Commit Graph
52 Commits
Author SHA1 Message Date
Penny Zheng a5aa6a7379 arm/mpu: implement setup_virt_paging for MPU systems
Implement setup_virt_paging for AArch64 MPU systems, taking care of
stage 2 address translation regime, IPA bits, supported VMID length
configuration and VTCR_EL2/VSTCR_EL2 register programming.

Implement also the Armv8-R specific changes to ID_AA64MMFR0_EL1,
related to the supported memory system architecture (PMSA/VMSA)
and check that when MPU is built, the underlying HW is compatible
with PMSA. By default MPU at EL2 and EL1 is required.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Signed-off-by: Hari Limaye <hari.limaye@arm.com>
Signed-off-by: Harry Ramsey <harry.ramsey@arm.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2026-05-15 09:08:19 +02:00
Penny Zheng 4b3cad91a1 arm/mpu: Map domain page in MPU systems
In MPU systems, we implement map_domain_page()/unmap_domain_page()
through mapping the domain page with a MPU region on demand.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Signed-off-by: Harry Ramsey <harry.ramsey@arm.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2026-01-16 09:38:30 +01:00
Penny Zheng e232aa054c arm: Use secure hypervisor timer in MPU system
As MPU systems only have one secure state, we have to use secure EL2
hypervisor timer for Xen in secure EL2.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Signed-off-by: Harry Ramsey <harry.ramsey@arm.com>
Reviewed-by: Ayan Kumar Halder <ayan.kumar.halder@amd.com>
Acked-by: Michal Orzel <michal.orzel@amd.com>
2026-01-16 09:38:30 +01:00
Penny Zheng 342ac31d1f arm/mpu: Implement free_init_memory for MPU systems
Implement the function `free_init_memory` for MPU systems. In order to
support this, the function `modify_xen_mappings` is implemented.

On MPU systems, we map the init text and init data sections using
separate MPU memory regions. Therefore these are removed separately in
`free_init_memory`.

Additionally remove warning messages from `is_mm_attr_match` as some
attributes can now be updated by `xen_mpumap_update_entry`.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Signed-off-by: Hari Limaye <hari.limaye@arm.com>
Signed-off-by: Harry Ramsey <harry.ramsey@arm.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2026-01-16 09:38:30 +01:00
Penny Zheng 8181956698 arm/mpu: Destroy an existing entry in Xen MPU memory mapping table
This commit expands xen_mpumap_update/xen_mpumap_update_entry to include
destroying an existing entry.

We define a new helper "disable_mpu_region_from_index" to disable the MPU
region based on index. If region is within [0, 31], we could quickly
disable the MPU region through PRENR_EL2 which provides direct access to the
PRLAR_EL2.EN bits of EL2 MPU regions.

Rignt now, we only support destroying a *WHOLE* MPU memory region,
part-region removing is not supported, as in worst case, it will
leave two fragments behind.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Signed-off-by: Hari Limaye <hari.limaye@arm.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2025-07-23 09:51:50 +02:00
Penny Zheng 37671e52cf arm/mpu: Populate a new region in Xen MPU mapping table
Introduce map_pages_to_xen() that is implemented using a new helper,
xen_mpumap_update(), which is responsible for updating Xen MPU memory
mapping table(xen_mpumap), including creating a new entry, updating
or destroying an existing one, it is equivalent to xen_pt_update in MMU.

This commit only implements populating a new entry in Xen MPU memory mapping
table(xen_mpumap).

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Signed-off-by: Hari Limaye <hari.limaye@arm.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2025-07-23 09:50:43 +02:00
Penny Zheng e67914d91b arm/mpu: Introduce MPU memory region map structure
Introduce pr_t typedef which is a structure having the prbar
and prlar members, each being structured as the registers of
the AArch64 Armv8-R architecture.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2025-05-30 08:44:15 +02:00
Penny Zheng 2705f1adb9 xen: introduce Kconfig ARCH_PAGING_MEMPOOL
ARM MPU system doesn't need to use paging memory pool, as MPU memory
mapping table at most takes only one 4KB page, which is enough to
manage the maximum 255 MPU memory regions, for all EL2 stage 1
translation and EL1 stage 2 translation.

