Hi-- On 7/30/23 18:25, zhanghao1 wrote: > A new virtio pci driver is added for listening to vcpus > inside guest. Each vcpu creates a corresponding thread to > periodically send data to qemu's back-end watchdog device. > If a vCPU is in the stall state, data cannot be sent to > back-end virtio device. As a result, the back-end device > can detect that the guest is in the stall state. > > The driver is mainly used with the back-end watchdog device of qemu. > > The qemu backend watchdog device is implemented as follow: > https://lore.kernel.org/qemu-devel/20230705081813.411526-1-zhanghao1@xxxxxxxxxx/ > > Signed-off-by: zhanghao1 <zhanghao1@xxxxxxxxxx> > --- > drivers/virtio/Kconfig | 9 + > drivers/virtio/Makefile | 1 + > drivers/virtio/virtio_vcpu_stall_detector.c | 299 ++++++++++++++++++++ > 3 files changed, 309 insertions(+) > create mode 100644 drivers/virtio/virtio_vcpu_stall_detector.c > > diff --git a/drivers/virtio/Kconfig b/drivers/virtio/Kconfig > index 0a53a61231c2..869323e345a1 100644 > --- a/drivers/virtio/Kconfig > +++ b/drivers/virtio/Kconfig > @@ -173,4 +173,13 @@ config VIRTIO_DMA_SHARED_BUFFER > This option adds a flavor of dma buffers that are backed by > virtio resources. > > +config VIRTIO_VCPU_WATCHDOG > + tristate "Virtio vcpu watchdog driver" > + depends on VIRTIO_PCI > + help > + When this driver is bound inside a KVM guest, it will > + periodically "pet" an PCI virtio watchdog device from each vCPU a PCI > + and allow the host to detect vCPU stalls. > + > + If you do not intend to run this kernel as a guest, say N. Kconfig help text should be indented with one tab + 2 spaces according to coding-style.rst. > endif # VIRTIO_MENU > diff --git a/drivers/virtio/Makefile b/drivers/virtio/Makefile > index 8e98d24917cc..c7341f078a34 100644 > --- a/drivers/virtio/Makefile > +++ b/drivers/virtio/Makefile > @@ -12,3 +12,4 @@ obj-$(CONFIG_VIRTIO_INPUT) += virtio_input.o > obj-$(CONFIG_VIRTIO_VDPA) += virtio_vdpa.o > obj-$(CONFIG_VIRTIO_MEM) += virtio_mem.o > obj-$(CONFIG_VIRTIO_DMA_SHARED_BUFFER) += virtio_dma_buf.o > +obj-$(CONFIG_VIRTIO_VCPU_WATCHDOG) += virtio_vcpu_stall_detector.o > diff --git a/drivers/virtio/virtio_vcpu_stall_detector.c b/drivers/virtio/virtio_vcpu_stall_detector.c > new file mode 100644 > index 000000000000..58344ca528be > --- /dev/null > +++ b/drivers/virtio/virtio_vcpu_stall_detector.c > @@ -0,0 +1,299 @@ > +// SPDX-License-Identifier: GPL-2.0-only > +// > +// VCPU stall detector. > +// Copyright (C) Kylin Software, 2023 > + > +#include <linux/cpu.h> > +#include <linux/init.h> > +#include <linux/io.h> > +#include <linux/kernel.h> > + > +#include <linux/device.h> > +#include <linux/interrupt.h> > +#include <linux/module.h> > +#include <linux/nmi.h> > +#include <uapi/linux/virtio_ids.h> > +#include <linux/virtio_config.h> > +#include <linux/param.h> > +#include <linux/percpu.h> > +#include <linux/slab.h> > + > +#define VCPU_STALL_REG_STATUS (0x00) > +#define VCPU_STALL_REG_LOAD_CNT (0x04) > +#define VCPU_STALL_REG_CURRENT_CNT (0x08) > +#define VCPU_STALL_REG_CLOCK_FREQ_HZ (0x0C) > +#define VCPU_STALL_REG_LEN (0x10) > +#define VCPU_STALL_REG_TIMEOUT_SEC (0x14) > + > +#define VCPU_STALL_DEFAULT_CLOCK_HZ (10) > +#define VCPU_STALL_MAX_CLOCK_HZ (100) > +#define VCPU_STALL_DEFAULT_TIMEOUT_SEC (8) > +#define VCPU_STALL_MAX_TIMEOUT_SEC (600) > + > +struct vcpu_stall_detect_config { > + u32 clock_freq_hz; > + u32 stall_timeout_sec; > + > + enum cpuhp_state hp_online; > +}; > + > +struct vcpu_stall_priv { > + struct hrtimer vcpu_hrtimer; > + struct virtio_device *vdev; > + u32 cpu_id; > +}; > + > +struct vcpu_stall { > + struct vcpu_stall_priv *priv; > + struct virtqueue *vq; > + spinlock_t lock; > + struct pet_event { > + u32 cpu_id; > + bool is_initialized; > + u32 ticks; > + } pet_event; > +}; > + > +static const struct virtio_device_id vcpu_stall_id_table[] = { > + { VIRTIO_ID_WATCHDOG, VIRTIO_DEV_ANY_ID }, > + { 0, }, > +}; > + > +/* The vcpu stall configuration structure which applies to all the CPUs */ > +static struct vcpu_stall_detect_config vcpu_stall_config; > +static struct vcpu_stall *vcpu_stall; > + > +static struct vcpu_stall_priv __percpu *vcpu_stall_detectors; > + > +static enum hrtimer_restart > +vcpu_stall_detect_timer_fn(struct hrtimer *hrtimer) One line instead of the 2 lines above. > +{ -- ~Randy _______________________________________________ Virtualization mailing list Virtualization@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linuxfoundation.org/mailman/listinfo/virtualization
