Re: [Qemu-devel] [PATCH] qga: add command guest-get-devices for reporting VirtIO devices

[Tomáš Golembiovský]

On Mon, Sep 16, 2019 at 04:31:49PM +0400, Marc-André Lureau wrote:
> Hi
> 
> On Thu, Aug 29, 2019 at 8:06 PM Tomáš Golembiovský <address@hidden> wrote:
> >
> > Add command for reporting devices on Windows guest. The intent is not so
> > much to report the devices but more importantly the driver (and its
> > version) that is assigned to the device.
> >
> > Signed-off-by: Tomáš Golembiovský <address@hidden>
> > ---
> >  qga/commands-posix.c |  11 +++
> >  qga/commands-win32.c | 195 ++++++++++++++++++++++++++++++++++++++++++-
> >  qga/qapi-schema.json |  32 +++++++
> >  3 files changed, 237 insertions(+), 1 deletion(-)
> >
> > diff --git a/qga/commands-posix.c b/qga/commands-posix.c
> > index dfc05f5b8a..9adf8bb520 100644
> > --- a/qga/commands-posix.c
> > +++ b/qga/commands-posix.c
> > @@ -2709,6 +2709,7 @@ int64_t qmp_guest_fsfreeze_thaw(Error **errp)
> >
> >      return 0;
> >  }
> > +
> >  #endif /* CONFIG_FSFREEZE */
> 
> extra line
> 
> 
> >
> >  #if !defined(CONFIG_FSTRIM)
> > @@ -2757,6 +2758,8 @@ GList *ga_command_blacklist_init(GList *blacklist)
> >      blacklist = g_list_append(blacklist, g_strdup("guest-fstrim"));
> >  #endif
> >
> > +    blacklist = g_list_append(blacklist, g_strdup("guest-get-devices"));
> > +
> >      return blacklist;
> >  }
> >
> > @@ -2977,3 +2980,11 @@ GuestOSInfo *qmp_guest_get_osinfo(Error **errp)
> >
> >      return info;
> >  }
> > +
> > +GuestDeviceInfoList *qmp_guest_get_devices(Error **errp)
> > +{
> > +    error_setg(errp, QERR_UNSUPPORTED);
> > +
> > +    return NULL;
> > +}
> > +
> 
> extra EOF line
> 
> > diff --git a/qga/commands-win32.c b/qga/commands-win32.c
> > index 6b67f16faf..0bb93422c7 100644
> > --- a/qga/commands-win32.c
> > +++ b/qga/commands-win32.c
> > @@ -21,10 +21,11 @@
> >  #ifdef CONFIG_QGA_NTDDSCSI
> >  #include <winioctl.h>
> >  #include <ntddscsi.h>
> > +#endif
> >  #include <setupapi.h>
> >  #include <cfgmgr32.h>
> >  #include <initguid.h>
> > -#endif
> > +#include <devpropdef.h>
> >  #include <lm.h>
> >  #include <wtsapi32.h>
> >  #include <wininet.h>
> > @@ -38,6 +39,36 @@
> >  #include "qemu/host-utils.h"
> >  #include "qemu/base64.h"
> >
> > +
> > +/* The following should be in devpkey.h, but it isn't */
> > +DEFINE_DEVPROPKEY(DEVPKEY_NAME, 0xb725f130, 0x47ef, 0x101a, 0xa5, 0xf1, 
> > 0x02,
> > +    0x60, 0x8c, 0x9e, 0xeb, 0xac, 10);  /* DEVPROP_TYPE_STRING */
> > +DEFINE_DEVPROPKEY(DEVPKEY_Device_HardwareIds, 0xa45c254e, 0xdf1c, 0x4efd, 
> > 0x80,
> > +    0x20, 0x67, 0xd1, 0x46, 0xa8, 0x50, 0xe0, 3);
> > +    /* DEVPROP_TYPE_STRING_LIST */
> > +DEFINE_DEVPROPKEY(DEVPKEY_Device_DriverDate, 0xa8b865dd, 0x2e3d, 0x4094, 
> > 0xad,
> > +    0x97, 0xe5, 0x93, 0xa7, 0xc, 0x75, 0xd6, 2);  /* DEVPROP_TYPE_FILETIME 
> > */
> > +DEFINE_DEVPROPKEY(DEVPKEY_Device_DriverVersion, 0xa8b865dd, 0x2e3d, 0x4094,
> > +    0xad, 0x97, 0xe5, 0x93, 0xa7, 0xc, 0x75, 0xd6, 3);
> 
> perhaps use a qemu prefix to avoid future clash?