Introduce ARCH_PAGING_MEMPOOL Kconfig common symbol, selected for Arm
MMU systems and x86. Removed stubs from RISC-V now that the common code
provide them and the functions are not gonna be used.

Wrap the code inside 'construct_domU' that deal with p2m paging
allocation in a new function 'domain_p2m_set_allocation', protected
by ARCH_PAGING_MEMPOOL, this is done in this way to prevent polluting
the former function with #ifdefs and improve readability

Introduce arch_{get,set}_paging_mempool_size stubs for architecture
with !ARCH_PAGING_MEMPOOL.

Remove 'struct paging_domain' from Arm 'struct arch_domain' when the
field is not required.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com> # arm
Reviewed-by: Oleksii Kurochko <oleksii.kurochko@gmail.com> # riscv
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Jan Beulich <jbeulich@suse.com>
2025-04-02 11:15:10 +02:00
Penny Zheng 8523954fc5 xen/arm: Implement virt/maddr conversion in MPU system
virt_to_maddr and maddr_to_virt are used widely in Xen code. So
even there is no VMSA in MPU system, we keep the interface in MPU to
to avoid changing the existing common code.

In order to do that, move the virt_to_maddr() and maddr_to_virt()
definitions to mmu/mm.h, move the include of memory management
subsystems (MMU/MPU) on a different place because the mentioned
helpers needs visibility of some macro in asm/mm.h.

Finally implement virt_to_maddr() and maddr_to_virt() for MPU systems
under mpu/mm.h, the MPU version of virt/maddr conversion is simple since
VA==PA.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2025-04-02 11:15:10 +02:00
Penny Zheng 4cde11cdae xen/arm: Check for Static Heap feature when freeing resources
If the Xen heap is statically configured in Device Tree, its size is
definite, so only the defined memory shall be given to the boot
allocator. Have a check where init_domheap_pages() is called
which takes into account if static heap feature is used.

Extract static_heap flag from init data bootinfo, as it will be needed
after destroying the init data section, rename it to using_static_heap
and use it to tell whether the Xen static heap feature is enabled.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2024-12-17 09:58:47 +01:00
Penny Zheng d39a92aefe xen/mmu: enable SMMU subsystem only in MMU
In Xen, SMMU subsystem is supported for MMU system only. The reason being SMMU
driver uses the same page tables as MMU.
Thus, we make it dependent on CONFIG_MMU.

Signed-off-by: Penny Zheng <Penny.Zheng@arm.com>
Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@amd.com>
Acked-by: Julien Grall <jgrall@amazon.com>
2024-12-06 19:06:27 +00:00
Penny Zheng 82b8aa7680 xen: make VMAP support in MMU system only
Introduce CONFIG_HAS_VMAP which is selected by the architectures that
use MMU. vm_init() does not do anything if CONFIG_HAS_VMAP is not
enabled.

HAS_VMAP is widely used in ALTERNATIVE feature to remap a range of
memory with new memory attributes. Since this is highly dependent on
virtual address translation, we choose to make HAS_VMAP selected by
MMU. And ALTERNATIVE depends on HAS_VMAP.

At the moment, the users of HARDEN_BRANCH_PREDICTOR requires to use the
vmap() to update the exceptions vectors. While it might be possible to
rework the code, it is believed that speculative attackes would be
difficult to exploit on non-MMU because the software is tightly
controlled. So for now make HARDEN_BRANCH_PREDICTOR to depend on the
MMU.

Also took the opportunity to remove "#ifdef VMAP_VIRT_START .. endif"
from vmap.c. Instead vmap.c is compiled when HAS_VMAP is enabled. Thus,
HAS_VMAP is now enabled from x86, ppc and riscv architectures as all of
them use MMU and has VMAP_VIRT_START defined.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Ayan Kumar Halder <ayan.kumar.halder@amd.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2024-09-03 19:40:20 -07:00
Penny Zheng 8b4243a9b5 xen/docs: Describe static shared memory when host address is not provided
This commit describe the new scenario where host address is not provided
in "xen,shared-mem" property and a new example is added to the page to
explain in details.

