From 0b97ae72bc054da8f9af736dac51611307133890 Mon Sep 17 00:00:00 2001 From: Marc Zyngier Date: Fri, 9 Jun 2017 12:49:36 +0100 Subject: [PATCH] KVM: arm64: vgic-v3: Add ICV_IAR1_EL1 handler BugLink: https://bugs.launchpad.net/bugs/1673564 Add a handler for reading the guest's view of the ICC_IAR1_EL1 register. This involves finding the highest priority Group-1 interrupt, checking against both PMR and the active group priority, activating the interrupt and setting the group priority as active. Tested-by: Alexander Graf Acked-by: David Daney Reviewed-by: Eric Auger Signed-off-by: Marc Zyngier Reviewed-by: Christoffer Dall Signed-off-by: Christoffer Dall (backported from commit 132a324ab62fe4fb8d6dcc2ab4eddb0e93b69afe) [ dannf: Dropped SYS_ prefix on ICV_IAR1_EL1 macro, which wasn't added upstream until 0e9884fe ] Signed-off-by: dann frazier Acked-by: Stefan Bader Acked-by: Kleber Sacilotto de Souza Signed-off-by: Kleber Sacilotto de Souza --- include/linux/irqchip/arm-gic-v3.h | 1 + virt/kvm/arm/hyp/vgic-v3-sr.c | 163 +++++++++++++++++++++++++++++ 2 files changed, 164 insertions(+) diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h index 7f6d904a62c6..53095d085217 100644 --- a/include/linux/irqchip/arm-gic-v3.h +++ b/include/linux/irqchip/arm-gic-v3.h @@ -392,6 +392,7 @@ #define ICH_LR_PHYS_ID_SHIFT 32 #define ICH_LR_PHYS_ID_MASK (0x3ffULL << ICH_LR_PHYS_ID_SHIFT) #define ICH_LR_PRIORITY_SHIFT 48 +#define ICH_LR_PRIORITY_MASK (0xffULL << ICH_LR_PRIORITY_SHIFT) /* These are for GICv2 emulation only */ #define GICH_LR_VIRTUALID (0x3ffUL << 0) diff --git a/virt/kvm/arm/hyp/vgic-v3-sr.c b/virt/kvm/arm/hyp/vgic-v3-sr.c index 61c9831d6528..dff42ae5ef3d 100644 --- a/virt/kvm/arm/hyp/vgic-v3-sr.c +++ b/virt/kvm/arm/hyp/vgic-v3-sr.c @@ -24,6 +24,7 @@ #define vtr_to_max_lr_idx(v) ((v) & 0xf) #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 __hyp_text __gic_v3_get_lr(unsigned int lr) { @@ -430,6 +431,88 @@ static int __hyp_text __vgic_v3_bpr_min(void) return 8 - vtr_to_nr_pre_bits(read_gicreg(ICH_VTR_EL2)); } +static int __hyp_text __vgic_v3_get_group(struct kvm_vcpu *vcpu) +{ + u32 esr = kvm_vcpu_get_hsr(vcpu); + u8 crm = (esr & ESR_ELx_SYS64_ISS_CRM_MASK) >> ESR_ELx_SYS64_ISS_CRM_SHIFT; + + return crm != 8; +} + +#define GICv3_IDLE_PRIORITY 0xff + +static int __hyp_text __vgic_v3_highest_priority_lr(struct kvm_vcpu *vcpu, + u32 vmcr, + u64 *lr_val) +{ + unsigned int used_lrs = vcpu->arch.vgic_cpu.used_lrs; + u8 priority = GICv3_IDLE_PRIORITY; + int i, lr = -1; + + for (i = 0; i < used_lrs; i++) { + u64 val = __gic_v3_get_lr(i); + u8 lr_prio = (val & ICH_LR_PRIORITY_MASK) >> ICH_LR_PRIORITY_SHIFT; + + /* Not pending in the state? */ + if ((val & ICH_LR_STATE) != ICH_LR_PENDING_BIT) + continue; + + /* Group-0 interrupt, but Group-0 disabled? */ + if (!(val & ICH_LR_GROUP) && !(vmcr & ICH_VMCR_ENG0_MASK)) + continue; + + /* Group-1 interrupt, but Group-1 disabled? */ + if ((val & ICH_LR_GROUP) && !