hw/nvme: Add support for Secondary Controller List

Introduce handling for Secondary Controller List (Identify command with
CNS value of 15h).

Secondary controller ids are unique in the subsystem, hence they are
reserved by it upon initialization of the primary controller to the
number of sriov_max_vfs.

ID reservation requires the addition of an intermediate controller slot
state, so the reserved controller has the address 0xFFFF.
A secondary controller is in the reserved state when it has no virtual
function assigned, but its primary controller is realized.
Secondary controller reservations are released to NULL when its primary
controller is unregistered.

Signed-off-by: Lukasz Maniak <lukasz.maniak@linux.intel.com>
Acked-by: Michael S. Tsirkin <mst@redhat.com>
Reviewed-by: Klaus Jensen <k.jensen@samsung.com>
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>

1 files changed, 66 insertions, 9 deletions

diff --git a/hw/nvme/subsys.c b/hw/nvme/subsys.c
index 691a90d209..9d2643678b 100644
--- a/hw/nvme/subsys.c
+++ b/hw/nvme/subsys.c
@@ -11,20 +11,71 @@
 
 #include "nvme.h"
 
-int nvme_subsys_register_ctrl(NvmeCtrl *n, Error **errp)
+static int nvme_subsys_reserve_cntlids(NvmeCtrl *n, int start, int num)
 {
     NvmeSubsystem *subsys = n->subsys;
-    int cntlid, nsid;
+    NvmeSecCtrlList *list = &n->sec_ctrl_list;
+    NvmeSecCtrlEntry *sctrl;
+    int i, cnt = 0;
+
+    for (i = start; i < ARRAY_SIZE(subsys->ctrls) && cnt < num; i++) {
+        if (!subsys->ctrls[i]) {
+            sctrl = &list->sec[cnt];
+            sctrl->scid = cpu_to_le16(i);
+            subsys->ctrls[i] = SUBSYS_SLOT_RSVD;
+            cnt++;
+        }
+    }
+
+    return cnt;
+}
 
-    for (cntlid = 0; cntlid < ARRAY_SIZE(subsys->ctrls); cntlid++) {
-        if (!subsys->ctrls[cntlid]) {
-            break;
+static void nvme_subsys_unreserve_cntlids(NvmeCtrl *n)
+{
+    NvmeSubsystem *subsys = n->subsys;
+    NvmeSecCtrlList *list = &n->sec_ctrl_list;
+    NvmeSecCtrlEntry *sctrl;
+    int i, cntlid;
+
+    for (i = 0; i < n->params.sriov_max_vfs; i++) {
+        sctrl = &list->sec[i];
+        cntlid = le16_to_cpu(sctrl->scid);
+
+        if (cntlid) {
+            assert(subsys->ctrls[cntlid] == SUBSYS_SLOT_RSVD);
+            subsys->ctrls[cntlid] = NULL;
+            sctrl->scid = 0;
         }
     }
+}
 
-    if (cntlid == ARRAY_SIZE(subsys->ctrls)) {
-        error_setg(errp, "no more free controller id");
-        return -1;
+int nvme_subsys_register_ctrl(NvmeCtrl *n, Error **errp)
+{
+    NvmeSubsystem *subsys = n->subsys;
+    NvmeSecCtrlEntry *sctrl = nvme_sctrl(n);
+    int cntlid, nsid, num_rsvd, num_vfs = n->params.sriov_max_vfs;
+
+    if (pci_is_vf(&n->parent_obj)) {
+        cntlid = le16_to_cpu(sctrl->scid);
+    } else {
+        for (cntlid = 0; cntlid < ARRAY_SIZE(subsys->ctrls); cntlid++) {
+            if (!subsys->ctrls[cntlid]) {
+                break;
+            }
+        }
+
+        if (cntlid == ARRAY_SIZE(subsys->ctrls)) {
+            error_setg(errp, "no more free controller id");
+            return -1;
+        }
+
+        num_rsvd = nvme_subsys_reserve_cntlids(n, cntlid + 1, num_vfs);
+        if (num_rsvd != num_vfs) {
+            nvme_subsys_unreserve_cntlids(n);
+            error_setg(errp,
+                       "no more free controller ids for secondary controllers");
+            return -1;
+        }
     }
 
     if (!subsys->serial) {
@@ -48,7 +99,13 @@ int nvme_subsys_register_ctrl(NvmeCtrl *n, Error **errp)
 
 void nvme_subsys_unregister_ctrl(NvmeSubsystem *subsys, NvmeCtrl *n)
 {
-    subsys->ctrls[n->cntlid] = NULL;
+    if (pci_is_vf(&n->parent_obj)) {
+        subsys->ctrls[n->cntlid] = SUBSYS_SLOT_RSVD;
+    } else {
+        subsys->ctrls[n->cntlid] = NULL;
+        nvme_subsys_unreserve_cntlids(n);
+    }
+
     n->cntlid = -1;
 }