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author | Marc Zyngier <maz@kernel.org> | 2021-04-13 15:41:45 +0100 |
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committer | Marc Zyngier <maz@kernel.org> | 2021-04-13 15:41:45 +0100 |
commit | e629003215e03a8260326b5626fdd655618a79bd (patch) | |
tree | 02fd33f55627a4657ff91b4e36c41bdc46927040 | |
parent | c90aad55c52e032b0a39a2459c68702c9de543d4 (diff) | |
parent | 8082d50f4817ff6a7e08f4b7e9b18e5f8bfa290d (diff) | |
download | linux-e629003215e03a8260326b5626fdd655618a79bd.tar.gz linux-e629003215e03a8260326b5626fdd655618a79bd.tar.bz2 linux-e629003215e03a8260326b5626fdd655618a79bd.zip |
Merge branch 'kvm-arm64/vlpi-save-restore' into kvmarm-master/next
Signed-off-by: Marc Zyngier <maz@kernel.org>
-rw-r--r-- | Documentation/virt/kvm/devices/arm-vgic-its.rst | 2 | ||||
-rw-r--r-- | arch/arm64/kvm/vgic/vgic-its.c | 6 | ||||
-rw-r--r-- | arch/arm64/kvm/vgic/vgic-v3.c | 66 | ||||
-rw-r--r-- | arch/arm64/kvm/vgic/vgic-v4.c | 38 | ||||
-rw-r--r-- | arch/arm64/kvm/vgic/vgic.h | 1 | ||||
-rw-r--r-- | drivers/irqchip/irq-gic-v3-its.c | 18 |
6 files changed, 119 insertions, 12 deletions
diff --git a/Documentation/virt/kvm/devices/arm-vgic-its.rst b/Documentation/virt/kvm/devices/arm-vgic-its.rst index 6c304fd2b1b4..d257eddbae29 100644 --- a/Documentation/virt/kvm/devices/arm-vgic-its.rst +++ b/Documentation/virt/kvm/devices/arm-vgic-its.rst @@ -80,7 +80,7 @@ KVM_DEV_ARM_VGIC_GRP_CTRL -EFAULT Invalid guest ram access -EBUSY One or more VCPUS are running -EACCES The virtual ITS is backed by a physical GICv4 ITS, and the - state is not available + state is not available without GICv4.1 ======= ========================================================== KVM_DEV_ARM_VGIC_GRP_ITS_REGS diff --git a/arch/arm64/kvm/vgic/vgic-its.c b/arch/arm64/kvm/vgic/vgic-its.c index 40cbaca81333..ec7543a9617c 100644 --- a/arch/arm64/kvm/vgic/vgic-its.c +++ b/arch/arm64/kvm/vgic/vgic-its.c @@ -2218,10 +2218,10 @@ static int vgic_its_save_itt(struct vgic_its *its, struct its_device *device) /* * If an LPI carries the HW bit, this means that this * interrupt is controlled by GICv4, and we do not - * have direct access to that state. Let's simply fail - * the save operation... + * have direct access to that state without GICv4.1. + * Let's simply fail the save operation... */ - if (ite->irq->hw) + if (ite->irq->hw && !kvm_vgic_global_state.has_gicv4_1) return -EACCES; ret = vgic_its_save_ite(its, device, ite, gpa, ite_esz); diff --git a/arch/arm64/kvm/vgic/vgic-v3.c b/arch/arm64/kvm/vgic/vgic-v3.c index 6f530925a231..41ecf219c333 100644 --- a/arch/arm64/kvm/vgic/vgic-v3.c +++ b/arch/arm64/kvm/vgic/vgic-v3.c @@ -1,6 +1,8 @@ // SPDX-License-Identifier: GPL-2.0-only #include <linux/irqchip/arm-gic-v3.h> +#include <linux/irq.h> +#include <linux/irqdomain.h> #include <linux/kvm.h> #include <linux/kvm_host.h> #include <kvm/arm_vgic.h> @@ -356,6 +358,32 @@ retry: return 0; } +/* + * The deactivation of the doorbell interrupt will trigger the + * unmapping of the associated vPE. + */ +static void unmap_all_vpes(struct vgic_dist *dist) +{ + struct irq_desc *desc; + int i; + + for (i = 0; i < dist->its_vm.nr_vpes; i++) { + desc = irq_to_desc(dist->its_vm.vpes[i]->irq); + irq_domain_deactivate_irq(irq_desc_get_irq_data(desc)); + } +} + +static void map_all_vpes(struct vgic_dist *dist) +{ + struct irq_desc *desc; + int i; + + for (i = 0; i < dist->its_vm.nr_vpes; i++) { + desc = irq_to_desc(dist->its_vm.vpes[i]->irq); + irq_domain_activate_irq(irq_desc_get_irq_data(desc), false); + } +} + /** * vgic_v3_save_pending_tables - Save the pending tables into guest RAM * kvm lock and all vcpu lock must be held @@ -365,13 +393,28 @@ int vgic_v3_save_pending_tables(struct kvm *kvm) struct vgic_dist *dist = &kvm->arch.vgic; struct vgic_irq *irq; gpa_t last_ptr = ~(gpa_t)0; - int ret; + bool vlpi_avail = false; + int ret = 0; u8 val; + if (unlikely(!vgic_initialized(kvm))) + return -ENXIO; + + /* + * A preparation for getting any VLPI states. + * The above vgic initialized check also ensures that the allocation + * and enabling of the doorbells have already been done. + */ + if (kvm_vgic_global_state.has_gicv4_1) { + unmap_all_vpes(dist); + vlpi_avail = true; + } + list_for_each_entry(irq, &dist->lpi_list_head, lpi_list) { int byte_offset, bit_nr; struct