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Re: [Qemu-devel] [PATCH] hmp: add 'info virtio-pci-status id' command
From: |
Dr. David Alan Gilbert |
Subject: |
Re: [Qemu-devel] [PATCH] hmp: add 'info virtio-pci-status id' command |
Date: |
Tue, 2 May 2017 15:37:59 +0100 |
User-agent: |
Mutt/1.8.0 (2017-02-23) |
* Stefan Hajnoczi (address@hidden) wrote:
> On Tue, May 02, 2017 at 10:38:11AM +0800, ZhiPeng Lu wrote:
> > Add command to query a virtio pci device status.
> > we can get id of the virtio pci device by 'info pci' command.
> > HMP Test case:
> > ==============
> > virsh # qemu-monitor-command --hmp 3 info pci
> > Bus 0, device 3, function 0:
> > Ethernet controller: PCI device 1af4:1000
> > IRQ 11.
> > BAR0: I/O at 0xc000 [0xc03f].
> > BAR1: 32 bit memory at 0xfebd1000 [0xfebd1fff].
> > BAR4: 64 bit prefetchable memory at 0xfe000000 [0xfe003fff].
> > BAR6: 32 bit memory at 0xffffffffffffffff [0x0003fffe].
> > id "net0"
> > Bus 0, device 4, function 0:
> > USB controller: PCI device 8086:24cd
> > IRQ 11.
> > BAR0: 32 bit memory at 0xfebd2000 [0xfebd2fff].
> > id "usb"
> > virsh # qemu-monitor-command 3 --hmp "info virtio-pci-status net0"
> > status=15
> >
> > virsh # qemu-monitor-command 3 --hmp "info virtio-pci-status usb"
> > the 'info virtio_pci_status' command only supports virtio pci devices
>
> This information can be useful for troubleshooting virtio devices, but
> I'm concerned about adding new ad-hoc HMP commands.
>
> Adding new commands for one specific field of device state lead to
> inconsistent user interfaces. It adds a maintenance burden because all
> future versions of QEMU must continue to support this command for
> compatibility.
>
> QMP should also be supported by new commands unless there is a reason to
> make the command HMP-only.
>
> There is already a trace event called "virtio_set_status" so you can
> observe status changes from the host without adding a new monitor
> command. Unfortunately tracing does not allow you to query the current
> value so it might not be possible to trigger the trace event at the
> appropriate time.
>
> One option is to make the virtio status a QOM property so the existing
> qom-get command can be used to fetch the value without adding a new
> monitor command.
Unfortunately there is no HMP equivalent of qom-get, my previous attempts
at it didn't get anywhere.
> Does anyone have other ideas?
I think it should be at least at the level of 'info virtio-pci'.
Dave
> > Signed-off-by: ZhiPeng Lu <address@hidden>
> > ---
> > hmp-commands-info.hx | 14 ++++++++++++++
> > hw/pci/pci-stub.c | 6 ++++++
> > hw/virtio/virtio-pci.c | 47
> > +++++++++++++++++++++++++++++++++++++++++++++++
> > include/sysemu/sysemu.h | 1 +
> > 4 files changed, 68 insertions(+)
> >
> > diff --git a/hmp-commands-info.hx b/hmp-commands-info.hx
> > index a53f105..7b9c4db 100644
> > --- a/hmp-commands-info.hx
> > +++ b/hmp-commands-info.hx
> > @@ -815,6 +815,20 @@ ETEXI
> > .cmd = hmp_info_vm_generation_id,
> > },
> >
> > + {
> > + .name = "virtio-pci-status",
> > + .args_type = "id:s",
> > + .params = "id",
> > + .help = "show virtio pci device status",
> > + .cmd = hmp_info_virtio_pci_status,
> > + },
> > +
> > +STEXI
> > address@hidden info virtio-pci-status @var{id}
> > address@hidden virtio-pci-status
> > +Show status about virtio pci device
> > +ETEXI
> > +
> > STEXI
> > @end table
> > ETEXI
