[PATCH v4 07/24] nvme: add support for the abort command

[Klaus Jensen]

Required for compliance with NVMe revision 1.2.1. See NVM Express 1.2.1,
Section 5.1 ("Abort command").

The Abort command is a best effort command; for now, the device always
fails to abort the given command.

Signed-off-by: Klaus Jensen <klaus.jen...@cnexlabs.com>
---
 hw/block/nvme.c | 28 ++++++++++++++++++++++++++++
 1 file changed, 28 insertions(+)

diff --git a/hw/block/nvme.c b/hw/block/nvme.c
index a41ebf578f04..d41ea5beab08 100644
--- a/hw/block/nvme.c
+++ b/hw/block/nvme.c
@@ -731,6 +731,18 @@ static uint16_t nvme_identify(NvmeCtrl *n, NvmeCmd *cmd)
     }
 }
 
+static uint16_t nvme_abort(NvmeCtrl *n, NvmeCmd *cmd, NvmeRequest *req)
+{
+    uint16_t sqid = le32_to_cpu(cmd->cdw10) & 0xffff;
+
+    req->cqe.result = 1;
+    if (nvme_check_sqid(n, sqid)) {
+        return NVME_INVALID_FIELD | NVME_DNR;
+    }
+
+    return NVME_SUCCESS;
+}
+
 static inline void nvme_set_timestamp(NvmeCtrl *n, uint64_t ts)
 {
     trace_nvme_dev_setfeat_timestamp(ts);
@@ -848,6 +860,7 @@ static uint16_t nvme_set_feature(NvmeCtrl *n, NvmeCmd *cmd, 
NvmeRequest *req)
         trace_nvme_dev_err_invalid_setfeat(dw10);
         return NVME_INVALID_FIELD | NVME_DNR;
     }
+
     return NVME_SUCCESS;
 }
 
@@ -864,6 +877,8 @@ static uint16_t nvme_admin_cmd(NvmeCtrl *n, NvmeCmd *cmd, 
NvmeRequest *req)
         return nvme_create_cq(n, cmd);
     case NVME_ADM_CMD_IDENTIFY:
         return nvme_identify(n, cmd);
+    case NVME_ADM_CMD_ABORT:
+        return nvme_abort(n, cmd, req);
     case NVME_ADM_CMD_SET_FEATURES:
         return nvme_set_feature(n, cmd, req);
     case NVME_ADM_CMD_GET_FEATURES:
@@ -1377,6 +1392,19 @@ static void nvme_realize(PCIDevice *pci_dev, Error 
**errp)
     id->ieee[2] = 0xb3;
     id->ver = cpu_to_le32(NVME_SPEC_VER);
     id->oacs = cpu_to_le16(0);
+
+    /*
+     * Because the controller always completes the Abort command immediately,
+     * there can never be more than one concurrently executing Abort command,
+     * so this value is never used for anything. Note that there can easily be
+     * many Abort commands in the queues, but they are not considered
+     * "executing" until processed by nvme_abort.
+     *
+     * The specification recommends a value of 3 for Abort Command Limit (four
+     * concurrently outstanding Abort commands), so lets use that though it is
+     * inconsequential.
+     */
+    id->acl = 3;
     id->frmw = 7 << 1;
     id->lpa = 1 << 0;
     id->sqes = (0x6 << 4) | 0x6;
-- 
2.24.1