diff options
Diffstat (limited to 'arch/s390/kvm/pv.c')
| -rw-r--r-- | arch/s390/kvm/pv.c | 638 |
1 files changed, 616 insertions, 22 deletions
diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c index cc7c9599f43e..75e81ba26d04 100644 --- a/arch/s390/kvm/pv.c +++ b/arch/s390/kvm/pv.c @@ -7,13 +7,62 @@ */ #include <linux/kvm.h> #include <linux/kvm_host.h> +#include <linux/minmax.h> #include <linux/pagemap.h> #include <linux/sched/signal.h> #include <asm/gmap.h> #include <asm/uv.h> #include <asm/mman.h> +#include <linux/pagewalk.h> +#include <linux/sched/mm.h> +#include <linux/mmu_notifier.h> #include "kvm-s390.h" +bool kvm_s390_pv_is_protected(struct kvm *kvm) +{ + lockdep_assert_held(&kvm->lock); + return !!kvm_s390_pv_get_handle(kvm); +} +EXPORT_SYMBOL_GPL(kvm_s390_pv_is_protected); + +bool kvm_s390_pv_cpu_is_protected(struct kvm_vcpu *vcpu) +{ + lockdep_assert_held(&vcpu->mutex); + return !!kvm_s390_pv_cpu_get_handle(vcpu); +} +EXPORT_SYMBOL_GPL(kvm_s390_pv_cpu_is_protected); + +/** + * struct pv_vm_to_be_destroyed - Represents a protected VM that needs to + * be destroyed + * + * @list: list head for the list of leftover VMs + * @old_gmap_table: the gmap table of the leftover protected VM + * @handle: the handle of the leftover protected VM + * @stor_var: pointer to the variable storage of the leftover protected VM + * @stor_base: address of the base storage of the leftover protected VM + * + * Represents a protected VM that is still registered with the Ultravisor, + * but which does not correspond any longer to an active KVM VM. It should + * be destroyed at some point later, either asynchronously or when the + * process terminates. + */ +struct pv_vm_to_be_destroyed { + struct list_head list; + unsigned long old_gmap_table; + u64 handle; + void *stor_var; + unsigned long stor_base; +}; + +static void kvm_s390_clear_pv_state(struct kvm *kvm) +{ + kvm->arch.pv.handle = 0; + kvm->arch.pv.guest_len = 0; + kvm->arch.pv.stor_base = 0; + kvm->arch.pv.stor_var = NULL; +} + int kvm_s390_pv_destroy_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc) { int cc; @@ -32,7 +81,7 @@ int kvm_s390_pv_destroy_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc) free_pages(vcpu->arch.pv.stor_base, get_order(uv_info.guest_cpu_stor_len)); - free_page(sida_origin(vcpu->arch.sie_block)); + free_page((unsigned long)sida_addr(vcpu->arch.sie_block)); vcpu->arch.sie_block->pv_handle_cpu = 0; vcpu->arch.sie_block->pv_handle_config = 0; memset(&vcpu->arch.pv, 0, sizeof(vcpu->arch.pv)); @@ -54,6 +103,7 @@ int kvm_s390_pv_create_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc) .header.cmd = UVC_CMD_CREATE_SEC_CPU, .header.len = sizeof(uvcb), }; + void *sida_addr; int cc; if (kvm_s390_pv_cpu_get_handle(vcpu)) @@ -67,16 +117,17 @@ int kvm_s390_pv_create_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc) /* Input */ uvcb.guest_handle = kvm_s390_pv_get_handle(vcpu->kvm); uvcb.num = vcpu->arch.sie_block->icpua; - uvcb.state_origin = (u64)vcpu->arch.sie_block; - uvcb.stor_origin = (u64)vcpu->arch.pv.stor_base; + uvcb.state_origin = virt_to_phys(vcpu->arch.sie_block); + uvcb.stor_origin = virt_to_phys((void *)vcpu->arch.pv.stor_base); /* Alloc Secure Instruction Data Area Designation */ - vcpu->arch.sie_block->sidad = __get_free_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO); - if (!vcpu->arch.sie_block->sidad) { + sida_addr = (void *)__get_free_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO); + if (!sida_addr) { free_pages(vcpu->arch.pv.stor_base, get_order(uv_info.guest_cpu_stor_len)); return -ENOMEM; } + vcpu->arch.sie_block->sidad = virt_to_phys(sida_addr); cc = uv_call(0, (u64)&uvcb); *rc = uvcb.header.rc; @@ -108,7 +159,7 @@ static void kvm_s390_pv_dealloc_vm(struct kvm *kvm) vfree(kvm->arch.pv.stor_var); free_pages(kvm->arch.pv.stor_base, get_order(uv_info.guest_base_stor_len)); - memset(&kvm->arch.pv, 0, sizeof(kvm->arch.pv)); + kvm_s390_clear_pv_state(kvm); } static int kvm_s390_pv_alloc_vm(struct kvm *kvm) @@ -147,26 +198,363 @@ out_err: return -ENOMEM; } -/* this should not fail, but if it does, we must not free the donated memory */ -int kvm_s390_pv_deinit_vm(struct kvm *kvm, u16 *rc, u16 *rrc) +/** + * kvm_s390_pv_dispose_one_leftover - Clean up one leftover protected VM. + * @kvm: the KVM that was associated with this leftover protected VM + * @leftover: details about the leftover protected VM that needs a clean up + * @rc: the RC code of the Destroy Secure Configuration UVC + * @rrc: the RRC code of the Destroy Secure Configuration UVC + * + * Destroy one leftover protected VM. + * On success, kvm->mm->context.protected_count will be decremented atomically + * and all other resources used by the VM will be freed. + * + * Return: 0 in case of success, otherwise 1 + */ +static int kvm_s390_pv_dispose_one_leftover(struct kvm *kvm, + struct pv_vm_to_be_destroyed *leftover, + u16 *rc, u16 *rrc) { int cc; - /* make all pages accessible before destroying the guest */ - s390_reset_acc(kvm->mm); + /* It used the destroy-fast UVC, nothing left to do here */ + if (!leftover->handle) + goto done_fast; + cc = uv_cmd_nodata(leftover->handle, UVC_CMD_DESTROY_SEC_CONF, rc, rrc); + KVM_UV_EVENT(kvm, 3, "PROTVIRT DESTROY LEFTOVER VM: rc %x rrc %x", *rc, *rrc); + WARN_ONCE(cc, "protvirt destroy leftover vm failed rc %x rrc %x", *rc, *rrc); + if (cc) + return cc; + /* + * Intentionally leak unusable memory. If the UVC fails, the memory + * used for the VM and its metadata is permanently unusable. + * This can only happen in case of a serious KVM or hardware bug; it + * is not expected to happen in normal operation. + */ + free_pages(leftover->stor_base, get_order(uv_info.guest_base_stor_len)); + free_pages(leftover->old_gmap_table, CRST_ALLOC_ORDER); + vfree(leftover->stor_var); +done_fast: + atomic_dec(&kvm->mm->context.protected_count); + return 0; +} + +/** + * kvm_s390_destroy_lower_2g - Destroy the first 2GB of protected guest memory. + * @kvm: the VM whose memory is to be cleared. + * + * Destroy the first 2GB of guest memory, to avoid prefix issues after reboot. + * The CPUs of the protected VM need to be destroyed beforehand. + */ +static void kvm_s390_destroy_lower_2g(struct kvm *kvm) +{ + const unsigned long pages_2g = SZ_2G / PAGE_SIZE; + struct kvm_memory_slot *slot; + unsigned long len; + int srcu_idx; + + srcu_idx = srcu_read_lock(&kvm->srcu); + + /* Take the memslot containing guest absolute address 0 */ + slot = gfn_to_memslot(kvm, 0); + /* Clear all slots or parts thereof that are below 2GB */ + while (slot && slot->base_gfn < pages_2g) { + len = min_t(u64, slot->npages, pages_2g - slot->base_gfn) * PAGE_SIZE; + s390_uv_destroy_range(kvm->mm, slot->userspace_addr, slot->userspace_addr + len); + /* Take the next memslot */ + slot = gfn_to_memslot(kvm, slot->base_gfn + slot->npages); + } + + srcu_read_unlock(&kvm->srcu, srcu_idx); +} + +static