arm/arm64: KVM: Use set/way op trapping to track the state of the caches

Trying to emulate the behaviour of set/way cache ops is fairly
pointless, as there are too many ways we can end-up missing stuff.
Also, there is some system caches out there that simply ignore
set/way operations.

So instead of trying to implement them, let's convert it to VA ops,
and use them as a way to re-enable the trapping of VM ops. That way,
we can detect the point when the MMU/caches are turned off, and do
a full VM flush (which is what the guest was trying to do anyway).

This allows a 32bit zImage to boot on the APM thingy, and will
probably help bootloaders in general.

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>

1 files changed, 10 insertions, 0 deletions

diff --git a/arch/arm/include/asm/kvm_emulate.h b/arch/arm/include/asm/kvm_emulate.h
index 66ce17655bb9..7b0152321b20 100644
--- a/arch/arm/include/asm/kvm_emulate.h
+++ b/arch/arm/include/asm/kvm_emulate.h
@@ -38,6 +38,16 @@ static inline void vcpu_reset_hcr(struct kvm_vcpu *vcpu)
 	vcpu->arch.hcr = HCR_GUEST_MASK;
 }
 
+static inline unsigned long vcpu_get_hcr(struct kvm_vcpu *vcpu)
+{
+	return vcpu->arch.hcr;
+}
+
+static inline void vcpu_set_hcr(struct kvm_vcpu *vcpu, unsigned long hcr)
+{
+	vcpu->arch.hcr = hcr;
+}
+
 static inline bool vcpu_mode_is_32bit(struct kvm_vcpu *vcpu)
 {
 	return 1;