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2021-09-27docs/nvdimm: Update nvdimm option value in machine examplePankaj Gupta
Update nvdimm option value in example command from "-machine pc,nvdimm" to "-machine pc,nvdimm=on" as former complains with the below error: "qemu-system-x86_64: -machine pc,nvdimm: Expected '=' after parameter 'nvdimm'" Reviewed-by: Laurent Vivier <laurent@vivier.eu> Signed-off-by: Pankaj Gupta <pankaj.gupta.linux@gmail.com> Message-Id: <20210923103015.135262-1-pankaj.gupta.linux@gmail.com> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2021-02-01nvdimm: check -object memory-backend-file, readonly=on optionStefan Hajnoczi
Check that -device nvdimm,unarmed=on is used when -object memory-backend-file,readonly=on and document that -device nvdimm,unarmed=on|off controls whether the NVDIMM appears read-only to the guest. Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Liam Merwick <liam.merwick@oracle.com> Acked-by: Michael S. Tsirkin <mst@redhat.com> Message-Id: <20210104171320.575838-4-stefanha@redhat.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-06-26docs/nvdimm: add description of alignment requirement of device daxJingqi Liu
For device dax (e.g., /dev/dax0.0), the NUM of 'align=NUM' option needs to match the alignment requirement of the device dax. It must be larger than or equal to the 'align' of device dax. Reviewed-by: Joao Martins <joao.m.martins@oracle.com> Signed-off-by: Jingqi Liu <jingqi.liu@intel.com> Message-Id: <20200429085011.63752-3-jingqi.liu@intel.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2019-09-16docs/nvdimm: add example on persistent backend setupWei Yang
Persistent backend setup requires some knowledge about nvdimm and ndctl tool. Some users report they may struggle to gather these knowledge and have difficulty to setup it properly. Here we provide two examples for persistent backend and gives the link to ndctl. By doing so, user could try it directly and do more investigation on persistent backend setup with ndctl. Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> Reviewed-by: Pankaj Gupta <pagupta@redhat.com> Message-Id: <20190801004053.7021-1-richardw.yang@linux.intel.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2019-04-25util/mmap-alloc: support MAP_SYNC in qemu_ram_mmap()Zhang Yi
When a file supporting DAX is used as vNVDIMM backend, mmap it with MAP_SYNC flag in addition which can ensure file system metadata synced in each guest writes to the backend file, without other QEMU actions (e.g., periodic fsync() by QEMU). Current, We have below different possible use cases: 1. pmem=on is set, shared=on is set, MAP_SYNC supported: a: backend is a dax supporting file. - MAP_SYNC will active. b: backend is not a dax supporting file. - mmap will trigger a warning. then MAP_SYNC flag will be ignored 2. The rest of cases: - we will never pass the MAP_SYNC to mmap2 Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> Signed-off-by: Zhang Yi <yi.z.zhang@linux.intel.com> [ehabkost: Rebased patch to latest code on master] Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> Signed-off-by: Wei Yang <richardw.yang@linux.intel.com> Tested-by: Wei Yang <richardw.yang@linux.intel.com> Message-Id: <20190422004849.26463-2-richardw.yang@linux.intel.com> [ehabkost: squashed documentation patch] Message-Id: <20190422004849.26463-3-richardw.yang@linux.intel.com> [ehabkost: documentation fixup] Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Pankaj Gupta <pagupta@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2018-10-29nvdimm: Add docs hint for Linux driver nameKees Cook
I spent way too much time trying to figure out why the emulated NVDIMM was missing under Linux. In an effort to help others who might be looking for these kinds of things in the future, include a hint. Signed-off-by: Kees Cook <keescook@chromium.org> Message-id: 20181018201351.GA25286@beast Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2018-08-10hostmem-file: add the 'pmem' optionJunyan He
When QEMU emulates vNVDIMM labels and migrates vNVDIMM devices, it needs to know whether the backend storage is a real persistent memory, in order to decide whether special operations should be performed to ensure the data persistence. This boolean option 'pmem' allows users to specify whether the backend storage of memory-backend-file is a real persistent memory. If 'pmem=on', QEMU will set the flag RAM_PMEM in the RAM block of the corresponding memory region. If 'pmem' is set while lack of libpmem support, a error is generated. Signed-off-by: Junyan He <junyan.he@intel.com> Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Igor Mammedov <imammedo@redhat.com> Reviewed-by: Richard Henderson <richard.henderson@linaro.org> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-06-11nvdimm: make persistence option symbolicRoss Zwisler
Replace the "nvdimm-cap" option which took numeric arguments such as "2" with a more user friendly "nvdimm-persistence" option which takes symbolic arguments "cpu" or "mem-ctrl". Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Suggested-by: Michael S. Tsirkin <mst@redhat.com> Suggested-by: Dan Williams <dan.j.williams@intel.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-06-01nvdimm, acpi: support NFIT platform capabilitiesRoss Zwisler
Add a machine command line option to allow the user to control the Platform Capabilities Structure in the virtualized NFIT. This Platform Capabilities Structure was added in ACPI 6.2 Errata A. Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2018-01-19nvdimm: add 'unarmed' optionHaozhong Zhang
Currently the only vNVDIMM backend can guarantee the guest write persistence is device DAX on Linux, because no host-side kernel cache is involved in the guest access to it. The approach to detect whether the backend is device DAX needs to access sysfs, which may not work with SELinux. Instead, we add the 'unarmed' option to device 'nvdimm', so that users or management utils, which have enough knowledge about the backend, can control the unarmed flag in guest ACPI NFIT via this option. The guest Linux NVDIMM driver, for example, will mark the corresponding vNVDIMM device read-only if the unarmed flag in guest NFIT is set. The default value of 'unarmed' option is 'off' in order to keep the backwards compatibility. Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> Message-Id: <20171211072806.2812-4-haozhong.zhang@intel.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2018-01-19hostmem-file: add "align" optionHaozhong Zhang
When mmap(2) the backend files, QEMU uses the host page size (getpagesize(2)) by default as the alignment of mapping address. However, some backends may require alignments different than the page size. For example, mmap a device DAX (e.g., /dev/dax0.0) on Linux kernel 4.13 to an address, which is 4K-aligned but not 2M-aligned, fails with a kernel message like [617494.969768] dax dax0.0: qemu-system-x86: dax_mmap: fail, unaligned vma (0x7fa37c579000 - 0x7fa43c579000, 0x1fffff) Because there is no common approach to get such alignment requirement, we add the 'align' option to 'memory-backend-file', so that users or management utils, which have enough knowledge about the backend, can specify a proper alignment via this option. Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> Message-Id: <20171211072806.2812-2-haozhong.zhang@intel.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> [ehabkost: fixed typo, fixed error_setg() format string] Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2017-02-17docs: add document to explain the usage of vNVDIMMHaozhong Zhang
Signed-off-by: Haozhong Zhang <haozhong.zhang@intel.com> Reviewed-by: Xiao Guangrong <guangrong.xiao@linux.intel.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Reviewed-by: Michael S. Tsirkin <mst@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>