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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH for 4.5 v7 1/1] Add mmio_hole_size
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>
---
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
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