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Author SHA1 Message Date
Marc Zyngier
47eb2d68d1 KVM: arm64: nv: Expose BTI and CSV_frac to a guest hypervisor
Now that we expose PAC to NV guests, we can also expose BTI (as
the two as joined at the hip, due to some of the PAC instructions
being landing pads).

While we're at it, also propagate CSV_frac, which requires no
particular emulation.

Fixes: f4f6a95bac ("KVM: arm64: nv: Advertise support for PAuth")
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240528100632.1831995-3-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-05-30 17:36:22 +01:00
Marc Zyngier
f4f6a95bac KVM: arm64: nv: Advertise support for PAuth
Now that we (hopefully) correctly handle ERETAx, drop the masking
of the PAuth feature (something that was not even complete, as
APA3 and AGA3 were still exposed).

Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20240419102935.1935571-15-maz@kernel.org
Signed-off-by: Marc Zyngier <maz@kernel.org>
2024-04-20 12:42:51 +01:00
Marc Zyngier
d39051d392 KVM: arm64: nv: Add sanitising to VNCR-backed HCRX_EL2
Just like its little friends, HCRX_EL2 gets the feature set treatment
when backed by VNCR.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-7-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:00 +00:00
Marc Zyngier
11adda4010 KVM: arm64: nv: Add sanitising to VNCR-backed FGT sysregs
Fine Grained Traps are controlled by a whole bunch of features.
Each one of them must be checked and the corresponding masks
computed so that we don't let the guest apply traps it shouldn't
be using.

This takes care of HFG[IRW]TR_EL2, HDFG[RW]TR_EL2, and HAFGRTR_EL2.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20240214131827.2856277-6-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:00 +00:00
Marc Zyngier
81ffcace31 KVM: arm64: nv: Add sanitising to EL2 configuration registers
We can now start making use of our sanitising masks by setting them
to values that depend on the guest's configuration.

First up are VTTBR_EL2, VTCR_EL2, VMPIDR_EL2 and HCR_EL2.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240214131827.2856277-5-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:00 +00:00
Marc Zyngier
888f088070 KVM: arm64: nv: Add sanitising to VNCR-backed sysregs
VNCR-backed "registers" are actually only memory. Which means that
there is zero control over what the guest can write, and that it
is the hypervisor's job to actually sanitise the content of the
backing store. Yeah, this is fun.

In order to preserve some form of sanity, add a repainting mechanism
that makes use of a per-VM set of RES0/RES1 masks, one pair per VNCR
register. These masks get applied on access to the backing store via
__vcpu_sys_reg(), ensuring that the state that is consumed by KVM is
correct.

So far, nothing populates these masks, but stay tuned.

Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Joey Gouly <joey.gouly@arm.com>
Link: https://lore.kernel.org/r/20240214131827.2856277-4-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-19 17:13:00 +00:00
Marc Zyngier
c21df6e43f KVM: arm64: Expose ID_AA64MMFR4_EL1 to guests
We can now expose ID_AA64MMFR4_EL1 to guests, and let NV guests
understand that they cannot really switch HCR_EL2.E2H to 0 on
some platforms.

Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20240122181344.258974-9-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2024-02-08 15:12:45 +00:00
Marc Zyngier
3ed0b5123c KVM: arm64: nv: Compute NV view of idregs as a one-off
Now that we have a full copy of the idregs for each VM, there is
no point in repainting the sysregs on each access. Instead, we
can simply perform the transmation as a one-off and be done
with it.

Reviewed-by: Oliver Upton <oliver.upton@linux.dev>
Signed-off-by: Marc Zyngier <maz@kernel.org>
2023-12-19 09:51:00 +00:00
Marc Zyngier
03fb54d0aa KVM: arm64: nv: Add support for HCRX_EL2
HCRX_EL2 has an interesting effect on HFGITR_EL2, as it conditions
the traps of TLBI*nXS.

Expand the FGT support to add a new Fine Grained Filter that will
get checked when the instruction gets trapped, allowing the shadow
register to override the trap as needed.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Jing Zhang <jingzhangos@google.com>
Link: https://lore.kernel.org/r/20230815183903.2735724-29-maz@kernel.org
2023-08-17 10:00:28 +01:00
Marc Zyngier
0a5d28433a KVM: arm64: nv: Expose FGT to nested guests
Now that we have FGT support, expose the feature to NV guests.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Reviewed-by: Jing Zhang <jingzhangos@google.com>
Link: https://lore.kernel.org/r/20230815183903.2735724-27-maz@kernel.org
2023-08-17 10:00:28 +01:00
Marc Zyngier
a0b70fb00d KVM: arm64: nv: Expose FEAT_EVT to nested guests
Now that we properly implement FEAT_EVT (as we correctly forward
traps), expose it to guests.

Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Jing Zhang <jingzhangos@google.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230815183903.2735724-17-maz@kernel.org
2023-08-17 10:00:27 +01:00
Oliver Upton
3fb901cdc9 KVM: arm64: nv: Use reg_to_encoding() to get sysreg ID
Avoid open-coding and just use the helper to encode the ID from the
sysreg table entry.

No functional change intended.

Acked-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230211190742.49843-1-oliver.upton@linux.dev
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-02-11 22:10:34 +00:00
Marc Zyngier
9f75b6d447 KVM: arm64: nv: Filter out unsupported features from ID regs
As there is a number of features that we either can't support,
or don't want to support right away with NV, let's add some
basic filtering so that we don't advertize silly things to the
EL2 guest.

Whilst we are at it, advertize FEAT_TTL as well as FEAT_GTG, which
the NV implementation will implement.

Reviewed-by: Ganapatrao Kulkarni <gankulkarni@os.amperecomputing.com>
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/20230209175820.1939006-18-maz@kernel.org
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
2023-02-11 10:13:30 +00:00