[PATCH 14/31] KVM: arm64: vgic-v3: Add ICV_EOIR1_EL1 handler

Marc Zyngier
2017-05-03T10:43:36Z

Add a handler for writing the guest's view of the ICC_EOIR1_EL1
register. This involves dropping the priority of the interrupt,
and deactivating it if required (EOImode == 0).

Signed-off-by: Marc Zyngier <marc.zyngier@arm.com>
---
include/linux/irqchip/arm-gic-v3.h | 2 +
virt/kvm/arm/hyp/vgic-v3-sr.c | 119 +++++++++++++++++++++++++++++++++++++
2 files changed, 121 insertions(+)

diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h
index 7610ea4e8337..c56d9bc2c904 100644
--- a/include/linux/irqchip/arm-gic-v3.h
+++ b/include/linux/irqchip/arm-gic-v3.h
@@ -403,6 +403,8 @@

#define ICH_HCR_EN (1 << 0)
#define ICH_HCR_UIE (1 << 1)
+#define ICH_HCR_EOIcount_SHIFT 27
+#define ICH_HCR_EOIcount_MASK (0x1f << ICH_HCR_EOIcount_SHIFT)

#define ICH_VMCR_CBPR_SHIFT 4
#define ICH_VMCR_CBPR_MASK (1 << ICH_VMCR_CBPR_SHIFT)
diff --git a/virt/kvm/arm/hyp/vgic-v3-sr.c b/virt/kvm/arm/hyp/vgic-v3-sr.c
index 49aad1de3ac8..a76351b3ad66 100644
--- a/virt/kvm/arm/hyp/vgic-v3-sr.c
+++ b/virt/kvm/arm/hyp/vgic-v3-sr.c
@@ -425,6 +425,26 @@ static int __hyp_text __vgic_v3_highest_priority_lr(struct kvm_vcpu *vcpu,
return lr;
}

+static int __hyp_text __vgic_v3_find_active_lr(struct kvm_vcpu *vcpu,
+ int intid, u64 *lr_val)
+{
+ unsigned int used_lrs = vcpu->arch.vgic_cpu.used_lrs;
+ int i;
+
+ for (i = 0; i < used_lrs; i++) {
+ u64 val = __gic_v3_get_lr(i);
+
+ if ((val & ICH_LR_VIRTUAL_ID_MASK) == intid &&
+ (val & ICH_LR_ACTIVE_BIT)) {
+ *lr_val = val;
+ return i;
+ }
+ }
+
+ *lr_val = ICC_IAR1_EL1_SPURIOUS;
+ return -1;
+}
+
static int __hyp_text __vgic_v3_get_highest_active_priority(void)
{
u8 nr_pre_bits = vtr_to_nr_pre_bits(read_gicreg(ICH_VTR_EL2));
@@ -490,6 +510,44 @@ static void __hyp_text __vgic_v3_set_active_priority(u8 pre)
__vgic_v3_write_ap1rn(val | bit, apr);
}

+static int __hyp_text __vgic_v3_clear_highest_active_priority(void)
+{
+ u8 nr_pre_bits = vtr_to_nr_pre_bits(read_gicreg(ICH_VTR_EL2));
+ u8 nr_aprs = 1 << (nr_pre_bits - 5);
+ u32 hap = 0;
+ int i;
+
+ for (i = 0; i < nr_aprs; i++) {
+ u32 ap0, ap1;
+ int c0, c1;
+
+ ap0 = __vgic_v3_read_ap0rn(i);
+ ap1 = __vgic_v3_read_ap1rn(i);
+ if (!ap0 && !ap1) {
+ hap += 32;
+ continue;
+ }
+
+ c0 = ap0 ? __ffs(ap0) : 32;
+ c1 = ap1 ? __ffs(ap1) : 32;
+
+ /* Always clear the LSB, which is the highest priority */
+ if (c0 < c1) {
+ ap0 &= ap0 - 1;
+ __vgic_v3_write_ap0rn(ap0, i);
+ hap += c0;
+ } else {
+ ap1 &= ap1 - 1;
+ __vgic_v3_write_ap1rn(ap1, i);
+ hap += c1;
+ }
+
+ return hap << (8 - nr_pre_bits);
+ }
+
+ return GICv3_IDLE_PRIORITY;
+}
+
static void __hyp_text __vgic_v3_read_iar(struct kvm_vcpu *vcpu, u32 vmcr, int rt)
{
u64 lr_val;
@@ -526,6 +584,64 @@ static void __hyp_text __vgic_v3_read_iar(struct kvm_vcpu *vcpu, u32 vmcr, int r
vcpu_set_reg(vcpu, rt, ICC_IAR1_EL1_SPURIOUS);
}

+static void __hyp_text __vgic_v3_clear_active_lr(int lr, u64 lr_val)
+{
+ lr_val &= ~ICH_LR_ACTIVE_BIT;
+ if (lr_val & ICH_LR_HW) {
+ u32 pid;
+ pid = (lr_val & ICH_LR_PHYS_ID_MASK) >> ICH_LR_PHYS_ID_SHIFT;
+ gic_write_dir(pid);
+ }
+
+ __gic_v3_set_lr(lr_val, lr);
+}
+
+static void __hyp_text __vgic_v3_bump_eoicount(void)
+{
+ u32 hcr;
+
+ hcr = read_gicreg(ICH_HCR_EL2);
+ hcr += 1 << ICH_HCR_EOIcount_SHIFT;
+ write_gicreg(hcr, ICH_HCR_EL2);
+}
+
+static void __hyp_text __vgic_v3_write_eoir(struct kvm_vcpu *vcpu, u32 vmcr, int rt)
+{
+ u32 vid = vcpu_get_reg(vcpu, rt);
+ u64 lr_val;
+ u8 lr_prio, act_prio;
+ int lr, grp;
+
+ grp = __vgic_v3_get_group(vcpu);
+
+ /* Drop priority in any case */
+ act_prio = __vgic_v3_clear_highest_active_priority();
+
+ /* If EOIing an LPI, no deactivate to be performed */
+ if (vid >= VGIC_MIN_LPI)
+ return;
+
+ /* EOImode == 1, nothing to be done here */
+ if (vmcr & ICH_VMCR_EOIM_MASK)
+ return;
+
+ lr = __vgic_v3_find_active_lr(vcpu, vid, &lr_val);
+ if (lr == -1) {
+ __vgic_v3_bump_eoicount();
+ return;
+ }
+
+ lr_prio = (lr_val & ICH_LR_PRIORITY_MASK) >> ICH_LR_PRIORITY_SHIFT;
+
+ /* If priorities or group do not match, the guest has fscked-up. */
+ if (grp != !!(lr_val & ICH_LR_GROUP) ||
+ __vgic_v3_pri_to_pre(lr_prio, vmcr, grp) != act_prio)
+ return;
+
+ /* Let's now perform the deactivation */
+ __vgic_v3_clear_active_lr(lr, lr_val);
+}
+
static void __hyp_text __vgic_v3_read_igrpen1(struct kvm_vcpu *vcpu, u32 vmcr, int rt)
{
vcpu_set_reg(vcpu, rt, !!(vmcr & ICH_VMCR_ENG1_MASK));
@@ -591,6 +707,9 @@ int __hyp_text __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu)
case SYS_ICC_IAR1_EL1:
fn = __vgic_v3_read_iar;
break;
+ case SYS_ICC_EOIR1_EL1:
+ fn = __vgic_v3_write_eoir;
+ break;
case SYS_ICC_GRPEN1_EL1:
if (is_read)
fn = __vgic_v3_read_igrpen1;
--
2.11.0