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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] Re: [Xen-devel] [PATCH for 4.5 v7 1/1] Add mmio_hole_size
On Mon, Oct 13, 2014 at 1:51 PM, Don Slutz <dslutz@xxxxxxxxxxx> wrote:
> If you add enough PCI devices then all mmio may not fit below 4G
> which may not be the layout the user wanted. This allows you to
> increase the below 4G address space that PCI devices can use and
> therefore in more cases not have any mmio that is above 4G.
>
> There are real PCI cards that do not support mmio over 4G, so if you
> want to emulate them precisely, you may also need to increase the
> space below 4G for them. There are drivers for these cards that also
> do not work if they have their mmio space mapped above 4G.
>
> This allows growing the MMIO hole to the size needed.
>
> This may help with using pci passthru and HVM.
>
> Signed-off-by: Don Slutz <dslutz@xxxxxxxxxxx>
I haven't done a full review, but all of my previous concerns have
been addressed:
Acked-by: George Dunlap <george.dunlap@xxxxxxxxxxxxx>
> ---
> v7:
> QEMU 2.1.0 reference confusing.
> Dropped.
> Why have assert(i < 9) & assert(i < 11)
> Dropped.
> This check for 256MB is surely obfuscated by the macros.
> Added comment to help.
>
> v6:
> I think we should get rid of xc_hvm_build_with_hole() entirely.
> Done.
> Add text describing restrictions on hole size
> Done.
> "<=", to be consistent with the check in
> libxl__domain_create_info_setdefault ()
> Done
>
> v5:
> Add LIBXL_HAVE_BUILDINFO_HVM_MMIO_HOLE_SIZE.
>
> v4:
> s/pci_hole_min_size/mmio_hole_size/
> s/HVM_BELOW_4G_RAM_END/HVM_BELOW_4G_MMIO_START/
> Add ignore to hvmloader message
> Adjust commit message
> Dropped min; stopped mmio_hole_size changing in hvmloader
>
>
> docs/man/xl.cfg.pod.5 | 15 +++++++++
> tools/firmware/hvmloader/config.h | 1 -
> tools/firmware/hvmloader/pci.c | 71
> +++++++++++++++++++++++++++------------
> tools/libxl/libxl.h | 5 +++
> tools/libxl/libxl_create.c | 27 +++++++++++----
> tools/libxl/libxl_dm.c | 24 +++++++++++--
> tools/libxl/libxl_dom.c | 8 +++++
> tools/libxl/libxl_types.idl | 1 +
> tools/libxl/xl_cmdimpl.c | 16 +++++++++
> 9 files changed, 137 insertions(+), 31 deletions(-)
>
> diff --git a/docs/man/xl.cfg.pod.5 b/docs/man/xl.cfg.pod.5
> index 8bba21c..10e995a 100644
> --- a/docs/man/xl.cfg.pod.5
> +++ b/docs/man/xl.cfg.pod.5
> @@ -1111,6 +1111,21 @@ wallclock (i.e., real) time.
>
> =back
>
> +=head3 Memory layout
> +
> +=over 4
> +
> +=item B<mmio_hole_size=BYTES>
> +
> +Specifies the size the MMIO hole below 4GiB will be. Only valid for
> +device_model_version = "qemu-xen".
> +
> +Cannot be smaller than 256MiB. Cannot be larger than 3840MiB.
> +
> +Known good large value is 3GiB (3221225472).
