Re: [RFC PATCH 1/1] Add pci_hole_min_size

[Boris Ostrovsky <boris.ostrovsky@oracle.com>]

On 02/28/2014 03:15 PM, Don Slutz wrote:
> This allows growing the pci_hole to the size needed.
>
> Signed-off-by: Don Slutz<dslutz@verizon.com>
> ---
>   tools/firmware/hvmloader/pci.c | 10 ++++++++++
>   tools/libxc/xc_hvm_build_x86.c | 22 ++++++++++++++++++++++
>   tools/libxc/xenguest.h         | 11 +++++++++++
>   tools/libxl/libxl_create.c     |  4 +++-
>   tools/libxl/libxl_dm.c         | 13 +++++++++++--
>   tools/libxl/libxl_dom.c        |  3 ++-
>   tools/libxl/libxl_types.idl    |  1 +
>   tools/libxl/xl_cmdimpl.c       |  6 ++++++
>   8 files changed, 66 insertions(+), 4 deletions(-)
>
> diff --git a/tools/firmware/hvmloader/pci.c b/tools/firmware/hvmloader/pci.c
> index 627e8cb..b36d00b 100644
> --- a/tools/firmware/hvmloader/pci.c
> +++ b/tools/firmware/hvmloader/pci.c
> @@ -58,6 +58,7 @@ void pci_setup(void)
>           uint64_t bar_sz;
>       } *bars = (struct bars *)scratch_start;
>       unsigned int i, nr_bars = 0;
> +    uint64_t pci_hole_min_size;
>   
>       const char *s;
>       /*
> @@ -85,6 +86,9 @@ void pci_setup(void)
>       printf("Relocating guest memory for lowmem MMIO space %s\n",
>              allow_memory_relocate?"enabled":"disabled");
>   
> +    s = xenstore_read("platform/pci_hole_min_size", "0");

'if (s)'

> +    pci_hole_min_size = strtoll(s, NULL, 0);
> +
>       /* Program PCI-ISA bridge with appropriate link routes. */
>       isa_irq = 0;
>       for ( link = 0; link < 4; link++ )
> @@ -236,6 +240,12 @@ void pci_setup(void)
>           pci_writew(devfn, PCI_COMMAND, cmd);
>       }
>   
> +    if (pci_hole_min_size) {
> +        pci_mem_start = (1ull << 32) - pci_hole_min_size;
> +        printf("pci_mem_start=0x%lx (was 0x%x) for pci_hole_min_size=%llu\n",
> +               pci_mem_start, PCI_MEM_START, pci_hole_min_size);
> +    }
> +
>       /*
>        * At the moment qemu-xen can't deal with relocated memory regions.
>        * It's too close to the release to make a proper fix; for now,

...

> diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
> index a604cd8..24ceac6 100644
> --- a/tools/libxl/libxl_create.c
> +++ b/tools/libxl/libxl_create.c
> @@ -388,13 +388,15 @@ int libxl__domain_build(libxl__gc *gc,
>           vments[4] = "start_time";
>           vments[5] = libxl__sprintf(gc, "%lu.%02d", start_time.tv_sec,(int)start_time.tv_usec/10000);
>   
> -        localents = libxl__calloc(gc, 7, sizeof(char *));
> +        localents = libxl__calloc(gc, 9, sizeof(char *));
>           localents[0] = "platform/acpi";
>           localents[1] = libxl_defbool_val(info->u.hvm.acpi) ? "1" : "0";
>           localents[2] = "platform/acpi_s3";
>           localents[3] = libxl_defbool_val(info->u.hvm.acpi_s3) ? "1" : "0";
>           localents[4] = "platform/acpi_s4";
>           localents[5] = libxl_defbool_val(info->u.hvm.acpi_s4) ? "1" : "0";
> +        localents[6] = "platform/pci_hole_min_size";
> +        localents[7] = libxl__sprintf(gc, "%llu", (unsigned long long)info->u.hvm.pci_hole_min_size);

Do you want to always store this parameter? There is a default already 
(HVM_BELOW_4G_MMIO_LENGTH) so if it's not set in the config file it may 
be safe to omit it.

...


> diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
> index 4fc46eb..fe247ee 100644
> --- a/tools/libxl/xl_cmdimpl.c
> +++ b/tools/libxl/xl_cmdimpl.c
> @@ -1025,6 +1025,12 @@ static void parse_config_data(const char *config_source,
>           xlu_cfg_get_defbool(config, "hpet", &b_info->u.hvm.hpet, 0);
>           xlu_cfg_get_defbool(config, "vpt_align", &b_info->u.hvm.vpt_align, 0);
>   
> +        if (!xlu_cfg_get_long(config, "pci_hole_min_size", &l, 0)) {
> +            b_info->u.hvm.pci_hole_min_size = (uint64_t) l;
> +            if (dom_info->debug)
> +                fprintf(stderr, "pci_hole_min_size: %llu\n", (unsigned long long) b_info->u.hvm.pci_hole_min_size);
> +        }

You probably want to set b_info->u.hvm.pci_hole_min_size to 0 (or 
HVM_BELOW_4G_MMIO_LENGTH?) in case it's not specified in 
libxl__domain_build_info_setdefault().

-boris


> +
>           if (!xlu_cfg_get_long(config, "timer_mode", &l, 1)) {
>               const char *s = libxl_timer_mode_to_string(l);
>               fprintf(stderr, "WARNING: specifying \"timer_mode\" as an integer is deprecated. "