Re: [Qemu-devel] [PATCH v3 1/4] vl.c: extend -m option to support options for memory hotplug

[Igor Mammedov]

On Fri, 09 May 2014 14:35:03 +0200
Christian Borntraeger <address@hidden> wrote:

> On 07/05/14 20:05, Matthew Rosato wrote:
> > From: Igor Mammedov <address@hidden>
> > 
> > From: Igor Mammedov <address@hidden>
> > 
> > Add following parameters:
> >   "slots" - total number of hotplug memory slots
> >   "maxmem" - maximum possible memory
> > 
> > "slots" and "maxmem" should go in pair and "maxmem" should be greater
> > than "mem" for memory hotplug to be enabled.
> > 
> > Signed-off-by: Matthew Rosato <address@hidden>
> 
> I would prefer if Igor could resend his latest version and one of the overall 
> maintainer applies this as it is not s390-specific.
> What happened to the x86 implementation?
I'm rebasing it on current master and chasing migration bug.

> 
> Christian
> > ---
> >  include/hw/boards.h |    2 ++
> >  qemu-options.hx     |    9 ++++++---
> >  vl.c                |   51 
> > +++++++++++++++++++++++++++++++++++++++++++++++++++
> >  3 files changed, 59 insertions(+), 3 deletions(-)
> > 
> > diff --git a/include/hw/boards.h b/include/hw/boards.h
> > index 4345bd0..5b3a903 100644
> > --- a/include/hw/boards.h
> > +++ b/include/hw/boards.h
> > @@ -11,6 +11,8 @@
> >  typedef struct QEMUMachineInitArgs {
> >      const MachineClass *machine;
> >      ram_addr_t ram_size;
> > +    ram_addr_t maxram_size;
> > +    uint64_t   ram_slots;
> >      const char *boot_order;
> >      const char *kernel_filename;
> >      const char *kernel_cmdline;
> > diff --git a/qemu-options.hx b/qemu-options.hx
> > index 781af14..c6411c4 100644
> > --- a/qemu-options.hx
> > +++ b/qemu-options.hx
> > @@ -210,17 +210,20 @@ use is discouraged as it may be removed from future 
> > versions.
> >  ETEXI
> > 
> >  DEF("m", HAS_ARG, QEMU_OPTION_m,
> > -    "-m [size=]megs\n"
> > +    "-m[emory] [size=]megs[,slots=n,maxmem=size]\n"
> >      "                configure guest RAM\n"
> >      "                size: initial amount of guest memory (default: "
> > -    stringify(DEFAULT_RAM_SIZE) "MiB)\n",
> > +    stringify(DEFAULT_RAM_SIZE) "MiB)\n"
> > +    "                slots: number of hotplug slots (default: none)\n"
> > +    "                maxmem: maximum amount of guest memory (default: 
> > none)\n",
> >      QEMU_ARCH_ALL)
> >  STEXI
> >  @item -m address@hidden
> >  @findex -m
> >  Set virtual RAM size to @var{megs} megabytes. Default is 128 MiB.  
> > Optionally,
> >  a suffix of ``M'' or ``G'' can be used to signify a value in megabytes or
> > -gigabytes respectively.
> > +gigabytes respectively. Optional pair @var{slots}, @var{maxmem} could be 
> > used
> > +to set amount of hotluggable memory slots and possible maximum amount of 
> > memory.
> >  ETEXI
> > 
> >  DEF("mem-path", HAS_ARG, QEMU_OPTION_mempath,
> > diff --git a/vl.c b/vl.c
> > index 73e0661..36ad82c 100644
> > --- a/vl.c
> > +++ b/vl.c
> > @@ -520,6 +520,14 @@ static QemuOptsList qemu_mem_opts = {
> >              .name = "size",
> >              .type = QEMU_OPT_SIZE,
> >          },
> > +        {
> > +            .name = "slots",
> > +            .type = QEMU_OPT_NUMBER,
> > +        },
> > +        {
> > +            .name = "maxmem",
> > +            .type = QEMU_OPT_SIZE,
> > +        },
> >          { /* end of list */ }
> >      },
> >  };
> > @@ -2988,6 +2996,8 @@ int main(int argc, char **argv, char **envp)
> >      const char *trace_file = NULL;
