If we go through the "need a bigger buffer" path in seq_read_iter(), which
is likely to happen as we're dumping page tables, we will pass the
populated-by-last-run st::parser_state to
kvm_pgtable_walk()/kvm_ptdump_visitor(). As a result, the output of
stage2_page_tables on my box looks like
0x0000000240000000-0x0000000000000000 17179869175G 1
0x0000000000000000-0x0000000000200000 2M 2 R px ux AF BLK
0x0000000000200000-0x0000000040000000 1022M 2
0x0000000040000000-0x0000000040200000 2M 2 R W PXNUXN AF BLK
[...]
Fix it by always initializing st::parser_state before starting a new
pgtable walk.
Besides, remove st::range as it's not used by note_page(); remove the
explicit initialization of parser_state::start_address as it will be
initialized in note_page() anyway.
Signed-off-by: Zenghui Yu (Huawei) <zenghui.yu@linux.dev>
Link: https://patch.msgid.link/20260328053155.12219-1-zenghui.yu@linux.dev
[maz: rebased on top of NV support]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Exposing shadow page tables in debugfs improves the debugability and
testability of NV. With this patch a new directory "nested" is created
for each VM created if the host is NV capable. Within the directory each
valid s2 mmu will have its shadow page table exposed as a readable file
with the file name formatted as 0x<vttbr>-0x<vtcr>-s2-{en,dis}abled. The
creation and removal of the files happen at the points when an s2 mmu
becomes valid, or the context it represents change. In the future the
"nested" directory can also hold other NV related information.
This is gated behind CONFIG_PTDUMP_STAGE2_DEBUGFS.
Suggested-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Sebastian Ene <sebastianene@google.com>
Signed-off-by: Wei-Lin Chang <weilin.chang@arm.com>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://patch.msgid.link/20260317182638.1592507-3-weilin.chang@arm.com
[maz: minor refactor, full 16 chars addresses]
Signed-off-by: Marc Zyngier <maz@kernel.org>
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:
Single allocations: kmalloc(sizeof(TYPE), ...)
are replaced with: kmalloc_obj(TYPE, ...)
Array allocations: kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with: kmalloc_objs(TYPE, COUNT, ...)
Flex array allocations: kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with: kmalloc_flex(*PTR, FAM, COUNT, ...)
(where TYPE may also be *VAR)
The resulting allocations no longer return "void *", instead returning
"TYPE *".
Signed-off-by: Kees Cook <kees@kernel.org>
Although KVM doesn't make direct use of the feature, guest hypervisors
can use FEAT_XNX which influences the permissions of the shadow stage-2.
Update ptdump to separately print the privileged and unprivileged
execute permissions.
Reviewed-by: Marc Zyngier <maz@kernel.org>
Tested-by: Marc Zyngier <maz@kernel.org>
Link: https://msgid.link/20251124190158.177318-5-oupton@kernel.org
Signed-off-by: Oliver Upton <oupton@kernel.org>
The attribute masks and test values in the ptdump code are meant for
individual attributes, however for stage-2 ptdump we included PTE_VALID
while testing for R, W, X, and AF. This led to some confusion and the
flipped output for the executable attribute.
Remove PTE_VALID from all attribute masks and values so that each test
matches only the relevant bits.
Additionally, the executable attribute printing is updated to align with
stage-1 ptdump, printing "NX" for non-executable regions and "x " for
executable ones.
Suggested-by: Anshuman Khandual <anshuman.khandual@arm.com>
Suggested-by: Mark Rutland <mark.rutland@arm.com>
Suggested-by: Sebastian Ene <sebastianene@google.com>
Signed-off-by: Wei-Lin Chang <r09922117@csie.ntu.edu.tw>
Acked-by: Will Deacon <will@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
While arch/*/mem/ptdump handles the kernel pagetable dumping code,
introduce KVM/ptdump to show the guest stage-2 pagetables. The
separation is necessary because most of the definitions from the
stage-2 pagetable reside in the KVM path and we will be invoking
functionality specific to KVM. Introduce the PTDUMP_STAGE2_DEBUGFS config.
When a guest is created, register a new file entry under the guest
debugfs dir which allows userspace to show the contents of the guest
stage-2 pagetables when accessed.
[maz: moved function prototypes from kvm_host.h to kvm_mmu.h]
Signed-off-by: Sebastian Ene <sebastianene@google.com>
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Link: https://lore.kernel.org/r/20240909124721.1672199-6-sebastianene@google.com
Signed-off-by: Marc Zyngier <maz@kernel.org>
