1 files changed, 138 insertions, 31 deletions

diff --git a/arch/arm64/kvm/hyp/vgic-v3-sr.c b/arch/arm64/kvm/hyp/vgic-v3-sr.c
index 6cb638b184b1..f162b0df5cae 100644
--- a/arch/arm64/kvm/hyp/vgic-v3-sr.c
+++ b/arch/arm64/kvm/hyp/vgic-v3-sr.c
@@ -18,7 +18,7 @@
 #define vtr_to_nr_pre_bits(v)		((((u32)(v) >> 26) & 7) + 1)
 #define vtr_to_nr_apr_regs(v)		(1 << (vtr_to_nr_pre_bits(v) - 5))
 
-static u64 __gic_v3_get_lr(unsigned int lr)
+u64 __gic_v3_get_lr(unsigned int lr)
 {
 	switch (lr & 0xf) {
 	case 0:
@@ -218,7 +218,7 @@ void __vgic_v3_save_state(struct vgic_v3_cpu_if *cpu_if)
 
 		elrsr = read_gicreg(ICH_ELRSR_EL2);
 
-		write_gicreg(cpu_if->vgic_hcr & ~ICH_HCR_EN, ICH_HCR_EL2);
+		write_gicreg(cpu_if->vgic_hcr & ~ICH_HCR_EL2_En, ICH_HCR_EL2);
 
 		for (i = 0; i < used_lrs; i++) {
 			if (elrsr & (1 << i))
@@ -268,8 +268,16 @@ void __vgic_v3_activate_traps(struct vgic_v3_cpu_if *cpu_if)
 	 * starting to mess with the rest of the GIC, and VMCR_EL2 in
 	 * particular.  This logic must be called before
 	 * __vgic_v3_restore_state().
+	 *
+	 * However, if the vgic is disabled (ICH_HCR_EL2.EN==0), no GIC is
+	 * provisioned at all. In order to prevent illegal accesses to the
+	 * system registers to trap to EL1 (duh), force ICC_SRE_EL1.SRE to 1
+	 * so that the trap bits can take effect. Yes, we *loves* the GIC.
 	 */
-	if (!cpu_if->vgic_sre) {
+	if (!(cpu_if->vgic_hcr & ICH_HCR_EL2_En)) {
+		write_gicreg(ICC_SRE_EL1_SRE, ICC_SRE_EL1);
+		isb();
+	} else if (!cpu_if->vgic_sre) {
 		write_gicreg(0, ICC_SRE_EL1);
 		isb();
 		write_gicreg(cpu_if->vgic_vmcr, ICH_VMCR_EL2);
@@ -288,8 +296,9 @@ void __vgic_v3_activate_traps(struct vgic_v3_cpu_if *cpu_if)
 	}
 
 	/*
-	 * Prevent the guest from touching the GIC system registers if
-	 * SRE isn't enabled for GICv3 emulation.
+	 * Prevent the guest from touching the ICC_SRE_EL1 system
+	 * register. Note that this may not have any effect, as
+	 * ICC_SRE_EL2.Enable being RAO/WI is a valid implementation.
 	 */
 	write_gicreg(read_gicreg(ICC_SRE_EL2) & ~ICC_SRE_EL2_ENABLE,
 		     ICC_SRE_EL2);
@@ -297,10 +306,11 @@ void __vgic_v3_activate_traps(struct vgic_v3_cpu_if *cpu_if)
 	/*
 	 * If we need to trap system registers, we must write
 	 * ICH_HCR_EL2 anyway, even if no interrupts are being
-	 * injected,
+	 * injected. Note that this also applies if we don't expect
+	 * any system register access (no vgic at all).
 	 */
 	if (static_branch_unlikely(&vgic_v3_cpuif_trap) ||
-	    cpu_if->its_vpe.its_vm)
+	    cpu_if->its_vpe.its_vm || !cpu_if->vgic_sre)
 		write_gicreg(cpu_if->vgic_hcr, ICH_HCR_EL2);
 }
 
@@ -326,11 +336,11 @@ void __vgic_v3_deactivate_traps(struct vgic_v3_cpu_if *cpu_if)
 	 * no interrupts were being injected, and we disable it again here.
 	 */
 	if (static_branch_unlikely(&vgic_v3_cpuif_trap) ||
-	    cpu_if->its_vpe.its_vm)
+	    cpu_if->its_vpe.its_vm || !cpu_if->vgic_sre)
 		write_gicreg(0, ICH_HCR_EL2);
 }
 
-void __vgic_v3_save_aprs(struct vgic_v3_cpu_if *cpu_if)
+static void __vgic_v3_save_aprs(struct vgic_v3_cpu_if *cpu_if)
 {
 	u64 val;
 	u32 nr_pre_bits;
@@ -363,7 +373,7 @@ void __vgic_v3_save_aprs(struct vgic_v3_cpu_if *cpu_if)
 	}
 }
 