> +
> +=back
> +
> =head3 Support for Paravirtualisation of HVM Guests
>
> The following options allow Paravirtualised features (such as devices)
> diff --git a/tools/firmware/hvmloader/config.h
> b/tools/firmware/hvmloader/config.h
> index 80bea46..b838cf9 100644
> --- a/tools/firmware/hvmloader/config.h
> +++ b/tools/firmware/hvmloader/config.h
> @@ -53,7 +53,6 @@ extern struct bios_config ovmf_config;
> #define PCI_ISA_IRQ_MASK 0x0c20U /* ISA IRQs 5,10,11 are PCI connected */
>
> /* MMIO hole: Hardcoded defaults, which can be dynamically expanded. */
> -#define PCI_MEM_START 0xf0000000
> #define PCI_MEM_END 0xfc000000
>
> extern unsigned long pci_mem_start, pci_mem_end;
> diff --git a/tools/firmware/hvmloader/pci.c b/tools/firmware/hvmloader/pci.c
> index 3712988..4e8d803 100644
> --- a/tools/firmware/hvmloader/pci.c
> +++ b/tools/firmware/hvmloader/pci.c
> @@ -28,9 +28,10 @@
> #include <xen/memory.h>
> #include <xen/hvm/ioreq.h>
> #include <xen/hvm/hvm_xs_strings.h>
> +#include <xen/hvm/e820.h>
> #include <stdbool.h>
>
> -unsigned long pci_mem_start = PCI_MEM_START;
> +unsigned long pci_mem_start = HVM_BELOW_4G_MMIO_START;
> unsigned long pci_mem_end = PCI_MEM_END;
> uint64_t pci_hi_mem_start = 0, pci_hi_mem_end = 0;
>
> @@ -59,6 +60,7 @@ void pci_setup(void)
> uint64_t bar_sz;
> } *bars = (struct bars *)scratch_start;
> unsigned int i, nr_bars = 0;
> + uint64_t mmio_hole_size = 0;
>
> const char *s;
> /*
> @@ -86,6 +88,10 @@ void pci_setup(void)
> printf("Relocating guest memory for lowmem MMIO space %s\n",
> allow_memory_relocate?"enabled":"disabled");
>
> + s = xenstore_read("platform/mmio_hole_size", NULL);
> + if ( s )
> + mmio_hole_size = strtoll(s, NULL, 0);
> +
> /* Program PCI-ISA bridge with appropriate link routes. */
> isa_irq = 0;
> for ( link = 0; link < 4; link++ )
> @@ -237,26 +243,49 @@ void pci_setup(void)
> pci_writew(devfn, PCI_COMMAND, cmd);
> }
>
> - /*
> - * 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,
> - * only allow the MMIO hole to grow large enough to move guest memory
> - * if we're running qemu-traditional. Items that don't fit will be
> - * relocated into the 64-bit address space.
> - *
> - * This loop now does the following:
> - * - If allow_memory_relocate, increase the MMIO hole until it's
> - * big enough, or until it's 2GiB
> - * - If !allow_memory_relocate, increase the MMIO hole until it's
> - * big enough, or until it's 2GiB, or until it overlaps guest
> - * memory
> - */
> - while ( (mmio_total > (pci_mem_end - pci_mem_start))
> - && ((pci_mem_start << 1) != 0)
> - && (allow_memory_relocate
> - || (((pci_mem_start << 1) >> PAGE_SHIFT)
> - >= hvm_info->low_mem_pgend)) )
> - pci_mem_start <<= 1;
> + if ( mmio_hole_size )
> + {
> + uint64_t max_ram_below_4g = (1ULL << 32) - mmio_hole_size;
> +
> + if ( max_ram_below_4g > HVM_BELOW_4G_MMIO_START )
> + {
> + printf("max_ram_below_4g=0x"PRIllx
> + " too big for mmio_hole_size=0x"PRIllx
> + " has been ignored.\n",
> + PRIllx_arg(max_ram_below_4g),
> + PRIllx_arg(mmio_hole_size));
> + }
> + else
> + {
> + pci_mem_start = max_ram_below_4g;
> + printf("pci_mem_start=0x%lx (was 0x%x) for mmio_hole_size=%lu\n",
> + pci_mem_start, HVM_BELOW_4G_MMIO_START,
> + (long)mmio_hole_size);
> + }
> + }
> + else
> + {
> + /*
> + * 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,
> + * only allow the MMIO hole to grow large enough to move guest memory
> + * if we're running qemu-traditional. Items that don't fit will be
> + * relocated into the 64-bit address space.
> + *
> + * This loop now does the following:
> + * - If allow_memory_relocate, increase the MMIO hole until it's
> + * big enough, or until it's 2GiB
> + * - If !allow_memory_relocate, increase the MMIO hole until it's
> + * big enough, or until it's 2GiB, or until it overlaps guest
> + * memory
> + */
> + while ( (mmio_total > (pci_mem_end - pci_mem_start))
> + && ((pci_mem_start << 1) != 0)
> + && (allow_memory_relocate
> + || (((pci_mem_start << 1) >> PAGE_SHIFT)
> + >= hvm_info->low_mem_pgend)) )
> + pci_mem_start <<= 1;
> + }
>
> if ( mmio_total > (pci_mem_end - pci_mem_start) )
> {
> diff --git a/tools/libxl/libxl.h b/tools/libxl/libxl.h
> index 2700cc1..eb29037 100644
> --- a/tools/libxl/libxl.h
> +++ b/tools/libxl/libxl.h
> @@ -158,6 +158,11 @@
> #define LIBXL_BUILDINFO_HVM_VIRIDIAN_ENABLE_DISABLE_WIDTH 64
>
> /*
> + * libxl_domain_build_info has the u.hvm.mmio_hole_size field.
