aboutsummaryrefslogtreecommitdiff
path: root/backends/hostmem-memfd.c
AgeCommit message (Collapse)AuthorFilesLines
2021-06-15hostmem: Wire up RAM_NORESERVE via "reserve" propertyDavid Hildenbrand1-0/+1
Let's provide a way to control the use of RAM_NORESERVE via memory backends using the "reserve" property which defaults to true (old behavior). Only Linux currently supports clearing the flag (and support is checked at runtime, depending on the setting of "/proc/sys/vm/overcommit_memory"). Windows and other POSIX systems will bail out with "reserve=false". The target use case is virtio-mem, which dynamically exposes memory inside a large, sparse memory area to the VM. This essentially allows avoiding to set "/proc/sys/vm/overcommit_memory == 0") when using virtio-mem and also supporting hugetlbfs in the future. As really only Linux implements RAM_NORESERVE right now, let's expose the property only with CONFIG_LINUX. Setting the property to "false" will then only fail in corner cases -- for example on very old kernels or when memory overcommit was completely disabled by the admin. Reviewed-by: Peter Xu <peterx@redhat.com> Reviewed-by: Eduardo Habkost <ehabkost@redhat.com> Reviewed-by: Markus Armbruster <armbru@redhat.com> Acked-by: Eduardo Habkost <ehabkost@redhat.com> for memory backend and machine core Cc: Markus Armbruster <armbru@redhat.com> Cc: Eric Blake <eblake@redhat.com> Cc: Igor Mammedov <imammedo@redhat.com> Signed-off-by: David Hildenbrand <david@redhat.com> Message-Id: <20210510114328.21835-11-david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-06-15softmmu/memory: Pass ram_flags to qemu_ram_alloc_from_fd()David Hildenbrand1-3/+4
Let's pass in ram flags just like we do with qemu_ram_alloc_from_file(), to clean up and prepare for more flags. Simplify the documentation of passed ram flags: Looking at our documentation of RAM_SHARED and RAM_PMEM is sufficient, no need to be repetitive. Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com> Reviewed-by: Peter Xu <peterx@redhat.com> Acked-by: Eduardo Habkost <ehabkost@redhat.com> for memory backend and machine core Signed-off-by: David Hildenbrand <david@redhat.com> Message-Id: <20210510114328.21835-5-david@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2021-05-02Do not include sysemu/sysemu.h if it's not really necessaryThomas Huth1-1/+0
Stop including sysemu/sysemu.h in files that don't need it. Signed-off-by: Thomas Huth <thuth@redhat.com> Message-Id: <20210416171314.2074665-2-thuth@redhat.com> Signed-off-by: Laurent Vivier <laurent@vivier.eu>
2021-02-09memory: alloc RAM from file at offsetJagannathan Raman1-1/+1
Allow RAM MemoryRegion to be created from an offset in a file, instead of allocating at offset of 0 by default. This is needed to synchronize RAM between QEMU & remote process. Signed-off-by: Jagannathan Raman <jag.raman@oracle.com> Signed-off-by: John G Johnson <john.g.johnson@oracle.com> Signed-off-by: Elena Ufimtseva <elena.ufimtseva@oracle.com> Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com> Message-id: 609996697ad8617e3b01df38accc5c208c24d74e.1611938319.git.jag.raman@oracle.com Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
2020-09-18Use OBJECT_DECLARE_SIMPLE_TYPE when possibleEduardo Habkost1-3/+1
This converts existing DECLARE_INSTANCE_CHECKER usage to OBJECT_DECLARE_SIMPLE_TYPE when possible. $ ./scripts/codeconverter/converter.py -i \ --pattern=AddObjectDeclareSimpleType $(git grep -l '' -- '*.[ch]') Signed-off-by: Eduardo Habkost <ehabkost@redhat.com> Acked-by: Paul Durrant <paul@xen.org> Message-Id: <20200916182519.415636-6-ehabkost@redhat.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-09-09Use DECLARE_*CHECKER* macrosEduardo Habkost1-2/+2
Generated using: $ ./scripts/codeconverter/converter.py -i \ --pattern=TypeCheckMacro $(git grep -l '' -- '*.[ch]') Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Message-Id: <20200831210740.126168-12-ehabkost@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Message-Id: <20200831210740.126168-13-ehabkost@redhat.com> Message-Id: <20200831210740.126168-14-ehabkost@redhat.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-09-09Move QOM typedefs and add missing includesEduardo Habkost1-1/+2
Some typedefs and macros are defined after the type check macros. This makes it difficult to automatically replace their definitions with OBJECT_DECLARE_TYPE. Patch generated using: $ ./scripts/codeconverter/converter.py -i \ --pattern=QOMStructTypedefSplit $(git grep -l '' -- '*.[ch]') which will split "typdef struct { ... } TypedefName" declarations. Followed by: $ ./scripts/codeconverter/converter.py -i --pattern=MoveSymbols \ $(git grep -l '' -- '*.[ch]') which will: - move the typedefs and #defines above the type check macros - add missing #include "qom/object.h" lines if necessary Reviewed-by: Daniel P. Berrangé <berrange@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Message-Id: <20200831210740.126168-9-ehabkost@redhat.com> Reviewed-by: Juan Quintela <quintela@redhat.com> Message-Id: <20200831210740.126168-10-ehabkost@redhat.com> Message-Id: <20200831210740.126168-11-ehabkost@redhat.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2020-07-10error: Eliminate error_propagate() with Coccinelle, part 1Markus Armbruster1-3/+1
When all we do with an Error we receive into a local variable is propagating to somewhere else, we can just as well receive it there right away. Convert if (!foo(..., &err)) { ... error_propagate(errp, err); ... return ... } to if (!foo(..., errp)) { ... ... return ... } where nothing else needs @err. Coccinelle script: @rule1 forall@ identifier fun, err, errp, lbl; expression list args, args2; binary operator op; constant c1, c2; symbol false; @@ if ( ( - fun(args, &err, args2) + fun(args, errp, args2) | - !fun(args, &err, args2) + !fun(args, errp, args2) | - fun(args, &err, args2) op c1 + fun(args, errp, args2) op c1 ) ) { ... when != err when != lbl: when strict - error_propagate(errp, err); ... when != err ( return; | return c2; | return false; ) } @rule2 forall@ identifier fun, err, errp, lbl; expression list args, args2; expression var; binary operator op; constant c1, c2; symbol false; @@ - var = fun(args, &err, args2); + var = fun(args, errp, args2); ... when != err if ( ( var | !var | var op c1 ) ) { ... when != err when != lbl: when strict - error_propagate(errp, err); ... when != err ( return; | return c2; | return false; | return var; ) } @depends on rule1 || rule2@ identifier err; @@ - Error *err = NULL; ... when != err Not exactly elegant, I'm afraid. The "when != lbl:" is necessary to avoid transforming if (fun(args, &err)) { goto out } ... out: error_propagate(errp, err); even though other paths to label out still need the error_propagate(). For an actual example, see sclp_realize(). Without the "when strict", Coccinelle transforms vfio_msix_setup(), incorrectly. I don't know what exactly "when strict" does, only that it helps here. The match of return is narrower than what I want, but I can't figure out how to express "return where the operand doesn't use @err". For an example where it's too narrow, see vfio_intx_enable(). Silently fails to convert hw/arm/armsse.c, because Coccinelle gets confused by ARMSSE being used both as typedef and function-like macro there. Converted manually. Line breaks tidied up manually. One nested declaration of @local_err deleted manually. Preexisting unwanted blank line dropped in hw/riscv/sifive_e.c. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200707160613.848843-35-armbru@redhat.com>
2020-07-10error: Avoid unnecessary error_propagate() after error_setg()Markus Armbruster1-8/+7
