- Host driver for GICv5, the next generation interrupt controller for
arm64, including support for interrupt routing, MSIs, interrupt
translation and wired interrupts.
- Use FEAT_GCIE_LEGACY on GICv5 systems to virtualize GICv3 VMs on
GICv5 hardware, leveraging the legacy VGIC interface.
- Userspace control of the 'nASSGIcap' GICv3 feature, allowing
userspace to disable support for SGIs w/o an active state on hardware
that previously advertised it unconditionally.
- Map supporting endpoints with cacheable memory attributes on systems
with FEAT_S2FWB and DIC where KVM no longer needs to perform cache
maintenance on the address range.
- Nested support for FEAT_RAS and FEAT_DoubleFault2, allowing the guest
hypervisor to inject external aborts into an L2 VM and take traps of
masked external aborts to the hypervisor.
- Convert more system register sanitization to the config-driven
implementation.
- Fixes to the visibility of EL2 registers, namely making VGICv3 system
registers accessible through the VGIC device instead of the ONE_REG
vCPU ioctls.
- Various cleanups and minor fixes.
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Merge tag 'kvmarm-6.17' of https://git.kernel.org/pub/scm/linux/kernel/git/kvmarm/kvmarm into HEAD
KVM/arm64 changes for 6.17, round #1
- Host driver for GICv5, the next generation interrupt controller for
arm64, including support for interrupt routing, MSIs, interrupt
translation and wired interrupts.
- Use FEAT_GCIE_LEGACY on GICv5 systems to virtualize GICv3 VMs on
GICv5 hardware, leveraging the legacy VGIC interface.
- Userspace control of the 'nASSGIcap' GICv3 feature, allowing
userspace to disable support for SGIs w/o an active state on hardware
that previously advertised it unconditionally.
- Map supporting endpoints with cacheable memory attributes on systems
with FEAT_S2FWB and DIC where KVM no longer needs to perform cache
maintenance on the address range.
- Nested support for FEAT_RAS and FEAT_DoubleFault2, allowing the guest
hypervisor to inject external aborts into an L2 VM and take traps of
masked external aborts to the hypervisor.
- Convert more system register sanitization to the config-driven
implementation.
- Fixes to the visibility of EL2 registers, namely making VGICv3 system
registers accessible through the VGIC device instead of the ONE_REG
vCPU ioctls.
- Various cleanups and minor fixes.
A common idiom in the KVM code is to check if we are currently
dealing with a "nested" context, defined as having NV enabled,
but being in the EL1&0 translation regime.
This is usually expressed as:
if (vcpu_has_nv(vcpu) && !is_hyp_ctxt(vcpu) ... )
which is a mouthful and a bit hard to read, specially when followed
by additional conditions.
Introduce a new helper that encapsulate these two terms, allowing
the above to be written as
if (is_nested_context(vcpu) ... )
which is both shorter and easier to read, and makes more obvious
the potential for simplification on some code paths.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250708172532.1699409-4-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
The state of the vcpu's MI line should be asserted when its
ICH_HCR_EL2.En is set and ICH_MISR_EL2 is non-zero. Using bitwise AND
(&=) directly for this calculation will not give us the correct result
when the LSB of the vcpu's ICH_MISR_EL2 isn't set. Correct this by
directly computing the line level with a logical AND operation.
Signed-off-by: Wei-Lin Chang <r09922117@csie.ntu.edu.tw>
Link: https://lore.kernel.org/r/20250625084709.3968844-1-r09922117@csie.ntu.edu.tw
[maz: drop the level check from the original code]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Wei-Lin reports that the tracking of shadow list registers is
majorly broken when resync'ing the L2 state after a run, as
we confuse the guest's LR index with the host's, potentially
losing the interrupt state.
While this could be fixed by adding yet another side index to
track it (Wei-Lin's fix), it may be better to refactor this
code to avoid having a side index altogether, limiting the
risk to introduce this class of bugs.
A key observation is that the shadow index is always the number
of bits in the lr_map bitmap. With that, the parallel indexing
scheme can be completely dropped.
