xen/arch/arm/efi/efi-boot.h | 3 ++- xen/arch/arm/static-shmem.c | 2 +- xen/common/device-tree/bootfdt.c | 9 ++++++- xen/common/device-tree/bootinfo.c | 39 +++++++++++++++++++++++-------- xen/include/xen/bootfdt.h | 20 +++++++++++++--- 5 files changed, 57 insertions(+), 16 deletions(-)
There are some cases where the device tree exposes a memory range
in both /memreserve/ and reserved-memory node, in this case the
current code will stop Xen to boot since it will find that the
latter range is clashing with the already recorded /memreserve/
ranges.
Furthermore, u-boot lists boot modules ranges, such as ramdisk,
in the /memreserve/ part and even in this case this will prevent
Xen to boot since it will see that the module memory range that
it is going to add in 'add_boot_module' clashes with a /memreserve/
range.
When Xen populate the data structure that tracks the memory ranges,
it also adds a memory type described in 'enum membank_type', so
in order to fix this behavior, allow overlapping with the /memreserve/
ranges in the 'check_reserved_regions_overlap' function when a flag
is set.
In order to implement this solution, there is a distinction between
the 'struct membanks *' handled by meminfo_overlap_check(...) that
needs to be done, because the static shared memory banks doesn't have
a usable bank[].type field and so it can't be accessed, hence now
the 'struct membanks_hdr' have a 'enum region_type type' field in order
to be able to identify static shared memory banks in meminfo_overlap_check(...).
While there, set a type for the memory recorded using meminfo_add_bank()
from efi-boot.h.
Fixes: 53dc37829c31 ("xen/arm: Add DT reserve map regions to bootinfo.reserved_mem")
Reported-by: Shawn Anastasio <sanastasio@raptorengineering.com>
Reported-by: Grygorii Strashko <grygorii_strashko@epam.com>
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
---
Changes from v1:
- fixed commit message
- used boolean to allow /memreserve/ overlap or not
- now 'struct membanks *' have a type, while it might seem a waste of space,
it might be used in the future to consolidate also the 'struct bootmodules'
and 'struct bootcmdlines' to use the same 'struct membanks *' interface.
Also the added space is limited to 3/4 enum size.
- The change above allowed this version to remove the "hack" when dealing with
static shared memory banks, that doesn't have a type.
I tested this patch adding the same range in a /memreserve/ entry and
/reserved-memory node, and by letting u-boot pass a ramdisk.
I've also tested that a configuration running static shared memory still works
fine.
---
---
xen/arch/arm/efi/efi-boot.h | 3 ++-
xen/arch/arm/static-shmem.c | 2 +-
xen/common/device-tree/bootfdt.c | 9 ++++++-
xen/common/device-tree/bootinfo.c | 39 +++++++++++++++++++++++--------
xen/include/xen/bootfdt.h | 20 +++++++++++++---
5 files changed, 57 insertions(+), 16 deletions(-)
diff --git a/xen/arch/arm/efi/efi-boot.h b/xen/arch/arm/efi/efi-boot.h
index 199f5260229d..a80a5a7ab326 100644
--- a/xen/arch/arm/efi/efi-boot.h
+++ b/xen/arch/arm/efi/efi-boot.h
@@ -167,13 +167,14 @@ static bool __init meminfo_add_bank(struct membanks *mem,
if ( mem->nr_banks >= mem->max_banks )
return false;
#ifdef CONFIG_ACPI
- if ( check_reserved_regions_overlap(start, size) )
+ if ( check_reserved_regions_overlap(start, size, false) )
return false;
#endif
bank = &mem->bank[mem->nr_banks];
bank->start = start;
bank->size = size;
+ bank->type = MEMBANK_DEFAULT;
mem->nr_banks++;
diff --git a/xen/arch/arm/static-shmem.c b/xen/arch/arm/static-shmem.c
index aa80756c3ca5..66088a426785 100644
--- a/xen/arch/arm/static-shmem.c
+++ b/xen/arch/arm/static-shmem.c
@@ -696,7 +696,7 @@ int __init process_shm_node(const void *fdt, int node, uint32_t address_cells,
if (i < mem->max_banks)
{
if ( (paddr != INVALID_PADDR) &&
- check_reserved_regions_overlap(paddr, size) )
+ check_reserved_regions_overlap(paddr, size, false) )
return -EINVAL;
/* Static shared memory shall be reserved from any other use. */
diff --git a/xen/common/device-tree/bootfdt.c b/xen/common/device-tree/bootfdt.c
index 927f59c64b0d..241810212c02 100644
--- a/xen/common/device-tree/bootfdt.c
+++ b/xen/common/device-tree/bootfdt.c
@@ -176,8 +176,15 @@ static int __init device_tree_get_meminfo(const void *fdt, int node,
for ( i = 0; i < banks && mem->nr_banks < mem->max_banks; i++ )
{
device_tree_get_reg(&cell, address_cells, size_cells, &start, &size);
+ /*
+ * Some valid device trees, such as those generated by OpenPOWER
+ * skiboot firmware, expose all reserved memory regions in the
+ * FDT memory reservation block AND in the reserved-memory node which
+ * has already been parsed. Thus, any matching overlaps in the
+ * reserved_mem banks should be ignored.