kvm_vcpu *vcpu; gpa_t pendbase, ptr; + bool is_pending; bool stored; vcpu = irq->target_vcpu; @@ -387,24 +430,35 @@ int vgic_v3_save_pending_tables(struct kvm *kvm) if (ptr != last_ptr) { ret = kvm_read_guest_lock(kvm, ptr, &val, 1); if (ret) - return ret; + goto out; last_ptr = ptr; } stored = val & (1U << bit_nr); - if (stored == irq->pending_latch) + + is_pending = irq->pending_latch; + + if (irq->hw && vlpi_avail) + vgic_v4_get_vlpi_state(irq, &is_pending); + + if (stored == is_pending) continue; - if (irq->pending_latch) + if (is_pending) val |= 1 << bit_nr; else val &= ~(1 << bit_nr); ret = kvm_write_guest_lock(kvm, ptr, &val, 1); if (ret) - return ret; + goto out; } - return 0; + +out: + if (vlpi_avail) + map_all_vpes(dist); + + return ret; } /** diff --git a/arch/arm64/kvm/vgic/vgic-v4.c b/arch/arm64/kvm/vgic/vgic-v4.c index 66508b03094f..c1845d8f5f7e 100644 --- a/arch/arm64/kvm/vgic/vgic-v4.c +++ b/arch/arm64/kvm/vgic/vgic-v4.c @@ -203,6 +203,25 @@ void vgic_v4_configure_vsgis(struct kvm *kvm) kvm_arm_resume_guest(kvm); } +/* + * Must be called with GICv4.1 and the vPE unmapped, which + * indicates the invalidation of any VPT caches associated + * with the vPE, thus we can get the VLPI state by peeking + * at the VPT. + */ +void vgic_v4_get_vlpi_state(struct vgic_irq *irq, bool *val) +{ + struct its_vpe *vpe = &irq->target_vcpu->arch.vgic_cpu.vgic_v3.its_vpe; + int mask = BIT(irq->intid % BITS_PER_BYTE); + void *va; + u8 *ptr; + + va = page_address(vpe->vpt_page); + ptr = va + irq->intid / BITS_PER_BYTE; + + *val = !!(*ptr & mask); +} + /** * vgic_v4_init - Initialize the GICv4 data structures * @kvm: Pointer to the VM being initialized @@ -385,6 +404,7 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq, struct vgic_its *its; struct vgic_irq *irq; struct its_vlpi_map map; + unsigned long flags; int ret; if (!vgic_supports_direct_msis(kvm)) @@ -430,6 +450,24 @@ int kvm_vgic_v4_set_forwarding(struct kvm *kvm, int virq, irq->host_irq = virq; atomic_inc(&map.vpe->vlpi_count); + /* Transfer pending state */ + raw_spin_lock_irqsave(&irq->irq_lock, flags); + if (irq->pending_latch) { + ret = irq_set_irqchip_state(irq->host_irq, + IRQCHIP_STATE_PENDING, + irq->pending_latch); + WARN_RATELIMIT(ret, "IRQ %d", irq->host_irq); + + /* + * Clear pending_latch and communicate this state + * change via vgic_queue_irq_unlock. + */ + irq->pending_latch = false; + vgic_queue_irq_unlock(kvm, irq, flags); + } else { + raw_spin_unlock_irqrestore(&irq->irq_lock, flags); + } + out: mutex_unlock(&its->its_lock); return ret; diff --git a/arch/arm64/kvm/vgic/vgic.h b/arch/arm64/kvm/vgic/vgic.h index bc418c2c1214..dc1f3d1657ee 100644 --- a/arch/arm64/kvm/vgic/vgic.h +++ b/arch/arm64/kvm/vgic/vgic.h @@ -318,5 +318,6 @@ bool vgic_supports_direct_msis(struct kvm *kvm); int vgic_v4_init(struct kvm *kvm); void vgic_v4_teardown(struct kvm *kvm); void vgic_v4_configure_vsgis(struct kvm *kvm); +void vgic_v4_get_vlpi_state(struct vgic_irq *irq, bool *val); #endif diff --git a/drivers/irqchip/irq-gic-v3-its.c b/drivers/irqchip/irq-gic-v3-its.c index ed46e6057e33..d205fafede37 100644 --- a/drivers/irqchip/irq-gic-v3-its.c +++ b/drivers/irqchip/irq-gic-v3-its.c @@ -794,8 +794,13 @@ static struct its_vpe *its_build_vmapp_cmd(struct its_node *its, its_encode_alloc(cmd, alloc); - /* We can only signal PTZ when alloc==1. Why do we have two bits? */ - its_encode_ptz(cmd, alloc); + /* + * GICv4.1 provides a way to get the VLPI state, which needs the vPE + * to be unmapped first, and in this case, we may remap the vPE + * back while the VPT is not empty. So we can't assume that the + * VPT is empty on map. This is why we never advertise PTZ. + */ + its_encode_ptz(cmd, false); its_encode_vconf_addr(cmd, vconf_addr); its_encode_vmapp_default_db(cmd, desc->its_vmapp_cmd.vpe->vpe_db_lpi); @@ -4554,6 +4559,15 @@ static void its_vpe_irq_domain_deactivate(struct irq_domain *domain, its_send_vmapp(its, vpe, false); } + + /* + * There may be a direct read to the VPT after unmapping the + * vPE, to guarantee the validity of this, we make the VPT + * memory coherent with the CPU caches here. + */ + if (find_4_1_its() && !atomic_read(&vpe->vmapp_count)) + gic_flush_dcache_to_poc(page_address(vpe->vpt_page), + LPI_PENDBASE_SZ); } static const struct irq_domain_ops its_vpe_domain_ops = { |