Commit Graph

61 Commits

Author SHA1 Message Date
Marc Zyngier ca71228b42 arm64: KVM: Always set ICH_HCR_EL2.EN if GICv4 is enabled
The normal interrupt flow is not to enable the vgic when no virtual
interrupt is to be injected (i.e. the LRs are empty). But when a guest
is likely to use GICv4 for LPIs, we absolutely need to switch it on
at all times. Otherwise, VLPIs only get delivered when there is something
in the LRs, which doesn't happen very often.

Reported-by: Nianyao Tang <tangnianyao@huawei.com>
Tested-by: Shameerali Kolothum Thodi <shameerali.kolothum.thodi@huawei.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2019-03-19 17:56:34 +00:00
Marc Zyngier b98c079ba4 KVM: arm64: Fix ICH_ELRSR_EL2 sysreg naming
We previously incorrectly named the define for this system register.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@arm.com>
2019-02-19 21:05:39 +00:00
Mark Rutland bd7d95cafb arm64: KVM: Consistently advance singlestep when emulating instructions
When we emulate a guest instruction, we don't advance the hardware
singlestep state machine, and thus the guest will receive a software
step exception after a next instruction which is not emulated by the
host.

We bodge around this in an ad-hoc fashion. Sometimes we explicitly check
whether userspace requested a single step, and fake a debug exception
from within the kernel. Other times, we advance the HW singlestep state
rely on the HW to generate the exception for us. Thus, the observed step
behaviour differs for host and guest.

Let's make this simpler and consistent by always advancing the HW
singlestep state machine when we skip an instruction. Thus we can rely
on the hardware to generate the singlestep exception for us, and never
need to explicitly check for an active-pending step, nor do we need to
fake a debug exception from the guest.

Cc: Peter Maydell <peter.maydell@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-12-18 14:11:37 +00:00
Marc Zyngier 5fbb0df6f6 kvm/arm fixes for 4.16, take 2
- Peace of mind locking fix in vgic_mmio_read_pending
 - Allow hw-mapped interrupts to be reset when the VM resets
 - Fix GICv2 multi-source SGI injection
 - Fix MMIO synchronization for GICv2 on v3 emulation
 - Remove excess verbosity on the console
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Merge tag 'kvm-arm-fixes-for-v4.16-2' into HEAD

Resolve conflicts with current mainline
2018-03-19 17:43:01 +00:00
Christoffer Dall 2d0e63e030 KVM: arm/arm64: Avoid VGICv3 save/restore on VHE with no IRQs
We can finally get completely rid of any calls to the VGICv3
save/restore functions when the AP lists are empty on VHE systems.  This
requires carefully factoring out trap configuration from saving and
restoring state, and carefully choosing what to do on the VHE and
non-VHE path.

One of the challenges is that we cannot save/restore the VMCR lazily
because we can only write the VMCR when ICC_SRE_EL1.SRE is cleared when
emulating a GICv2-on-GICv3, since otherwise all Group-0 interrupts end
up being delivered as FIQ.

To solve this problem, and still provide fast performance in the fast
path of exiting a VM when no interrupts are pending (which also
optimized the latency for actually delivering virtual interrupts coming
from physical interrupts), we orchestrate a dance of only doing the
activate/deactivate traps in vgic load/put for VHE systems (which can
have ICC_SRE_EL1.SRE cleared when running in the host), and doing the
configuration on every round-trip on non-VHE systems.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:21 +00:00
Christoffer Dall 923a2e30e5 KVM: arm/arm64: Move VGIC APR save/restore to vgic put/load
The APRs can only have bits set when the guest acknowledges an interrupt
in the LR and can only have a bit cleared when the guest EOIs an
interrupt in the LR.  Therefore, if we have no LRs with any
pending/active interrupts, the APR cannot change value and there is no
need to clear it on every exit from the VM (hint: it will have already
been cleared when we exited the guest the last time with the LRs all
EOIed).

