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| author | Christoffer Dall <christoffer.dall@linaro.org> | 2014-11-27 10:35:03 +0100 |
|---|---|---|
| committer | Christoffer Dall <christoffer.dall@linaro.org> | 2014-12-13 14:15:27 +0100 |
| commit | 957db105c99792ae8ef61ffc9ae77d910f6471da (patch) | |
| tree | 7a752a94484cc703dfdbf62424f0ef496e03fa88 /arch/arm/kvm/arm.c | |
| parent | cf5d318865e25f887d49a0c6083bbc6dcd1905b1 (diff) | |
| download | lwn-957db105c99792ae8ef61ffc9ae77d910f6471da.tar.gz lwn-957db105c99792ae8ef61ffc9ae77d910f6471da.zip | |
arm/arm64: KVM: Introduce stage2_unmap_vm
Introduce a new function to unmap user RAM regions in the stage2 page
tables. This is needed on reboot (or when the guest turns off the MMU)
to ensure we fault in pages again and make the dcache, RAM, and icache
coherent.
Using unmap_stage2_range for the whole guest physical range does not
work, because that unmaps IO regions (such as the GIC) which will not be
recreated or in the best case faulted in on a page-by-page basis.
Call this function on secondary and subsequent calls to the
KVM_ARM_VCPU_INIT ioctl so that a reset VCPU will detect the guest
Stage-1 MMU is off when faulting in pages and make the caches coherent.
Acked-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Diffstat (limited to 'arch/arm/kvm/arm.c')
| -rw-r--r-- | arch/arm/kvm/arm.c | 7 |
1 files changed, 7 insertions, 0 deletions
diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c index 4043769583e7..da87c07d8577 100644 --- a/arch/arm/kvm/arm.c +++ b/arch/arm/kvm/arm.c @@ -701,6 +701,13 @@ static int kvm_arch_vcpu_ioctl_vcpu_init(struct kvm_vcpu *vcpu, if (ret) return ret; + /* + * Ensure a rebooted VM will fault in RAM pages and detect if the + * guest MMU is turned off and flush the caches as needed. + */ + if (vcpu->arch.has_run_once) + stage2_unmap_vm(vcpu->kvm); + vcpu_reset_hcr(vcpu); /* |