int kvm_s390_pv_deinit_vm_fast(struct kvm *kvm, u16 *rc, u16 *rrc) +{ + struct uv_cb_destroy_fast uvcb = { + .header.cmd = UVC_CMD_DESTROY_SEC_CONF_FAST, + .header.len = sizeof(uvcb), + .handle = kvm_s390_pv_get_handle(kvm), + }; + int cc; + + cc = uv_call_sched(0, (u64)&uvcb); + if (rc) + *rc = uvcb.header.rc; + if (rrc) + *rrc = uvcb.header.rrc; + WRITE_ONCE(kvm->arch.gmap->guest_handle, 0); + KVM_UV_EVENT(kvm, 3, "PROTVIRT DESTROY VM FAST: rc %x rrc %x", + uvcb.header.rc, uvcb.header.rrc); + WARN_ONCE(cc && uvcb.header.rc != 0x104, + "protvirt destroy vm fast failed handle %llx rc %x rrc %x", + kvm_s390_pv_get_handle(kvm), uvcb.header.rc, uvcb.header.rrc); + /* Intended memory leak on "impossible" error */ + if (!cc) + kvm_s390_pv_dealloc_vm(kvm); + return cc ? -EIO : 0; +} + +static inline bool is_destroy_fast_available(void) +{ + return test_bit_inv(BIT_UVC_CMD_DESTROY_SEC_CONF_FAST, uv_info.inst_calls_list); +} + +/** + * kvm_s390_pv_set_aside - Set aside a protected VM for later teardown. + * @kvm: the VM + * @rc: return value for the RC field of the UVCB + * @rrc: return value for the RRC field of the UVCB + * + * Set aside the protected VM for a subsequent teardown. The VM will be able + * to continue immediately as a non-secure VM, and the information needed to + * properly tear down the protected VM is set aside. If another protected VM + * was already set aside without starting its teardown, this function will + * fail. + * The CPUs of the protected VM need to be destroyed beforehand. + * + * Context: kvm->lock needs to be held + * + * Return: 0 in case of success, -EINVAL if another protected VM was already set + * aside, -ENOMEM if the system ran out of memory. + */ +int kvm_s390_pv_set_aside(struct kvm *kvm, u16 *rc, u16 *rrc) +{ + struct pv_vm_to_be_destroyed *priv; + int res = 0; + + lockdep_assert_held(&kvm->lock); + /* + * If another protected VM was already prepared for teardown, refuse. + * A normal deinitialization has to be performed instead. + */ + if (kvm->arch.pv.set_aside) + return -EINVAL; + + /* Guest with segment type ASCE, refuse to destroy asynchronously */ + if ((kvm->arch.gmap->asce & _ASCE_TYPE_MASK) == _ASCE_TYPE_SEGMENT) + return -EINVAL; + + priv = kzalloc(sizeof(*priv), GFP_KERNEL); + if (!priv) + return -ENOMEM; + + if (is_destroy_fast_available()) { + res = kvm_s390_pv_deinit_vm_fast(kvm, rc, rrc); + } else { + priv->stor_var = kvm->arch.pv.stor_var; + priv->stor_base = kvm->arch.pv.stor_base; + priv->handle = kvm_s390_pv_get_handle(kvm); + priv->old_gmap_table = (unsigned long)kvm->arch.gmap->table; + WRITE_ONCE(kvm->arch.gmap->guest_handle, 0); + if (s390_replace_asce(kvm->arch.gmap)) + res = -ENOMEM; + } + + if (res) { + kfree(priv); + return res; + } + + kvm_s390_destroy_lower_2g(kvm); + kvm_s390_clear_pv_state(kvm); + kvm->arch.pv.set_aside = priv; + + *rc = UVC_RC_EXECUTED; + *rrc = 42; + return 0; +} + +/** + * kvm_s390_pv_deinit_vm - Deinitialize the current protected VM + * @kvm: the KVM whose protected VM needs to be deinitialized + * @rc: the RC code of the UVC + * @rrc: the RRC code of the UVC + * + * Deinitialize the current protected VM. This function will destroy and + * cleanup the current protected VM, but it will not cleanup the guest + * memory. This function should only be called when the protected VM has + * just been created and therefore does not have any guest memory, or when + * the caller