Hi On Mon, Jul 12, 2021 at 9:07 PM Steven Sistare <steven.sist...@oracle.com> wrote:
> On 7/8/2021 10:20 AM, Marc-André Lureau wrote: > > Hi > > > > On Wed, Jul 7, 2021 at 9:39 PM Steve Sistare <steven.sist...@oracle.com > <mailto:steven.sist...@oracle.com>> wrote: > > > > Allocate anonymous memory using memfd_create if the memfd-alloc > machine > > option is set. > > > > > > Nice, I'd suggest you send this patch separately. (we had discussions > about an option like this several times) > > I would like to keep it with this series to make sure it meets our needs > as the patches are > reviewed and evolve. We can always push it solo later if the series > stalls. > > > Signed-off-by: Steve Sistare <steven.sist...@oracle.com <mailto: > steven.sist...@oracle.com>> > > --- > > hw/core/machine.c | 19 +++++++++++++++++++ > > include/hw/boards.h | 1 + > > qemu-options.hx | 5 +++++ > > softmmu/physmem.c | 42 +++++++++++++++++++++++++++++++++--------- > > trace-events | 1 + > > util/qemu-config.c | 4 ++++ > > 6 files changed, 63 insertions(+), 9 deletions(-) > > > > diff --git a/hw/core/machine.c b/hw/core/machine.c > > index 57c18f9..f0656a8 100644 > > --- a/hw/core/machine.c > > +++ b/hw/core/machine.c > > @@ -383,6 +383,20 @@ static void machine_set_mem_merge(Object *obj, > bool value, Error **errp) > > ms->mem_merge = value; > > } > > > > +static bool machine_get_memfd_alloc(Object *obj, Error **errp) > > +{ > > + MachineState *ms = MACHINE(obj); > > + > > + return ms->memfd_alloc; > > +} > > + > > +static void machine_set_memfd_alloc(Object *obj, bool value, Error > **errp) > > +{ > > + MachineState *ms = MACHINE(obj); > > + > > + ms->memfd_alloc = value; > > +} > > + > > static bool machine_get_usb(Object *obj, Error **errp) > > { > > MachineState *ms = MACHINE(obj); > > @@ -917,6 +931,11 @@ static void machine_class_init(ObjectClass *oc, > void *data) > > object_class_property_set_description(oc, "mem-merge", > > "Enable/disable memory merge support"); > > > > + object_class_property_add_bool(oc, "memfd-alloc", > > + machine_get_memfd_alloc, machine_set_memfd_alloc); > > + object_class_property_set_description(oc, "memfd-alloc", > > + "Enable/disable allocating anonymous memory using > memfd_create"); > > + > > object_class_property_add_bool(oc, "usb", > > machine_get_usb, machine_set_usb); > > object_class_property_set_description(oc, "usb", > > diff --git a/include/hw/boards.h b/include/hw/boards.h > > index accd6ef..299e1ca 100644 > > --- a/include/hw/boards.h > > +++ b/include/hw/boards.h > > @@ -305,6 +305,7 @@ struct MachineState { > > char *dt_compatible; > > bool dump_guest_core; > > bool mem_merge; > > + bool memfd_alloc; > > bool usb; > > bool usb_disabled; > > char *firmware; > > diff --git a/qemu-options.hx b/qemu-options.hx > > index 8965dab..fa53734 100644 > > --- a/qemu-options.hx > > +++ b/qemu-options.hx > > @@ -30,6 +30,7 @@ DEF("machine", HAS_ARG, QEMU_OPTION_machine, \ > > " vmport=on|off|auto controls emulation of > vmport (default: auto)\n" > > " dump-guest-core=on|off include guest memory in > a core dump (default=on)\n" > > " mem-merge=on|off controls memory merge support > (default: on)\n" > > + " memfd-alloc=on|off controls allocating > anonymous memory using memfd_create (default: off)\n" > > " aes-key-wrap=on|off controls support for AES > key wrapping (default=on)\n" > > " dea-key-wrap=on|off controls support for DEA > key wrapping (default=on)\n" > > " suppress-vmdesc=on|off disables > self-describing migration (default=off)\n" > > @@ -76,6 +77,10 @@ SRST > > supported by the host, de-duplicates identical memory pages > > among VMs instances (enabled by default). > > > > + ``memfd-alloc=on|off`` > > + Enables or disables allocation of anonymous memory using > memfd_create. > > + (disabled by default). > > + > > ``aes-key-wrap=on|off`` > > Enables or disables AES key wrapping support on s390-ccw > hosts. > > This feature controls whether AES wrapping keys will be > created > > diff --git a/softmmu/physmem.c b/softmmu/physmem.c > > index 9b171c9..b149250 100644 > > --- a/softmmu/physmem.c > > +++ b/softmmu/physmem.c > > @@ -64,6 +64,7 @@ > > > > #include "qemu/pmem.h" > > > > +#include "qemu/memfd.h" > > #include "migration/vmstate.h" > > > > #include "qemu/range.h" > > @@ -1960,35 +1961,58 @@ static void ram_block_add(RAMBlock > *new_block, Error **errp) > > const bool shared = qemu_ram_is_shared(new_block); > > RAMBlock *block; > > RAMBlock *last_block = NULL; > > + struct MemoryRegion *mr = new_block->mr; > > ram_addr_t old_ram_size, new_ram_size; > > Error *err = NULL; > > + const char *name; > > + void *addr = 0; > > + size_t maxlen; > > + MachineState *ms = MACHINE(qdev_get_machine()); > > > > old_ram_size = last_ram_page(); > > > > qemu_mutex_lock_ramlist(); > > - new_block->offset = find_ram_offset(new_block->max_length); > > + maxlen = new_block->max_length; > > + new_block->offset = find_ram_offset(maxlen); > > > > if (!new_block->host) { > > if (xen_enabled()) { > > - xen_ram_alloc(new_block->offset, new_block->max_length, > > - new_block->mr, &err); > > + xen_ram_alloc(new_block->offset, maxlen, new_block->mr, > &err); > > if (err) { > > error_propagate(errp, err); > > qemu_mutex_unlock_ramlist(); > > return; > > } > > } else { > > - new_block->host = > qemu_anon_ram_alloc(new_block->max_length, > > - > &new_block->mr->align, > > - shared, > noreserve); > > - if (!new_block->host) { > > + name = memory_region_name(new_block->mr); > > + if (ms->memfd_alloc) { > > + int mfd = -1; /* placeholder until next > patch */ > > + mr->align = QEMU_VMALLOC_ALIGN; > > + if (mfd < 0) { > > + mfd = qemu_memfd_create(name, maxlen + > mr->align, > > + 0, 0, 0, &err); > > + if (mfd < 0) { > > + return; > > + } > > + } > > + new_block->flags |= RAM_SHARED; > > > > > > I wonder if ram_backend_memory_alloc() shouldn't be updated to reflect > that the memory backend is "share" = true. > > It already does this: > ram_flags = backend->share ? RAM_SHARED : 0; > Did you have something else in mind? > I mean the backend->share value should be updated, as it's always RAM_SHARED. > > And I would say so in the doc as well. > > Will do. > > - Steve > > > + addr = file_ram_alloc(new_block, maxlen, mfd, > > + false, false, 0, errp); > > + trace_anon_memfd_alloc(name, maxlen, addr, mfd); > > + } else { > > + addr = qemu_anon_ram_alloc(maxlen, &mr->align, > > + shared, noreserve); > > + } > > + > > + if (!addr) { > > error_setg_errno(errp, errno, > > "cannot set up guest memory '%s'", > > - memory_region_name(new_block->mr)); > > + name); > > qemu_mutex_unlock_ramlist(); > > return; > > } > > - memory_try_enable_merging(new_block->host, > new_block->max_length); > > + memory_try_enable_merging(addr, maxlen); > > + new_block->host = addr; > > } > > } > > > > diff --git a/trace-events b/trace-events > > index 765fe25..6dbcd0e 100644 > > --- a/trace-events > > +++ b/trace-events > > @@ -40,6 +40,7 @@ ram_block_discard_range(const char *rbname, void > *hva, size_t length, bool need_ > > # accel/tcg/cputlb.c > > memory_notdirty_write_access(uint64_t vaddr, uint64_t ram_addr, > unsigned size) "0x%" PRIx64 " ram_addr 0x%" PRIx64 " size %u" > > memory_notdirty_set_dirty(uint64_t vaddr) "0x%" PRIx64 > > +anon_memfd_alloc(const char *name, size_t size, void *ptr, int fd) > "%s size %zu ptr %p fd %d" > > > > # gdbstub.c > > gdbstub_op_start(const char *device) "Starting gdbstub using device > %s" > > diff --git a/util/qemu-config.c b/util/qemu-config.c > > index 84ee6dc..6162b4d 100644 > > --- a/util/qemu-config.c > > +++ b/util/qemu-config.c > > @@ -207,6 +207,10 @@ static QemuOptsList machine_opts = { > > .type = QEMU_OPT_BOOL, > > .help = "enable/disable memory merge support", > > },{ > > + .name = "memfd-alloc", > > + .type = QEMU_OPT_BOOL, > > + .help = "enable/disable memfd_create for anonymous > memory", > > + },{ > > .name = "usb", > > .type = QEMU_OPT_BOOL, > > .help = "Set on/off to enable/disable usb", > > -- > > 1.8.3.1 > > > > > > > > > > -- > > Marc-André Lureau > -- Marc-André Lureau
