KVM: arm64: nv: Honor MDCR_EL2.TDE routing for debug exceptions

Inject debug exceptions into vEL2 if MDCR_EL2.TDE is set.

Tested-by: James Clark <james.clark@linaro.org>
Signed-off-by: Oliver Upton <oliver.upton@linux.dev>
Link: https://lore.kernel.org/r/20241219224116.3941496-17-oliver.upton@linux.dev
Signed-off-by: Marc Zyngier <maz@kernel.org>

diff --git a/arch/arm64/include/asm/kvm_nested.h b/arch/arm64/include/asm/kvm_nested.h
index 233e65522716441c95f2cf9ddbd56fc825e6bf72..ec6e28d63d26fd4fd21f19578e45256009ed70b6 100644 (file)
--- a/arch/arm64/include/asm/kvm_nested.h
+++ b/arch/arm64/include/asm/kvm_nested.h
@@ -64,6 +64,7 @@ static inline u64 translate_ttbr0_el2_to_ttbr0_el1(u64 ttbr0)
 }
 
 extern bool forward_smc_trap(struct kvm_vcpu *vcpu);
+extern bool forward_debug_exception(struct kvm_vcpu *vcpu);
 extern void kvm_init_nested(struct kvm *kvm);
 extern int kvm_vcpu_init_nested(struct kvm_vcpu *vcpu);
 extern void kvm_init_nested_s2_mmu(struct kvm_s2_mmu *mmu);

diff --git a/arch/arm64/kvm/emulate-nested.c b/arch/arm64/kvm/emulate-nested.c
index 1ffbfd1c3cf2ecfa50284f8d4f54a22d06079ed2..e37fb598cc2424676d061b37a82d037d9371eaa5 100644 (file)
--- a/arch/arm64/kvm/emulate-nested.c
+++ b/arch/arm64/kvm/emulate-nested.c
@@ -2345,14 +2345,14 @@ inject:
        return true;
 }
 
-static bool forward_traps(struct kvm_vcpu *vcpu, u64 control_bit)
+static bool __forward_traps(struct kvm_vcpu *vcpu, unsigned int reg, u64 control_bit)
 {
        bool control_bit_set;
 
        if (!vcpu_has_nv(vcpu))
                return false;
 
-       control_bit_set = __vcpu_sys_reg(vcpu, HCR_EL2) & control_bit;
+       control_bit_set = __vcpu_sys_reg(vcpu, reg) & control_bit;
        if (!is_hyp_ctxt(vcpu) && control_bit_set) {
                kvm_inject_nested_sync(vcpu, kvm_vcpu_get_esr(vcpu));
                return true;
@@ -2360,9 +2360,24 @@ static bool forward_traps(struct kvm_vcpu *vcpu, u64 control_bit)
        return false;
 }
 
+static bool forward_hcr_traps(struct kvm_vcpu *vcpu, u64 control_bit)
+{
+       return __forward_traps(vcpu, HCR_EL2, control_bit);
+}
+
 bool forward_smc_trap(struct kvm_vcpu *vcpu)
 {
-       return forward_traps(vcpu, HCR_TSC);
+       return forward_hcr_traps(vcpu, HCR_TSC);
+}
+
+static bool forward_mdcr_traps(struct kvm_vcpu *vcpu, u64 control_bit)
+{
+       return __forward_traps(vcpu, MDCR_EL2, control_bit);
+}
+
+bool forward_debug_exception(struct kvm_vcpu *vcpu)
+{
+       return forward_mdcr_traps(vcpu, MDCR_EL2_TDE);
 }
 
 static u64 kvm_check_illegal_exception_return(struct kvm_vcpu *vcpu, u64 spsr)
@@ -2406,7 +2421,7 @@ void kvm_emulate_nested_eret(struct kvm_vcpu *vcpu)
         * Forward this trap to the virtual EL2 if the virtual
         * HCR_EL2.NV bit is set and this is coming from !EL2.
         */
-       if (forward_traps(vcpu, HCR_NV))
+       if (forward_hcr_traps(vcpu, HCR_NV))
                return;
 
        spsr = vcpu_read_sys_reg(vcpu, SPSR_EL2);

diff --git a/arch/arm64/kvm/handle_exit.c b/arch/arm64/kvm/handle_exit.c
index 1e302f0c8903e3ff48add8f5e84022d0e6216681..512d152233ff20eb6c65abbf731b4bcb543a7d07 100644 (file)
--- a/arch/arm64/kvm/handle_exit.c
+++ b/arch/arm64/kvm/handle_exit.c
@@ -183,6 +183,9 @@ static int kvm_handle_guest_debug(struct kvm_vcpu *vcpu)
        struct kvm_run *run = vcpu->run;
        u64 esr = kvm_vcpu_get_esr(vcpu);
 
+       if (!vcpu->guest_debug && forward_debug_exception(vcpu))
+               return 1;
+
        run->exit_reason = KVM_EXIT_DEBUG;
        run->debug.arch.hsr = lower_32_bits(esr);
        run->debug.arch.hsr_high = upper_32_bits(esr);