @@ -1623,6 +1640,11 @@ static int balloon_connect_vsp(struct hv_device *dev) > cap_msg.hdr.size = sizeof(struct dm_capabilities); > cap_msg.hdr.trans_id = atomic_inc_return(&trans_id); > > + /* > + * When hibernation (i.e. virtual ACPI S4 state) is enabled, the host > + * currently still requires the bits to be set, so we have to add code > + * to fail the host's hot-add and balloon up/down requests, if any. > + */ > cap_msg.caps.cap_bits.balloon = 1; > cap_msg.caps.cap_bits.hot_add = 1; > > @@ -1672,6 +1694,24 @@ static int balloon_probe(struct hv_device *dev, > { > int ret; > > +#if 0 I am not sure if that's a good idea. Can't you base this series on hv_is_hibernation_supported() ? > + /* > + * The patch to implement hv_is_hibernation_supported() is going > + * through the tip tree. For now, let's hardcode allow_hibernation > + * to false to keep the current behavior of hv_balloon. If people > + * want to test hibernation, please blacklist hv_balloon fow now > + * or do not enable Dynamid Memory and Memory Resizing. > + * > + * We'll remove the conditional compilation as soon as > + * hv_is_hibernation_supported() is available in the mainline tree. > + */ > + allow_hibernation = hv_is_hibernation_supported(); > +#else > + allow_hibernation = false; > +#endif > + if (allow_hibernation) > + hot_add = false; > + > #ifdef CONFIG_MEMORY_HOTPLUG > do_hot_add = hot_add; > #else > @@ -1711,6 +1751,8 @@ static int balloon_probe(struct hv_device *dev, > return 0; > > probe_error: > + dm_device.state = DM_INIT_ERROR; > + dm_device.thread = NULL; > vmbus_close(dev->channel); > #ifdef CONFIG_MEMORY_HOTPLUG > unregister_memory_notifier(&hv_memory_nb); > @@ -1752,6 +1794,59 @@ static int balloon_remove(struct hv_device *dev) > return 0; > } > > +static int balloon_suspend(struct hv_device *hv_dev) > +{ > + struct hv_dynmem_device *dm = hv_get_drvdata(hv_dev); > + > + tasklet_disable(&hv_dev->channel->callback_event); > + > + cancel_work_sync(&dm->balloon_wrk.wrk); > + cancel_work_sync(&dm->ha_wrk.wrk); > + > + if (dm->thread) { > + kthread_stop(dm->thread); > + dm->thread = NULL; > + vmbus_close(hv_dev->channel); > + } > + > + tasklet_enable(&hv_dev->channel->callback_event); > + > + return 0; > + > +} > + > +static int balloon_resume(struct hv_device *dev) > +{ > + int ret; > + > + dm_device.state = DM_INITIALIZING; > + > + ret = balloon_connect_vsp(dev); > + > + if (ret != 0) > + goto out; > + > + dm_device.thread = > + kthread_run(dm_thread_func, &dm_device, "hv_balloon"); > + if (IS_ERR(dm_device.thread)) { > + ret = PTR_ERR(dm_device.thread); > + dm_device.thread = NULL; > + goto close_channel; > + } > + > + dm_device.state = DM_INITIALIZED; > + return 0; > +close_channel: > + vmbus_close(dev->channel); > +out: > + dm_device.state = DM_INIT_ERROR; > +#ifdef CONFIG_MEMORY_HOTPLUG > + unregister_memory_notifier(&hv_memory_nb); > + restore_online_page_callback(&hv_online_page); > +#endif > + return ret; > +} > + > static const struct hv_vmbus_device_id id_table[] = { > /* Dynamic Memory Class ID */ > /* 525074DC-8985-46e2-8057-A307DC18A502 */ > @@ -1766,6 +1861,8 @@ static int balloon_remove(struct hv_device *dev) > .id_table = id_table, > .probe = balloon_probe, > .remove = balloon_remove, > + .suspend = balloon_suspend, > + .resume = balloon_resume, > .driver = { > .probe_type = PROBE_PREFER_ASYNCHRONOUS, > }, > -- Thanks, David / dhildenb
