Re: HVM support for e820_host (Was: Bug: Limitation of <=2GB RAM in domU persists with 4.3.0)

[Gordan Bobic <gordan@bobich.net>]

 On Tue, 3 Sep 2013 17:08:33 -0400, Konrad Rzeszutek Wilk 
 <konrad.wilk@oracle.com> wrote:

> Oh, and something like this probably should do it - not compile 
> tested
> in any way:
>
> diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
> index 1fcaed0..7b38890 100644
> --- a/xen/arch/x86/hvm/hvm.c
> +++ b/xen/arch/x86/hvm/hvm.c
> @@ -3146,6 +3146,7 @@ static long hvm_memory_op(int cmd,
> XEN_GUEST_HANDLE_PARAM(void) arg)
>      case XENMEM_machine_memory_map:
>      case XENMEM_machphys_mapping:
>          return -ENOSYS;
> +    case XENMEM_memory_map:
>      case XENMEM_decrease_reservation:
>          rc = do_memory_op(cmd, arg);
>          current->domain->arch.hvm_domain.qemu_mapcache_invalidate = 
> 1;

 This seems to work better. :)

 --- a/xen/arch/x86/hvm/hvm.c
 +++ b/xen/arch/x86/hvm/hvm.c
 @@ -3142,10 +3142,10 @@ static long hvm_memory_op(int cmd, 
 XEN_GUEST_HANDLE_PARAM(void) arg)

      switch ( cmd & MEMOP_CMD_MASK )
      {
 -    case XENMEM_memory_map:
      case XENMEM_machine_memory_map:
      case XENMEM_machphys_mapping:
          return -ENOSYS;
 +    case XENMEM_memory_map:
      case XENMEM_decrease_reservation:
          rc = do_memory_op(cmd, arg);
          current->domain->arch.hvm_domain.qemu_mapcache_invalidate = 1;


> diff --git a/tools/firmware/hvmloader/e820.c
> b/tools/firmware/hvmloader/e820.c
> index 2e05e93..86fb20a 100644
> --- a/tools/firmware/hvmloader/e820.c
> +++ b/tools/firmware/hvmloader/e820.c
> @@ -68,16 +68,42 @@ void dump_e820_table(struct e820entry *e820,
> unsigned int nr)
>      }
>  }
>
> +static const char *e820_names(int type)
> +{
> +    switch (type) {
> +        case E820_RAM: return "RAM";
> +        case E820_RESERVED: return "Reserved";
> +        case E820_ACPI: return "ACPI";
> +        case E820_NVS: return "ACPI NVS";
> +        case E820_UNUSABLE: return "Unusable";
> +        default: break;
> +    }
> +    return "Unknown";
> +}

 To make this work I also added:

 --- tools/firmware/hvmloader/e820.h.orig	2013-09-04 10:55:38.317275183 
 +0100
 +++ tools/firmware/hvmloader/e820.h	2013-09-04 10:56:14.374595809 +0100
 @@ -8,6 +8,7 @@
  #define E820_RESERVED     2
  #define E820_ACPI         3
  #define E820_NVS          4
 +#define E820_UNUSBLE      5
 
  struct e820entry {
      uint64_t addr;

 It that OK?

>  /* Create an E820 table based on memory parameters provided in 
> hvm_info. */
>  int build_e820_table(struct e820entry *e820,
>                       unsigned int lowmem_reserved_base,
>                       unsigned int bios_image_base)
>  {
>      unsigned int nr = 0;
> +    struct xen_memory_map op;
> +    struct e820entry map[E820MAX];
> +    int rc;
>
>      if ( !lowmem_reserved_base )
>              lowmem_reserved_base = 0xA0000;
>
> +    set_xen_guest_handle(op.buffer, map);
> +
> +    rc = hypercall_memory_op ( XENMEM_memory_op, &op);

 Where is XENMEM_memory_op defined?
 Should that be XENMEM_memory_map? Or maybe XENMEM_populate_physmap?

 Gordan