The only case we need to take care of is when we migrate the VCPU away
from a CPU or migrate a new VCPU onto a CPU, or when we return to
userspace to capture the state of the VCPU for migration.  To make sure
this works, factor out the APR save/restore functionality into separate
functions called from the VCPU (and by extension VGIC) put/load hooks.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:21 +00:00
Christoffer Dall 8a43a2b34b KVM: arm/arm64: Move arm64-only vgic-v2-sr.c file to arm64
The vgic-v2-sr.c file now only contains the logic to replay unaligned
accesses to the virtual CPU interface on 16K and 64K page systems, which
is only relevant on 64-bit platforms.  Therefore move this file to the
arm64 KVM tree, remove the compile directive from the 32-bit side
makefile, and remove the ifdef in the C file.

Since this file also no longer saves/restores anything, rename the file
to vgic-v2-cpuif-proxy.c to more accurately describe the logic in this
file.

Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:20 +00:00
Christoffer Dall 75174ba6ca KVM: arm/arm64: Handle VGICv2 save/restore from the main VGIC code
We can program the GICv2 hypervisor control interface logic directly
from the core vgic code and can instead do the save/restore directly
from the flush/sync functions, which can lead to a number of future
optimizations.

Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:20 +00:00
Christoffer Dall bb5ed70359 KVM: arm/arm64: Get rid of vgic_elrsr
There is really no need to store the vgic_elrsr on the VGIC data
structures as the only need we have for the elrsr is to figure out if an
LR is inactive when we save the VGIC state upon returning from the
guest.  We can might as well store this in a temporary local variable.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:20 +00:00
Christoffer Dall 04fef05700 KVM: arm64: Remove noop calls to timer save/restore from VHE switch
The VHE switch function calls __timer_enable_traps and
__timer_disable_traps which don't do anything on VHE systems.
Therefore, simply remove these calls from the VHE switch function and
make the functions non-conditional as they are now only called from the
non-VHE switch path.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Andrew Jones <drjones@redhat.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-19 10:53:14 +00:00
Marc Zyngier 27e91ad1e7 kvm: arm/arm64: vgic-v3: Tighten synchronization for guests using v2 on v3
On guest exit, and when using GICv2 on GICv3, we use a dsb(st) to
force synchronization between the memory-mapped guest view and
the system-register view that the hypervisor uses.

This is incorrect, as the spec calls out the need for "a DSB whose
required access type is both loads and stores with any Shareability
attribute", while we're only synchronizing stores.

We also lack an isb after the dsb to ensure that the latter has
actually been executed before we start reading stuff from the sysregs.

The fix is pretty easy: turn dsb(st) into dsb(sy), and slap an isb()
just after.

Cc: stable@vger.kernel.org
Fixes: f68d2b1b73 ("arm64: KVM: Implement vgic-v3 save/restore")
Acked-by: Christoffer Dall <cdall@kernel.org>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2018-03-14 18:31:26 +00:00
Marc Zyngier d68119864e KVM: arm/arm64: Detangle kvm_mmu.h from kvm_hyp.h
kvm_hyp.h has an odd dependency on kvm_mmu.h, which makes the
opposite inclusion impossible. Let's start with breaking that
useless dependency.

Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2018-01-08 15:20:43 +01:00
Christoffer Dall fc396e0663 KVM: arm/arm64: Fix broken GICH_ELRSR big endian conversion
We are incorrectly rearranging 32-bit words inside a 64-bit typed value
for big endian systems, which would result in never marking a virtual
interrupt as inactive on big endian systems (assuming 32 or fewer LRs on
the hardware).  Fix this by not doing any word order manipulation for
the typed values.

Cc: <stable@vger.kernel.org>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-12-04 14:25:33 +01:00
Christoffer Dall ec6449a9c2 KVM: arm/arm64: Don't enable/disable physical timer access on VHE
After the timer optimization rework we accidentally end up calling
physical timer enable/disable functions on VHE systems, which is neither
needed nor correct, since the CNTHCTL_EL2 register format is
different when HCR_EL2.E2H is set.

