Extend the pKVM page ownership selftests to donate and reclaim a page
to/from a guest.
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-34-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Add some initial documentation for pKVM to help people understand what
is supported, the limitations of protected VMs when compared to
non-protected VMs and also what is left to do.
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-33-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Introduce a new VM type for KVM/arm64 to allow userspace to request the
creation of a "protected VM" when the host has booted with pKVM enabled.
For now, this feature results in a taint on first use as many aspects of
a protected VM are not yet protected!
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-32-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Implement the ARM_SMCCC_KVM_FUNC_MEM_UNSHARE hypercall to allow
protected VMs to unshare memory that was previously shared with the host
using the ARM_SMCCC_KVM_FUNC_MEM_SHARE hypercall.
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-31-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Implement the ARM_SMCCC_KVM_FUNC_MEM_SHARE hypercall to allow protected
VMs to share memory (e.g. the swiotlb bounce buffers) back to the host.
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-30-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Add a hypercall handler at EL2 for hypercalls originating from protected
VMs. For now, this implements only the FEATURES and MEMINFO calls, but
subsequent patches will implement the SHARE and UNSHARE functions
necessary for virtio.
Unhandled hypercalls (including PSCI) are passed back to the host.
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-29-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
If a protected vCPU faults on an IPA which appears to be mapped, query
the hypervisor to determine whether or not the faulting pte has been
poisoned by a forceful reclaim. If the pte has been poisoned, return
-EFAULT back to userspace rather than retrying the instruction forever.
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-28-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Host kernel accesses to pages that are inaccessible at stage-2 result in
the injection of a translation fault, which is fatal unless an exception
table fixup is registered for the faulting PC (e.g. for user access
routines). This is undesirable, since a get_user_pages() call could be
used to obtain a reference to a donated page and then a subsequent
access via a kernel mapping would lead to a panic().
Rework the spurious fault handler so that stage-2 faults injected back
into the host result in the target page being forcefully reclaimed when
no exception table fixup handler is registered.
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-27-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Introduce a new hypercall, __pkvm_force_reclaim_guest_page(), to allow
the host to forcefully reclaim a physical page that was previous donated
to a protected guest. This results in the page being zeroed and the
previous guest mapping being poisoned so that new pages cannot be
subsequently donated at the same IPA.
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-26-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Handling host kernel faults arising from accesses to donated guest
memory will require an rmap-like mechanism to identify the guest mapping
of the faulting page.
Extend the page donation logic to encode the guest handle and gfn
alongside the owner information in the host stage-2 pte.
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-25-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
'pkvm_handle_t' doesn't need to be a 32-bit type and subsequent patches
will rely on it being no more than 16 bits so that it can be encoded
into a pte annotation.
Change 'pkvm_handle_t' to a u16 and add a compile-type check that the
maximum handle fits into the reduced type.
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-24-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Rework host_stage2_set_owner_locked() to add a new helper function,
host_stage2_set_owner_metadata_locked(), which will allow us to store
additional metadata alongside a 3-bit owner ID for invalid host stage-2
entries.
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-23-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
kvm_pgtable_stage2_set_owner() can be generalised into a way to store
up to 59 bits in the page tables alongside a 4-bit 'type' identifier
specific to the format of the 59-bit payload.
Introduce kvm_pgtable_stage2_annotate() and move the existing invalid
ptes (for locked ptes and donated pages) over to the new scheme.
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-22-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
When a page is transitioned to host ownership, we can eagerly map it
into the host stage-2 page-table rather than going via the convoluted
step of a faulting annotation to trigger the mapping.
Call host_stage2_idmap_locked() directly when transitioning a page to
be owned by the host.
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-21-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
The pKVM hypervisor will currently panic if the host tries to access
memory that it doesn't own (e.g. protected guest memory). Sadly, as
guest memory can still be mapped into the VMM's address space, userspace
can trivially crash the kernel/hypervisor by poking into guest memory.