Take the occasion to fix some typos in the page.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2024-06-14 10:46:01 +01:00
Penny Zheng 3e2121ce47 xen/p2m: put reference for level 2 superpage
We are doing foreign memory mapping for static shared memory, and
there is a great possibility that it could be super mapped.
But today, p2m_put_l3_page could not handle superpages.

This commits implements a new function p2m_put_l2_superpage to handle
level 2 superpages, specifically for helping put extra references for
foreign superpages.

Modify relinquish_p2m_mapping as well to take into account preemption
when we have a level-2 foreign mapping.

Currently level 1 superpages are not handled because Xen is not
preemptible and therefore some work is needed to handle such superpages,
for which at some point Xen might end up freeing memory and therefore
for such a big mapping it could end up in a very long operation.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
2024-06-14 10:45:55 +01:00
Penny Zheng 51a2b3f109 xen/arm: fix duplicate /reserved-memory node in Dom0
In case there is a /reserved-memory node already present in the host
dtb, current Xen codes would create yet another /reserved-memory node
when the static shared memory feature is enabled and static shared
memory regions are present.
This would result in an incorrect device tree generation and hwdom
would not be able to detect the static shared memory region.

Avoid this issue by checking the presence of the /reserved-memory
node and appending the nodes instead of generating a duplicate
/reserved-memory.

Make make_shm_memory_node externally visible and rename it to
make_shm_resv_memory_node to make clear it produces childs for
/reserved-memory.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2024-04-24 19:13:35 +01:00
Penny Zheng a0fee882c1 xen/arm: remove shm holes from extended regions
Static shared memory acts as reserved memory in guest, so it shall be
excluded from extended regions.

Extended regions are taken care of under three different scenarios:
normal DomU, direct-map domain with iommu on, and direct-map domain
with iommu off.

For normal DomU, we create a new function "remove_shm_holes_for_domU",
to firstly transfer original outputs into the format of
"struct rangeset", then use "remove_shm_from_rangeset" to remove static
shm from them.

For direct-map domain with iommu on, after we get guest shm info from "kinfo",
we use "remove_shm_from_rangeset" to remove static shm.

For direct-map domain with iommu off, as static shm has already been taken
care of through find_unallocated_memory, we do nothing.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2024-04-24 19:13:35 +01:00
Penny Zheng 6d14a742f8 xen/arm: avoid repetitive checking in process_shm_node
Putting overlap and overflow checking in the loop is causing repetitive
operation, so this commit extracts both checking outside the loop.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2024-04-24 19:13:35 +01:00
Penny Zheng ab327c8e8b xen/arm: remove stale addr_cells/size_cells in assign_shared_memory
Function parameters {addr_cells,size_cells} are stale parameters in
assign_shared_memory, so we shall remove them.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Luca Fancellu <luca.fancellu@arm.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
2024-04-24 19:13:35 +01:00
Penny Zheng ee0f41fda3 xen/arm: mmu: move MMU specific P2M code to mmu/p2m.{c,h}
Current P2M implementation is designed for MMU system only.
We move the MMU-specific codes into mmu/p2m.c, and only keep generic
codes in p2m.c, like VMID allocator, etc. We also move MMU-specific
definitions and declarations to mmu/p2m.h, such as p2m_tlb_flush_sync().
Also expose previously static functions p2m_vmid_allocator_init(),
p2m_alloc_vmid() for further MPU usage. Since with the code movement
p2m_free_vmid() is now used in two files, also expose p2m_free_vmid().

With the code movement, global variable max_vmid is used in multiple
files instead of a single file (and will be used in MPU P2M
implementation), declare it in the header and remove the "static" of
this variable.

Also, since p2m_invalidate_root() should be MMU only and after the
code movement the only caller of p2m_invalidate_root() outside of
mmu/p2m.c is arch_domain_creation_finished(), creating a new function
named p2m_domain_creation_finished() in mmu/p2m.c for the original
code in arch_domain_creation_finished(), and marking
p2m_invalidate_root() as static.

