kernel_optimize_test/arch/arm64/kvm
Russell King f5523423de arm64: kvm: Fix IDMAP overlap with HYP VA
Booting 5.4 on LX2160A reveals that KVM is non-functional:

kvm: Limiting the IPA size due to kernel Virtual Address limit
kvm [1]: IPA Size Limit: 43bits
kvm [1]: IDMAP intersecting with HYP VA, unable to continue
kvm [1]: error initializing Hyp mode: -22

Debugging shows:

kvm [1]: IDMAP page: 81a26000
kvm [1]: HYP VA range: 0:22ffffffff

as RAM is located at:

80000000-fbdfffff : System RAM
2080000000-237fffffff : System RAM

Comparing this with the same kernel on Armada 8040 shows:

kvm: Limiting the IPA size due to kernel Virtual Address limit
kvm [1]: IPA Size Limit: 43bits
kvm [1]: IDMAP page: 2a26000
kvm [1]: HYP VA range: 4800000000:493fffffff
...
kvm [1]: Hyp mode initialized successfully

which indicates that hyp_va_msb is set, and is always set to the
opposite value of the idmap page to avoid the overlap. This does not
happen with the LX2160A.

Further debugging shows vabits_actual = 39, kva_msb = 38 on LX2160A and
kva_msb = 33 on Armada 8040. Looking at the bit layout of the HYP VA,
there is still one bit available for hyp_va_msb. Set this bit
appropriately. This allows KVM to be functional on the LX2160A, but
without any HYP VA randomisation:

kvm: Limiting the IPA size due to kernel Virtual Address limit
kvm [1]: IPA Size Limit: 43bits
kvm [1]: IDMAP page: 81a24000
kvm [1]: HYP VA range: 4000000000:62ffffffff
...
kvm [1]: Hyp mode initialized successfully

Fixes: ed57cac83e ("arm64: KVM: Introduce EL2 VA randomisation")
Signed-off-by: Russell King <rmk+kernel@armlinux.org.uk>
[maz: small additional cleanups, preserved case where the tag
 is legitimately 0 and we can just use the mask, Fixes tag]
Signed-off-by: Marc Zyngier <maz@kernel.org>
Link: https://lore.kernel.org/r/E1ilAiY-0000MA-RG@rmk-PC.armlinux.org.uk
2020-01-19 16:05:23 +00:00
..
hyp Merge branches 'for-next/elf-hwcap-docs', 'for-next/smccc-conduit-cleanup', 'for-next/zone-dma', 'for-next/relax-icc_pmr_el1-sync', 'for-next/double-page-fault', 'for-next/misc', 'for-next/kselftest-arm64-signal' and 'for-next/kaslr-diagnostics' into for-next/core 2019-11-08 17:46:11 +00:00
debug.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
fpsimd.c arm64/fpsimd: Introduce fpsimd_save_and_flush_cpu_state() and use it 2019-06-04 13:17:30 +01:00
guest.c Merge remote-tracking branch 'kvmarm/misc-5.5' into kvmarm/next 2019-11-08 11:27:29 +00:00
handle_exit.c KVM: arm/arm64: Factor out hypercall handling from PSCI code 2019-10-21 19:20:26 +01:00
hyp-init.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
hyp.S treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
inject_fault.c KVM: arm/arm64: Allow user injection of external data aborts 2019-10-21 18:59:51 +01:00
irq.h treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 422 2019-06-05 17:37:15 +02:00
Kconfig KVM: arm64: Select TASK_DELAY_ACCT+TASKSTATS rather than SCHEDSTATS 2019-10-24 14:49:45 +01:00
Makefile KVM: arm64: Implement PV_TIME_FEATURES call 2019-10-21 19:20:27 +01:00
pmu.c KVM: arm64: Move pmu hyp code under hyp's Makefile to avoid instrumentation 2019-05-24 14:53:20 +01:00
regmap.c arm64: KVM: regmap: Fix unexpected switch fall-through 2019-07-26 15:33:41 +01:00
reset.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
sys_regs_generic_v8.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 234 2019-06-19 17:09:07 +02:00
sys_regs.c KVM/arm fixes for .5.5, take #1 2019-12-18 17:47:38 +01:00
sys_regs.h KVM: arm64: Sanely ratelimit sysreg messages 2019-12-06 11:41:45 +00:00
trace.h arm64: KVM: Add trapped system register access tracepoint 2018-12-19 17:47:08 +00:00
va_layout.c arm64: kvm: Fix IDMAP overlap with HYP VA 2020-01-19 16:05:23 +00:00
vgic-sys-reg-v3.c treewide: Replace GPLv2 boilerplate/reference with SPDX - rule 174 2019-05-30 11:26:41 -07:00