Hi Penny,
On 28/07/2021 11:27, Penny Zheng wrote:
This patch introduces static memory initialization, during system boot up.
The new function init_staticmem_pages is responsible for static memory
initialization.
Helper free_staticmem_pages is the equivalent of free_heap_pages, to free
nr_mfns pages of static memory.
This commit also introduces new CONFIG_STATIC_MEMORY to avoid bringing dead
codes in other archs.
Put asynchronous scrubbing for pages of static memory in TODO list.
Signed-off-by: Penny Zheng <penny.zh...@arm.com>
---
v4 change:
- move the option CONFIG_STATIC_MEMORY to common code, and with Arm
"select"ing it
- replace round_pg{down,up}() with PFN_DOWN()/PFN_UP()
---
xen/arch/arm/Kconfig | 1 +
xen/arch/arm/setup.c | 24 ++++++++++++++++++++++++
xen/common/Kconfig | 3 +++
xen/common/page_alloc.c | 20 ++++++++++++++++++++
xen/include/xen/mm.h | 6 ++++++
5 files changed, 54 insertions(+)
diff --git a/xen/arch/arm/Kconfig b/xen/arch/arm/Kconfig
index ecfa6822e4..cc7a943d27 100644
--- a/xen/arch/arm/Kconfig
+++ b/xen/arch/arm/Kconfig
@@ -15,6 +15,7 @@ config ARM
select HAS_PASSTHROUGH
select HAS_PDX
select IOMMU_FORCE_PT_SHARE
+ select STATIC_MEMORY
Given the list of TODOs, I think it would be better if STATIC_MEMORY is
user selectable and gated by UNSUPPORTED.
We can remove the dependency on UNSUPPORTED once every have been addressed.
config ARCH_DEFCONFIG
string
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index f569134317..369f6631ee 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -622,6 +622,26 @@ static void __init init_pdx(void)
}
}
+/* Static memory initialization */
+static void __init init_staticmem_pages(void)
+{
+ unsigned int bank;
+
+ /* TODO: Considering NUMA-support scenario. */
+ for ( bank = 0 ; bank < bootinfo.static_mem.nr_banks; bank++ )
+ {
+ unsigned long bank_start =
PFN_UP(bootinfo.static_mem.bank[bank].start);
I would prefer if bank_start is a mfn_t.
+ unsigned long bank_size =
PFN_DOWN(bootinfo.static_mem.bank[bank].size);
NIT: I would suggest to name it bank_pages or bank_nr_pages. This would
make clear in the user that this contains pages.
+ unsigned long bank_end = bank_start + bank_size;
mfn_t please.
+
+ if ( bank_end <= bank_start )
This will mean you will need to use mfn_x() for both. This code would be
less nice but at least it avoids mixing address and MFN.
+ return;
+
+ free_staticmem_pages(mfn_to_page(_mfn(bank_start)),
+ bank_size, false);
+ }
+}
+
#ifdef CONFIG_ARM_32
static void __init setup_mm(void)
{
@@ -749,6 +769,8 @@ static void __init setup_mm(void)
/* Add xenheap memory that was not already added to the boot allocator. */
init_xenheap_pages(mfn_to_maddr(xenheap_mfn_start),
mfn_to_maddr(xenheap_mfn_end));
+
+ init_staticmem_pages();
}
#else /* CONFIG_ARM_64 */
static void __init setup_mm(void)
@@ -802,6 +824,8 @@ static void __init setup_mm(void)
setup_frametable_mappings(ram_start, ram_end);
max_page = PFN_DOWN(ram_end);
+
+ init_staticmem_pages();
}
#endif
diff --git a/xen/common/Kconfig b/xen/common/Kconfig
index 0ddd18e11a..8f736eea82 100644
--- a/xen/common/Kconfig
+++ b/xen/common/Kconfig
@@ -67,6 +67,9 @@ config MEM_ACCESS
config NEEDS_LIBELF
bool
+config STATIC_MEMORY
+ bool
+
menu "Speculative hardening"
config SPECULATIVE_HARDEN_ARRAY
diff --git a/xen/common/page_alloc.c b/xen/common/page_alloc.c
index a3ee5eca9e..2acb73e323 100644
--- a/xen/common/page_alloc.c
+++ b/xen/common/page_alloc.c
@@ -1519,6 +1519,26 @@ static void free_heap_pages(
spin_unlock(&heap_lock);
}
+#ifdef CONFIG_STATIC_MEMORY
+/* Equivalent of free_heap_pages to free nr_mfns pages of static memory. */
+void __init free_staticmem_pages(struct page_info *pg, unsigned long nr_mfns,
+ bool need_scrub)
+{
+ mfn_t mfn = page_to_mfn(pg);
+ unsigned long i;
+
+ for ( i = 0; i < nr_mfns; i++ )
+ {
+ mark_page_free(&pg[i], mfn_add(mfn, i));
+
+ if ( need_scrub )
+ {
+ /* TODO: asynchronous scrubbing for pages of static memory. */
+ scrub_one_page(pg);
+ }
+ }
+}
+#endif
/*
* Following rules applied for page offline:
diff --git a/xen/include/xen/mm.h b/xen/include/xen/mm.h
index 667f9dac83..8e8fb5a615 100644
--- a/xen/include/xen/mm.h
+++ b/xen/include/xen/mm.h
@@ -85,6 +85,12 @@ bool scrub_free_pages(void);
} while ( false )
#define FREE_XENHEAP_PAGE(p) FREE_XENHEAP_PAGES(p, 0)
+#ifdef CONFIG_STATIC_MEMORY
+/* These functions are for static memory */
+void free_staticmem_pages(struct page_info *pg, unsigned long nr_mfns,
+ bool need_scrub);
+#endif
+
/* Map machine page range in Xen virtual address space. */
int map_pages_to_xen(
unsigned long virt,
Cheers,
--
Julien Grall