> > diff --git a/hw/pci/pci-stub.c b/hw/pci/pci-stub.c
> > index 36d2c43..3609a52 100644
> > --- a/hw/pci/pci-stub.c
> > +++ b/hw/pci/pci-stub.c
> > @@ -35,3 +35,9 @@ void hmp_pcie_aer_inject_error(Monitor *mon, const QDict
> > *qdict)
> > {
> > monitor_printf(mon, "PCI devices not supported\n");
> > }
> > +
> > +void hmp_info_virtio_pci_status(Monitor *mon, const QDict *qdict)
> > +{
> > + monitor_printf(mon, "PCI devices not supported\n");
> > +}
> > +
> > diff --git a/hw/virtio/virtio-pci.c b/hw/virtio/virtio-pci.c
> > index f9b7244..5fa862b 100644
> > --- a/hw/virtio/virtio-pci.c
> > +++ b/hw/virtio/virtio-pci.c
> > @@ -37,6 +37,7 @@
> > #include "qemu/range.h"
> > #include "hw/virtio/virtio-bus.h"
> > #include "qapi/visitor.h"
> > +#include "monitor/monitor.h"
> >
> > #define VIRTIO_PCI_REGION_SIZE(dev)
> > VIRTIO_PCI_CONFIG_OFF(msix_present(dev))
> >
> > @@ -50,6 +51,7 @@ static void virtio_pci_bus_new(VirtioBusState *bus,
> > size_t bus_size,
> > VirtIOPCIProxy *dev);
> > static void virtio_pci_reset(DeviceState *qdev);
> >
> > +static void query_virtio_pci_status(Monitor *mon, const char *id);
> > /* virtio device */
> > /* DeviceState to VirtIOPCIProxy. For use off data-path. TODO: use QOM. */
> > static inline VirtIOPCIProxy *to_virtio_pci_proxy(DeviceState *d)
> > @@ -2556,6 +2558,51 @@ static void virtio_pci_bus_new(VirtioBusState *bus,
> > size_t bus_size,
> > virtio_bus_name);
> > }
> >
> > +static void query_virtio_pci_status(Monitor *mon, const char *id)
> > +{
> > + int ret = 0, i = 0;
> > + PCIDevice *dev = NULL;
> > + hwaddr addr = 0;
> > + uint8_t val = 0;
> > + const char *devtype = NULL;
> > +
> > + ret = pci_qdev_find_device(id, &dev);
> > + if (ret) {
> > + monitor_printf(mon, "Can not find device %s\n", id);
> > + return;
> > + }
> > + devtype = object_get_typename(OBJECT(dev));
> > + if (strncmp("virtio-", devtype, 7) == 0) {
> > + for (i = 0; i < PCI_NUM_REGIONS; i++) {
> > + if (dev->io_regions[i].type == PCI_BASE_ADDRESS_SPACE_IO) {
> > + addr = dev->io_regions[i].addr;
> > + break;
> > + }
> > + }
> > + if (addr != -1 && addr != 0) {
> > + address_space_rw(&address_space_io, addr + VIRTIO_PCI_STATUS,
> > + MEMTXATTRS_UNSPECIFIED, &val, 1, 0);
> > + if (val & VIRTIO_CONFIG_S_DRIVER_OK) {
> > + fprintf(stderr, "driver is ok\n");
> > + } else {
> > + fprintf(stderr, "driver is not ok\n");
> > + }
> > + monitor_printf(mon, "status=%d", val);
> > + } else {
> > + monitor_printf(mon, "status=%d", val);
> > + }
> > + } else {
> > + monitor_printf(mon, "the 'info virtio_pci_status' command "
> > + "only supports virtio pci devices");
> > + }
> > +}
> > +
> > +void hmp_info_virtio_pci_status(Monitor *mon, const QDict *qdict)
> > +{
> > + const char *id = qdict_get_try_str(qdict, "id");
> > + query_virtio_pci_status(mon, id);
> > +}
> > +
> > static void virtio_pci_bus_class_init(ObjectClass *klass, void *data)
> > {
> > BusClass *bus_class = BUS_CLASS(klass);
> > diff --git a/include/sysemu/sysemu.h b/include/sysemu/sysemu.h
> > index 576c7ce..de66cc0 100644
> > --- a/include/sysemu/sysemu.h
> > +++ b/include/sysemu/sysemu.h
> > @@ -238,4 +238,5 @@ extern QemuOptsList qemu_net_opts;
> > extern QemuOptsList qemu_global_opts;
> > extern QemuOptsList qemu_mon_opts;
> >
> > +extern void hmp_info_virtio_pci_status(Monitor *mon, const QDict *qdict);
> > #endif
> > --
> > 1.8.3.1
> >
> >
> >
--
Dr. David Alan Gilbert / address@hidden / Manchester, UK