cleans up the guest memory separately. + * + * This function should not fail, but if it does, the donated memory must + * not be freed. + * + * Context: kvm->lock needs to be held + * + * Return: 0 in case of success, otherwise -EIO + */ +int kvm_s390_pv_deinit_vm(struct kvm *kvm, u16 *rc, u16 *rrc) +{ + int cc; cc = uv_cmd_nodata(kvm_s390_pv_get_handle(kvm), UVC_CMD_DESTROY_SEC_CONF, rc, rrc); WRITE_ONCE(kvm->arch.gmap->guest_handle, 0); - atomic_set(&kvm->mm->context.is_protected, 0); + if (!cc) { + atomic_dec(&kvm->mm->context.protected_count); + kvm_s390_pv_dealloc_vm(kvm); + } else { + /* Intended memory leak on "impossible" error */ + s390_replace_asce(kvm->arch.gmap); + } KVM_UV_EVENT(kvm, 3, "PROTVIRT DESTROY VM: rc %x rrc %x", *rc, *rrc); WARN_ONCE(cc, "protvirt destroy vm failed rc %x rrc %x", *rc, *rrc); - /* Inteded memory leak on "impossible" error */ - if (!cc) - kvm_s390_pv_dealloc_vm(kvm); + return cc ? -EIO : 0; } +/** + * kvm_s390_pv_deinit_cleanup_all - Clean up all protected VMs associated + * with a specific KVM. + * @kvm: the KVM to be cleaned up + * @rc: the RC code of the first failing UVC + * @rrc: the RRC code of the first failing UVC + * + * This function will clean up all protected VMs associated with a KVM. + * This includes the active one, the one prepared for deinitialization with + * kvm_s390_pv_set_aside, and any still pending in the need_cleanup list. + * + * Context: kvm->lock needs to be held unless being called from + * kvm_arch_destroy_vm. + * + * Return: 0 if all VMs are successfully cleaned up, otherwise -EIO + */ +int kvm_s390_pv_deinit_cleanup_all(struct kvm *kvm, u16 *rc, u16 *rrc) +{ + struct pv_vm_to_be_destroyed *cur; + bool need_zap = false; + u16 _rc, _rrc; + int cc = 0; + + /* + * Nothing to do if the counter was already 0. Otherwise make sure + * the counter does not reach 0 before calling s390_uv_destroy_range. + */ + if (!atomic_inc_not_zero(&kvm->mm->context.protected_count)) + return 0; + + *rc = 1; + /* If the current VM is protected, destroy it */ + if (kvm_s390_pv_get_handle(kvm)) { + cc = kvm_s390_pv_deinit_vm(kvm, rc, rrc); + need_zap = true; + } + + /* If a previous protected VM was set aside, put it in the need_cleanup list */ + if (kvm->arch.pv.set_aside) { + list_add(kvm->arch.pv.set_aside, &kvm->arch.pv.need_cleanup); + kvm->arch.pv.set_aside = NULL; + } + + /* Cleanup all protected VMs in the need_cleanup list */ + while (!list_empty(&kvm->arch.pv.need_cleanup)) { + cur = list_first_entry(&kvm->arch.pv.need_cleanup, typeof(*cur), list); + need_zap = true; + if (kvm_s390_pv_dispose_one_leftover(kvm, cur, &_rc, &_rrc)) { + cc = 1; + /* + * Only return the first error rc and rrc, so make + * sure it is not overwritten. All destroys will + * additionally be reported via KVM_UV_EVENT(). + */ + if (*rc == UVC_RC_EXECUTED) { + *rc = _rc; + *rrc = _rrc; + } + } + list_del(&cur->list); + kfree(cur); + } + + /* + * If the mm still has a mapping, try to mark all its pages as + * accessible. The counter should not reach zero before this + * cleanup has been performed. + */ + if (need_zap && mmget_not_zero(kvm->mm)) { + s390_uv_destroy_range(kvm->mm, 0, TASK_SIZE); + mmput(kvm->mm); + } + + /* Now the counter can safely reach 0 */ + atomic_dec(&kvm->mm->context.protected_count); + return cc ? -EIO : 0; +} + +/** + * kvm_s390_pv_deinit_aside_vm - Teardown a previously set aside protected VM. + * @kvm: the VM previously