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2018-08-10hostmem-file: add the 'pmem' optionJunyan He1-0/+22
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 Zwisler1-19/+12
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 Zwisler1-0/+27
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 Zhang1-0/+15
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 Zhang1-0/+16
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 Zhang1-0/+124
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>