Commit Graph

10 Commits

Author SHA1 Message Date
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
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