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[Qemu-block] [PATCH v6 8/9] docs: Add section for NVMe VFIO driver
From: |
Fam Zheng |
Subject: |
[Qemu-block] [PATCH v6 8/9] docs: Add section for NVMe VFIO driver |
Date: |
Tue, 16 Jan 2018 14:09:00 +0800 |
Signed-off-by: Fam Zheng <address@hidden>
Message-Id: <address@hidden>
Reviewed-by: Stefan Hajnoczi <address@hidden>
---
docs/qemu-block-drivers.texi | 37 +++++++++++++++++++++++++++++++++++++
1 file changed, 37 insertions(+)
diff --git a/docs/qemu-block-drivers.texi b/docs/qemu-block-drivers.texi
index 503c1847aa..cd74767ed3 100644
--- a/docs/qemu-block-drivers.texi
+++ b/docs/qemu-block-drivers.texi
@@ -785,6 +785,43 @@ warning: ssh server @code{ssh.example.com:22} does not
support fsync
With sufficiently new versions of libssh2 and OpenSSH, @code{fsync} is
supported.
address@hidden disk_images_nvme
address@hidden NVMe disk images
+
+NVM Express (NVMe) storage controllers can be accessed directly by a userspace
+driver in QEMU. This bypasses the host kernel file system and block layers
+while retaining QEMU block layer functionalities, such as block jobs, I/O
+throttling, image formats, etc. Disk I/O performance is typically higher than
+with @code{-drive file=/dev/sda} using either thread pool or linux-aio.
+
+The controller will be exclusively used by the QEMU process once started. To be
+able to share storage between multiple VMs and other applications on the host,
+please use the file based protocols.
+
+Before starting QEMU, bind the host NVMe controller to the host vfio-pci
+driver. For example:
+
address@hidden
+# modprobe vfio-pci
+# lspci -n -s 0000:06:0d.0
+06:0d.0 0401: 1102:0002 (rev 08)
+# echo 0000:06:0d.0 > /sys/bus/pci/devices/0000:06:0d.0/driver/unbind
+# echo 1102 0002 > /sys/bus/pci/drivers/vfio-pci/new_id
+
+# qemu-system-x86_64 -drive
file=nvme://@var{host}:@var{bus}:@address@hidden/@var{namespace}
address@hidden example
+
+Alternative syntax using properties:
+
address@hidden
+qemu-system-x86_64 -drive
file.driver=nvme,address@hidden:@var{bus}:@address@hidden,address@hidden
address@hidden example
+
address@hidden:@var{bus}:@address@hidden is the NVMe controller's PCI device
+address on the host.
+
address@hidden is the NVMe namespace number, starting from 1.
+
@node disk_image_locking
@subsection Disk image file locking
--
2.14.3
- [Qemu-block] [PATCH v6 0/9] block: Add VFIO based driver for NVMe device, Fam Zheng, 2018/01/16
- [Qemu-block] [PATCH v6 1/9] stubs: Add stubs for ram block API, Fam Zheng, 2018/01/16
- [Qemu-block] [PATCH v6 2/9] util: Introduce vfio helpers, Fam Zheng, 2018/01/16
- [Qemu-block] [PATCH v6 3/9] block: Add VFIO based NVMe driver, Fam Zheng, 2018/01/16
- [Qemu-block] [PATCH v6 4/9] block: Introduce buf register API, Fam Zheng, 2018/01/16
- [Qemu-block] [PATCH v6 5/9] block/nvme: Implement .bdrv_(un)register_buf, Fam Zheng, 2018/01/16
- [Qemu-block] [PATCH v6 6/9] qemu-img: Map bench buffer, Fam Zheng, 2018/01/16
- [Qemu-block] [PATCH v6 7/9] block: Move NVMe constants to a separate header, Fam Zheng, 2018/01/16
- [Qemu-block] [PATCH v6 8/9] docs: Add section for NVMe VFIO driver,
Fam Zheng <=
- [Qemu-block] [PATCH v6 9/9] qapi: Add NVMe driver options to the schema, Fam Zheng, 2018/01/16
- Re: [Qemu-block] [PATCH v6 0/9] block: Add VFIO based driver for NVMe device, Stefan Hajnoczi, 2018/01/22