> >      const ram_addr_t default_ram_size = (ram_addr_t)DEFAULT_RAM_SIZE *
> >                                          1024 * 1024;
> > +    ram_addr_t maxram_size = default_ram_size;
> > +    uint64_t ram_slots = 0;
> > 
> >      atexit(qemu_run_exit_notifiers);
> >      error_set_progname(argv[0]);
> > @@ -3324,6 +3334,7 @@ int main(int argc, char **argv, char **envp)
> >              case QEMU_OPTION_m: {
> >                  uint64_t sz;
> >                  const char *mem_str;
> > +                const char *maxmem_str, *slots_str;
> > 
> >                  opts = qemu_opts_parse(qemu_find_opts("memory"),
> >                                         optarg, 1);
> > @@ -3365,6 +3376,44 @@ int main(int argc, char **argv, char **envp)
> >                      error_report("ram size too large");
> >                      exit(EXIT_FAILURE);
> >                  }
> > +
> > +                maxmem_str = qemu_opt_get(opts, "maxmem");
> > +                slots_str = qemu_opt_get(opts, "slots");
> > +                if (maxmem_str && slots_str) {
> > +                    uint64_t slots;
> > +
> > +                    sz = qemu_opt_get_size(opts, "maxmem", 0);
> > +                    if (sz < ram_size) {
> > +                        fprintf(stderr, "qemu: invalid -m option value: 
> > maxmem "
> > +                                "(%" PRIu64 ") <= initial memory (%"
> > +                                PRIu64 ")\n", sz, ram_size);
> > +                        exit(EXIT_FAILURE);
> > +                    }
> > +
> > +                    slots = qemu_opt_get_number(opts, "slots", 0);
> > +                    if ((sz > ram_size) && !slots) {
> > +                        fprintf(stderr, "qemu: invalid -m option value: 
> > maxmem "
> > +                                "(%" PRIu64 ") more than initial memory (%"
> > +                                PRIu64 ") but no hotplug slots where "
> > +                                "specified\n", sz, ram_size);
> > +                        exit(EXIT_FAILURE);
> > +                    }
> > +
> > +                    if ((sz <= ram_size) && slots) {
> > +                        fprintf(stderr, "qemu: invalid -m option value:  %"
> > +                                PRIu64 " hotplug slots where specified but 
> > "
> > +                                "maxmem (%" PRIu64 ") <= initial memory (%"
> > +                                PRIu64 ")\n", slots, sz, ram_size);
> > +                        exit(EXIT_FAILURE);
> > +                    }
> > +                    maxram_size = sz;
> > +                    ram_slots = slots;
> > +                } else if ((!maxmem_str && slots_str) ||
> > +                           (maxmem_str && !slots_str)) {
> > +                    fprintf(stderr, "qemu: invalid -m option value: 
> > missing "
> > +                            "'%s' option\n", slots_str ? "maxmem" : 
> > "slots");
> > +                    exit(EXIT_FAILURE);
> > +                }
> >                  break;
> >              }
> >  #ifdef CONFIG_TPM
> > @@ -4424,6 +4473,8 @@ int main(int argc, char **argv, char **envp)
> >      current_machine->init_args = (QEMUMachineInitArgs) {
> >          .machine = machine_class,
> >          .ram_size = ram_size,
> > +        .maxram_size = maxram_size,
> > +        .ram_slots = ram_slots,
> >          .boot_order = boot_order,
> >          .kernel_filename = kernel_filename,
> >          .kernel_cmdline = kernel_cmdline,
> > 
>