We plan to support different migration ABIs, ie. characterizing the ITS table layout format in guest RAM. Typically a new ABI will be needed if vLPIs get supported for nested use case.
So let's introduce an array of supported ABIs (at the moment a single ABI is supported though). The following characteristics are foreseen to vary with the ABI: size of table entries, save/restore operation. By default the MAX_ABI_REV is applied on its creation. In subsequent patches we will introduce a way for the userspace to change the ABI in use. The entry sizes now are set according to the ABI version and not hardcoded anymore. Signed-off-by: Eric Auger <[email protected]> --- v5: creation and squash KVM: arm64: ITS: Report the ITE size in GITS_TYPER --- include/kvm/arm_vgic.h | 3 ++ include/linux/irqchip/arm-gic-v3.h | 4 ++ virt/kvm/arm/vgic/vgic-its.c | 82 ++++++++++++++++++++++++++++++++++++-- 3 files changed, 85 insertions(+), 4 deletions(-) diff --git a/include/kvm/arm_vgic.h b/include/kvm/arm_vgic.h index c0b3d99..285474a 100644 --- a/include/kvm/arm_vgic.h +++ b/include/kvm/arm_vgic.h @@ -162,6 +162,9 @@ struct vgic_its { u32 creadr; u32 cwriter; + /* migration ABI revision in use */ + u32 abi_rev; + /* Protects the device and collection lists */ struct mutex its_lock; struct list_head device_list; diff --git a/include/linux/irqchip/arm-gic-v3.h b/include/linux/irqchip/arm-gic-v3.h index 97cbca1..9648bad 100644 --- a/include/linux/irqchip/arm-gic-v3.h +++ b/include/linux/irqchip/arm-gic-v3.h @@ -132,6 +132,8 @@ #define GIC_BASER_SHAREABILITY(reg, type) \ (GIC_BASER_##type << reg##_SHAREABILITY_SHIFT) +#define GIC_ENCODE_SZ(n, w) (((unsigned long)(n) - 1) & GENMASK_ULL(((w) - 1), 0)) + #define GICR_PROPBASER_SHAREABILITY_SHIFT (10) #define GICR_PROPBASER_INNER_CACHEABILITY_SHIFT (7) #define GICR_PROPBASER_OUTER_CACHEABILITY_SHIFT (56) @@ -232,6 +234,7 @@ #define GITS_CTLR_QUIESCENT (1U << 31) #define GITS_TYPER_PLPIS (1UL << 0) +#define GITS_TYPER_ITT_ENTRY_SIZE_SHIFT 4 #define GITS_TYPER_IDBITS_SHIFT 8 #define GITS_TYPER_DEVBITS_SHIFT 13 #define GITS_TYPER_DEVBITS(r) ((((r) >> GITS_TYPER_DEVBITS_SHIFT) & 0x1f) + 1) @@ -290,6 +293,7 @@ #define GITS_BASER_TYPE(r) (((r) >> GITS_BASER_TYPE_SHIFT) & 7) #define GITS_BASER_ENTRY_SIZE_SHIFT (48) #define GITS_BASER_ENTRY_SIZE(r) ((((r) >> GITS_BASER_ENTRY_SIZE_SHIFT) & 0x1f) + 1) +#define GITS_BASER_ENTRY_SIZE_MASK GENMASK_ULL(52, 48) #define GITS_BASER_SHAREABILITY_SHIFT (10) #define GITS_BASER_InnerShareable \ GIC_BASER_SHAREABILITY(GITS_BASER, InnerShareable) diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c index 79ed1c2..69ecfe4 100644 --- a/virt/kvm/arm/vgic/vgic-its.c +++ b/virt/kvm/arm/vgic/vgic-its.c @@ -33,6 +33,12 @@ #include "vgic.h" #include "vgic-mmio.h" +/* Highest migration ABI revision supported by this code */ +#define MAX_ABI_REV 0 + +static int vgic_its_set_abi(struct vgic_its *its, int rev); +static const struct vgic_its_abi *vgic_its_get_abi(struct vgic_its *its); + /* * Creates a new (reference to a) struct vgic_irq for a given LPI. * If this LPI is already mapped on another ITS, we increase its refcount @@ -123,6 +129,15 @@ struct its_ite { u32 event_id; }; +struct vgic_its_abi { + int cte_esz; + int dte_esz; + int ite_esz; + int (*save_tables)(struct vgic_its *its); + int (*restore_tables)(struct vgic_its *its); + int (*commit)(struct vgic_its *its); +}; + /* * Find and returns a device in the device table for