Yes, this looks like the only option.

> 
> > +    /* DEVPROP_TYPE_STRING */
> > +/* The following should be in sal.h, but it isn't */
> > +#ifndef _Out_writes_bytes_opt_
> > +#define _Out_writes_bytes_opt_(s)
> > +#endif
> 
> It got added in da215fcf5f001d1fdedf82e2f1407e8ff0b6d453
> ('include/sal: Update sal definitions').

Right, but that's still not available on CentOS. Anyway, I am dropping
all the _*_ keywords from the definition below in followup version.

> 
> #ifndef protects it, ok
> 
> > +/* The following shoud be in cfgmgr32.h, but it isn't */
> > +#ifndef CM_Get_DevNode_Property
> > +CMAPI CONFIGRET WINAPI CM_Get_DevNode_PropertyW(
> > +    _In_  DEVINST               dnDevInst,
> > +    _In_  CONST DEVPROPKEY    * PropertyKey,
> > +    _Out_ DEVPROPTYPE         * PropertyType,
> > +    _Out_writes_bytes_opt_(*PropertyBufferSize) PBYTE PropertyBuffer,
> > +    _Inout_ PULONG              PropertyBufferSize,
> > +    _In_  ULONG                 ulFlags
> > +    );
> > +#define CM_Get_DevNode_Property                  CM_Get_DevNode_PropertyW
> > +#endif
> > +
> 
> #ifndef should protect it from future clash, ok
> 
> Did you open bugs for mingw64 updates?

It was stuck on my TODO list for some time, but yeah I already posted a
patch for that. Thanks for reminding me.

> 
> > +
> >  #ifndef SHTDN_REASON_FLAG_PLANNED
> >  #define SHTDN_REASON_FLAG_PLANNED 0x80000000
> >  #endif
> > @@ -2234,3 +2265,165 @@ GuestOSInfo *qmp_guest_get_osinfo(Error **errp)
> >
> >      return info;
> >  }
> > +
> > +/*
> > + * Safely get device property. Returned strings are using wide characters.
> > + * Caller is responsible for freeing the buffer.
> > + */
> > +static LPBYTE cm_get_property(DEVINST devInst, const DEVPROPKEY *propName,
> > +    PDEVPROPTYPE propType)
> > +{
> > +    CONFIGRET cr;
> > +    LPBYTE buffer = NULL;
> > +    ULONG bufferLen = 0;
> > +
> > +    /* First query for needed space */
> > +    cr = CM_Get_DevNode_Property(devInst, propName, propType,
> > +        buffer, &bufferLen, 0);
> 
> I think qemu-ga win32 code generally prefers to be explicit about A()
> vs W(), call the W function explicitely, remove the generic define.
> 
> > +    if ((cr != CR_SUCCESS) && (cr != CR_BUFFER_SMALL)) {
> 
> 
> This file is not a good example, but in general we avoid the extra
> parenthesis. Please drop them.
> 
> > +
> > +        g_debug(
> > +            "failed to get size of device property, device error code=%lx",
> > +            cr);
> 
> That file uses a mix of slog and g_debug..
> 
> I think slog() is higher level and preferable here. At least, try to
> make it fit on one line would be nice.
> 
> > +        return NULL;
> > +    }
> > +    buffer = (LPBYTE)g_malloc(bufferLen);
> 
> I'd suggest g_malloc0(len+1) to avoid surprises.
> 
> Drop the cast.
> 
> > +    cr = CM_Get_DevNode_Property(devInst, propName, propType,
> > +        buffer, &bufferLen, 0);
> > +    if (cr != CR_SUCCESS) {
> > +        g_free(buffer);
> 
> you could use g_auto declaration these days (I know, it wasn't there
> when you started, but now it is ;).
> 
> > +        g_debug(
> > +            "failed to get device property, device error code=%lx", cr);
> 
> same about slog
> 
> > +        return NULL;
> > +    }
> > +    return buffer;
> > +}
> > +
> > +/*
> > + * 
> > https://docs.microsoft.com/en-us/windows-hardware/drivers/install/identifiers-for-pci-devices
> > + */
> > +#define DEVICE_PCI_RE "PCI\\\\VEN_(1AF4|1B36)&DEV_([0-9A-B]{4})(&|$)"
> > +
> > +GuestDeviceInfoList *qmp_guest_get_devices(Error **errp)
> > +{
> > +    GuestDeviceInfoList *head = NULL, *cur_item = NULL, *item = NULL;
> > +    HDEVINFO dev_info = INVALID_HANDLE_VALUE;
> > +    SP_DEVINFO_DATA dev_info_data;
> > +    int i;
> > +    GError *gerr = NULL;
> > +    GRegex *device_pci_re = NULL;
> > +
> > +    device_pci_re = g_regex_new(DEVICE_PCI_RE,
> > +        G_REGEX_ANCHORED | G_REGEX_OPTIMIZE, 0,
> > +        &gerr);
> > +
> > +    if (gerr) {
> > +        error_setg(errp, QERR_QGA_COMMAND_FAILED, gerr->message);
> > +        g_error_free(gerr);
> > +        goto out;
> > +    }
> 
> given that the rule is static, I think you could simplify error
> handling and use g_assert(device_pci_re != NULL) instead.
> 
> > +
> > +    dev_info_data.cbSize = sizeof(SP_DEVINFO_DATA);
> > +    dev_info = SetupDiGetClassDevs(0, 0, 0, DIGCF_PRESENT | 
> > DIGCF_ALLCLASSES);
> > +    if (dev_info == INVALID_HANDLE_VALUE) {
> > +        error_setg(errp, "failed to get device tree");
> > +        goto out;
> > +    }
> > +
> > +    g_debug("enumerating devices");
> > +    for (i = 0; SetupDiEnumDeviceInfo(dev_info, i, &dev_info_data); i++) {
> > +        LPWSTR name = NULL, hwIDs = NULL, lpValue;
> > +        bool skip = true;
> > +        DEVPROPTYPE cmType;
> > +        SYSTEMTIME stUTC;
> > +        LPFILETIME pfdDriverDate;
> > +        LPWSTR driverVersion;
> > +
> > +        GuestDeviceInfo *device = g_new0(GuestDeviceInfo, 1);
> > +
> > +        name = (LPWSTR)cm_get_property(dev_info_data.DevInst, 
> > &DEVPKEY_NAME,
> > +            &cmType);
> > +        if (name == NULL) {
> > +            g_debug("failed to get device description");
> > +            goto next;
> > +        }
> > +        device->driver_name = guest_wctomb_dup(name);
> 
> QMP strings should be utf8 encoded.
> 
> No idea why guest_wctomb_dup() was introduced in the first place to use ANSI 
> CP.
> 
> Imho, every strings returned by W() functions should go through
> g_utf16_to_utf8().

Great! guest_wctomb_dup() seemed fishy to me from the start.

> 
> 
> > +        g_free(name);
> > +        g_debug("querying device: %s", device->driver_name);
> > +
> > +        hwIDs = (LPWSTR)cm_get_property(dev_info_data.DevInst,
> > +            &DEVPKEY_Device_HardwareIds, &cmType);
> > +        if (hwIDs == NULL) {
> > +            g_debug("failed to get hardware IDs");
> > +            goto next;
> > +        }
> > +        for (lpValue = hwIDs;
> > +            '\0' != *lpValue;
> > +            lpValue += lstrlenW(lpValue) + 1) {
> 
> ok (alternatively, introduce a function that returns a GStrv to make
> caller life easier.

I don't think I follow. Which part would you like to move into a
function?

> 
> > +            GMatchInfo *match_info;
> > +            char *hwID = guest_wctomb_dup(lpValue);
> > +            /* g_debug("hwID: %s", hwID); */
> > +            if (!g_regex_match(device_pci_re, hwID, 0, &match_info)) {
> > +                continue;
> 
> leaks hwID
> 
> > +            }
> > +            skip = false;
> > +            device->vendor_id = g_match_info_fetch(match_info, 1);
> > +            device->device_id = g_match_info_fetch(match_info, 2);
> > +            g_match_info_free(match_info);
> > +        }
> > +        free(hwIDs);
> 
> Let's stick to g_free() as you g_malloc()
> 
> > +
> > +        if (skip) {
> > +            goto next;
> > +        }
> > +
> > +        driverVersion = (LPWSTR)cm_get_property(dev_info_data.DevInst,
> > +            &DEVPKEY_Device_DriverVersion, &cmType);
> > +        if (driverVersion == NULL) {
> > +            g_debug("failed to get driver version");
> > +            goto next;
> > +        }
> > +        device->driver_version = guest_wctomb_dup(driverVersion);
> 
> I'd use g_utf16_to_utf8()
> 
> > +        free(driverVersion);
> 
> g_free()
> 
> > +
> > +        pfdDriverDate = (LPFILETIME)cm_get_property(dev_info_data.DevInst,
> > +            &DEVPKEY_Device_DriverDate, &cmType);
> > +        if (driverVersion == NULL) {
> > +            g_debug("failed to get driver date");
> > +            goto next;
> > +        }
> > +        FileTimeToSystemTime(pfdDriverDate, &stUTC);
> > +        free(pfdDriverDate);
> 
> g_free()
> 
> > +        device->driver_date = g_strdup_printf("%02d/%02d/%04d",
> > +            stUTC.wMonth, stUTC.wDay, stUTC.wYear);
> > +        g_debug("Driver Version: %s,%s\n", device->driver_date,
> > +            device->driver_version);
> > +
> > +        item = g_new0(GuestDeviceInfoList, 1);
> > +        item->value = device;
> > +        if (!cur_item) {
> > +            head = cur_item = item;
> > +        } else {
> > +            cur_item->next = item;
> > +            cur_item = item;
> > +        }
> > +        continue;
> > +
> > +next:
> > +        g_free(device->vendor_id);
> > +        g_free(device->device_id);
> > +        g_free(device->driver_date);
> > +        g_free(device->driver_name);
> > +        g_free(device->driver_version);
> > +        g_free(device);
> 
> Please switch to g_auto

Aye, aye, captain!

> 
> > +    }
> > +
> > +out:
> > +
> > +    if (dev_info != INVALID_HANDLE_VALUE) {
> > +        SetupDiDestroyDeviceInfoList(dev_info);
> > +    }
> > +    g_regex_unref(device_pci_re);
> > +
> > +    return head;
> > +}
> > diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json
> > index fb4605cc19..ed73b0b1c6 100644
> > --- a/qga/qapi-schema.json
> > +++ b/qga/qapi-schema.json
> > @@ -1242,3 +1242,35 @@
> >  ##
> >  { 'command': 'guest-get-osinfo',
> >    'returns': 'GuestOSInfo' }
> > +
> > +##
> > +# @GuestDeviceInfo:
> > +#
> > +# @vendor-id: vendor ID as hexadecimal string in uper case without 0x 
> > prefix
> > +# @device-id: device ID as hexadecimal string in uper case without 0x 
> > prefix
> > +# @driver-name: name of the associated driver
> > +# @driver-date: driver release date in format MM/DD/YY
> > +# @driver-version: driver version
> > +#
> > +# Since: 4.1.1
> > +##
> > +{ 'struct': 'GuestDeviceInfo',
> > +  'data': {
> > +      'vendor-id': 'str',
> > +      'device-id': 'str',
> > +      'driver-name': 'str',
> > +      'driver-date': 'str',
> > +      'driver-version': 'str'
> > +      } }
> > +
> > +##
> > +# @guest-get-devices:
> > +#
> > +# Retrieve information about device drivers in Windows guest
> > +#
> > +# Returns: @GuestOSInfo
> 
> @GuestDeviceInfo
> 
> > +#
> > +# Since: 4.1.1
> > +##
> > +{ 'command': 'guest-get-devices',
> > +  'returns': ['GuestDeviceInfo'] }
> > --
> > 2.22.0
> >
> >
> 
> 
> -- 
> Marc-André Lureau

-- 
Tomáš Golembiovský <address@hidden>