sysctl: add sysctl interface for querying PCI topology

Signed-off-by: Boris Ostrovsky <boris.ostrovsky@oracle.com>
Acked-by: Daniel De Graaf <dgdegra@tycho.nsa.gov>
Reviewed-by: Andrew Cooper <andrew.cooper3@citrix.com>

xen/common/sysctl.c

@@ -412,6 +412,61 @@ long do_sysctl(XEN_GUEST_HANDLE_PARAM(xen_sysctl_t) u_sysctl)
         break;
 #endif
 
+#ifdef HAS_PCI
+    case XEN_SYSCTL_pcitopoinfo:
+    {
+        xen_sysctl_pcitopoinfo_t *ti = &op->u.pcitopoinfo;
+        unsigned int i = 0;
+
+        if ( guest_handle_is_null(ti->devs) ||
+             guest_handle_is_null(ti->nodes) )
+        {
+            ret = -EINVAL;
+            break;
+        }
+
+        while ( i < ti->num_devs )
+        {
+            physdev_pci_device_t dev;
+            uint32_t node;
+            const struct pci_dev *pdev;
+
+            if ( copy_from_guest_offset(&dev, ti->devs, i, 1) )
+            {
+                ret = -EFAULT;
+                break;
+            }
+
+            spin_lock(&pcidevs_lock);
+            pdev = pci_get_pdev(dev.seg, dev.bus, dev.devfn);
+            if ( !pdev )
+                node = XEN_INVALID_DEV;
+            else if ( pdev->node == NUMA_NO_NODE )
+                node = XEN_INVALID_NODE_ID;
+            else
+                node = pdev->node;
+            spin_unlock(&pcidevs_lock);
+
+            if ( copy_to_guest_offset(ti->nodes, i, &node, 1) )
+            {
+                ret = -EFAULT;
+                break;
+            }
+
+            if ( (++i > 0x3f) && hypercall_preempt_check() )
+                break;
+        }
+
+        if ( !ret && (ti->num_devs != i) )
+        {
+            ti->num_devs = i;
+            if ( __copy_field_to_guest(u_sysctl, op, u.pcitopoinfo.num_devs) )
+                ret = -EFAULT;
+        }
+        break;
+    }
+#endif
+
     default:
         ret = arch_do_sysctl(op, u_sysctl);
         copyback = 0;

xen/include/public/sysctl.h

@@ -33,6 +33,7 @@
 
 #include "xen.h"
 #include "domctl.h"
+#include "physdev.h"
 
 #define XEN_SYSCTL_INTERFACE_VERSION 0x0000000C
 
@@ -669,6 +670,30 @@ struct xen_sysctl_psr_cmt_op {
 typedef struct xen_sysctl_psr_cmt_op xen_sysctl_psr_cmt_op_t;
 DEFINE_XEN_GUEST_HANDLE(xen_sysctl_psr_cmt_op_t);
 
+/* XEN_SYSCTL_pcitopoinfo */
+#define XEN_INVALID_DEV (XEN_INVALID_NODE_ID - 1)
+struct xen_sysctl_pcitopoinfo {
+    /*
+     * IN: Number of elements in 'pcitopo' and 'nodes' arrays.
+     * OUT: Number of processed elements of those arrays.
+     */
+    uint32_t num_devs;
+
+    /* IN: list of devices for which node IDs are requested. */
+    XEN_GUEST_HANDLE_64(physdev_pci_device_t) devs;
+
+    /*
+     * OUT: node identifier for each device.
+     * If information for a particular device is not available then
+     * corresponding entry will be set to XEN_INVALID_NODE_ID. If
+     * device is not known to the hypervisor then XEN_INVALID_DEV
+     * will be provided.
+     */
+    XEN_GUEST_HANDLE_64(uint32) nodes;
+};
+typedef struct xen_sysctl_pcitopoinfo xen_sysctl_pcitopoinfo_t;
+DEFINE_XEN_GUEST_HANDLE(xen_sysctl_pcitopoinfo_t);
+
 struct xen_sysctl {
     uint32_t cmd;
 #define XEN_SYSCTL_readconsole                    1
@@ -691,12 +716,14 @@ struct xen_sysctl {
 #define XEN_SYSCTL_scheduler_op                  19
 #define XEN_SYSCTL_coverage_op                   20
 #define XEN_SYSCTL_psr_cmt_op                    21
+#define XEN_SYSCTL_pcitopoinfo                   22
     uint32_t interface_version; /* XEN_SYSCTL_INTERFACE_VERSION */
     union {
         struct xen_sysctl_readconsole       readconsole;
         struct xen_sysctl_tbuf_op           tbuf_op;
         struct xen_sysctl_physinfo          physinfo;
         struct xen_sysctl_cputopoinfo       cputopoinfo;
+        struct xen_sysctl_pcitopoinfo       pcitopoinfo;
         struct xen_sysctl_numainfo          numainfo;
         struct xen_sysctl_sched_id          sched_id;
         struct xen_sysctl_perfc_op          perfc_op;

xen/xsm/flask/hooks.c

@@ -783,6 +783,7 @@ static int flask_sysctl(int cmd)
     case XEN_SYSCTL_physinfo:
     case XEN_SYSCTL_cputopoinfo:
     case XEN_SYSCTL_numainfo:
+    case XEN_SYSCTL_pcitopoinfo:
         return domain_has_xen(current->domain, XEN__PHYSINFO);
 
     case XEN_SYSCTL_psr_cmt_op:

xen/xsm/flask/policy/access_vectors

@@ -28,6 +28,7 @@ class xen
 # XENPF_microcode_update
     microcode
 # XEN_SYSCTL_physinfo, XEN_SYSCTL_cputopoinfo, XEN_SYSCTL_numainfo
+# XEN_SYSCTL_pcitopoinfo
     physinfo
 # XENPF_platform_quirk
     quirk