Replace error_setg(&err, ...); error_propagate(errp, err); by error_setg(errp, ...); Related pattern: if (...) { error_setg(&err, ...); goto out; } ... out: error_propagate(errp, err); return; When all paths to label out are that way, replace by if (...) { error_setg(errp, ...); return; } and delete the label along with the error_propagate(). When we have at most one other path that actually needs to propagate, and maybe one at the end that where propagation is unnecessary, e.g. foo(..., &err); if (err) { goto out; } ... bar(..., &err); out: error_propagate(errp, err); return; move the error_propagate() to where it's needed, like if (...) { foo(..., &err); error_propagate(errp, err); return; } ... bar(..., errp); return; and transform the error_setg() as above. In some places, the transformation results in obviously unnecessary error_propagate(). The next few commits will eliminate them. Bonus: the elimination of gotos will make later patches in this series easier to review. Candidates for conversion tracked down with this Coccinelle script: @@ identifier err, errp; expression list args; @@ - error_setg(&err, args); + error_setg(errp, args); ... when != err error_propagate(errp, err); Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Message-Id: <20200707160613.848843-34-armbru@redhat.com>
2020-07-10qapi: Use returned bool to check for failure, Coccinelle partMarkus Armbruster1-2/+1
The previous commit enables conversion of visit_foo(..., &err); if (err) { ... } to if (!visit_foo(..., errp)) { ... } for visitor functions that now return true / false on success / error. Coccinelle script: @@ identifier fun =~ "check_list|input_type_enum|lv_start_struct|lv_type_bool|lv_type_int64|lv_type_str|lv_type_uint64|output_type_enum|parse_type_bool|parse_type_int64|parse_type_null|parse_type_number|parse_type_size|parse_type_str|parse_type_uint64|print_type_bool|print_type_int64|print_type_null|print_type_number|print_type_size|print_type_str|print_type_uint64|qapi_clone_start_alternate|qapi_clone_start_list|qapi_clone_start_struct|qapi_clone_type_bool|qapi_clone_type_int64|qapi_clone_type_null|qapi_clone_type_number|qapi_clone_type_str|qapi_clone_type_uint64|qapi_dealloc_start_list|qapi_dealloc_start_struct|qapi_dealloc_type_anything|qapi_dealloc_type_bool|qapi_dealloc_type_int64|qapi_dealloc_type_null|qapi_dealloc_type_number|qapi_dealloc_type_str|qapi_dealloc_type_uint64|qobject_input_check_list|qobject_input_check_struct|qobject_input_start_alternate|qobject_input_start_list|qobject_input_start_struct|qobject_input_type_any|qobject_input_type_bool|qobject_input_type_bool_keyval|qobject_input_type_int64|qobject_input_type_int64_keyval|qobject_input_type_null|qobject_input_type_number|qobject_input_type_number_keyval|qobject_input_type_size_keyval|qobject_input_type_str|qobject_input_type_str_keyval|qobject_input_type_uint64|qobject_input_type_uint64_keyval|qobject_output_start_list|qobject_output_start_struct|qobject_output_type_any|qobject_output_type_bool|qobject_output_type_int64|qobject_output_type_null|qobject_output_type_number|qobject_output_type_str|qobject_output_type_uint64|start_list|visit_check_list|visit_check_struct|visit_start_alternate|visit_start_list|visit_start_struct|visit_type_.*"; expression list args; typedef Error; Error *err; @@ - fun(args, &err); - if (err) + if (!fun(args, &err)) { ... } A few line breaks tidied up manually. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Message-Id: <20200707160613.848843-19-armbru@redhat.com>
2020-05-15qom: Drop parameter @errp of object_property_add() & friendsMarkus Armbruster1-5/+3
The only way object_property_add() can fail is when a property with the same name already exists. Since our property names are all hardcoded, failure is a programming error, and the appropriate way to handle it is passing &error_abort. Same for its variants, except for object_property_add_child(), which additionally fails when the child already has a parent. Parentage is also under program control, so this is a programming error, too. We have a bit over 500 callers. Almost half of them pass &error_abort, slightly fewer ignore errors, one test case handles errors, and the remaining few callers pass them to their own callers. The previous few commits demonstrated once again that ignoring programming errors is a bad idea. Of the few ones that pass on errors, several violate the Error API. The Error ** argument must be NULL, &error_abort, &error_fatal, or a pointer to a variable containing NULL. Passing an argument of the latter kind twice without clearing it in between is wrong: if the first call sets an error, it no longer points to NULL for the second call. ich9_pm_add_properties(), sparc32_ledma_realize(), sparc32_dma_realize(), xilinx_axidma_realize(), xilinx_enet_realize() are wrong that way. When the one appropriate choice of argument is &error_abort, letting users pick the argument is a bad idea. Drop parameter @errp and assert the preconditions instead. There's one exception to "duplicate property name is a programming error": the way object_property_add() implements the magic (and undocumented) "automatic arrayification". Don't drop @errp there. Instead, rename object_property_add() to object_property_try_add(), and add the obvious wrapper object_property_add(). Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20200505152926.18877-15-armbru@redhat.com> [Two semantic rebase conflicts resolved]
2020-05-15qom: Drop object_property_set_description() parameter @errpMarkus Armbruster1-6/+3
object_property_set_description() and object_class_property_set_description() fail only when property @name is not found. There are 85 calls of object_property_set_description() and object_class_property_set_description(). None of them can fail: * 84 immediately follow the creation of the property. * The one in spapr_rng_instance_init() refers to a property created in spapr_rng_class_init(), from spapr_rng_properties[]. Every one of them still gets to decide what to pass for @errp. 51 calls pass &error_abort, 32 calls pass NULL, one receives the error and propagates it to &error_abort, and one propagates it to &error_fatal. I'm actually surprised none of them violates the Error API. What are we gaining by letting callers handle the "property not found" error? Use when the property is not known to exist is simpler: you don't have to guard the call with a check. We haven't found such a use in 5+ years. Until we do, let's make life a bit simpler and drop the @errp parameter. Signed-off-by: Markus Armbruster <armbru@redhat.com> Reviewed-by: Eric Blake <eblake@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com> Message-Id: <20200505152926.18877-8-armbru@redhat.com> [One semantic rebase conflict resolved]
2020-02-19hostmem: fix strict bind policyIgor Mammedov1-1/+0
When option -mem-prealloc is used with one or more memory-backend objects, created backends may not obey configured bind policy or creation may fail after kernel attempts to move pages according to bind policy. Reason is in file_ram_alloc(), which will pre-allocate any descriptor based RAM if global mem_prealloc != 0 and that happens way before bind policy is applied to memory range. One way to fix it would be to extend memory_region_foo() API and add more invariants that could broken later due implicit dependencies that's hard to track. Another approach is to drop adhoc main RAM allocation and consolidate it around memory-backend. That allows to have single place that allocates guest RAM (main and memdev) in the same way and then global mem_prealloc could be replaced by backend's property[s] that will affect created memory-backend objects but only in correct order this time. With main RAM now converted to hostmem backends, there is no point in keeping global mem_prealloc around, so alias -mem-prealloc to "memory-backend.prealloc=on" machine compat[*] property and make mem_prealloc a local variable to only stir registration of compat property. *) currently user accessible -global works only with DEVICE based objects and extra work is needed to make it work with hostmem backends. But that is convenience option and out of scope of this already huge refactoring. Hence machine compat properties were used. Signed-off-by: Igor Mammedov <imammedo@redhat.com> Message-Id: <20200219160953.13771-78-imammedo@redhat.com>
2019-06-12Include qemu/module.h where needed, drop it from qemu-common.hMarkus Armbruster1-1/+2
Signed-off-by: Markus Armbruster <armbru@redhat.com> Message-Id: <20190523143508.25387-4-armbru@redhat.com> [Rebased with conflicts resolved automatically, except for hw/usb/dev-hub.c hw/misc/exynos4210_rng.c hw/misc/bcm2835_rng.c hw/misc/aspeed_scu.c hw/display/virtio-vga.c hw/arm/stm32f205_soc.c; ui/cocoa.m fixed up]
2019-03-11hostmem-memfd: disable for systems without sealing supportIlya Maximets1-10/+8
