arm64: KVM: enable trapping of all debug registers
Enable trapping of the debug registers, preventing the guests to
mess with the host state (and allowing guests to use the debug
infrastructure as well).
Reviewed-by: Anup Patel <anup.patel@linaro.org>
Reviewed-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
diff --git a/arch/arm64/kvm/hyp.S b/arch/arm64/kvm/hyp.S
index 100494b..b72aa9f 100644
--- a/arch/arm64/kvm/hyp.S
+++ b/arch/arm64/kvm/hyp.S
@@ -770,6 +770,14 @@
mrs x2, mdcr_el2
and x2, x2, #MDCR_EL2_HPMN_MASK
orr x2, x2, #(MDCR_EL2_TPM | MDCR_EL2_TPMCR)
+ orr x2, x2, #(MDCR_EL2_TDRA | MDCR_EL2_TDOSA)
+
+ // Check for KVM_ARM64_DEBUG_DIRTY, and set debug to trap
+ // if not dirty.
+ ldr x3, [x0, #VCPU_DEBUG_FLAGS]
+ tbnz x3, #KVM_ARM64_DEBUG_DIRTY_SHIFT, 1f
+ orr x2, x2, #MDCR_EL2_TDA
+1:
msr mdcr_el2, x2
.endm