Re: [PATCH RFC 1/1] msix: add hmp interface to dump MSI-X info

[Jason Wang]

在 2021/4/23 下午12:47, Dongli Zhang 写道:
> This patch is to add the HMP interface to dump MSI-X table and PBA, in
> order to help diagnose the loss of IRQ issue in VM (e.g., if an MSI-X
> vector is erroneously masked permanently). Here is the example with
> vhost-scsi:
>
> (qemu) info msix /machine/peripheral/vscsi0
> MSI-X Table
> 0xfee01004 0x00000000 0x00000022 0x00000000
> 0xfee02004 0x00000000 0x00000023 0x00000000
> 0xfee01004 0x00000000 0x00000023 0x00000000
> 0xfee01004 0x00000000 0x00000021 0x00000000
> 0xfee02004 0x00000000 0x00000022 0x00000000
> 0x00000000 0x00000000 0x00000000 0x00000001
> 0x00000000 0x00000000 0x00000000 0x00000001
> MSI-X PBA
> 0 0 0 0 0 0 0
>
> Since the number of MSI-X entries is not determined and might be very
> large, it is sometimes inappropriate to dump via QMP.
>
> Therefore, this patch dumps MSI-X information only via HMP, which is
> similar to the implementation of hmp_info_mem().


Besides PBA, I think it should be also useful to introduce device 
specifc callbacks for dump the MSI messages used by the device.