Take the opportunity to fix the incorrect coding style when possible.
When there is bit shift in macros, take the opportunity to add the
missing 'U' as a compliance of MISRA.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Wei Chen <wei.chen@arm.com>
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
Acked-by: Julien Grall <jgrall@amazon.com>
2023-11-20 19:07:45 +00:00
Penny Zheng 1bf5c104fe xen/arm: Rename init_secondary_pagetables() to prepare_secondary_mm()
init_secondary_pagetables() is a function in the common code path
of both MMU and future MPU support. Since "page table" is a MMU
specific concept, rename init_secondary_pagetables() to a generic
name prepare_secondary_mm() as the preparation for MPU support.

Reword the in-code comment on top of prepare_secondary_mm() because
this function is now supposed to be MMU/MPU agnostic.

Take the opportunity to fix the incorrect coding style of the in-code
comments.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Signed-off-by: Henry Wang <Henry.Wang@arm.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
2023-11-20 19:07:45 +00:00
Penny Zheng 826956157d xen: Add static memory sharing in SUPPORT.md
on ARM, static memory sharing is tech preview, which shall be documented
in SUPPORT.md

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Michal Orzel <michal.orzel@amd.com>
Acked-by: Julien Grall <jgrall@amazon.com>
2022-09-09 13:00:10 -07:00
Penny Zheng 09c0a8976a xen/arm: enable statically shared memory on Dom0
To add statically shared memory nodes in Dom0, user shall put according
static shared memory configuration under /chosen node.

This commit adds shm-processing function process_shm in construct_dom0
to enable statically shared memory on Dom0.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2022-09-09 13:00:10 -07:00
Penny Zheng c7fe72607a xen/arm: create shared memory nodes in guest device tree
We expose the shared memory to the domU using the "xen,shared-memory-v1"
reserved-memory binding. See
Documentation/devicetree/bindings/reserved-memory/xen,shared-memory.txt
in Linux for the corresponding device tree binding.

To save the cost of re-parsing shared memory device tree configuration when
creating shared memory nodes in guest device tree, this commit adds new field
"shm_mem" to store shm-info per domain.

For each shared memory region, a range is exposed under
the /reserved-memory node as a child node. Each range sub-node is
named xen-shmem@<address> and has the following properties:
- compatible:
        compatible = "xen,shared-memory-v1"
- reg:
        the base guest physical address and size of the shared memory region
- xen,id:
        a string that identifies the shared memory region.
- xen,offset: (borrower VMs only)
        64 bit integer offset within the owner virtual machine's shared
        memory region used for the mapping in the borrower VM.
Currently, we provide "xen,offset=<0x0>" as a temporary placeholder.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Bertrand Marquis <bertrand.marquis@arm.com>
[stefano: fix code style, add return -EOPNOTSUPP;]
Signed-off-by: Stefano Stabellini <stefano.stabellini@amd.com>
2022-09-09 12:59:10 -07:00
Penny Zheng b7133c10a3 xen/arm: set up shared memory foreign mapping for borrower domain
This commit sets up shared memory foreign mapping for borrower domain.

If owner domain is the default dom_io, all shared domain are treated as
borrower domain.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2022-09-09 12:58:00 -07:00
Penny Zheng 041957bad3 xen/arm: Add additional reference to owner domain when the owner is allocated
Borrower domain will fail to get a page ref using the owner domain
during allocation, when the owner is created after borrower.

So here, we decide to get and add the right amount of reference, which
is the number of borrowers, when the owner is allocated.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Acked-by: Julien Grall <jgrall@amazon.com>
2022-09-09 12:58:00 -07:00
Penny Zheng 5951b856d8 xen/arm: introduce put_page_nr and get_page_nr
Later, we need to add the right amount of references, which should be
the number of borrower domains, to the owner domain. Since we only have
get_page() to increment the page reference by 1, a loop is needed per
page, which is inefficient and time-consuming.

To save the loop time, this commit introduces a set of new helpers
put_page_nr() and get_page_nr() to increment/drop the page reference by nr.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Reviewed-by: Julien Grall <jgrall@amazon.com>
2022-09-09 12:57:59 -07:00
Penny Zheng 83d55ba817 xen/arm: allocate static shared memory to a specific owner domain
If owner property is defined, then owner domain of a static shared memory
region is not the default dom_io anymore, but a specific domain.

