hw/block/nvme: allow cmb and pmr to coexist

With BAR 4 now free to use, allow PMR and CMB to be enabled
simultaneously.

Reviewed-by: Minwoo Im <minwoo.im.dev@gmail.com>
Reviewed-by: Keith Busch <kbusch@kernel.org>
Signed-off-by: Klaus Jensen <k.jensen@samsung.com>

1 files changed, 8 insertions, 9 deletions

diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index 85d3c43c4f..4ce75642f1 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -29,14 +29,13 @@
  * Note cmb_size_mb denotes size of CMB in MB. CMB is assumed to be at
  * offset 0 in BAR2 and supports only WDS, RDS and SQS for now.
  *
- * cmb_size_mb= and pmrdev= options are mutually exclusive due to limitation
- * in available BAR's. cmb_size_mb= will take precedence over pmrdev= when
- * both provided.
  * Enabling pmr emulation can be achieved by pointing to memory-backend-file.
  * For example:
  * -object memory-backend-file,id=<mem_id>,share=on,mem-path=<file_path>, \
  *  size=<size> .... -device nvme,...,pmrdev=<mem_id>
  *
+ * The PMR will use BAR 4/5 exclusively.
+ *
  *
  * nvme device parameters
  * ~~~~~~~~~~~~~~~~~~~~~~
@@ -109,7 +108,7 @@
 #define NVME_DB_SIZE  4
 #define NVME_SPEC_VER 0x00010300
 #define NVME_CMB_BIR 2
-#define NVME_PMR_BIR 2
+#define NVME_PMR_BIR 4
 #define NVME_TEMPERATURE 0x143
 #define NVME_TEMPERATURE_WARNING 0x157
 #define NVME_TEMPERATURE_CRITICAL 0x175
@@ -4121,7 +4120,7 @@ static void nvme_check_constraints(NvmeCtrl *n, Error **errp)
         return;
     }
 
-    if (!n->params.cmb_size_mb && n->pmrdev) {
+    if (n->pmrdev) {
         if (host_memory_backend_is_mapped(n->pmrdev)) {
             error_setg(errp, "can't use already busy memdev: %s",
                        object_get_canonical_path_component(OBJECT(n->pmrdev)));
@@ -4218,9 +4217,6 @@ static void nvme_init_cmb(NvmeCtrl *n, PCIDevice *pci_dev)
 
 static void nvme_init_pmr(NvmeCtrl *n, PCIDevice *pci_dev)
 {
-    /* Controller Capabilities register */
-    NVME_CAP_SET_PMRS(n->bar.cap, 1);
-
     /* PMR Capabities register */
     n->bar.pmrcap = 0;
     NVME_PMRCAP_SET_RDS(n->bar.pmrcap, 0);
@@ -4321,7 +4317,9 @@ static int nvme_init_pci(NvmeCtrl *n, PCIDevice *pci_dev, Error **errp)
 
     if (n->params.cmb_size_mb) {
         nvme_init_cmb(n, pci_dev);
-    } else if (n->pmrdev) {
+    }
+
+    if (n->pmrdev) {
         nvme_init_pmr(n, pci_dev);
     }
 
@@ -4394,6 +4392,7 @@ static void nvme_init_ctrl(NvmeCtrl *n, PCIDevice *pci_dev)
     NVME_CAP_SET_CSS(n->bar.cap, NVME_CAP_CSS_ADMIN_ONLY);
     NVME_CAP_SET_MPSMAX(n->bar.cap, 4);
     NVME_CAP_SET_CMBS(n->bar.cap, n->params.cmb_size_mb ? 1 : 0);
+    NVME_CAP_SET_PMRS(n->bar.cap, n->pmrdev ? 1 : 0);
 
     n->bar.vs = NVME_SPEC_VER;
     n->bar.intmc = n->bar.intms = 0;