Thanks


> Cc: Jason Wang <jasowang@redhat.com>
> Cc: Joe Jin <joe.jin@oracle.com>
> Signed-off-by: Dongli Zhang <dongli.zhang@oracle.com>
> ---
>   hmp-commands-info.hx   | 13 +++++++++++
>   hw/pci/msix.c          | 49 ++++++++++++++++++++++++++++++++++++++++++
>   include/hw/pci/msix.h  |  2 ++
>   include/monitor/hmp.h  |  1 +
>   softmmu/qdev-monitor.c | 25 +++++++++++++++++++++
>   5 files changed, 90 insertions(+)
>
> diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx
> index ab0c7aa5ee..cbd056442b 100644
> --- a/hmp-commands-info.hx
> +++ b/hmp-commands-info.hx
> @@ -221,6 +221,19 @@ SRST
>       Show PCI information.
>   ERST
>   
> +    {
> +        .name       = "msix",
> +        .args_type  = "dev:s",
> +        .params     = "dev",
> +        .help       = "dump MSI-X information",
> +        .cmd        = hmp_info_msix,
> +    },
> +
> +SRST
> +  ``info msix`` *dev*
> +    Dump MSI-X information for device *dev*.
> +ERST
> +
>   #if defined(TARGET_I386) || defined(TARGET_SH4) || defined(TARGET_SPARC) || \
>       defined(TARGET_PPC) || defined(TARGET_XTENSA) || defined(TARGET_M68K)
>       {
> diff --git a/hw/pci/msix.c b/hw/pci/msix.c
> index ae9331cd0b..a93d31da9f 100644
> --- a/hw/pci/msix.c
> +++ b/hw/pci/msix.c
> @@ -22,6 +22,7 @@
>   #include "sysemu/xen.h"
>   #include "migration/qemu-file-types.h"
>   #include "migration/vmstate.h"
> +#include "monitor/monitor.h"
>   #include "qemu/range.h"
>   #include "qapi/error.h"
>   #include "trace.h"
> @@ -669,3 +670,51 @@ const VMStateDescription vmstate_msix = {
>           VMSTATE_END_OF_LIST()
>       }
>   };
> +
> +static void msix_dump_table(Monitor *mon, PCIDevice *dev)
> +{
> +    int vector, i, offset;
> +    uint32_t val;
> +
> +    monitor_printf(mon, "MSI-X Table\n");
> +
> +    for (vector = 0; vector < dev->msix_entries_nr; vector++) {
> +        for (i = 0; i < 4; i++) {
> +            offset = vector * PCI_MSIX_ENTRY_SIZE + i * 4;
> +            val = pci_get_long(dev->msix_table + offset);
> +
> +            monitor_printf(mon, "0x%08x ", val);
> +        }
> +        monitor_printf(mon, "\n");
> +    }
> +}
> +
> +static void msix_dump_pba(Monitor *mon, PCIDevice *dev)
> +{
> +    int vector;
> +
> +    monitor_printf(mon, "MSI-X PBA\n");
> +
> +    for (vector = 0; vector < dev->msix_entries_nr; vector++) {
> +        monitor_printf(mon, "%d ", !!msix_is_pending(dev, vector));
> +
> +        if (vector % 16 == 15) {
> +            monitor_printf(mon, "\n");
> +        }
> +    }
> +
> +    if (vector % 16 != 15) {
> +        monitor_printf(mon, "\n");
> +    }
> +}
> +
> +void msix_dump_info(Monitor *mon, PCIDevice *dev, Error **errp)
> +{
> +    if (!msix_present(dev)) {
> +        error_setg(errp, "MSI-X not available");
> +        return;
> +    }
> +
> +    msix_dump_table(mon, dev);
> +    msix_dump_pba(mon, dev);
> +}
> diff --git a/include/hw/pci/msix.h b/include/hw/pci/msix.h
> index 4c4a60c739..10a4500295 100644
> --- a/include/hw/pci/msix.h
> +++ b/include/hw/pci/msix.h
> @@ -47,6 +47,8 @@ int msix_set_vector_notifiers(PCIDevice *dev,
>                                 MSIVectorPollNotifier poll_notifier);
>   void msix_unset_vector_notifiers(PCIDevice *dev);
>   
> +void msix_dump_info(Monitor *mon, PCIDevice *dev, Error **errp);
> +
>   extern const VMStateDescription vmstate_msix;
>   
>   #define VMSTATE_MSIX_TEST(_field, _state, _test) {                   \
> diff --git a/include/monitor/hmp.h b/include/monitor/hmp.h
> index 605d57287a..46e0efc213 100644
> --- a/include/monitor/hmp.h
> +++ b/include/monitor/hmp.h
> @@ -36,6 +36,7 @@ void hmp_info_irq(Monitor *mon, const QDict *qdict);
>   void hmp_info_pic(Monitor *mon, const QDict *qdict);
>   void hmp_info_rdma(Monitor *mon, const QDict *qdict);
>   void hmp_info_pci(Monitor *mon, const QDict *qdict);
> +void hmp_info_msix(Monitor *mon, const QDict *qdict);
>   void hmp_info_tpm(Monitor *mon, const QDict *qdict);
>   void hmp_info_iothreads(Monitor *mon, const QDict *qdict);
>   void hmp_quit(Monitor *mon, const QDict *qdict);
> diff --git a/softmmu/qdev-monitor.c b/softmmu/qdev-monitor.c
> index a9955b97a0..2a37d03fb7 100644
> --- a/softmmu/qdev-monitor.c
> +++ b/softmmu/qdev-monitor.c
> @@ -19,6 +19,7 @@
>   
>   #include "qemu/osdep.h"
>   #include "hw/sysbus.h"
> +#include "hw/pci/msix.h"
>   #include "monitor/hmp.h"
>   #include "monitor/monitor.h"
>   #include "monitor/qdev.h"
> @@ -1006,3 +1007,27 @@ bool qmp_command_available(const QmpCommand *cmd, Error 
> **errp)
>       }
>       return true;
>   }
> +
> +void hmp_info_msix(Monitor *mon, const QDict *qdict)
> +{
> +    const char *name = qdict_get_str(qdict, "dev");
> +    DeviceState *dev = find_device_state(name, NULL);
> +    PCIDevice *pci_dev;
> +    Error *err = NULL;
> +
> +    if (!dev) {
> +        error_setg(&err, "Device %s not found", name);
> +        goto exit;
> +    }
> +
> +    if (!object_dynamic_cast(OBJECT(dev), TYPE_PCI_DEVICE)) {
> +        error_setg(&err, "Not a PCI device");
> +        goto exit;
> +    }
> +
> +    pci_dev = PCI_DEVICE(dev);
> +    msix_dump_info(mon, pci_dev, &err);
> +
> +exit:
> +    hmp_handle_error(mon, err);
> +}