This patch saves the device table entries into guest RAM. Both flat table and 2 stage tables are supported. DeviceId indexing is used.
For each device listed in the device table, we also save the translation table using the vgic_its_save/restore_itt routines. Those functions will be implemented in a subsequent patch. On restore, devices are re-allocated and their itt are re-built. Signed-off-by: Eric Auger <[email protected]> --- v5 -> v6: - accomodate vgic_its_alloc_device change of proto - define bit fields for L1 entries - s/handle_l1_entry/handle_l1_dte - s/ite_esz/dte_esz in handle_l1_dte - check BASER valid bit - s/nb_eventid_bits/num_eventid_bits - new convention for returned values - itt functions implemented in subsequent patch v4 -> v5: - sort the device list by deviceid on device table save - use defines for shifts and masks - use abi->dte_esz - clatify entry sizes for L1 and L2 tables v3 -> v4: - use the new proto for its_alloc_device - compute_next_devid_offset, vgic_its_flush/restore_itt become static in this patch - change in the DTE entry format with the introduction of the valid bit and next field width decrease; ittaddr encoded on its full range - fix handle_l1_entry entry handling - correct vgic_its_table_restore error handling v2 -> v3: - fix itt_addr bitmask in vgic_its_restore_dte - addition of return 0 in vgic_its_restore_ite moved to the ITE related patch v1 -> v2: - use 8 byte format for DTE and ITE - support 2 stage format - remove kvm parameter - ITT flush/restore moved in a separate patch - use deviceid indexing --- virt/kvm/arm/vgic/vgic-its.c | 194 +++++++++++++++++++++++++++++++++++++++++-- virt/kvm/arm/vgic/vgic.h | 10 +++ 2 files changed, 199 insertions(+), 5 deletions(-) diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c index 90afc83..3dea626 100644 --- a/virt/kvm/arm/vgic/vgic-its.c +++ b/virt/kvm/arm/vgic/vgic-its.c @@ -23,6 +23,7 @@ #include <linux/interrupt.h> #include <linux/list.h> #include <linux/uaccess.h> +#include <linux/list_sort.h> #include <linux/irqchip/arm-gic-v3.h> @@ -1735,7 +1736,8 @@ int vgic_its_attr_regs_access(struct kvm_device *dev, return ret; } -u32 compute_next_devid_offset(struct list_head *h, struct its_device *dev) +static u32 compute_next_devid_offset(struct list_head *h, + struct its_device *dev) { struct its_device *next; u32 next_offset; @@ -1789,8 +1791,8 @@ typedef int (*entry_fn_t)(struct vgic_its *its, u32 id, void *entry, * Return: < 0 on error, 0 if last element was identified, 1 otherwise * (the last element may not be found on second level tables) */ -int scan_its_table(struct vgic_its *its, gpa_t base, int size, int esz, - int start_id, entry_fn_t fn, void *opaque) +static int scan_its_table(struct vgic_its *its, gpa_t base, int size, int esz, + int start_id, entry_fn_t fn, void *opaque) { void *entry = kzalloc(esz, GFP_KERNEL); struct kvm *kvm = its->dev->kvm; @@ -1825,13 +1827,171 @@ int scan_its_table(struct vgic_its *its, gpa_t base, int size, int esz, return ret; } +static int vgic_its_save_itt(struct vgic_its *its, struct its_device *device) +{ + return -ENXIO; +} + +static int vgic_its_restore_itt(struct vgic_its *its, struct its_device *dev) +{ + return -ENXIO; +} + +/** + * vgic_its_save_dte - Save a device table entry at a given GPA + * + * @its: ITS handle + * @dev: ITS device + * @ptr: GPA + */ +static int vgic_its_save_dte(struct vgic_its *its, struct its_device *dev, + gpa_t ptr, int dte_esz) +{ + struct kvm *kvm = its->dev->kvm; + u64 val, itt_addr_field; + u32 next_offset; + + itt_addr_field = dev->itt_addr >> 8; + next_offset = compute_next_devid_offset(&its->device_list, dev); + val = (1ULL << KVM_ITS_DTE_VALID_SHIFT | + ((u64)next_offset << KVM_ITS_DTE_NEXT_SHIFT) | + (itt_addr_field << KVM_ITS_DTE_ITTADDR_SHIFT) | + (dev->num_eventid_bits - 1)); + val = cpu_to_le64(val); + return kvm_write_guest(kvm, ptr, &val, dte_esz); +} + +/** + * vgic_its_restore_dte - restore a device table entry + * + * @its: its handle + * @id: device id the DTE corresponds to + * @ptr: kernel VA where the 8 byte DTE is located + * @opaque: unused + * + * Return: < 0 on error, 0 if the dte is the last one, id offset to the + * next dte otherwise + */ +static int vgic_its_restore_dte(struct vgic_its *its, u32 id, + void *ptr, void *opaque) +{ + struct its_device *dev; + gpa_t itt_addr; + u8 num_eventid_bits; + u64 entry = *(u64 *)ptr; + bool