an ITS. * Must be called with the its_lock mutex held. @@ -364,6 +379,7 @@ static unsigned long vgic_mmio_read_its_typer(struct kvm *kvm, struct vgic_its *its, gpa_t addr, unsigned int len) { + const struct vgic_its_abi *abi = vgic_its_get_abi(its); u64 reg = GITS_TYPER_PLPIS; /* @@ -376,6 +392,7 @@ static unsigned long vgic_mmio_read_its_typer(struct kvm *kvm, */ reg |= 0x0f << GITS_TYPER_DEVBITS_SHIFT; reg |= 0x0f << GITS_TYPER_IDBITS_SHIFT; + reg |= GIC_ENCODE_SZ(abi->ite_esz, 4) << GITS_TYPER_ITT_ENTRY_SIZE_SHIFT; return extract_bytes(reg, addr & 7, len); } @@ -1268,6 +1285,7 @@ static void vgic_mmio_write_its_baser(struct kvm *kvm, gpa_t addr, unsigned int len, unsigned long val) { + const struct vgic_its_abi *abi = vgic_its_get_abi(its); u64 entry_size, device_type; u64 reg, *regptr, clearbits = 0; @@ -1278,12 +1296,12 @@ static void vgic_mmio_write_its_baser(struct kvm *kvm, switch (BASER_INDEX(addr)) { case 0: regptr = &its->baser_device_table; - entry_size = 8; + entry_size = abi->dte_esz; device_type = GITS_BASER_TYPE_DEVICE; break; case 1: regptr = &its->baser_coll_table; - entry_size = 8; + entry_size = abi->cte_esz; device_type = GITS_BASER_TYPE_COLLECTION; clearbits = GITS_BASER_INDIRECT; break; @@ -1425,7 +1443,6 @@ static int vgic_register_its_iodev(struct kvm *kvm, struct vgic_its *its) (GIC_BASER_CACHEABILITY(GITS_BASER, INNER, RaWb) | \ GIC_BASER_CACHEABILITY(GITS_BASER, OUTER, SameAsInner) | \ GIC_BASER_SHAREABILITY(GITS_BASER, InnerShareable) | \ - ((8ULL - 1) << GITS_BASER_ENTRY_SIZE_SHIFT) | \ GITS_BASER_PAGE_SIZE_64K) #define INITIAL_PROPBASER_VALUE \ @@ -1465,7 +1482,7 @@ static int vgic_its_create(struct kvm_device *dev, u32 type) dev->private = its; - return 0; + return vgic_its_set_abi(its, MAX_ABI_REV); } static void vgic_its_destroy(struct kvm_device *kvm_dev) @@ -1592,6 +1609,63 @@ int vgic_its_attr_regs_access(struct kvm_device *dev, return ret; } +/** + * vgic_its_save_tables_v0 - Save the ITS tables into guest ARM + * according to v0 ABI + */ +static int vgic_its_save_tables_v0(struct vgic_its *its) +{ + return -ENXIO; +} + +/** + * vgic_its_restore_tables_v0 - Restore the ITS tables from guest RAM + * to internal data structs according to V0 ABI + * + */ +static int vgic_its_restore_tables_v0(struct vgic_its *its) +{ + return -ENXIO; +} + +static int vgic_its_commit_v0(struct vgic_its *its) +{ + const struct vgic_its_abi *abi; + + abi = vgic_its_get_abi(its); + its->baser_coll_table &= ~GITS_BASER_ENTRY_SIZE_MASK; + its->baser_device_table &= ~GITS_BASER_ENTRY_SIZE_MASK; + + its->baser_coll_table |= (GIC_ENCODE_SZ(abi->cte_esz, 5) + << GITS_BASER_ENTRY_SIZE_SHIFT); + + its->baser_device_table |= (GIC_ENCODE_SZ(abi->dte_esz, 5) + << GITS_BASER_ENTRY_SIZE_SHIFT); + return 0; +} + +static const struct vgic_its_abi abi[MAX_ABI_REV + 1] = { + {.cte_esz = 8, .dte_esz = 8, .ite_esz = 8, + .save_tables = vgic_its_save_tables_v0, + .restore_tables = vgic_its_restore_tables_v0, + . commit = vgic_its_commit_v0, + }, +}; + +inline const struct vgic_its_abi *vgic_its_get_abi(struct vgic_its *its) +{ + return &abi[its->abi_rev]; +} + +int vgic_its_set_abi(struct vgic_its *its, int rev) +{ + const struct vgic_its_abi *abi; + + its->abi_rev = rev; + abi = vgic_its_get_abi(its); + return abi->commit(its); +} + static int vgic_its_has_attr(struct kvm_device *dev, struct kvm_device_attr *attr) { -- 2.5.5 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