The CNTHCTL_EL2 is initialized when CPUs become online in
kvm_timer_init_vhe() and we don't have to call these functions on VHE
systems, which also allows us to inline the non-VHE functionality.

Reported-by: Jintack Lim <jintack@cs.columbia.edu>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-11-29 16:46:09 +01:00
Marc Zyngier 374be35e23 KVM: arm/arm64: GICv4: Enable virtual cpuif if VLPIs can be delivered
In order for VLPIs to be delivered to the guest, we must make sure that
the virtual cpuif is always enabled, irrespective of the presence of
virtual interrupt in the LRs.

Acked-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-11-10 09:43:56 +01:00
Christoffer Dall 688c50aa72 KVM: arm/arm64: Move timer save/restore out of the hyp code
As we are about to be lazy with saving and restoring the timer
registers, we prepare by moving all possible timer configuration logic
out of the hyp code.  All virtual timer registers can be programmed from
EL1 and since the arch timer is always a level triggered interrupt we
can safely do this with interrupts disabled in the host kernel on the
way to the guest without taking vtimer interrupts in the host kernel
(yet).

The downside is that the cntvoff register can only be programmed from
hyp mode, so we jump into hyp mode and back to program it.  This is also
safe, because the host kernel doesn't use the virtual timer in the KVM
code.  It may add a little performance performance penalty, but only
until following commits where we move this operation to vcpu load/put.

Signed-off-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
2017-11-06 16:23:13 +01:00
Mark Rutland 21bc528177 arm64/kvm: sysreg: fix typo'd SYS_ICC_IGRPEN*_EL1
Per ARM DDI 0487B.a, the registers are named ICC_IGRPEN*_EL1 rather than
ICC_GRPEN*_EL1. Correct our mnemonics and comments to match, before we
add more GICv3 register definitions.

Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: kvmarm@lists.cs.columbia.edu
Acked-by: Christoffer Dall <cdall@linaro.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15 09:45:07 +01:00
Marc Zyngier 7b1dba1f73 KVM: arm64: Log an error if trapping a write-to-read-only GICv3 access
A write-to-read-only GICv3 access should UNDEF at EL1. But since
we're in complete paranoia-land with broken CPUs, let's assume the
worse and gracefully handle the case.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15 09:45:07 +01:00
Marc Zyngier e7f1d1eef4 KVM: arm64: Log an error if trapping a read-from-write-only GICv3 access
A read-from-write-only GICv3 access should UNDEF at EL1. But since
we're in complete paranoia-land with broken CPUs, let's assume the
worse and gracefully handle the case.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15 09:45:06 +01:00
Marc Zyngier 6293d6514d KVM: arm64: vgic-v3: Add ICV_PMR_EL1 handler
Add a handler for reading/writing the guest's view of the ICC_PMR_EL1
register, which is located in the ICH_VMCR_EL2.VPMR field.

Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Acked-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15 09:45:05 +01:00
Marc Zyngier d840b2d37d KVM: arm64: vgic-v3: Add ICV_CTLR_EL1 handler
Add a handler for reading/writing the guest's view of the ICV_CTLR_EL1
register. only EOIMode and CBPR are of interest here, as all the other
bits directly come from ICH_VTR_EL2 and are Read-Only.

Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Acked-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15 09:45:05 +01:00
Marc Zyngier 43515894c0 KVM: arm64: vgic-v3: Add ICV_RPR_EL1 handler
Add a handler for reading the guest's view of the ICV_RPR_EL1
register, returning the highest active priority.

Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Acked-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15 09:45:05 +01:00
Marc Zyngier 40228ba57c KVM: arm64: vgic-v3: Add ICV_DIR_EL1 handler
Add a handler for writing the guest's view of the ICC_DIR_EL1
register, performing the deactivation of an interrupt if EOImode
is set ot 1.

Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15 09:45:04 +01:00
Marc Zyngier eab0b2dc4f KVM: arm64: vgic-v3: Add misc Group-0 handlers
A number of Group-0 registers can be handled by the same accessors
as that of Group-1, so let's add the required system register encodings
and catch them in the dispatching function.

Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Acked-by: Christoffer Dall <cdall@linaro.org>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15 09:45:02 +01:00
Marc Zyngier fbc48a0011 KVM: arm64: vgic-v3: Add ICV_IGNREN0_EL1 handler
Add a handler for reading/writing the guest's view of the ICC_IGRPEN0_EL1
register, which is located in the ICH_VMCR_EL2.VENG0 field.

Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15 09:45:02 +01:00
Marc Zyngier 423de85a98 KVM: arm64: vgic-v3: Add ICV_BPR0_EL1 handler
Add a handler for reading/writing the guest's view of the ICC_BPR0_EL1
register, which is located in the ICH_VMCR_EL2.BPR0 field.

Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15 09:45:02 +01:00
Marc Zyngier 9c7bfc288c KVM: arm64: vgic-v3: Enable trapping of Group-1 system registers
In order to be able to trap Group-1 GICv3 system registers, we need to
set ICH_HCR_EL2.TALL1 before entering the guest. This is conditionally
done after having restored the guest's state, and cleared on exit.

Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Acked-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15 09:45:01 +01:00
Marc Zyngier 2724c11a1d KVM: arm64: vgic-v3: Add ICV_HPPIR1_EL1 handler
Add a handler for reading the guest's view of the ICV_HPPIR1_EL1
register. This is a simple parsing of the available LRs, extracting the
highest available interrupt.

Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15 09:45:01 +01:00
Marc Zyngier f9e7449c78 KVM: arm64: vgic-v3: Add ICV_AP1Rn_EL1 handler
Add a handler for reading/writing the guest's view of the ICV_AP1Rn_EL1
registers. We just map them to the corresponding ICH_AP1Rn_EL2 registers.

Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15 09:45:00 +01:00
Marc Zyngier b6f49035b4 KVM: arm64: vgic-v3: Add ICV_EOIR1_EL1 handler
Add a handler for writing the guest's view of the ICC_EOIR1_EL1
register. This involves dropping the priority of the interrupt,
and deactivating it if required (EOImode == 0).

Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15 09:45:00 +01:00
Marc Zyngier 132a324ab6 KVM: arm64: vgic-v3: Add ICV_IAR1_EL1 handler
Add a handler for reading the guest's view of the ICC_IAR1_EL1
register. This involves finding the highest priority Group-1
interrupt, checking against both PMR and the active group
priority, activating the interrupt and setting the group
priority as active.

Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15 09:45:00 +01:00
Marc Zyngier f8b630bc54 KVM: arm64: vgic-v3: Add ICV_IGRPEN1_EL1 handler
Add a handler for reading/writing the guest's view of the ICC_IGRPEN1_EL1
register, which is located in the ICH_VMCR_EL2.VENG1 field.

Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15 09:44:59 +01:00
Marc Zyngier d70c7b31a6 KVM: arm64: vgic-v3: Add ICV_BPR1_EL1 handler
Add a handler for reading/writing the guest's view of the ICC_BPR1_EL1
register, which is located in the ICH_VMCR_EL2.BPR1 field.

Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15 09:44:59 +01:00
Marc Zyngier 59da1cbfd8 KVM: arm64: vgic-v3: Add hook to handle guest GICv3 sysreg accesses at EL2
In order to start handling guest access to GICv3 system registers,
let's add a hook that will get called when we trap a system register
access. This is gated by a new static key (vgic_v3_cpuif_trap).

Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15 09:44:59 +01:00
Marc Zyngier 63000dd800 KVM: arm/arm64: vgic-v3: Add accessors for the ICH_APxRn_EL2 registers
As we're about to access the Active Priority registers a lot more,
let's define accessors that take the register number as a parameter.