valid; + u32 offset; + int ret; + + entry = le64_to_cpu(entry); + + valid = entry >> KVM_ITS_DTE_VALID_SHIFT; + num_eventid_bits = (entry & KVM_ITS_DTE_SIZE_MASK) + 1; + itt_addr = ((entry & KVM_ITS_DTE_ITTADDR_MASK) + >> KVM_ITS_DTE_ITTADDR_SHIFT) << 8; + + if (!valid) + return 1; + + /* dte entry is valid */ + offset = (entry & KVM_ITS_DTE_NEXT_MASK) >> KVM_ITS_DTE_NEXT_SHIFT; + + dev = vgic_its_alloc_device(its, id, itt_addr, num_eventid_bits); + if (IS_ERR(dev)) + return PTR_ERR(dev); + + ret = vgic_its_restore_itt(its, dev); + if (ret) + return ret; + + return offset; +} + +static int vgic_its_device_cmp(void *priv, struct list_head *a, + struct list_head *b) +{ + struct its_device *deva = container_of(a, struct its_device, dev_list); + struct its_device *devb = container_of(b, struct its_device, dev_list); + + if (deva->device_id < devb->device_id) + return -1; + else + return 1; +} + /** * vgic_its_save_device_tables - Save the device table and all ITT * into guest RAM + * + * L1/L2 handling is hidden by vgic_its_check_id() helper which directly + * returns the GPA of the device entry */ static int vgic_its_save_device_tables(struct vgic_its *its) { - return -ENXIO; + const struct vgic_its_abi *abi = vgic_its_get_abi(its); + struct its_device *dev; + int dte_esz = abi->dte_esz; + u64 baser; + + baser = its->baser_device_table; + + list_sort(NULL, &its->device_list, vgic_its_device_cmp); + + list_for_each_entry(dev, &its->device_list, dev_list) { + int ret; + gpa_t eaddr; + + if (!vgic_its_check_id(its, baser, + dev->device_id, &eaddr)) + return -EINVAL; + + ret = vgic_its_save_itt(its, dev); + if (ret) + return ret; + + ret = vgic_its_save_dte(its, dev, eaddr, dte_esz); + if (ret) + return ret; + } + return 0; +} + +/** + * handle_l1_dte - callback used for L1 device table entries (2 stage case) + * + * @its: its handle + * @id: index of the entry in the L1 table + * @addr: kernel VA + * @opaque: unused + * + * L1 table entries are scanned by steps of 1 entry + * Return < 0 if error, 0 if last dte was found when scanning the L2 + * table, +1 otherwise (meaning next L1 entry must be scanned) + */ +static int handle_l1_dte(struct vgic_its *its, u32 id, void *addr, + void *opaque) +{ + const struct vgic_its_abi *abi = vgic_its_get_abi(its); + int l2_start_id = id * (SZ_64K / abi->dte_esz); + u64 entry = *(u64 *)addr; + int dte_esz = abi->dte_esz; + gpa_t gpa; + int ret; + + entry = le64_to_cpu(entry); + + if (!(entry & KVM_ITS_L1E_VALID_MASK)) + return 1; + + gpa = entry & KVM_ITS_L1E_ADDR_MASK; + + ret = scan_its_table(its, gpa, SZ_64K, dte_esz, + l2_start_id, vgic_its_restore_dte, NULL); + + if (ret <= 0) + return ret; + + return 1; } /** @@ -1840,7 +2000,31 @@ static int vgic_its_save_device_tables(struct vgic_its *its) */ static int vgic_its_restore_device_tables(struct vgic_its *its) { - return -ENXIO; + const struct vgic_its_abi *abi = vgic_its_get_abi(its); + u64 baser = its->baser_device_table; + int l1_esz, ret; + int l1_tbl_size = GITS_BASER_NR_PAGES(baser) * SZ_64K; + gpa_t l1_gpa; + + if (!(baser & GITS_BASER_VALID)) + return 0; + + l1_gpa = BASER_ADDRESS(baser); + + if (baser & GITS_BASER_INDIRECT) { + l1_esz = GITS_LVL1_ENTRY_SIZE; + ret = scan_its_table(its, l1_gpa, l1_tbl_size, l1_esz, 0, + handle_l1_dte, NULL); + } else { + l1_esz = abi->dte_esz; + ret = scan_its_table(its, l1_gpa, l1_tbl_size, l1_esz, 0, + vgic_its_restore_dte, NULL); + } + + if (ret > 0) + ret = -EINVAL; + + return ret; } static int vgic_its_save_cte(struct vgic_its *its, diff --git a/virt/kvm/arm/vgic/vgic.h b/virt/kvm/arm/vgic/vgic.h index 58adcae..e896114 100644 --- a/virt/kvm/arm/vgic/vgic.h +++ b/virt/kvm/arm/vgic/vgic.h @@ -81,6 +81,16 @@ #define KVM_ITS_CTE_VALID_MASK BIT_ULL(63) #define KVM_ITS_CTE_RDBASE_SHIFT 16 #define KVM_ITS_CTE_ICID_MASK GENMASK_ULL(15, 0) +#define KVM_ITS_DTE_VALID_SHIFT 63 +#define KVM_ITS_DTE_VALID_MASK BIT_ULL(63) +#define KVM_ITS_DTE_NEXT_SHIFT 49 +#define KVM_ITS_DTE_NEXT_MASK GENMASK_ULL(62, 49) +#define KVM_ITS_DTE_ITTADDR_SHIFT 5 +#define KVM_ITS_DTE_ITTADDR_MASK GENMASK_ULL(48, 5) +#define KVM_ITS_DTE_SIZE_MASK GENMASK_ULL(4, 0) +#define KVM_ITS_L1E_VALID_MASK BIT_ULL(63) +/* we only support 64 kB translation table page size */ +#define KVM_ITS_L1E_ADDR_MASK GENMASK_ULL(51, 16) static inline bool irq_is_pending(struct vgic_irq *irq) { -- 2.5.5 _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