-void __vgic_v3_restore_aprs(struct vgic_v3_cpu_if *cpu_if)
+static void __vgic_v3_restore_aprs(struct vgic_v3_cpu_if *cpu_if)
 {
 	u64 val;
 	u32 nr_pre_bits;
@@ -419,23 +429,27 @@ u64 __vgic_v3_get_gic_config(void)
 	/*
 	 * To check whether we have a MMIO-based (GICv2 compatible)
 	 * CPU interface, we need to disable the system register
-	 * view. To do that safely, we have to prevent any interrupt
-	 * from firing (which would be deadly).
+	 * view.
 	 *
-	 * Note that this only makes sense on VHE, as interrupts are
-	 * already masked for nVHE as part of the exception entry to
-	 * EL2.
-	 */
-	if (has_vhe())
-		flags = local_daif_save();
-
-	/*
 	 * Table 11-2 "Permitted ICC_SRE_ELx.SRE settings" indicates
 	 * that to be able to set ICC_SRE_EL1.SRE to 0, all the
 	 * interrupt overrides must be set. You've got to love this.
+	 *
+	 * As we always run VHE with HCR_xMO set, no extra xMO
+	 * manipulation is required in that case.
+	 *
+	 * To safely disable SRE, we have to prevent any interrupt
+	 * from firing (which would be deadly). This only makes sense
+	 * on VHE, as interrupts are already masked for nVHE as part
+	 * of the exception entry to EL2.
 	 */
-	sysreg_clear_set(hcr_el2, 0, HCR_AMO | HCR_FMO | HCR_IMO);
-	isb();
+	if (has_vhe()) {
+		flags = local_daif_save();
+	} else {
+		sysreg_clear_set_hcr(0, HCR_AMO | HCR_FMO | HCR_IMO);
+		isb();
+	}
+
 	write_gicreg(0, ICC_SRE_EL1);
 	isb();
 
@@ -443,11 +457,13 @@ u64 __vgic_v3_get_gic_config(void)
 
 	write_gicreg(sre, ICC_SRE_EL1);
 	isb();
-	sysreg_clear_set(hcr_el2, HCR_AMO | HCR_FMO | HCR_IMO, 0);
-	isb();
 
-	if (has_vhe())
+	if (has_vhe()) {
 		local_daif_restore(flags);
+	} else {
+		sysreg_clear_set_hcr(HCR_AMO | HCR_FMO | HCR_IMO, 0);
+		isb();
+	}
 
 	val  = (val & ICC_SRE_EL1_SRE) ? 0 : (1ULL << 63);
 	val |= read_gicreg(ICH_VTR_EL2);
@@ -455,16 +471,35 @@ u64 __vgic_v3_get_gic_config(void)
 	return val;
 }
 
-u64 __vgic_v3_read_vmcr(void)
+static u64 __vgic_v3_read_vmcr(void)
 {
 	return read_gicreg(ICH_VMCR_EL2);
 }
 
-void __vgic_v3_write_vmcr(u32 vmcr)
+static void __vgic_v3_write_vmcr(u32 vmcr)
 {
 	write_gicreg(vmcr, ICH_VMCR_EL2);
 }
 
+void __vgic_v3_save_vmcr_aprs(struct vgic_v3_cpu_if *cpu_if)
+{
+	__vgic_v3_save_aprs(cpu_if);
+	if (cpu_if->vgic_sre)
+		cpu_if->vgic_vmcr = __vgic_v3_read_vmcr();
+}
+
+void __vgic_v3_restore_vmcr_aprs(struct vgic_v3_cpu_if *cpu_if)
+{
+	/*
+	 * If dealing with a GICv2 emulation on GICv3, VMCR_EL2.VFIQen
+	 * is dependent on ICC_SRE_EL1.SRE, and we have to perform the
+	 * VMCR_EL2 save/restore in the world switch.
+	 */
+	if (cpu_if->vgic_sre)
+		__vgic_v3_write_vmcr(cpu_if->vgic_vmcr);
+	__vgic_v3_restore_aprs(cpu_if);
+}
+
 static int __vgic_v3_bpr_min(void)
 {
 	/* See Pseudocode for VPriorityGroup */
@@ -723,7 +758,7 @@ static void __vgic_v3_bump_eoicount(void)
 	u32 hcr;
 
 	hcr = read_gicreg(ICH_HCR_EL2);
-	hcr += 1 << ICH_HCR_EOIcount_SHIFT;
+	hcr += 1 << ICH_HCR_EL2_EOIcount_SHIFT;
 	write_gicreg(hcr, ICH_HCR_EL2);
 }
 
