Re: [Qemu-trivial] [Qemu-devel] [PATCH v2] hw/virtio/virtio-mmio: Convert DPRINTF to traces

[Yuval Shaia <yuval.shaia@oracle.com>]

On Wed, May 01, 2019 at 04:10:39PM +0800, Boxuan Li wrote:
> Signed-off-by: Boxuan Li <liboxuan@connect.hku.hk>
> ---
> v2: Instead of using conditional debugs, convert DPRINTF to traces
> ---
>  hw/virtio/trace-events  | 13 +++++++++++++
>  hw/virtio/virtio-mmio.c | 35 ++++++++++++-----------------------
>  2 files changed, 25 insertions(+), 23 deletions(-)
> 
> diff --git a/hw/virtio/trace-events b/hw/virtio/trace-events
> index 60c649c4bc..37c781b487 100644
> --- a/hw/virtio/trace-events
> +++ b/hw/virtio/trace-events
> @@ -46,3 +46,16 @@ virtio_balloon_handle_output(const char *name, uint64_t gpa) "section name: %s g
>  virtio_balloon_get_config(uint32_t num_pages, uint32_t actual) "num_pages: %d actual: %d"
>  virtio_balloon_set_config(uint32_t actual, uint32_t oldactual) "actual: %d oldactual: %d"
>  virtio_balloon_to_target(uint64_t target, uint32_t num_pages) "balloon target: 0x%"PRIx64" num_pages: %d"
> +
> +# virtio-mmio.c
> +virtio_mmio_read(int offset) "virtio_mmio_read offset 0x%x"
> +virtio_mmio_wrong_size_read(void) "wrong size access to register!"
> +virtio_mmio_read_interrupt(void) "read of write-only register"
> +virtio_mmio_bad_read_offset(void) "bad register offset"
> +virtio_mmio_write_offset(int offset, uint64_t value) "virtio_mmio_write offset 0x%x value 0x%" PRIx64
> +virtio_mmio_wrong_size_write(void) "wrong size access to register!"
> +virtio_mmio_guest_page(uint64_t size, int shift) "guest page size 0x%" PRIx64 " shift %d"
> +virtio_mmio_queue_write(int value, int max_size) "mmio_queue write %d max %d"
> +virtio_mmio_write_interrupt(void) "write to readonly register"
> +virtio_mmio_bad_write_offset(void) "bad register offset"
> +virtio_mmio_setting_irq(int level) "virtio_mmio setting IRQ %d"
> diff --git a/hw/virtio/virtio-mmio.c b/hw/virtio/virtio-mmio.c
> index 5807aa87fe..4251df399d 100644
> --- a/hw/virtio/virtio-mmio.c
> +++ b/hw/virtio/virtio-mmio.c
> @@ -27,16 +27,7 @@
>  #include "sysemu/kvm.h"
>  #include "hw/virtio/virtio-bus.h"
>  #include "qemu/error-report.h"
> -
> -/* #define DEBUG_VIRTIO_MMIO */
> -
> -#ifdef DEBUG_VIRTIO_MMIO
> -
> -#define DPRINTF(fmt, ...) \
> -do { printf("virtio_mmio: " fmt , ## __VA_ARGS__); } while (0)
> -#else
> -#define DPRINTF(fmt, ...) do {} while (0)
> -#endif
> +#include "trace.h"
>  
>  /* QOM macros */
>  /* virtio-mmio-bus */
> @@ -107,7 +98,7 @@ static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size)
>      VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque;
>      VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
>  
> -    DPRINTF("virtio_mmio_read offset 0x%x\n", (int)offset);
> +    trace_virtio_mmio_read((int)offset);
>  
>      if (!vdev) {
>          /* If no backend is present, we treat most registers as
> @@ -144,7 +135,7 @@ static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size)
>          }
>      }
>      if (size != 4) {
> -        DPRINTF("wrong size access to register!\n");
> +        trace_virtio_mmio_wrong_size_read();

Have you considered using qemu_error_report to report such errors?