(vmcr & ICH_VMCR_ENG1_MASK)) + continue; + + /* Not the highest priority? */ + if (lr_prio >= priority) + continue; + + /* This is a candidate */ + priority = lr_prio; + *lr_val = val; + lr = i; + } + + if (lr == -1) + *lr_val = ICC_IAR1_EL1_SPURIOUS; + + return lr; +} + +static int __hyp_text __vgic_v3_get_highest_active_priority(void) +{ + u8 nr_apr_regs = vtr_to_nr_apr_regs(read_gicreg(ICH_VTR_EL2)); + u32 hap = 0; + int i; + + for (i = 0; i < nr_apr_regs; i++) { + u32 val; + + /* + * The ICH_AP0Rn_EL2 and ICH_AP1Rn_EL2 registers + * contain the active priority levels for this VCPU + * for the maximum number of supported priority + * levels, and we return the full priority level only + * if the BPR is programmed to its minimum, otherwise + * we return a combination of the priority level and + * subpriority, as determined by the setting of the + * BPR, but without the full subpriority. + */ + val = __vgic_v3_read_ap0rn(i); + val |= __vgic_v3_read_ap1rn(i); + if (!val) { + hap += 32; + continue; + } + + return (hap + __ffs(val)) << __vgic_v3_bpr_min(); + } + + return GICv3_IDLE_PRIORITY; +} + static unsigned int __hyp_text __vgic_v3_get_bpr0(u32 vmcr) { return (vmcr & ICH_VMCR_BPR0_MASK) >> ICH_VMCR_BPR0_SHIFT; @@ -450,6 +533,83 @@ static unsigned int __hyp_text __vgic_v3_get_bpr1(u32 vmcr) return bpr; } +/* + * Convert a priority to a preemption level, taking the relevant BPR + * into account by zeroing the sub-priority bits. + */ +static u8 __hyp_text __vgic_v3_pri_to_pre(u8 pri, u32 vmcr, int grp) +{ + unsigned int bpr; + + if (!grp) + bpr = __vgic_v3_get_bpr0(vmcr) + 1; + else + bpr = __vgic_v3_get_bpr1(vmcr); + + return pri & (GENMASK(7, 0) << bpr); +} + +/* + * The priority value is independent of any of the BPR values, so we + * normalize it using the minumal BPR value. This guarantees that no + * matter what the guest does with its BPR, we can always set/get the + * same value of a priority. + */ +static void __hyp_text __vgic_v3_set_active_priority(u8 pri, u32 vmcr, int grp) +{ + u8 pre, ap; + u32 val; + int apr; + + pre = __vgic_v3_pri_to_pre(pri, vmcr, grp); + ap = pre >> __vgic_v3_bpr_min(); + apr = ap / 32; + + if (!grp) { + val = __vgic_v3_read_ap0rn(apr); + __vgic_v3_write_ap0rn(val | BIT(ap % 32), apr); + } else { + val = __vgic_v3_read_ap1rn(apr); + __vgic_v3_write_ap1rn(val | BIT(ap % 32), apr); + } +} + +static void __hyp_text __vgic_v3_read_iar(struct kvm_vcpu *vcpu, u32 vmcr, int rt) +{ + u64 lr_val; + u8 lr_prio, pmr; + int lr, grp; + + grp = __vgic_v3_get_group(vcpu); + + lr = __vgic_v3_highest_priority_lr(vcpu, vmcr, &lr_val); + if (lr < 0) + goto spurious; + + if (grp != !!(lr_val & ICH_LR_GROUP)) + goto spurious; + + pmr = (vmcr & ICH_VMCR_PMR_MASK) >> ICH_VMCR_PMR_SHIFT; + lr_prio = (lr_val & ICH_LR_PRIORITY_MASK) >> ICH_LR_PRIORITY_SHIFT; + if (pmr <= lr_prio) + goto spurious; + + if (__vgic_v3_get_highest_active_priority() <= __vgic_v3_pri_to_pre(lr_prio, vmcr, grp)) + goto spurious; + + lr_val &= ~ICH_LR_STATE; + /* No active state for LPIs */ + if ((lr_val & ICH_LR_VIRTUAL_ID_MASK) <= VGIC_MAX_SPI) + lr_val |= ICH_LR_ACTIVE_BIT; + __gic_v3_set_lr(lr_val, lr); + __vgic_v3_set_active_priority(lr_prio, vmcr, grp); + vcpu_set_reg(vcpu, rt, lr_val & ICH_LR_VIRTUAL_ID_MASK); + return; + +spurious: + vcpu_set_reg(vcpu, rt, ICC_IAR1_EL1_SPURIOUS); +} + 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)); @@ -514,6 +674,9 @@ int __hyp_text __vgic_v3_perform_cpuif_access(struct kvm_vcpu *vcpu) is_read = (esr & ESR_ELx_SYS64_ISS_DIR_MASK) == ESR_ELx_SYS64_ISS_DIR_READ; switch (sysreg) { + case ICC_IAR1_EL1: + fn = __vgic_v3_read_iar; + break; case ICC_GRPEN1_EL1: if (is_read) fn = __vgic_v3_read_igrpen1; -- 2.39.2