To prevent this, inject the abort back in the host with S1PTW set in the
ESR, hence allowing the host to differentiate this abort from normal
userspace faults and inject a SIGSEGV cleanly.
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-20-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Extend inject_host_exception() to support the injection of translation
faults on both the data and instruction side to 32-bit and 64-bit EL0
as well as 64-bit EL1. This will be used in a subsequent patch when
resolving an unhandled host stage-2 abort.
Cc: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-19-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
inject_undef64() open-codes the logic to inject an exception into the
pKVM host. In preparation for reusing this logic to inject a data abort
on an unhandled stage-2 fault from the host, factor out the meat and
potatoes of the function into a new inject_host_exception() function
which takes the ESR as a parameter.
Cc: Fuad Tabba <tabba@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-18-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
During teardown of a protected guest, its memory pages must be reclaimed
from the hypervisor by issuing the '__pkvm_reclaim_dying_guest_page'
hypercall.
Add a new helper, __pkvm_pgtable_stage2_reclaim(), which is called
during the VM teardown operation to reclaim pages from the hypervisor
and drop the GUP pin on the host.
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-17-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
To enable reclaim of pages from a protected VM during teardown,
introduce a new hypercall to reclaim a single page from a protected
guest that is in the dying state.
Since the EL2 code is non-preemptible, the new hypercall deliberately
acts on a single page at a time so as to allow EL1 to reschedule
frequently during the teardown operation.
Reviewed-by: Vincent Donnefort <vdonnefort@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Co-developed-by: Quentin Perret <qperret@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-16-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Introduce a new abort handler for resolving stage-2 page faults from
protected VMs by pinning and donating anonymous memory. This is
considerably simpler than the infamous user_mem_abort() as we only have
to deal with translation faults at the pte level.
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-15-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Mapping pages into a protected guest requires the donation of memory
from the host.
Extend pkvm_pgtable_stage2_map() to issue a donate hypercall when the
target VM is protected. Since the hypercall only handles a single page,
the splitting logic used for the share path is not required.
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-14-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
In preparation for supporting protected VMs, whose memory pages are
isolated from the host, introduce a new pKVM hypercall to allow the
donation of pages to a guest.
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-13-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
In preparation for reclaiming protected guest VM pages from the host
during teardown, split the current 'pkvm_teardown_vm' hypercall into
separate 'start' and 'finalise' calls.
The 'pkvm_start_teardown_vm' hypercall puts the VM into a new 'is_dying'
state, which is a point of no return past which no vCPU of the pVM is
allowed to run any more. Once in this new state,
'pkvm_finalize_teardown_vm' can be used to reclaim meta-data and
page-table pages from the VM. A subsequent patch will add support for
reclaiming the individual guest memory pages.
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Co-developed-by: Quentin Perret <qperret@google.com>
Signed-off-by: Quentin Perret <qperret@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-12-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
If the host takes a stage-2 translation fault on two CPUs at the same
time, one of them will get back -EAGAIN from the page-table mapping code
when it runs into the mapping installed by the other.
Rather than handle this explicitly in handle_host_mem_abort(), pass the
new KVM_PGTABLE_WALK_IGNORE_EAGAIN flag to kvm_pgtable_stage2_map() from
__host_stage2_idmap() and return -EEXIST if host_stage2_adjust_range()
finds a valid pte. This will avoid having to test for -EAGAIN on the
reclaim path in subsequent patches.
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-11-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Protected VMs do not support deleting or moving memslots after first
run nor do they support read-only or dirty logging.
Return -EPERM to userspace if such an operation is attempted.
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-10-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
In preparation for supporting the donation of pinned pages to protected
VMs, return early from the MMU notifiers when called for a protected VM,
as the necessary hypercalls are exposed only for non-protected guests.
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-9-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
When pKVM is not enabled, the host shouldn't issue pKVM-specific
hypercalls and so there's no point checking for this in the pKVM
hypercall handlers.