+ */
if ( mem == bootinfo_get_reserved_mem() &&
- check_reserved_regions_overlap(start, size) )
+ check_reserved_regions_overlap(start, size, true) )
return -EINVAL;
/* Some DT may describe empty bank, ignore them */
if ( !size )
diff --git a/xen/common/device-tree/bootinfo.c b/xen/common/device-tree/bootinfo.c
index f2e6a1145b7c..b36b05fd9224 100644
--- a/xen/common/device-tree/bootinfo.c
+++ b/xen/common/device-tree/bootinfo.c
@@ -99,7 +99,8 @@ static void __init dt_unreserved_regions(paddr_t s, paddr_t e,
*/
static bool __init meminfo_overlap_check(const struct membanks *mem,
paddr_t region_start,
- paddr_t region_size)
+ paddr_t region_size,
+ bool allow_memreserve_overlap)
{
paddr_t bank_start = INVALID_PADDR, bank_end = 0;
paddr_t region_end = region_start + region_size;
@@ -113,12 +114,23 @@ static bool __init meminfo_overlap_check(const struct membanks *mem,
if ( INVALID_PADDR == bank_start || region_end <= bank_start ||
region_start >= bank_end )
continue;
- else
- {
- printk("Region: [%#"PRIpaddr", %#"PRIpaddr") overlapping with bank[%u]: [%#"PRIpaddr", %#"PRIpaddr")\n",
- region_start, region_end, i, bank_start, bank_end);
- return true;
- }
+
+ /*
+ * If allow_memreserve_overlap is set, this check allows a region to be
+ * included in a MEMBANK_FDT_RESVMEM bank, but struct membanks *mem of
+ * type STATIC_SHARED_MEMORY don't set the bank[].type field because
+ * that is declared in a union with a field that is instead used,
+ * in any case this restriction is ok since STATIC_SHARED_MEMORY banks
+ * are not meant to clash with FDT /memreserve/ ranges.
+ */
+ if ( allow_memreserve_overlap && mem->type != STATIC_SHARED_MEMORY &&
+ region_start >= bank_start && region_end <= bank_end &&
+ mem->bank[i].type == MEMBANK_FDT_RESVMEM )
+ continue;
+
+ printk("Region: [%#"PRIpaddr", %#"PRIpaddr") overlapping with bank[%u]: [%#"PRIpaddr", %#"PRIpaddr")\n",
+ region_start, region_end, i, bank_start, bank_end);
+ return true;
}
return false;
@@ -171,7 +183,8 @@ void __init fw_unreserved_regions(paddr_t s, paddr_t e,
* existing reserved memory regions, otherwise false.
*/
bool __init check_reserved_regions_overlap(paddr_t region_start,
- paddr_t region_size)
+ paddr_t region_size,
+ bool allow_memreserve_overlap)
{
const struct membanks *mem_banks[] = {
bootinfo_get_reserved_mem(),
@@ -190,7 +203,8 @@ bool __init check_reserved_regions_overlap(paddr_t region_start,
* shared memory banks (when static shared memory feature is enabled)
*/
for ( i = 0; i < ARRAY_SIZE(mem_banks); i++ )
- if ( meminfo_overlap_check(mem_banks[i], region_start, region_size) )
+ if ( meminfo_overlap_check(mem_banks[i], region_start, region_size,
+ allow_memreserve_overlap) )
return true;
/* Check if input region is overlapping with bootmodules */
@@ -216,7 +230,12 @@ struct bootmodule __init *add_boot_module(bootmodule_kind kind,
return NULL;
}
- if ( check_reserved_regions_overlap(start, size) )
+ /*
+ * u-boot adds boot module such as ramdisk to the /memreserve/, since these
+ * ranges are saved in reserved_mem at this stage, allow an eventual exact
+ * match with MEMBANK_FDT_RESVMEM banks.
