From 13f8cf1536ca5222878d2c03802fb367e1340ef9 Mon Sep 17 00:00:00 2001
From: Jim Harris <james.r.harris@intel.com>
Date: Sat, 29 Apr 2017 12:21:32 -0700
Subject: [PATCH] nvme: add NVME_QUIRK_DELAY_AFTER_QUEUE_ALLOC

The VirtualBox emulated NVMe device will intermittently
hang on the first read/write command after an I/O
qpair has been allocated.  The frequency of the hang
diminishes if a delay is added after allocating the I/O
qpair - until it disappears completely with a 100us delay.
So add a quirk to insert this delay.

Note - the 100us delay was tested by running
the hello_world example app 50000 times.

Signed-off-by: Jim Harris <james.r.harris@intel.com>
Change-Id: I237e31b1b8a1a1e28262851ae0a21cd7345f0f1a
---
 include/spdk/pci_ids.h   | 1 +
 lib/nvme/nvme_ctrlr.c    | 4 ++++
 lib/nvme/nvme_internal.h | 6 ++++++
 lib/nvme/nvme_quirks.c   | 3 +++
 4 files changed, 14 insertions(+)

diff --git a/include/spdk/pci_ids.h b/include/spdk/pci_ids.h
index 3f9f25a91..5f7aa2949 100644
--- a/include/spdk/pci_ids.h
+++ b/include/spdk/pci_ids.h
@@ -47,6 +47,7 @@ extern "C" {
 #define SPDK_PCI_ANY_ID			0xffff
 #define SPDK_PCI_VID_INTEL		0x8086
 #define SPDK_PCI_VID_MEMBLAZE		0x1c5f
+#define SPDK_PCI_VID_VIRTUALBOX		0x80ee
 
 /**
  * PCI class code for NVMe devices.
diff --git a/lib/nvme/nvme_ctrlr.c b/lib/nvme/nvme_ctrlr.c
index d7cb083e6..25334bc5e 100644
--- a/lib/nvme/nvme_ctrlr.c
+++ b/lib/nvme/nvme_ctrlr.c
@@ -192,6 +192,10 @@ spdk_nvme_ctrlr_alloc_io_qpair(struct spdk_nvme_ctrlr *ctrlr,
 
 	nvme_robust_mutex_unlock(&ctrlr->ctrlr_lock);
 
+	if (ctrlr->quirks & NVME_QUIRK_DELAY_AFTER_QUEUE_ALLOC) {
+		spdk_delay_us(100);
+	}
+
 	return qpair;
 }
 
diff --git a/lib/nvme/nvme_internal.h b/lib/nvme/nvme_internal.h
index ad4c82fbc..8afd104fa 100644
--- a/lib/nvme/nvme_internal.h
+++ b/lib/nvme/nvme_internal.h
@@ -89,6 +89,12 @@
  */
 #define NVME_INTEL_QUIRK_STRIPING 0x8
 
+/*
+ * The controller needs a delay after allocating an I/O queue pair
+ * before it is ready to accept I/O commands.
+ */
+#define NVME_QUIRK_DELAY_AFTER_QUEUE_ALLOC 0x10
+
 #define NVME_MAX_ASYNC_EVENTS	(8)
 
 #define NVME_MIN_TIMEOUT_PERIOD		(5)
diff --git a/lib/nvme/nvme_quirks.c b/lib/nvme/nvme_quirks.c
index 7e552af83..fcd92144f 100644
--- a/lib/nvme/nvme_quirks.c
+++ b/lib/nvme/nvme_quirks.c
@@ -53,6 +53,9 @@ static const struct nvme_quirk nvme_quirks[] = {
 	{	{SPDK_PCI_VID_MEMBLAZE, 0x0540, SPDK_PCI_ANY_ID, SPDK_PCI_ANY_ID},
 		NVME_QUIRK_DELAY_BEFORE_CHK_RDY
 	},
+	{	{SPDK_PCI_VID_VIRTUALBOX, 0x4e56, SPDK_PCI_ANY_ID, SPDK_PCI_ANY_ID},
+		NVME_QUIRK_DELAY_AFTER_QUEUE_ALLOC
+	},
 	{	{0x0000, 0x0000, 0x0000, 0x0000}, 0}
 };