Remove the redundant is_protected_kvm_enabled() checks from each
hypercall and instead rejig the hypercall table so that the
pKVM-specific hypercalls are unreachable when pKVM is not being used.
Reviewed-by: Quentin Perret <qperret@google.com>
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-8-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Debug and trace are not currently supported for protected guests, so
trap accesses to the related registers and emulate them as RAZ/WI for
now. Although this isn't strictly compatible with the architecture, it's
sufficient for Linux guests and means that debug support can be added
later on.
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Fuad Tabba <tabba@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-7-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Both SVE and PMUv3 are treated as "restricted" features for protected
guests and attempts to access their corresponding architectural state
from a protected guest result in an undefined exception being injected
by the hypervisor.
Since these exceptions are unexpected and typically fatal for the guest,
don't advertise these features for protected guests.
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-6-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
In preparation for adding support for protected VMs, where pages are
donated rather than shared, rename __pkvm_pgtable_stage2_unmap() to
__pkvm_pgtable_stage2_unshare() to make it clearer about what is going
on.
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-5-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
When pKVM is enabled, a VM has a 'handle' allocated by the hypervisor
in kvm_arch_init_vm() and released later by kvm_arch_destroy_vm().
Consequently, the only time __pkvm_pgtable_stage2_unmap() can run into
an uninitialised 'handle' is on the kvm_arch_init_vm() failure path,
where we destroy the empty stage-2 page-table if we fail to allocate a
handle.
Move the handle check into pkvm_pgtable_stage2_destroy_range(), which
will additionally handle protected VMs in subsequent patches.
Reviewed-by: Fuad Tabba <tabba@google.com>
Tested-by: Fuad Tabba <tabba@google.com>
Tested-by: Mostafa Saleh <smostafa@google.com>
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-4-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
Commit 7cbf7c3771 ("KVM: arm64: Drop pkvm_mem_transition for host/hyp
sharing") removed the last users of PKVM_ID_FFA, so drop the definition
altogether.
Signed-off-by: Will Deacon <will@kernel.org>
Link: https://patch.msgid.link/20260330144841.26181-2-will@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
The pipe_src dump doesn't really fit in with the rest
of the guys (pixel_rate, port_clock, min_cdclk) included
on the same line. Split pipe_src onto its own line,
next to the related pfit stuff.
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20260325135849.12603-4-ville.syrjala@linux.intel.com
Reviewed-by: Michał Grzelak <michal.grzelak@intel.com>
Looks like I missed the drm_dp_enhanced_frame_cap() in the ivb/hsw CPU
eDP code when I introduced crtc_state->enhanced_framing. Fix it up so
that the state we program to the hardware is guaranteed to match what
we computed earlier.
Cc: stable@vger.kernel.org
Fixes: 3072a24c77 ("drm/i915: Introduce crtc_state->enhanced_framing")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20260325135849.12603-3-ville.syrjala@linux.intel.com
Reviewed-by: Michał Grzelak <michal.grzelak@intel.com>
Apparently I forgot about the pipe min_voltage_level when I
decoupled the CDCLK calculations from modesets. Even if the
CDCLK frequency doesn't need changing we may still need to
bump the voltage level to accommodate an increase in the
port clock frequency.
Currently, even if there is a full modeset, we won't notice the
need to go through the full CDCLK calculations/programming,
unless the set of enabled/active pipes changes, or the
pipe/dbuf min CDCLK changes.
Duplicate the same logic we use the pipe's min CDCLK frequency
to also deal with its min voltage level.
Note that the 'allow_voltage_level_decrease' stuff isn't
really useful here since the min voltage level can only
change during a full modeset. But I think sticking to the
same approach in the three similar parts (pipe min cdclk,
pipe min voltage level, dbuf min cdclk) is a good idea.