While doing this, introduce a couple of helpers that abstract
the index conversion and some of the LR repainting, making the
whole exercise much simpler.
Reported-by: Wei-Lin Chang <r09922117@csie.ntu.edu.tw>
Reviewed-by: Wei-Lin Chang <r09922117@csie.ntu.edu.tw>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250614145721.2504524-1-r09922117@csie.ntu.edu.tw
Link: https://lore.kernel.org/r/86qzzkc5xa.wl-maz@kernel.org
Assigning a value to a system register doesn't do what it is
supposed to be doing if that register is one that has RESx bits.
The main problem is that we use __vcpu_sys_reg(), which can be used
both as a lvalue and rvalue. When used as a lvalue, the bit masking
occurs *before* the new value is assigned, meaning that we (1) do
pointless work on the old cvalue, and (2) potentially assign an
invalid value as we fail to apply the masks to it.
Fix this by providing a new __vcpu_assign_sys_reg() that does
what it says on the tin, and sanitises the *new* value instead of
the old one. This comes with a significant amount of churn.
Reviewed-by: Miguel Luis <miguel.luis@oracle.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20250603070824.1192795-2-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
In the case of ICH_LR<n>.HW == 1, bit 41 of LR is just a part of pINTID
without EOI meaning, and bit 41 will be zeroed by the subsequent clearing
of ICH_LR_PHYS_ID_MASK anyway.
No functional changes intended.
Signed-off-by: Wei-Lin Chang <r09922117@csie.ntu.edu.tw>
Link: https://lore.kernel.org/r/20250512133223.866999-1-r09922117@csie.ntu.edu.tw
Signed-off-by: Marc Zyngier <maz@kernel.org>
Popular HW that is able to use NV also has a broken vgic implementation
that requires trapping.
On such HW, propagate the host trap bits into the guest's shadow
ICH_HCR_EL2 register, making sure we don't allow an L2 guest to bring
the system down.
This involves a bit of tweaking so that the emulation code correctly
poicks up the shadow state as needed, and to only partially sync
ICH_HCR_EL2 back with the guest state to capture EOIcount.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250225172930.1850838-15-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
We have so far made sure that L1 and L0 vgic contexts were
totally independent. There is however one spot of bother with
this approach, and that's in the GICv3 emulation code required by
our fruity friends.
The issue is that the emulation code needs to know how many LRs
are in flight. And while it is easy to reach the L0 version through
the vcpu pointer, doing so for the L1 is much more complicated,
as these structures are private to the nested code.
We could simply expose that structure and pick one or the other
depending on the context, but this seems extra complexity for not
much benefit.
Instead, just propagate the number of used LRs from the nested code
into the L0 context, and be done with it. Should this become a burden,
it can be easily rectified.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250225172930.1850838-14-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Emulating the vGIC means emulating the dreaded Maintenance Interrupt.
This is a two-pronged problem:
- while running L2, getting an MI translates into an MI injected
in the L1 based on the state of the HW.
- while running L1, we must accurately reflect the state of the
MI line, based on the in-memory state.
The MI INTID is added to the distributor, as expected on any
virtualisation-capable implementation, and further patches
will allow its configuration.
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250225172930.1850838-11-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
When entering a nested VM, we set up the hypervisor control interface
based on what the guest hypervisor has set. Especially, we investigate
each list register written by the guest hypervisor whether HW bit is
set. If so, we translate hw irq number from the guest's point of view
to the real hardware irq number if there is a mapping.
Co-developed-by: Jintack Lim <jintack@cs.columbia.edu>
Signed-off-by: Jintack Lim <jintack@cs.columbia.edu>
[Christoffer: Redesigned execution flow around vcpu load/put]
Co-developed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
[maz: Rewritten to support GICv3 instead of GICv2, NV2 support]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250225172930.1850838-9-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Wire the handling of all GICv3 EL2 registers, and provide emulation
for all the non memory-backed registers (ICC_SRE_EL2, ICH_VTR_EL2,
ICH_MISR_EL2, ICH_ELRSR_EL2, and ICH_EISR_EL2).
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20250225172930.1850838-7-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