+ */
+ if ( check_reserved_regions_overlap(start, size, true) )
return NULL;
for ( i = 0 ; i < mods->nr_mods ; i++ )
diff --git a/xen/include/xen/bootfdt.h b/xen/include/xen/bootfdt.h
index 16fa05f38f38..cea40ee11706 100644
--- a/xen/include/xen/bootfdt.h
+++ b/xen/include/xen/bootfdt.h
@@ -48,6 +48,12 @@ enum membank_type {
MEMBANK_FDT_RESVMEM,
};
+enum region_type {
+ MEMORY,
+ RESERVED_MEMORY,
+ STATIC_SHARED_MEMORY
+};
+
/* Indicates the maximum number of characters(\0 included) for shm_id */
#define MAX_SHM_ID_LENGTH 16
@@ -71,6 +77,7 @@ struct membanks {
__struct_group(membanks_hdr, common, ,
unsigned int nr_banks;
unsigned int max_banks;
+ enum region_type type;
);
struct membank bank[];
};
@@ -136,13 +143,17 @@ struct bootinfo {
};
#ifdef CONFIG_ACPI
-#define BOOTINFO_ACPI_INIT .acpi.common.max_banks = NR_MEM_BANKS,
+#define BOOTINFO_ACPI_INIT \
+ .acpi.common.max_banks = NR_MEM_BANKS, \
+ .acpi.common.type = MEMORY
#else
#define BOOTINFO_ACPI_INIT
#endif
#ifdef CONFIG_STATIC_SHM
-#define BOOTINFO_SHMEM_INIT .shmem.common.max_banks = NR_SHMEM_BANKS,
+#define BOOTINFO_SHMEM_INIT \
+ .shmem.common.max_banks = NR_SHMEM_BANKS, \
+ .shmem.common.type = STATIC_SHARED_MEMORY
#else
#define BOOTINFO_SHMEM_INIT
#endif
@@ -150,7 +161,9 @@ struct bootinfo {
#define BOOTINFO_INIT \
{ \
.mem.common.max_banks = NR_MEM_BANKS, \
+ .mem.common.type = MEMORY, \
.reserved_mem.common.max_banks = NR_MEM_BANKS, \
+ .reserved_mem.common.type = RESERVED_MEMORY, \
BOOTINFO_ACPI_INIT \
BOOTINFO_SHMEM_INIT \
}
@@ -158,7 +171,8 @@ struct bootinfo {
extern struct bootinfo bootinfo;
bool check_reserved_regions_overlap(paddr_t region_start,
- paddr_t region_size);
+ paddr_t region_size,
+ bool allow_memreserve_overlap);
struct bootmodule *add_boot_module(bootmodule_kind kind,
paddr_t start, paddr_t size, bool domU);
--
2.34.1Hi Luca,
On 14/11/2024 10:28, Luca Fancellu wrote:
> There are some cases where the device tree exposes a memory range
> in both /memreserve/ and reserved-memory node, in this case the
> current code will stop Xen to boot since it will find that the
> latter range is clashing with the already recorded /memreserve/
> ranges.
>
> Furthermore, u-boot lists boot modules ranges, such as ramdisk,
> in the /memreserve/ part and even in this case this will prevent
> Xen to boot since it will see that the module memory range that
> it is going to add in 'add_boot_module' clashes with a /memreserve/
> range.
>
> When Xen populate the data structure that tracks the memory ranges,
> it also adds a memory type described in 'enum membank_type', so
> in order to fix this behavior, allow overlapping with the /memreserve/
> ranges in the 'check_reserved_regions_overlap' function when a flag
> is set.
>
> In order to implement this solution, there is a distinction between
> the 'struct membanks *' handled by meminfo_overlap_check(...) that
> needs to be done, because the static shared memory banks doesn't have
> a usable bank[].type field and so it can't be accessed, hence now
> the 'struct membanks_hdr' have a 'enum region_type type' field in order
> to be able to identify static shared memory banks in meminfo_overlap_check(...).
>
> While there, set a type for the memory recorded using meminfo_add_bank()
> from efi-boot.h.
>
> Fixes: 53dc37829c31 ("xen/arm: Add DT reserve map regions to bootinfo.reserved_mem")
> Reported-by: Shawn Anastasio <sanastasio@raptorengineering.com>
> Reported-by: Grygorii Strashko <grygorii_strashko@epam.com>
> Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
I will give a few days for the others to review and Shawn to comment
whether it fixes his issue (I can't remember if it was already done).
Cheers,
--
Julien Grall
On 14.11.24 12:28, Luca Fancellu wrote:
> There are some cases where the device tree exposes a memory range
> in both /memreserve/ and reserved-memory node, in this case the
> current code will stop Xen to boot since it will find that the
> latter range is clashing with the already recorded /memreserve/
> ranges.
>
> Furthermore, u-boot lists boot modules ranges, such as ramdisk,
> in the /memreserve/ part and even in this case this will prevent
> Xen to boot since it will see that the module memory range that
> it is going to add in 'add_boot_module' clashes with a /memreserve/
> range.
>
> When Xen populate the data structure that tracks the memory ranges,
> it also adds a memory type described in 'enum membank_type', so
> in order to fix this behavior, allow overlapping with the /memreserve/
> ranges in the 'check_reserved_regions_overlap' function when a flag
> is set.
>
> In order to implement this solution, there is a distinction between
> the 'struct membanks *' handled by meminfo_overlap_check(...) that
> needs to be done, because the static shared memory banks doesn't have
> a usable bank[].type field and so it can't be accessed, hence now
> the 'struct membanks_hdr' have a 'enum region_type type' field in order
> to be able to identify static shared memory banks in meminfo_overlap_check(...).
>
> While there, set a type for the memory recorded using meminfo_add_bank()
> from efi-boot.h.
>
> Fixes: 53dc37829c31 ("xen/arm: Add DT reserve map regions to bootinfo.reserved_mem")
> Reported-by: Shawn Anastasio <sanastasio@raptorengineering.com>
> Reported-by: Grygorii Strashko <grygorii_strashko@epam.com>
> Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
> ---
> Changes from v1:
> - fixed commit message
> - used boolean to allow /memreserve/ overlap or not
> - now 'struct membanks *' have a type, while it might seem a waste of space,
> it might be used in the future to consolidate also the 'struct bootmodules'
> and 'struct bootcmdlines' to use the same 'struct membanks *' interface.
> Also the added space is limited to 3/4 enum size.
> - The change above allowed this version to remove the "hack" when dealing with
> static shared memory banks, that doesn't have a type.
>
> I tested this patch adding the same range in a /memreserve/ entry and
> /reserved-memory node, and by letting u-boot pass a ramdisk.
> I've also tested that a configuration running static shared memory still works
> fine.
> ---
> ---
> xen/arch/arm/efi/efi-boot.h | 3 ++-
> xen/arch/arm/static-shmem.c | 2 +-
> xen/common/device-tree/bootfdt.c | 9 ++++++-
> xen/common/device-tree/bootinfo.c | 39 +++++++++++++++++++++++--------
> xen/include/xen/bootfdt.h | 20 +++++++++++++---
> 5 files changed, 57 insertions(+), 16 deletions(-)
>
[...]
Dom0 started successfully with Initrd.
Tested-by: Grygorii Strashko <grygorii_strashko@epam.com>
Meminfo from boot log is below:
(XEN) Checking for initrd in /chosen
(XEN) Initrd 0000000084000040-0000000087bc5831
(XEN) RAM: 0000000048000000 - 00000000bfffffff
(XEN) RAM: 0000000480000000 - 00000004ffffffff
(XEN) RAM: 0000000600000000 - 00000006ffffffff
(XEN)
(XEN) MODULE[0]: 0000000048080000 - 00000000481ec000 Xen
(XEN) MODULE[1]: 0000000048000000 - 000000004801e080 Device Tree
(XEN) MODULE[2]: 0000000084000040 - 0000000087bc5831 Ramdisk
(XEN) MODULE[3]: 0000000048300000 - 000000004a300000 Kernel
(XEN) MODULE[4]: 0000000048070000 - 0000000048080000 XSM
(XEN) RESVD[0]: 0000000084000040 - 0000000087bc5830
(XEN) RESVD[1]: 0000000060000000 - 000000007fffffff
(XEN) RESVD[2]: 00000000b0000000 - 00000000bfffffff
(XEN) RESVD[3]: 00000000a0000000 - 00000000afffffff
Thank you,
-grygorii
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