Tested-by: Alexander Graf <agraf@suse.de>
Acked-by: David Daney <david.daney@cavium.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-06-15 09:44:58 +01:00
Christoffer Dall d68356cc51 KVM: arm/arm64: vgic-v3: Fix nr_pre_bits bitfield extraction
We used to extract PRIbits from the ICH_VT_EL2 which was the upper field
in the register word, so a mask wasn't necessary, but as we switched to
looking at PREbits, which is bits 26 through 28 with the PRIbits field
being potentially non-zero, we really need to mask off the field value,
otherwise fun things may happen.

Signed-off-by: Christoffer Dall <cdall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
2017-06-06 10:16:53 +02:00
Marc Zyngier 15d2bffdde KVM: arm/arm64: vgic-v3: Use PREbits to infer the number of ICH_APxRn_EL2 registers
The GICv3 documentation is extremely confusing, as it talks about
the number of priorities represented by the ICH_APxRn_EL2 registers,
while it should really talk about the number of preemption levels.

This leads to a bug where we may access undefined ICH_APxRn_EL2
registers, since PREbits is allowed to be smaller than PRIbits.
Thankfully, nobody seem to have taken this path so far...

The fix is to use ICH_VTR_EL2.PREbits instead.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-05-15 11:32:04 +02:00
Marc Zyngier cffcd9df10 KVM: arm/arm64: vgic-v3: Fix off-by-one LR access
When iterating over the used LRs, be careful not to try to access
an unused LR, or even an unimplemented one if you're unlucky...

Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-19 17:28:38 +02:00
Marc Zyngier ff567614d5 KVM: arm/arm64: vgic-v3: De-optimize VMCR save/restore when emulating a GICv2
When emulating a GICv2-on-GICv3, special care must be taken to only
save/restore VMCR_EL2 when ICC_SRE_EL1.SRE is cleared. Otherwise,
all Group-0 interrupts end-up being delivered as FIQ, which is
probably not what the guest expects, as demonstrated here with
an unhappy EFI:

	FIQ Exception at 0x000000013BD21CC4

This means that we cannot perform the load/put trick when dealing
with VMCR_EL2 (because the host has SRE set), and we have to deal
with it in the world-switch.

Fortunately, this is not the most common case (modern guests should
be able to deal with GICv3 directly), and the performance is not worse
than what it was before the VMCR optimization.

Reviewed-by: Christoffer Dall <cdall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-19 17:28:38 +02:00
Christoffer Dall 096f31c436 KVM: arm/arm64: vgic: Get rid of MISR and EISR fields
We don't use these fields anymore so let's nuke them completely.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-04-09 07:49:10 -07:00
Christoffer Dall b6095b084d KVM: arm/arm64: vgic: Get rid of unnecessary save_maint_int_state
Now when we don't look at the MISR and EISR values anymore, we can get
rid of the logic to save them in the GIC save/restore code.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-04-09 07:49:09 -07:00
Christoffer Dall 00dafa0fcf KVM: arm/arm64: vgic: Get rid of live_lrs
There is no need to calculate and maintain live_lrs when we always
populate the lowest numbered LRs first on every entry and clear all LRs
on every exit.

Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2017-04-09 07:45:31 -07:00
Christoffer Dall 328e566479 KVM: arm/arm64: vgic: Defer touching GICH_VMCR to vcpu_load/put
We don't have to save/restore the VMCR on every entry to/from the guest,
since on GICv2 we can access the control interface from EL1 and on VHE
systems with GICv3 we can access the control interface from KVM running
in EL2.

GICv3 systems without VHE becomes the rare case, which has to
save/restore the register on each round trip.

Note that userspace accesses may see out-of-date values if the VCPU is
running while accessing the VGIC state via the KVM device API, but this
is already the case and it is up to userspace to quiesce the CPUs before
reading the CPU registers from the GIC for an up-to-date view.

Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <cdall@cs.columbia.edu>
Signed-off-by: Christoffer Dall <cdall@linaro.org>
2017-04-09 07:45:22 -07:00
Jintack Lim 90de943a43 KVM: arm/arm64: Move cntvoff to each timer context
Make cntvoff per each timer context. This is helpful to abstract kvm
timer functions to work with timer context without considering timer
types (e.g. physical timer or virtual timer).

This also would pave the way for ever doing adjustments of the cntvoff
on a per-CPU basis if that should ever make sense.

Signed-off-by: Jintack Lim <jintack@cs.columbia.edu>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-02-08 15:13:33 +00:00
Jintack Lim fbb4aeec5f KVM: arm/arm64: Abstract virtual timer context into separate structure
Abstract virtual timer context into a separate structure and change all
callers referring to timer registers, irq state and so on. No change in
functionality.

This is about to become very handy when adding the EL1 physical timer.

Signed-off-by: Jintack Lim <jintack@cs.columbia.edu>
Acked-by: Christoffer Dall <christoffer.dall@linaro.org>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-02-08 15:13:32 +00:00
Jintack Lim 488f94d721 KVM: arm64: Access CNTHCTL_EL2 bit fields correctly on VHE systems
Current KVM world switch code is unintentionally setting wrong bits to
CNTHCTL_EL2 when E2H == 1, which may allow guest OS to access physical
timer.  Bit positions of CNTHCTL_EL2 are changing depending on
HCR_EL2.E2H bit.  EL1PCEN and EL1PCTEN are 1st and 0th bits when E2H is
not set, but they are 11th and 10th bits respectively when E2H is set.

In fact, on VHE we only need to set those bits once, not for every world
switch. This is because the host kernel runs in EL2 with HCR_EL2.TGE ==
1, which makes those bits have no effect for the host kernel execution.
So we just set those bits once for guests, and that's it.

Signed-off-by: Jintack Lim <jintack@cs.columbia.edu>
Reviewed-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
2017-01-13 11:19:25 +00:00
Vladimir Murzin 19f0ece439 arm64: KVM: Move vgic-v3 save/restore to virt/kvm/arm/hyp
So we can reuse the code under arch/arm

Signed-off-by: Vladimir Murzin <vladimir.murzin@arm.com>
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-22 13:21:46 +02:00
Marc Zyngier 3272f0d08e arm64: KVM: Inject a vSerror if detecting a bad GICV access at EL2
If, when proxying a GICV access at EL2, we detect that the guest is
doing something silly, report an EL1 SError instead ofgnoring the
access.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-08 12:53:00 +02:00
Marc Zyngier bf8feb3964 arm64: KVM: vgic-v2: Add GICV access from HYP
Now that we have the necessary infrastructure to handle MMIO accesses
in HYP, perform the GICV access on behalf of the guest. This requires
checking that the access is strictly 32bit, properly aligned, and
falls within the expected range.

When all condition are satisfied, we perform the access and tell
the rest of the HYP code that the instruction has been correctly
emulated.

Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-08 12:53:00 +02:00
Marc Zyngier fb5ee369cc arm64: KVM: vgic-v2: Add the GICV emulation infrastructure
In order to efficiently perform the GICV access on behalf of the
guest, we need to be able to avoid going back all the way to
the host kernel.

For this, we introduce a new hook in the world switch code,
conveniently placed just after populating the fault info.
At that point, we only have saved/restored the GP registers,
and we can quickly perform all the required checks (data abort,
translation fault, valid faulting syndrome, not an external
abort, not a PTW).

Coming back from the emulation code, we need to skip the emulated
instruction. This involves an additional bit of save/restore in
order to be able to access the guest's PC (and possibly CPSR if
this is a 32bit guest).

At this stage, no emulation code is provided.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
2016-09-08 12:53:00 +02:00