Re: [Qemu-devel] [PATCH v5 3/3] xen-hvm: Pass is_default to xen_hvm_init

[Don Slutz]

On 06/08/14 11:24, Michael S. Tsirkin wrote:
> On Fri, Jun 06, 2014 at 01:52:06PM -0400, Don Slutz wrote:
> > This is the xen part of "pc & q35: Add new machine opt max-ram-below-4g"
> >
> > Acked-by: Stefano Stabellini <address@hidden>
> > Signed-off-by: Don Slutz <address@hidden>
> > ---
> > v5:
> >    Added Acked-by: Stefano Stabellini
> >    Minor change of pmc to pcms.
> >
> >
> >   hw/i386/pc_piix.c    |  1 +
> >   hw/i386/pc_q35.c     |  1 +
> >   include/hw/xen/xen.h |  2 +-
> >   xen-hvm-stub.c       |  2 +-
> >   xen-hvm.c            | 36 ++++++++++++++++++++----------------
> >   5 files changed, 24 insertions(+), 18 deletions(-)
> >
> > diff --git a/hw/i386/pc_piix.c b/hw/i386/pc_piix.c
> > index 25f4727..27851c6 100644
> > --- a/hw/i386/pc_piix.c
> > +++ b/hw/i386/pc_piix.c
> > @@ -125,6 +125,7 @@ static void pc_init1(MachineState *machine,
> >       }
> >   
> >       if (xen_enabled() && xen_hvm_init(&below_4g_mem_size, &above_4g_mem_size,
> > +                                      !(pcms && pcms->max_ram_below_4g),
> >                                         &ram_memory) != 0) {
> >           fprintf(stderr, "xen hardware virtual machine initialisation 
> > failed\n");
> >           exit(1);
> > diff --git a/hw/i386/pc_q35.c b/hw/i386/pc_q35.c
> > index 155cdf1..6436fce 100644
> > --- a/hw/i386/pc_q35.c
> > +++ b/hw/i386/pc_q35.c
> > @@ -114,6 +114,7 @@ static void pc_q35_init(MachineState *machine)
> >       }
> >   
> >       if (xen_enabled() && xen_hvm_init(&below_4g_mem_size, &above_4g_mem_size,
> > +                                      !(pcms && pcms->max_ram_below_4g),
> >                                         &ram_memory) != 0) {
> >           fprintf(stderr, "xen hardware virtual machine initialisation 
> > failed\n");
> >           exit(1);
> > diff --git a/include/hw/xen/xen.h b/include/hw/xen/xen.h
> > index f71f2d8..6b94c14 100644
> > --- a/include/hw/xen/xen.h
> > +++ b/include/hw/xen/xen.h
> > @@ -41,7 +41,7 @@ void xenstore_store_pv_console_info(int i, struct 
> > CharDriverState *chr);
> >   
> >   #if defined(NEED_CPU_H) && !defined(CONFIG_USER_ONLY)
> >   int xen_hvm_init(ram_addr_t *below_4g_mem_size, ram_addr_t *above_4g_mem_size,
> > -                 MemoryRegion **ram_memory);
> > +                 bool is_default, MemoryRegion **ram_memory);
> >   void xen_ram_alloc(ram_addr_t ram_addr, ram_addr_t size,
> >                      struct MemoryRegion *mr);
> >   void xen_modified_memory(ram_addr_t start, ram_addr_t length);
> > diff --git a/xen-hvm-stub.c b/xen-hvm-stub.c
> > index 2d98696..d1bdb76 100644
> > --- a/xen-hvm-stub.c
> > +++ b/xen-hvm-stub.c
> > @@ -52,7 +52,7 @@ void xen_modified_memory(ram_addr_t start, ram_addr_t length)
> >   }
> >   
> >   int xen_hvm_init(ram_addr_t *below_4g_mem_size, ram_addr_t *above_4g_mem_size,
> > -                 MemoryRegion **ram_memory)
> > +                 bool is_default, MemoryRegion **ram_memory)
> >   {
> >       return 0;
> >   }
> > diff --git a/xen-hvm.c b/xen-hvm.c
> > index a0b6b5d..8d27ee6 100644
> > --- a/xen-hvm.c
> > +++ b/xen-hvm.c
> > @@ -156,31 +156,34 @@ qemu_irq *xen_interrupt_controller_init(void)
> >   /* Memory Ops */
> >   
> >   static void xen_ram_init(ram_addr_t *below_4g_mem_size,
> > -                         ram_addr_t *above_4g_mem_size,
> > +                         ram_addr_t *above_4g_mem_size, bool is_default,
> >                            ram_addr_t ram_size, MemoryRegion **ram_memory_p)
> >   {
> >       MemoryRegion *sysmem = get_system_memory();
> >       ram_addr_t block_len;
> >   
> > -    block_len = ram_size;
> > -    if (ram_size >= HVM_BELOW_4G_RAM_END) {
> > -        /* Xen does not allocate the memory continuously, and keep a hole at
> > -         * HVM_BELOW_4G_MMIO_START of HVM_BELOW_4G_MMIO_LENGTH
> > +    if (is_default) {
> > +        if (ram_size >= HVM_BELOW_4G_RAM_END) {
> > +            *above_4g_mem_size = ram_size - HVM_BELOW_4G_RAM_END;
> > +            *below_4g_mem_size = HVM_BELOW_4G_RAM_END;
> > +        } else {
> > +            *above_4g_mem_size = 0;
> > +            *below_4g_mem_size = ram_size;
> > +        }
> > +    }
> > +    if (!*above_4g_mem_size) {
> > +        block_len = ram_size;
> > +    } else {
> > +        /*
> > +         * Xen does not allocate the memory continuously, and keep a hole of
> > +         * of the size computed above or passed in.
> >            */
> Not your fault but this is ambigious.
> I guess this means "does not allocate the memory continuously, it keeps a
> hole ..."?

