SUPPORT.md doesn't seem to explicitly say whether static memory is
supported, so this commit updates SUPPORT.md to add feature static
allocation tech preview for now.
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Helper allocate_static_memory is not meant to be reachable when built with
!CONFIG_STATIC_MEMORY, so this commit adds ASSERT_UNREACHABLE in it to catch
potential misuse.
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Tested-by: Stefano Stabellini <sstabellini@kernel.org>
Cases where domU needs direct-map memory map:
* IOMMU not present in the system.
* IOMMU disabled if it doesn't cover a specific device and all the guests
are trusted. Thinking a mixed scenario, where a few devices with IOMMU and
a few without, then guest DMA security still could not be totally guaranteed.
So users may want to disable the IOMMU, to at least gain some performance
improvement from IOMMU disabled.
* IOMMU disabled as a workaround when it doesn't have enough bandwidth.
To be specific, in a few extreme situation, when multiple devices do DMA
concurrently, these requests may exceed IOMMU's transmission capacity.
* IOMMU disabled when it adds too much latency on DMA. For example,
TLB may be missing in some IOMMU hardware, which may bring latency in DMA
progress, so users may want to disable it in some realtime scenario.
* Guest OS relies on the host memory layout
This commit introduces a new helper assign_static_memory_11 to allocate
static memory as guest RAM for direct-map domain.
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Tested-by: Stefano Stabellini <sstabellini@kernel.org>
Later, we will introduce assign_static_memory_11 for allocating static
memory for direct-map domains, and it will share a lot common codes with
the existing allocate_static_memory.
In order not to bring a lot of duplicate codes, and also to make the whole
code more readable, this commit extracts common codes into two new helpers
parse_static_mem_prop and acquire_static_memory_bank.
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Tested-by: Stefano Stabellini <sstabellini@kernel.org>
Commit 540a637c34 defines a new
helper mark_page_free to extract common codes, while it accidently
breaks the local variable "tainted".
This patch fix it by letting mark_page_free() return bool of whether the
page is offlined and rename local variable "tainted" to "pg_offlined".
Coverity ID: 1491872
Fixes: 540a637c34 ("xen: introduce mark_page_free")
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
This commit introduces a new function allocate_static_memory to allocate
static memory as guest RAM for domains on Static Allocation.
It uses acquire_domstatic_pages to acquire pre-configured static memory
for the domain, and uses guest_physmap_add_pages to set up the P2M table.
These pre-defined static memory banks shall be mapped to the usual guest
memory addresses (GUEST_RAM0_BASE, GUEST_RAM1_BASE) defined by
xen/include/public/arch-arm.h.
In order to deal with the trouble of count-to-order conversion when page number
is not in a power-of-two, this commit exports p2m_insert_mapping and introduce
a new function guest_physmap_add_pages to cope with adding guest RAM p2m
mapping with nr_pages.
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
New function acquire_staticmem_pages aims to acquire nr_mfns contiguous pages
of static memory, starting at #smfn. And it is the equivalent of
alloc_heap_pages for static memory.
For each page, it shall check if the page is reserved(PGC_reserved)
and free. It shall also do a set of necessary initialization, which are
mostly the same ones in alloc_heap_pages, like, following the same
cache-coherency policy and turning page status into PGC_state_inuse, etc.
New function acquire_domstatic_pages is the equivalent of alloc_domheap_pages
for static memory, and it is to acquire nr_mfns contiguous pages of
static memory and assign them to one specific domain.
It uses acquire_staticmem_pages to acquire nr_mfns pages of static memory.
Then on success, it will use assign_pages to assign those pages to one
specific domain.
In order to differentiate pages of static memory from those allocated from
heap, this patch introduces a new page flag PGC_reserved, then mark pages of
static memory PGC_reserved when initializing them.
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
In order to deal with the trouble of count-to-order conversion when page number
is not in a power-of-two, this commit re-define assign_pages for nr pages and
assign_page for original page with a single order.
Backporting confusion could be helped by altering the order of assign_pages
parameters, such that the compiler would point out that adjustments at call
sites are needed.
[stefano: switch to unsigned int for nr]
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
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 a new CONFIG_STATIC_MEMORY option to wrap all
static-allocation-related code.
Put asynchronously scrubbing pages of static memory in TODO list.
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
This commit defines a new helper mark_page_free to extract common code,
like following the same cache/TLB coherency policy, between free_heap_pages
and the new function free_staticmem_pages, which will be introduced later.
The PDX compression makes that conversion between the MFN and the page can
be potentially non-trivial. As the function is internal, pass the MFN and
the page. They are both expected to match.
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
Static Allocation refers to system or sub-system(domains) for which memory
areas are pre-defined by configuration using physical address ranges.
Those pre-defined memory, -- Static Memory, as parts of RAM reserved in the
beginning, shall never go to heap allocator or boot allocator for any use.
Memory can be statically allocated to a domain using the property "xen,static-
mem" defined in the domain configuration. The number of cells for the address
and the size must be defined using respectively the properties
"#xen,static-mem-address-cells" and "#xen,static-mem-size-cells".
The property 'memory' is still needed and should match the amount of memory
given to the guest. Currently, it either comes from static memory or lets Xen
allocate from heap. *Mixing* is not supported.
The static memory will be mapped in the guest at the usual guest memory
addresses (GUEST_RAM0_BASE, GUEST_RAM1_BASE) defined by
xen/include/public/arch-arm.h.
This patch introduces this new `xen,static-mem` feature, and also documents
and parses this new attribute at boot time.
This patch also introduces a new field "bool xen_domain" in "struct membank"
to tell whether the memory bank is reserved as the whole hardware resource,
or bind to a xen domain node, through "xen,static-mem"
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
This commit creates a new helper device_tree_get_meminfo to iterate over a
device tree property to get memory info, like "reg".
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
CNTVCT_EL0 or CNTPCT_EL0 counter read in Cortex-A73 (all versions)
might return a wrong value when the counter crosses a 32bit boundary.
Until now, there is no case for Xen itself to access CNTVCT_EL0,
and it also should be the Guest OS's responsibility to deal with
this part.
But for CNTPCT, there exists several cases in Xen involving reading
CNTPCT, so a possible workaround is that performing the read twice,
and to return one or the other depending on whether a transition has
taken place.
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Wei Chen <Wei.Chen@arm.com>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Penny Zheng