> + */
> +#define LIBXL_HAVE_BUILDINFO_HVM_MMIO_HOLE_SIZE 1
> +
> +/*
> * libxl ABI compatibility
> *
> * The only guarantee which libxl makes regarding ABI compatibility
> diff --git a/tools/libxl/libxl_create.c b/tools/libxl/libxl_create.c
> index 8b82584..d6191e1 100644
> --- a/tools/libxl/libxl_create.c
> +++ b/tools/libxl/libxl_create.c
> @@ -23,6 +23,7 @@
> #include <xc_dom.h>
> #include <xenguest.h>
> #include <xen/hvm/hvm_info_table.h>
> +#include <xen/hvm/e820.h>
>
> int libxl__domain_create_info_setdefault(libxl__gc *gc,
> libxl_domain_create_info *c_info)
> @@ -428,13 +429,25 @@ 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[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 = libxl__calloc(gc, 9, sizeof(char *));
> + i = 0;
> + localents[i++] = "platform/acpi";
> + localents[i++] = libxl_defbool_val(info->u.hvm.acpi) ? "1" : "0";
> + localents[i++] = "platform/acpi_s3";
> + localents[i++] = libxl_defbool_val(info->u.hvm.acpi_s3) ? "1" : "0";
> + localents[i++] = "platform/acpi_s4";
> + localents[i++] = libxl_defbool_val(info->u.hvm.acpi_s4) ? "1" : "0";
> + if (info->u.hvm.mmio_hole_size) {
> + uint64_t max_ram_below_4g =
> + (1ULL << 32) - info->u.hvm.mmio_hole_size;
> +
> + if (max_ram_below_4g <= HVM_BELOW_4G_MMIO_START) {
> + localents[i++] = "platform/mmio_hole_size";
> + localents[i++] =
> + libxl__sprintf(gc, "%"PRIu64,
> + info->u.hvm.mmio_hole_size);
> + }
> + }
>
> break;
> case LIBXL_DOMAIN_TYPE_PV:
> diff --git a/tools/libxl/libxl_dm.c b/tools/libxl/libxl_dm.c
> index d8992bb..9f5b86a 100644
> --- a/tools/libxl/libxl_dm.c
> +++ b/tools/libxl/libxl_dm.c
> @@ -18,6 +18,7 @@
> #include "libxl_osdeps.h" /* must come before any other headers */
>
> #include "libxl_internal.h"
> +#include <xen/hvm/e820.h>
>
> static const char *libxl_tapif_script(libxl__gc *gc)
> {
> @@ -415,6 +416,7 @@ static char **
> libxl__build_device_model_args_new(libxl__gc *gc,
> const libxl_vnc_info *vnc = libxl__dm_vnc(guest_config);
> const libxl_sdl_info *sdl = dm_sdl(guest_config);
> const char *keymap = dm_keymap(guest_config);
> + char *machinearg;
> flexarray_t *dm_args;
> int i;
> uint64_t ram_size;
> @@ -696,10 +698,28 @@ static char **
> libxl__build_device_model_args_new(libxl__gc *gc,
> /* Switching here to the machine "pc" which does not add
> * the xen-platform device instead of the default "xenfv"
> machine.