How does (dropping the double of also):

Xen does not allocate the memory continuously, it keeps a hole of the size 
computed above or passed in.


   -Don Slutz



> > -        block_len += HVM_BELOW_4G_MMIO_LENGTH;
> > +        block_len = (1ULL << 32) + *above_4g_mem_size;
> >       }
> >       memory_region_init_ram(&ram_memory, NULL, "xen.ram", block_len);
> >       *ram_memory_p = &ram_memory;
> >       vmstate_register_ram_global(&ram_memory);
> >   
> > -    if (ram_size >= HVM_BELOW_4G_RAM_END) {
> > -        *above_4g_mem_size = ram_size - HVM_BELOW_4G_RAM_END;
> > -        *below_4g_mem_size = HVM_BELOW_4G_RAM_END;
> > -    } else {
> > -        *above_4g_mem_size = 0;
> > -        *below_4g_mem_size = ram_size;
> > -    }
> > -
> >       memory_region_init_alias(&ram_640k, NULL, "xen.ram.640k",
> >                                &ram_memory, 0, 0xa0000);
> >       memory_region_add_subregion(sysmem, 0, &ram_640k);
> > @@ -962,7 +965,7 @@ static void xen_wakeup_notifier(Notifier *notifier, void 
> > *data)
> >   }
> >   
> >   int xen_hvm_init(ram_addr_t *below_4g_mem_size, ram_addr_t *above_4g_mem_size,
> > -                 MemoryRegion **ram_memory)
> > +                 bool is_default, MemoryRegion **ram_memory)
> >   {
> >       int i, rc;
> >       unsigned long ioreq_pfn;
> > @@ -1040,7 +1043,8 @@ int xen_hvm_init(ram_addr_t *below_4g_mem_size, 
> > ram_addr_t *above_4g_mem_size,
> >   
> >       /* Init RAM management */
> >       xen_map_cache_init(xen_phys_offset_to_gaddr, state);
> > -    xen_ram_init(below_4g_mem_size, above_4g_mem_size, ram_size, ram_memory);
> > +    xen_ram_init(below_4g_mem_size, above_4g_mem_size, is_default, ram_size,
> > +                 ram_memory);
> >   
> >       qemu_add_vm_change_state_handler(xen_hvm_change_state_handler, state);
> >   
> > --
> > 1.8.4