Re: [Xen-devel] [v3][PATCH 14/16] tools/libxl: extend XENMEM_set_memory_map

[Wei Liu <wei.liu2@xxxxxxxxxx>]

On Thu, Jun 11, 2015 at 09:15:23AM +0800, Tiejun Chen wrote:
> Here we'll construct a basic guest e820 table via
> XENMEM_set_memory_map. This table includes lowmem, highmem
> and RDMs if they exist. And hvmloader would need this info
> later.
> 
> Signed-off-by: Tiejun Chen <tiejun.chen@xxxxxxxxx>
> ---
>  tools/libxl/libxl_dom.c      |  5 +++
>  tools/libxl/libxl_internal.h | 24 ++++++++++++++
>  tools/libxl/libxl_x86.c      | 78 
> ++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 107 insertions(+)
> 
> diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
> index 1777b32..3125ac0 100644
> --- a/tools/libxl/libxl_dom.c
> +++ b/tools/libxl/libxl_dom.c
> @@ -1004,6 +1004,11 @@ int libxl__build_hvm(libxl__gc *gc, uint32_t domid,
>          goto out;
>      }
>  
> +    if (libxl__domain_construct_e820(gc, d_config, domid, &args)) {
> +        LOG(ERROR, "setting domain memory map failed");
> +        goto out;
> +    }
> +
>      ret = hvm_build_set_params(ctx->xch, domid, info, state->store_port,
>                                 &state->store_mfn, state->console_port,
>                                 &state->console_mfn, state->store_domid,
> diff --git a/tools/libxl/libxl_internal.h b/tools/libxl/libxl_internal.h
> index 52f3831..d838639 100644
> --- a/tools/libxl/libxl_internal.h
> +++ b/tools/libxl/libxl_internal.h
> @@ -3713,6 +3713,30 @@ static inline void libxl__update_config_vtpm(libxl__gc 
> *gc,
>   */
>  void libxl__bitmap_copy_best_effort(libxl__gc *gc, libxl_bitmap *dptr,
>                                      const libxl_bitmap *sptr);
> +
> +/*
> + * Here we're just trying to set these kinds of e820 mappings:
> + *
> + * #1. Low memory region
> + *
> + * Low RAM starts at least from 1M to make sure all standard regions
> + * of the PC memory map, like BIOS, VGA memory-mapped I/O and vgabios,
> + * have enough space.
> + * Note: Those stuffs below 1M are still constructed with multiple
> + * e820 entries by hvmloader. At this point we don't change anything.
> + *
> + * #2. RDM region if it exists
> + *
> + * #3. High memory region if it exists
> + *
> + * Note: these regions are not overlapping since we already check
> + * to adjust them. Please refer to libxl__domain_device_construct_rdm().
> + */
> +int libxl__domain_construct_e820(libxl__gc *gc,
> +                                 libxl_domain_config *d_config,
> +                                 uint32_t domid,
> +                                 struct xc_hvm_build_args *args);
> +
>  #endif
>  
>  /*
> diff --git a/tools/libxl/libxl_x86.c b/tools/libxl/libxl_x86.c
> index ed2bd38..291f6ab 100644
> --- a/tools/libxl/libxl_x86.c
> +++ b/tools/libxl/libxl_x86.c
> @@ -438,6 +438,84 @@ int libxl__arch_domain_map_irq(libxl__gc *gc, uint32_t 
> domid, int irq)
>  }
>  
>  /*
> + * Here we're just trying to set these kinds of e820 mappings:
> + *
> + * #1. Low memory region
> + *
> + * Low RAM starts at least from 1M to make sure all standard regions
> + * of the PC memory map, like BIOS, VGA memory-mapped I/O and vgabios,
> + * have enough space.
> + * Note: Those stuffs below 1M are still constructed with multiple
> + * e820 entries by hvmloader. At this point we don't change anything.
> + *
> + * #2. RDM region if it exists
> + *
> + * #3. High memory region if it exists
> + *
> + * Note: these regions are not overlapping since we already check
> + * to adjust them. Please refer to libxl__domain_device_construct_rdm().
> + */
> +#define GUEST_LOW_MEM_START_DEFAULT 0x100000
> +int libxl__domain_construct_e820(libxl__gc *gc,
> +                                 libxl_domain_config *d_config,
> +                                 uint32_t domid,
> +                                 struct xc_hvm_build_args *args)
> +{
> +    unsigned int nr = 0, i;
> +    /* We always own at least one lowmem entry. */
> +    unsigned int e820_entries = 1;
> +    struct e820entry *e820 = NULL;
> +    uint64_t highmem_size =
> +                    args->highmem_end ? args->highmem_end - (1ull << 32) : 0;
> +
> +    /* Add all rdm entries. */
> +    for (i = 0; i < d_config->num_rdms; i++)
> +        if (d_config->rdms[i].flag != LIBXL_RDM_RESERVE_FLAG_INVALID)
> +            e820_entries++;
> +
> +
> +    /* If we should have a highmem range. */
> +    if (highmem_size)
> +        e820_entries++;
> +
> +    if (e820_entries >= E820MAX) {
> +        LOG(ERROR, "Ooops! Too many entries in the memory map!\n");
> +        return -1;

Please use goto style error handling.

> +    }
> +
> +    e820 = libxl__malloc(NOGC, sizeof(struct e820entry) * e820_entries);
> +

You should use libxl__malloc(gc,) here.

> +    /* Low memory */
> +    e820[nr].addr = GUEST_LOW_MEM_START_DEFAULT;
> +    e820[nr].size = args->lowmem_end - GUEST_LOW_MEM_START_DEFAULT;
> +    e820[nr].type = E820_RAM;
> +    nr++;
> +
> +    /* RDM mapping */
> +    for (i = 0; i < d_config->num_rdms; i++) {
> +        if (d_config->rdms[i].flag == LIBXL_RDM_RESERVE_FLAG_INVALID)
> +            continue;
> +
> +        e820[nr].addr = d_config->rdms[i].start;
> +        e820[nr].size = d_config->rdms[i].size;
> +        e820[nr].type = E820_RESERVED;
> +        nr++;
> +    }
> +
> +    /* High memory */
> +    if (highmem_size) {
> +        e820[nr].addr = ((uint64_t)1 << 32);
> +        e820[nr].size = highmem_size;
> +        e820[nr].type = E820_RAM;
> +    }
> +
> +    if (xc_domain_set_memory_map(CTX->xch, domid, e820, e820_entries) != 0)
> +        return -1;
> +
> +    return 0;
> +}
> +
> +/*
>   * Local variables:
>   * mode: C
>   * c-basic-offset: 4
> -- 
> 1.9.1

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