This commit implements allocating static shared memory to a specific domain
when owner property is defined.

Coding flow for dealing borrower domain will be introduced later in the
following commits.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2022-09-09 12:57:58 -07:00
Penny Zheng 5597f32f40 xen/arm: assign static shared memory to the default owner dom_io
This commit introduces process_shm to cope with static shared memory in
domain construction.

DOMID_IO will be the default owner of memory pre-shared among multiple domains
at boot time, when no explicit owner is specified.
And DOMID_IO is a fake domain and is not described in the Device-Tree.
Therefore When the owner of the shared region is DOMID_IO, we will only
find the borrowers when parsing the Device-Tree.
When we found the first borrower of the region, we need to assign the region to
DOMID_IO

This commit only considers allocating static shared memory to dom_io
when owner domain is not explicitly defined in device tree, all the left,
including the "borrower" code path, the "explicit owner" code path, shall
be introduced later in the following patches.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
2022-09-09 12:57:58 -07:00
Penny Zheng 1d98281adf xen/arm: introduce static shared memory
This patch series introduces a new feature: setting up static
shared memory on a dom0less system, through device tree configuration.

This commit parses shared memory node at boot-time, and reserve it in
bootinfo.reserved_mem to avoid other use.

This commits proposes a new Kconfig CONFIG_STATIC_SHM to wrap
static-shm-related codes, and this option depends on static memory(
CONFIG_STATIC_MEMORY). That's because that later we want to reuse a few
helpers, guarded with CONFIG_STATIC_MEMORY, like acquire_staticmem_pages, etc,
on static shared memory.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
2022-09-09 12:57:57 -07:00
Penny Zheng 172015009a xen: retrieve reserved pages on populate_physmap
When a static domain populates memory through populate_physmap at runtime,
it shall retrieve reserved pages from resv_page_list to make sure that
domain's RAM is still restricted in statically configured memory regions.
This commit also introduces a new helper acquire_reserved_page to make it work.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
2022-09-06 18:03:07 +01:00
Penny Zheng 142578a506 xen: rename free_staticmem_pages to unprepare_staticmem_pages
The name of free_staticmem_pages is inappropriate, considering it is
the opposite of function prepare_staticmem_pages.

Rename free_staticmem_pages to unprepare_staticmem_pages.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2022-09-06 17:53:35 +01:00
Penny Zheng 508d2d297f xen: introduce prepare_staticmem_pages
Later, we want to use acquire_domstatic_pages() for populating memory
for static domain on runtime, however, there are a lot of pointless work
(checking mfn_valid(), scrubbing the free part, cleaning the cache...)
considering we know the page is valid and belong to the guest.

This commit splits acquire_staticmem_pages() in two parts, and
introduces prepare_staticmem_pages to bypass all "pointless work".

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
2022-09-06 17:53:35 +01:00
Penny Zheng b01721f077 xen: unpopulate memory when domain is static
Today when a domain unpopulates the memory on runtime, they will always
hand the memory back to the heap allocator. And it will be a problem if domain
is static.

Pages as guest RAM for static domain shall be reserved to only this domain
and not be used for any other purposes, so they shall never go back to heap
allocator.

This commit puts reserved page on the new list resv_page_list after
it has been freed.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
2022-09-06 17:53:35 +01:00
Penny Zheng 5ebd3da7c9 xen/arm: introduce CDF_staticmem
In order to have an easy and quick way to find out whether this domain memory
is statically configured, this commit introduces a new flag CDF_staticmem and a
new helper is_domain_using_staticmem() to tell.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Acked-by: Julien Grall <jgrall@amazon.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
2022-09-06 17:53:35 +01:00
Penny Zheng d58b6aef96 xen: do not free reserved memory into heap
Pages used as guest RAM for static domain, shall be reserved to this
domain only.
So in case reserved pages being used for other purpose, users
shall not free them back to heap, even when last ref gets dropped.

This commit introduces a new helper free_domstatic_page to free
static page in runtime, and free_staticmem_pages will be called by it
in runtime, so let's drop the __init flag.