Cc: stable@vger.kernel.org
Tested-by: Mikhail Rudenko <mike.rudenko@gmail.com>
Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/15826
Fixes: ba91b9eecb ("drm/i915/cdclk: Decouple cdclk from state->modeset")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patch.msgid.link/20260325135849.12603-2-ville.syrjala@linux.intel.com
Reviewed-by: Michał Grzelak <michal.grzelak@intel.com>
PCI bridges are allowed to refuse activating VGA decoding, by simply
ignoring attempts to set the bit that enables it, so after setting the bit,
read it back to verify.
One example of such a bridge is the root bridge in IBM PowerNV, but this is
also useful for GPU passthrough into virtual machines, where it is
difficult to set up routing for legacy IO through IOMMU.
Signed-off-by: Simon Richter <Simon.Richter@hogyros.de>
[bhelgaas: subject, add comment about VGA Enable writability]
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Link: https://patch.msgid.link/20260307173538.763188-5-Simon.Richter@hogyros.de
Instead of discarding the saved unicode buffer when the console was
resized while in the alternate screen, resize it to the current
dimensions using vc_uniscr_copy_area() to preserve its content. This
properly restores the unicode screen on alt screen exit rather than
lazily rebuilding it from a lossy reverse glyph translation.
On allocation failure the stale buffer is freed and vc_uni_lines is
set to NULL so it gets lazily rebuilt via vc_uniscr_check() when next
needed.
Fixes: 40014493ce ("vt: discard stale unicode buffer on alt screen exit after resize")
Cc: stable <stable@kernel.org>
Signed-off-by: Nicolas Pitre <nico@fluxnic.net>
Link: https://patch.msgid.link/3nsr334n-079q-125n-7807-n4nq818758ns@syhkavp.arg
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When enter_alt_screen() saves vc_uni_lines into vc_saved_uni_lines and
sets vc_uni_lines to NULL, a subsequent console resize via vc_do_resize()
skips reallocating the unicode buffer because vc_uni_lines is NULL.
However, vc_saved_uni_lines still points to the old buffer allocated for
the original dimensions.
When leave_alt_screen() later restores vc_saved_uni_lines, the buffer
dimensions no longer match vc_rows/vc_cols. Any operation that iterates
over the unicode buffer using the current dimensions (e.g. csi_J clearing
the screen) will access memory out of bounds, causing a kernel oops:
BUG: unable to handle page fault for address: 0x0000002000000020
RIP: 0010:csi_J+0x133/0x2d0
The faulting address 0x0000002000000020 is two adjacent u32 space
characters (0x20) interpreted as a pointer, read from the row data area
past the end of the 25-entry pointer array in a buffer allocated for
80x25 but accessed with 240x67 dimensions.
Fix this by checking whether the console dimensions changed while in the
alternate screen. If they did, free the stale saved buffer instead of
restoring it. The unicode screen will be lazily rebuilt via
vc_uniscr_check() when next needed.
Fixes: 5eb608319b ("vt: save/restore unicode screen buffer for alternate screen")
Cc: stable <stable@kernel.org>
Tested-by: Liav Mordouch <liavmordouch@gmail.com>
Signed-off-by: Liav Mordouch <liavmordouch@gmail.com>
Reviewed-by: Nicolas Pitre <nico@fluxnic.net>
Link: https://patch.msgid.link/20260327170204.29706-1-liavmordouch@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
When the console out buffer is filled, __write_console() will return 0
as it cannot send any data. domU_write_console() will then spin in
`while (len)` as len doesn't decrement until xenconsoled attaches. This
would block a domU and nullify the parallelism of Hyperlaunch until dom0
userspace starts xenconsoled, which empties the buffer.
Xen 4.21 added a connection field to the xen console page. This is set
to XENCONSOLE_DISCONNECTED (1) when a domain is built, and xenconsoled
will set it to XENCONSOLE_CONNECTED (0) when it connects.
