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kvm: arm64: Configure VTCR_EL2 per VM

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Add support for setting the VTCR_EL2 per VM, rather than hard
coding a value at boot time per CPU. This would allow us to tune
the stage2 page table parameters per VM in the later changes.

We compute the VTCR fields based on the system wide sanitised
feature registers, except for the hardware management of Access
Flags (VTCR_EL2.HA). It is fine to run a system with a mix of
CPUs that may or may not update the page table Access Flags.
Since the bit is RES0 on CPUs that don't support it, the bit
should be ignored on them.

Suggested-by: Marc Zyngier <marc.zyngier@arm.com>
Acked-by: Christoffer Dall <cdall@kernel.org>
Signed-off-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
This commit is contained in:
Suzuki K Poulose
2018-09-26 17:32:43 +01:00
committed by Marc Zyngier
parent 5b6c6742b5
commit 7665f3a849
7 changed files with 45 additions and 81 deletions
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3
arch/arm64/include/asm/kvm_arm.h
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@@ -135,8 +135,7 @@
* 40 bits wide (T0SZ = 24). Systems with a PARange smaller than 40 bits are
* not known to exist and will break with this configuration.
*
* VTCR_EL2.PS is extracted from ID_AA64MMFR0_EL1.PARange at boot time
* (see hyp-init.S).
* The VTCR_EL2 is configured per VM and is initialised in kvm_arm_config_vm().
*
* Note that when using 4K pages, we concatenate two first level page tables
* together. With 16K pages, we concatenate 16 first level page tables.