If seals are not supported, memfd_create() will fail. Furthermore, there is no way to disable it in this case because '.seal' property is not registered. This issue leads to vhost-user-test failures on RHEL 7.2: qemu-system-x86_64: -object memory-backend-memfd,id=mem,size=2M,: \ failed to create memfd: Invalid argument and actually breaks the feature on such systems. Let's restrict memfd backend to systems with sealing support. Signed-off-by: Ilya Maximets <i.maximets@samsung.com> Message-Id: <20190311135850.6537-2-i.maximets@samsung.com> Signed-off-by: Eduardo Habkost <ehabkost@redhat.com>
2019-01-07hostmem: use object id for memory region name with >= 4.0Marc-André Lureau1-1/+1
hostmem-file and hostmem-memfd use the whole object path for the memory region name, and hostname-ram uses only the path component (the object id, or canonical path basename): qemu -m 1024 -object memory-backend-file,id=mem,size=1G,mem-path=/tmp/foo -numa node,memdev=mem -monitor stdio (qemu) info ramblock Block Name PSize Offset Used Total /objects/mem 4 KiB 0x0000000000000000 0x0000000040000000 0x0000000040000000 qemu -m 1024 -object memory-backend-memfd,id=mem,size=1G -numa node,memdev=mem -monitor stdio (qemu) info ramblock Block Name PSize Offset Used Total /objects/mem 4 KiB 0x0000000000000000 0x0000000040000000 0x0000000040000000 qemu -m 1024 -object memory-backend-ram,id=mem,size=1G -numa node,memdev=mem -monitor stdio (qemu) info ramblock Block Name PSize Offset Used Total mem 4 KiB 0x0000000000000000 0x0000000040000000 0x0000000040000000 For consistency, change to use object id for -file and -memfd as well with >= 4.0. Having a consistent naming allows to migrate to different hostmem backends. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Igor Mammedov <imammedo@redhat.com> Acked-by: Eduardo Habkost <ehabkost@redhat.com>
2018-11-28hostmem: no need to check for host_memory_backend_mr_inited() in alloc()Marc-André Lureau1-4/+0
memfd_backend_memory_alloc/file_backend_memory_alloc both needlessly are are calling host_memory_backend_mr_inited() which creates an illusion that alloc could be called multiple times but it isn't, it's called once from UserCreatable complete(). Suggested-by: Igor Mammedov <imammedo@redhat.com> Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Igor Mammedov <imammedo@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-11-27hostmem-memfd: honour share=on/off propertyMarc-André Lureau1-1/+3
The share=on/off property is used to modified mmap() MAP_SHARED setting. Make it on by default for convenience and compatibility reasons. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-05hostmem: add some properties descriptionMarc-André Lureau1-0/+9
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
2018-10-02hostmem-memfd: add checks before adding hostmem-memfd & propertiesMarc-André Lureau1-13/+19
Run some memfd-related checks before registering hostmem-memfd & various properties. This will help libvirt to figure out what the host is supposed to be capable of. qemu_memfd_check() is changed to a less optimized version, since it is used with various flags, it no longer caches the result. Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20180906161415.8543-1-marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
2018-02-07Add memfd based hostmemMarc-André Lureau1-0/+170
Add a new memory backend, similar to hostmem-file, except that it doesn't need to create files. It also enforces memory sealing. This backend is mainly useful for sharing the memory with other processes. Note that Linux supports transparent huge-pages of shmem/memfd memory since 4.8. It is relatively easier to set up THP than a dedicate hugepage mount point by using "madvise" in /sys/kernel/mm/transparent_hugepage/shmem_enabled. Since 4.14, memfd allows to set hugetlb requirement explicitly. Pending for merge in 4.16 is memfd sealing support for hugetlb backed memory. Usage: -object memory-backend-memfd,id=mem1,size=1G Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com> Message-Id: <20180201132757.23063-5-marcandre.lureau@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>