Wrapper #ifdef CONFIG_STATIC_MEMORY around function declaration(
free_staticmem_pages, free_domstatic_page, etc) is kinds of redundant,
so we decide to remove it here.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
2022-09-06 17:53:34 +01:00
Penny Zheng 8ac5bb92f3 xen: add field "flags" to cover all internal CDF_XXX
With more and more CDF_xxx internal flags in and to save the space, this
commit introduces a new field "flags" in struct domain to store CDF_*
internal flags directly.

Another new CDF_xxx will be introduced in the next patch.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Acked-by: Julien Grall <jgrall@amazon.com>
2022-08-24 10:36:20 +01:00
Penny Zheng 7d3f8a2a26 xen: do not merge reserved pages in free_heap_pages()
The code in free_heap_pages() will try to merge pages with the
successor/predecessor if pages are suitably aligned. So if the pages
reserved are right next to the pages given to the heap allocator,
free_heap_pages() will merge them, and give the reserved pages to heap
allocator accidentally as a result.

So in order to avoid the above scenario, this commit updates free_heap_pages()
to check whether the predecessor and/or successor has PGC_static set,
when trying to merge the about-to-be-freed chunk with the predecessor
and/or successor.

Suggested-by: Julien Grall <jgrall@amazon.com>
Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Reviewed-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Julien Grall <jgrall@amazon.com>
2022-08-24 10:36:20 +01:00
Penny Zheng 283abca299 xen/arm: rename PGC_reserved to PGC_static
PGC_reserved could be ambiguous, and we have to tell what the pages are
reserved for, so this commit intends to rename PGC_reserved to
PGC_static, which clearly indicates the page is reserved for static
memory.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
Acked-by: Julien Grall <jgrall@amazon.com>
2022-08-16 11:23:56 +02:00
Penny Zheng f81fcc3919 update SUPPORT.md for static allocation
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>
2022-07-08 09:42:14 +02:00
Penny Zheng ba41731323 xen/arm: gate make_gicv3_domU_node with CONFIG_GICV3
This commit gates function make_gicv3_domU_node with CONFIG_GICV3.

Signed-off-by: Penny Zheng <penny.zheng@arm.com>
Acked-by: Stefano Stabellini <sstabellini@kernel.org>
Tested-by: Stefano Stabellini <sstabellini@kernel.org>
2022-02-17 19:43:02 +00:00
Penny Zheng 489859a336 xen/arm: add ASSERT_UNREACHABLE in allocate_static_memory
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>
2022-02-17 19:43:02 +00:00
Penny Zheng 75591dcfe0 xen/arm: introduce direct-map for domUs
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>
2022-02-17 19:43:02 +00:00
Penny Zheng ba560aa0bd xen/arm: introduce new helper parse_static_mem_prop and acquire_static_memory_bank
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>
2022-02-17 19:43:02 +00:00
Penny Zheng 289610483f mm: fix broken tainted value in mark_page_free
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>
2021-09-22 16:18:30 +02:00
Penny Zheng 487975df53 xen/arm: introduce allocate_static_memory
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>
2021-09-13 14:15:04 -07:00
Penny Zheng c7fe462c0d xen/arm: introduce acquire_staticmem_pages and acquire_domstatic_pages
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>
2021-09-13 14:15:03 -07:00
Penny Zheng 5260e8fb93 xen: re-define assign_pages and introduce a new function assign_page
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>
2021-09-13 14:12:59 -07:00
Penny Zheng 4a9e73e6e5 xen/arm: static memory initialization
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>
2021-09-13 14:10:22 -07:00
Penny Zheng 540a637c34 xen: introduce mark_page_free
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>
2021-09-13 14:10:17 -07:00
Penny Zheng 41c031ff43 xen/arm: introduce domain on Static Allocation
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>
2021-09-13 14:10:14 -07:00
Penny Zheng 904ba3ce2e xen/arm: introduce new helper device_tree_get_meminfo
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>
2021-09-13 14:10:11 -07:00
Penny Zheng 5505f5f8e7 xen/arm: Add Cortex-A73 erratum 858921 workaround
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>
2020-11-11 13:44:33 -08:00