Re: [Xen-devel] [RFC][v2][PATCH 10/14] tools: extend XENMEM_set_memory_map

[Julien Grall <julien.grall@xxxxxxxxxx>]

Hi,

On 22/05/2015 10:35, 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 | 87 +++++++++++++++++++++++++++++++++++++++++++++++++
>   1 file changed, 87 insertions(+)
>
> diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
> index 84d5465..cc4b1a6 100644
> --- a/tools/libxl/libxl_dom.c
> +++ b/tools/libxl/libxl_dom.c
> @@ -913,6 +913,87 @@ out:
>       return rc;
>   }
>
> +/*
> + * 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
> +static int libxl__domain_construct_memmap(libxl__gc *gc,
> +                                          libxl_domain_config *d_config,
> +                                          uint32_t domid,
> +                                          struct xc_hvm_build_args *args)
The code within this function is x86 specific. Shouldn't it be moved in 
libxl_x86.c?
> +{
> +    libxl_ctx *ctx = libxl__gc_owner(gc);
> +    unsigned int nr = 0, i;
> +    /* We always own at least one lowmem entry. */
> +    unsigned int e820_entries = 1;
> +    uint64_t highmem_end = 0, highmem_size = args->mem_size - 
> args->lowmem_size;
> +    struct e820entry *e820 = NULL;
> +
> +    /* Add all rdm entries. */
> +    e820_entries += d_config->num_rdms;
> +
> +    /* If we should have a highmem range. */
> +    if (highmem_size)
> +    {
> +        highmem_end = (1ull<<32) + highmem_size;
> +        e820_entries++;
> +    }
> +
> +    if (e820_entries >= E820MAX) {
> +        LOG(ERROR, "Ooops! Too many entries in the memory map!\n");
> +        return -1;
> +    }
> +
> +    e820 = libxl__malloc(gc, sizeof(struct e820entry) * e820_entries);
> +
> +    /* Low memory */
> +    e820[nr].addr = GUEST_LOW_MEM_START_DEFAULT;
> +    e820[nr].size = args->lowmem_size - GUEST_LOW_MEM_START_DEFAULT;
> +    e820[nr].type = E820_RAM;
> +    nr++;
> +
> +    /* RDM mapping */
> +    for (i = 0; i < d_config->num_rdms; i++) {
> +        /*
> +         * We should drop this kind of rdm entry.
> +         */
> +        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;
> +}
> +
>   int libxl__build_hvm(libxl__gc *gc, uint32_t domid,
>                 libxl_domain_config *d_config,
>                 libxl__domain_build_state *state)
> @@ -1016,6 +1097,12 @@ int libxl__build_hvm(libxl__gc *gc, uint32_t domid,
>           ret = set_vnuma_info(gc, domid, info, state);
>           if (ret) goto out;
>       }
> +
> +    if (libxl__domain_construct_memmap(gc, d_config, domid, &args)) {
> +        LOG(ERROR, "setting domain rdm 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,
regards,

--
Julien Grall

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