>          return 0;
>      }
>      switch (offset) {
> @@ -182,10 +173,10 @@ static uint64_t virtio_mmio_read(void *opaque, hwaddr offset, unsigned size)
>      case VIRTIO_MMIO_QUEUE_ALIGN:
>      case VIRTIO_MMIO_QUEUE_NOTIFY:
>      case VIRTIO_MMIO_INTERRUPT_ACK:
> -        DPRINTF("read of write-only register\n");
> +        trace_virtio_mmio_read_interrupt();
>          return 0;
>      default:
> -        DPRINTF("bad register offset\n");
> +        trace_virtio_mmio_bad_read_offset();

Ditto to all other errors.

>          return 0;
>      }
>      return 0;
> @@ -197,8 +188,7 @@ static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value,
>      VirtIOMMIOProxy *proxy = (VirtIOMMIOProxy *)opaque;
>      VirtIODevice *vdev = virtio_bus_get_device(&proxy->bus);
>  
> -    DPRINTF("virtio_mmio_write offset 0x%x value 0x%" PRIx64 "\n",
> -            (int)offset, value);
> +    trace_virtio_mmio_write_offset((int)offset, value);
>  
>      if (!vdev) {
>          /* If no backend is present, we just make all registers
> @@ -226,7 +216,7 @@ static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value,
>          return;
>      }
>      if (size != 4) {
> -        DPRINTF("wrong size access to register!\n");
> +        trace_virtio_mmio_wrong_size_write();
>          return;
>      }
>      switch (offset) {
> @@ -246,8 +236,7 @@ static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value,
>          if (proxy->guest_page_shift > 31) {
>              proxy->guest_page_shift = 0;
>          }
> -        DPRINTF("guest page size %" PRIx64 " shift %d\n", value,
> -                proxy->guest_page_shift);
> +        trace_virtio_mmio_guest_page(value, proxy->guest_page_shift);
>          break;
>      case VIRTIO_MMIO_QUEUE_SEL:
>          if (value < VIRTIO_QUEUE_MAX) {
> @@ -255,7 +244,7 @@ static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value,
>          }
>          break;
>      case VIRTIO_MMIO_QUEUE_NUM:
> -        DPRINTF("mmio_queue write %d max %d\n", (int)value, VIRTQUEUE_MAX_SIZE);
> +        trace_virtio_mmio_queue_write((int)value, VIRTQUEUE_MAX_SIZE);
>          virtio_queue_set_num(vdev, vdev->queue_sel, value);
>          /* Note: only call this function for legacy devices */
>          virtio_queue_update_rings(vdev, vdev->queue_sel);
> @@ -303,11 +292,11 @@ static void virtio_mmio_write(void *opaque, hwaddr offset, uint64_t value,
>      case VIRTIO_MMIO_DEVICE_FEATURES:
>      case VIRTIO_MMIO_QUEUE_NUM_MAX:
>      case VIRTIO_MMIO_INTERRUPT_STATUS:
> -        DPRINTF("write to readonly register\n");
> +        trace_virtio_mmio_write_interrupt();
>          break;
>  
>      default:
> -        DPRINTF("bad register offset\n");
> +        trace_virtio_mmio_bad_write_offset();
>      }
>  }
>  
> @@ -327,7 +316,7 @@ static void virtio_mmio_update_irq(DeviceState *opaque, uint16_t vector)
>          return;
>      }
>      level = (atomic_read(&vdev->isr) != 0);
> -    DPRINTF("virtio_mmio setting IRQ %d\n", level);
> +    trace_virtio_mmio_setting_irq(level);
>      qemu_set_irq(proxy->irq, level);
>  }

I went through all code changes and found no mistakes but suggesting to
turn errors to errors and not just threat them as traces.

If you already considered it then fine.

>  
> -- 
> 2.13.2
> 
>