Update the hvc_xen driver to check the field. When the field is
disconnected, drop the write with -ENOTCONN. We only drop the write
when the field is XENCONSOLE_DISCONNECTED (1) to try for maximum
compatibility. The Xen toolstack has historically zero initialized the
console, so it should see XENCONSOLE_CONNECTED (0) by default. If an
implemenation used uninitialized memory, only checking for
XENCONSOLE_DISCONNECTED could have the lowest chance of not connecting.
This lets the hyperlaunched domU boot without stalling. Once dom0
starts xenconsoled, xl console can be used to access the domU's hvc0.
Paritally sync console.h from xen.git to bring in the new field.
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>
Signed-off-by: Jason Andryuk <jason.andryuk@amd.com>
Link: https://patch.msgid.link/20260318235326.14568-1-jason.andryuk@amd.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Add support for RZ/G3L RSCI. The RSCI IP found on the RZ/G3L SoC is
similar to RZ/G3E, but it has 3 clocks (2 module clocks + 1 external
clock) instead of 6 clocks (5 module clocks + 1 external clock) on the
RZ/G3E. Both RZ/G3L and RZ/G3E have a 32-bit FIFO, but RZ/G3L has a
single TCLK with internal dividers, whereas the RZ/G3E has explicit
clocks for TCLK and its dividers. Add a new port type
RSCI_PORT_SCIF32_SINGLE_TCLK to handle this clock difference.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Link: https://patch.msgid.link/20260312082708.98835-3-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Document the serial communication interface (RSCI) used on the Renesas
RZ/G3L (R9A08G046) SoC. This SoC integrates the same RSCI IP block as
the RZ/G3E (R9A09G047), but it has 3 clocks compared to 6 clocks on
the RZ/G3E SoC. The RZ/G3L has a single TCLK with internal dividers,
whereas the RZ/G3E has explicit clocks for TCLK and its dividers.
Signed-off-by: Biju Das <biju.das.jz@bp.renesas.com>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Rob Herring (Arm) <robh@kernel.org>
Link: https://patch.msgid.link/20260312082708.98835-2-biju.das.jz@bp.renesas.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The modem-status comparison that used irq_status_prev was
moved from atmel_tasklet_func() into atmel_handle_status() in
commit d033e82db9 ("tty/serial: at91: handle IRQ status
more safely"). Update the comment accordingly.
Assisted-by: unnamed:deepseek-v3.2 coccinelle
Signed-off-by: Kexin Sun <kexinsun@smail.nju.edu.cn>
Link: https://patch.msgid.link/20260324024857.3244-1-kexinsun@smail.nju.edu.cn
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Drop the newline character from the middle of the printk message.
This avoids breaking the message into two lines unnecessarily.
Signed-off-by: Kathiravan Thirumoorthy <kathiravan.thirumoorthy@oss.qualcomm.com>
Reviewed-by: Konrad Dybcio <konrad.dybcio@oss.qualcomm.com>
Link: https://patch.msgid.link/20260319-drop_stray_n-v1-1-37fb619538bb@oss.qualcomm.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Loongson 3A4000 is a MIPS-based Loongson64 CPU which also supports
8250_loongson (loongson-uart).
Enable building on MIPS Loongson64 so that Loongson 3A4000 can benefit
from it.
Signed-off-by: Rong Zhang <rongrong@oss.cipunited.com>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Link: https://patch.msgid.link/20260315184301.412844-3-rongrong@oss.cipunited.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The UART controller on Loongson 3A4000 is compatible with Loongson
2K1500, which is NS16550A-compatible with an additional fractional
frequency divisor register.
Add loongson,ls3a4000-uart as compatible with loongson,ls2k1500-uart.
Acked-by: Krzysztof Kozlowski <krzysztof.kozlowski@oss.qualcomm.com>
Signed-off-by: Rong Zhang <rongrong@oss.cipunited.com>
Reviewed-by: Jiaxun Yang <jiaxun.yang@flygoat.com>
Link: https://patch.msgid.link/20260315184301.412844-2-rongrong@oss.cipunited.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