@@ -983,9 +1018,6 @@ static void __vgic_v3_read_ctlr(struct kvm_vcpu *vcpu, u32 vmcr, int rt)
 	val = ((vtr >> 29) & 7) << ICC_CTLR_EL1_PRI_BITS_SHIFT;
 	/* IDbits */
 	val |= ((vtr >> 23) & 7) << ICC_CTLR_EL1_ID_BITS_SHIFT;
-	/* SEIS */
-	if (kvm_vgic_global_state.ich_vtr_el2 & ICH_VTR_SEIS_MASK)
-		val |= BIT(ICC_CTLR_EL1_SEIS_SHIFT);
 	/* A3V */
 	val |= ((vtr >> 21) & 1) << ICC_CTLR_EL1_A3V_SHIFT;
 	/* EOImode */
@@ -1013,6 +1045,75 @@ static void __vgic_v3_write_ctlr(struct kvm_vcpu *vcpu, u32 vmcr, int rt)
 	write_gicreg(vmcr, ICH_VMCR_EL2);
 }
 
+static bool __vgic_v3_check_trap_forwarding(struct kvm_vcpu *vcpu,
+					    u32 sysreg, bool is_read)
+{
+	u64 ich_hcr;
+
+	if (!vcpu_has_nv(vcpu) || is_hyp_ctxt(vcpu))
+		return false;
+
+	ich_hcr = __vcpu_sys_reg(vcpu, ICH_HCR_EL2);
+
+	switch (sysreg) {
+	case SYS_ICC_IGRPEN0_EL1:
+		if (is_read &&
+		    (__vcpu_sys_reg(vcpu, HFGRTR_EL2) & HFGRTR_EL2_ICC_IGRPENn_EL1))
+			return true;
+
+		if (!is_read &&
+		    (__vcpu_sys_reg(vcpu, HFGWTR_EL2) & HFGWTR_EL2_ICC_IGRPENn_EL1))
+			return true;
+
+		fallthrough;
+
+	case SYS_ICC_AP0Rn_EL1(0):
+	case SYS_ICC_AP0Rn_EL1(1):
+	case SYS_ICC_AP0Rn_EL1(2):
+	case SYS_ICC_AP0Rn_EL1(3):
+	case SYS_ICC_BPR0_EL1:
+	case SYS_ICC_EOIR0_EL1:
+	case SYS_ICC_HPPIR0_EL1:
+	case SYS_ICC_IAR0_EL1:
+		return ich_hcr & ICH_HCR_EL2_TALL0;
+
+	case SYS_ICC_IGRPEN1_EL1:
+		if (is_read &&
+		    (__vcpu_sys_reg(vcpu, HFGRTR_EL2) & HFGRTR_EL2_ICC_IGRPENn_EL1))
+			return true;
+
+		if (!is_read &&
+		    (__vcpu_sys_reg(vcpu, HFGWTR_EL2) & HFGWTR_EL2_ICC_IGRPENn_EL1))
+			return true;
+
+		fallthrough;
+
+	case SYS_ICC_AP1Rn_EL1(0):
+	case SYS_ICC_AP1Rn_EL1(1):
+	case SYS_ICC_AP1Rn_EL1(2):
+	case SYS_ICC_AP1Rn_EL1(3):
+	case SYS_ICC_BPR1_EL1:
+	case SYS_ICC_EOIR1_EL1:
+	case SYS_ICC_HPPIR1_EL1:
+	case SYS_ICC_IAR1_EL1:
+		return ich_hcr & ICH_HCR_EL2_TALL1;
+
+	case SYS_ICC_DIR_EL1:
+		if (ich_hcr & ICH_HCR_EL2_TDIR)
+			return true;
+
+		fallthrough;
+
+	case SYS_ICC_RPR_EL1:
+	case SYS_ICC_CTLR_EL1:
+	case SYS_ICC_PMR_EL1:
+		return ich_hcr & ICH_HCR_EL2_TC;
+
+	default:
+		return false;
+	}
+}
+
 int __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu)
 {
 	int rt;
@@ -1022,6 +1123,9 @@ int __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu)
 	bool is_read;
 	u32 sysreg;
 
+	if (kern_hyp_va(vcpu->kvm)->arch.vgic.vgic_model != KVM_DEV_TYPE_ARM_VGIC_V3)
+		return 0;
+
 	esr = kvm_vcpu_get_esr(vcpu);
 	if (vcpu_mode_is_32bit(vcpu)) {
 		if (!kvm_condition_valid(vcpu)) {
@@ -1036,6 +1140,9 @@ int __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu)
 
 	is_read = (esr & ESR_ELx_SYS64_ISS_DIR_MASK) == ESR_ELx_SYS64_ISS_DIR_READ;
 
+	if (__vgic_v3_check_trap_forwarding(vcpu, sysreg, is_read))
+		return 0;
+
 	switch (sysreg) {
 	case SYS_ICC_IAR0_EL1:
 	case SYS_ICC_IAR1_EL1: