[Qemu-devel] [PATCH 4/4] qga: added GuestPCIAddress information

["Denis V. Lunev" <den@openvz.org>]

From: Olga Krishtal <okrishtal@parallels.com>

PCIAddress inforfation is obtained via SetupApi, which provides the
information about address, bus, etc. We look throught entire device tree
in the system and try to find device object for given volume. For this PDO
SetupDiGetDeviceRegistryProperty is called, which reads PCI configuration
if it is possible for a given device.

This is the most convinient way for a userspace service. The lookup is
performed for every volume available. However, this information is
not mandatory for vss-provider.

In order to use SetupApi we need to notify linker about it. We do not need
to install additional libs, so we do not make separate configuration
option to use libsetupapi.su

SetupApi gives as the same information as kernel driver
with IRP_MN_QUERY_INTERFACE.
https://support.microsoft.com/en-us/kb/253232

Signed-off-by: Olga Krishtal <okrishtal@parallels.com>
Signed-off-by: Denis V. Lunev <den@openvz.org>
CC: Michael Roth <mdroth@linux.vnet.ibm.com>
---
 configure            |  2 +-
 qga/commands-win32.c | 96 +++++++++++++++++++++++++++++++++++++++++++++++++++-
 2 files changed, 96 insertions(+), 2 deletions(-)

diff --git a/configure b/configure
index 255d85b..5d62aa0 100755
--- a/configure
+++ b/configure
@@ -719,7 +719,7 @@ EOF
   sysconfdir="\${prefix}"
   local_statedir=
   confsuffix=""
-  libs_qga="-lws2_32 -lwinmm -lpowrprof $libs_qga"
+  libs_qga="-lsetupapi -lws2_32 -lwinmm -lpowrprof $libs_qga"
 fi
 
 werror=""
diff --git a/qga/commands-win32.c b/qga/commands-win32.c
index f3569e9..330b0d9 100644
--- a/qga/commands-win32.c
+++ b/qga/commands-win32.c
@@ -18,6 +18,8 @@
 #include <string.h>
 #include <winioctl.h>
 #include <ntddscsi.h>
+#include <setupapi.h>
+#include <initguid.h>
 #include "qga/guest-agent-core.h"
 #include "qga/vss-win32.h"
 #include "qga-qmp-commands.h"
@@ -28,6 +30,10 @@
 #define SHTDN_REASON_FLAG_PLANNED 0x80000000
 #endif
 
+DEFINE_GUID(GUID_DEVINTERFACE_VOLUME,
+        0x53f5630dL, 0xb6bf, 0x11d0, 0x94, 0xf2,
+        0x00, 0xa0, 0xc9, 0x1e, 0xfb, 0x8b);
+
 /* multiple of 100 nanoseconds elapsed between windows baseline
  *    (1/1/1601) and Unix Epoch (1/1/1970), accounting for leap years */
 #define W32_FT_OFFSET (10000000ULL * 60 * 60 * 24 * \
@@ -416,7 +422,95 @@ static void guest_file_init(void)
 
 static GuestPCIAddress *get_pci_info(char *guid, Error **errp)
 {
-    return NULL;
+    HDEVINFO dev_info;
+    SP_DEVINFO_DATA dev_info_data;
+    DWORD size = 0;
+    int i;
+    char dev_name[MAX_PATH];
+    char *buffer = NULL;
+    GuestPCIAddress *pci = NULL;
+    char *name = g_strdup(&guid[4]);
+
+    if (!QueryDosDevice(name, dev_name, ARRAY_SIZE(dev_name))) {
+        error_setg_win32(errp, GetLastError(), "failed to get dos device name");
+        goto out;
+    }
+
+    dev_info = SetupDiGetClassDevs(&GUID_DEVINTERFACE_VOLUME, 0, 0,
+                                   DIGCF_PRESENT | DIGCF_DEVICEINTERFACE);
+    if (dev_info == INVALID_HANDLE_VALUE) {
+        error_setg_win32(errp, GetLastError(), "failed to get devices tree");
+        goto out;
+    }
+
+    dev_info_data.cbSize = sizeof(SP_DEVINFO_DATA);
+    for (i = 0; SetupDiEnumDeviceInfo(dev_info, i, &dev_info_data); i++) {
+        DWORD addr, bus, slot, func, dev, data, size2;
+        while (!SetupDiGetDeviceRegistryProperty(dev_info, &dev_info_data,
+                                            SPDRP_PHYSICAL_DEVICE_OBJECT_NAME,
+                                            &data, buffer, size, &size2)) {
+            size = MAX(size, size2);
+            if (GetLastError() == ERROR_INSUFFICIENT_BUFFER) {
+                g_free(buffer);
+                /* Double the size to avoid problems on
+                 * W2k MBCS systems per KB 888609.
+                 * https://support.microsoft.com/en-us/kb/259695 */
+                buffer = g_malloc(size * 2);
+            } else {
+                error_setg_win32(errp, GetLastError(),
+                        "failed to get device name");
+                goto out;
+            }
+        }
+
+        if (g_strcmp0(buffer, dev_name)) {
+            continue;
+        }
+        /* There is no need to allocate buffer in the next functions. The size
+         * is known and ULONG according to
+         * https://support.microsoft.com/en-us/kb/253232
+         * https://msdn.microsoft.com/en-us/library/windows/hardware/ff543095(v=vs.85).aspx
+         */
+
+        if (!SetupDiGetDeviceRegistryProperty(dev_info, &dev_info_data,
+                   SPDRP_BUSNUMBER, &data, &bus, size, NULL)) {
+            break;
+        }
+
+        /* The function retrieves the device's address. This value will be
+         * transformed into device function and number */
+        if (!SetupDiGetDeviceRegistryProperty(dev_info, &dev_info_data,
+                   SPDRP_ADDRESS, &data, &addr, size, NULL)) {
+            break;
+        }
+
+        /* This call returns UINumber of DEVICE_CAPABILITIES structure.
+         * This number is typically a user-perceived slot number. */
+        if (!SetupDiGetDeviceRegistryProperty(dev_info, &dev_info_data,
+                   SPDRP_UI_NUMBER, &data, &slot, size, NULL)) {
+            break;
+        }
+
+        /* SetupApi gives us the same information as driver with
+         * IoGetDeviceProperty. According to Microsoft
+         * https://support.microsoft.com/en-us/kb/253232
+         * FunctionNumber = (USHORT)((propertyAddress) & 0x0000FFFF);
+         * DeviceNumber = (USHORT)(((propertyAddress) >> 16) & 0x0000FFFF);
+         * SPDRP_ADDRESS is propertyAddress, so we do the same.*/
+
+        func = addr & 0x0000FFFF;
+        dev = (addr >> 16) & 0x0000FFFF;
+        pci = g_malloc0(sizeof(*pci));
+        pci->domain = dev;
+        pci->slot = slot;
+        pci->function = func;
+        pci->bus = bus;
+        break;
+    }
+out:
+    g_free(buffer);
+    g_free(name);
+    return pci;
 }
 
 static int get_disk_bus_type(HANDLE vol_h, Error **errp)
-- 
1.9.1