> */
> - flexarray_append(dm_args, "pc,accel=xen");
> + machinearg = libxl__sprintf(gc, "pc,accel=xen");
> } else {
> - flexarray_append(dm_args, "xenfv");
> + machinearg = libxl__sprintf(gc, "xenfv");
> }
> + if (b_info->u.hvm.mmio_hole_size) {
> + uint64_t max_ram_below_4g = (1ULL << 32) -
> + b_info->u.hvm.mmio_hole_size;
> +
> + if (max_ram_below_4g > HVM_BELOW_4G_MMIO_START) {
> + LIBXL__LOG(ctx, LIBXL__LOG_WARNING,
> + "max-ram-below-4g=%"PRIu64
> + " (mmio_hole_size=%"PRIu64
> + ") too big > %u ignored.\n",
> + max_ram_below_4g,
> + b_info->u.hvm.mmio_hole_size,
> + HVM_BELOW_4G_MMIO_START);
> + } else {
> + machinearg = libxl__sprintf(gc,
> "%s,max-ram-below-4g=%"PRIu64,
> + machinearg, max_ram_below_4g);
> + }
> + }
> + flexarray_append(dm_args, machinearg);
> for (i = 0; b_info->extra_hvm && b_info->extra_hvm[i] != NULL; i++)
> flexarray_append(dm_args, b_info->extra_hvm[i]);
> break;
> diff --git a/tools/libxl/libxl_dom.c b/tools/libxl/libxl_dom.c
> index 9d830e1..76c3b95 100644
> --- a/tools/libxl/libxl_dom.c
> +++ b/tools/libxl/libxl_dom.c
> @@ -23,6 +23,7 @@
> #include <xc_dom.h>
> #include <xen/hvm/hvm_info_table.h>
> #include <xen/hvm/hvm_xs_strings.h>
> +#include <xen/hvm/e820.h>
>
> libxl_domain_type libxl__domain_type(libxl__gc *gc, uint32_t domid)
> {
> @@ -800,6 +801,13 @@ int libxl__build_hvm(libxl__gc *gc, uint32_t domid,
> args.mem_size = (uint64_t)(info->max_memkb - info->video_memkb) << 10;
> args.mem_target = (uint64_t)(info->target_memkb - info->video_memkb) <<
> 10;
> args.claim_enabled = libxl_defbool_val(info->claim_mode);
> + if (info->u.hvm.mmio_hole_size) {
> + uint64_t max_ram_below_4g = (1ULL << 32) -
> + info->u.hvm.mmio_hole_size;
> +
> + if (max_ram_below_4g < HVM_BELOW_4G_MMIO_START)
> + args.mmio_size = info->u.hvm.mmio_hole_size;
> + }
> if (libxl__domain_firmware(gc, info, &args)) {
> LOG(ERROR, "initializing domain firmware failed");
> goto out;
> diff --git a/tools/libxl/libxl_types.idl b/tools/libxl/libxl_types.idl
> index bbb03e2..2a71e9a 100644
> --- a/tools/libxl/libxl_types.idl
> +++ b/tools/libxl/libxl_types.idl
> @@ -391,6 +391,7 @@ libxl_domain_build_info = Struct("domain_build_info",[
> ("timeoffset", string),
> ("hpet", libxl_defbool),
> ("vpt_align", libxl_defbool),
> + ("mmio_hole_size", uint64),
> ("timer_mode",
> libxl_timer_mode),
> ("nested_hvm", libxl_defbool),
> ("smbios_firmware", string),
> diff --git a/tools/libxl/xl_cmdimpl.c b/tools/libxl/xl_cmdimpl.c
> index c734f79..083707f 100644
> --- a/tools/libxl/xl_cmdimpl.c
> +++ b/tools/libxl/xl_cmdimpl.c
> @@ -34,6 +34,7 @@
> #include <ctype.h>
> #include <inttypes.h>
> #include <limits.h>
> +#include <xen/hvm/e820.h>
>
> #include "libxl.h"
> #include "libxl_utils.h"
> @@ -1111,6 +1112,21 @@ static void parse_config_data(const char
> *config_source,
> exit(-ERROR_FAIL);
> }
>
> + if (!xlu_cfg_get_long(config, "mmio_hole_size", &l, 0)) {
> + b_info->u.hvm.mmio_hole_size = (uint64_t) l;
> + /*
> + * With HVM_BELOW_4G_RAM_END == 0xF0000000, mmio_hole_size
> + * must be >= 256 MiB and <= 3840 MiB.
> + */
> + if (b_info->u.hvm.mmio_hole_size < HVM_BELOW_4G_MMIO_LENGTH ||
> + b_info->u.hvm.mmio_hole_size > HVM_BELOW_4G_MMIO_START) {
> + fprintf(stderr, "ERROR: invalid value 0x%"PRIx64" (%"PRIu64
> + ") for \"mmio_hole_size\"\n",
> + b_info->u.hvm.mmio_hole_size,
> + b_info->u.hvm.mmio_hole_size);
> + exit (1);
> + }
> + }
> 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. "
> --
> 1.8.4
>
>
> _______________________________________________
> Xen-devel mailing list
> Xen-devel@xxxxxxxxxxxxx
> http://lists.xen.org/xen-devel
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