associated with the protected VM + * @rc: return value for the RC field of the UVCB + * @rrc: return value for the RRC field of the UVCB + * + * Tear down the protected VM that had been previously prepared for teardown + * using kvm_s390_pv_set_aside_vm. Ideally this should be called by + * userspace asynchronously from a separate thread. + * + * Context: kvm->lock must not be held. + * + * Return: 0 in case of success, -EINVAL if no protected VM had been + * prepared for asynchronous teardowm, -EIO in case of other errors. + */ +int kvm_s390_pv_deinit_aside_vm(struct kvm *kvm, u16 *rc, u16 *rrc) +{ + struct pv_vm_to_be_destroyed *p; + int ret = 0; + + lockdep_assert_not_held(&kvm->lock); + mutex_lock(&kvm->lock); + p = kvm->arch.pv.set_aside; + kvm->arch.pv.set_aside = NULL; + mutex_unlock(&kvm->lock); + if (!p) + return -EINVAL; + + /* When a fatal signal is received, stop immediately */ + if (s390_uv_destroy_range_interruptible(kvm->mm, 0, TASK_SIZE_MAX)) + goto done; + if (kvm_s390_pv_dispose_one_leftover(kvm, p, rc, rrc)) + ret = -EIO; + kfree(p); + p = NULL; +done: + /* + * p is not NULL if we aborted because of a fatal signal, in which + * case queue the leftover for later cleanup. + */ + if (p) { + mutex_lock(&kvm->lock); + list_add(&p->list, &kvm->arch.pv.need_cleanup); + mutex_unlock(&kvm->lock); + /* Did not finish, but pretend things went well */ + *rc = UVC_RC_EXECUTED; + *rrc = 42; + } + return ret; +} + +static void kvm_s390_pv_mmu_notifier_release(struct mmu_notifier *subscription, + struct mm_struct *mm) +{ + struct kvm *kvm = container_of(subscription, struct kvm, arch.pv.mmu_notifier); + u16 dummy; + int r; + + /* + * No locking is needed since this is the last thread of the last user of this + * struct mm. + * When the struct kvm gets deinitialized, this notifier is also + * unregistered. This means that if this notifier runs, then the + * struct kvm is still valid. + */ + r = kvm_s390_cpus_from_pv(kvm, &dummy, &dummy); + if (!r && is_destroy_fast_available() && kvm_s390_pv_get_handle(kvm)) + kvm_s390_pv_deinit_vm_fast(kvm, &dummy, &dummy); +} + +static const struct mmu_notifier_ops kvm_s390_pv_mmu_notifier_ops = { + .release = kvm_s390_pv_mmu_notifier_release, +}; + int kvm_s390_pv_init_vm(struct kvm *kvm, u16 *rc, u16 *rrc) { struct uv_cb_cgc uvcb = { @@ -184,27 +572,38 @@ int kvm_s390_pv_init_vm(struct kvm *kvm, u16 *rc, u16 *rrc) uvcb.guest_stor_origin = 0; /* MSO is 0 for KVM */ uvcb.guest_stor_len = kvm->arch.pv.guest_len; uvcb.guest_asce = kvm->arch.gmap->asce; - uvcb.guest_sca = (unsigned long)kvm->arch.sca; - uvcb.conf_base_stor_origin = (u64)kvm->arch.pv.stor_base; + uvcb.guest_sca = virt_to_phys(kvm->arch.sca); + uvcb.conf_base_stor_origin = + virt_to_phys((void *)kvm->arch.pv.stor_base); uvcb.conf_virt_stor_origin = (u64)kvm->arch.pv.stor_var; + uvcb.flags.ap_allow_instr = kvm->arch.model.uv_feat_guest.ap; + uvcb.flags.ap_instr_intr = kvm->arch.model.uv_feat_guest.ap_intr; cc = uv_call_sched(0, (u64)&uvcb); *rc = uvcb.header.rc; *rrc = uvcb.header.rrc; - KVM_UV_EVENT(kvm, 3, "PROTVIRT CREATE VM: handle %llx len %llx rc %x rrc %x", - uvcb.guest_handle, uvcb.guest_stor_len, *rc, *rrc); + KVM_UV_EVENT(kvm, 3, "PROTVIRT CREATE VM: handle %llx len %llx rc %x rrc %x flags %04x", + uvcb.guest_handle, uvcb.guest_stor_len, *rc, *rrc, uvcb.flags.raw); /* Outputs */ kvm->arch.pv.handle = uvcb.guest_handle; + atomic_inc(&kvm->mm->context.protected_count); if (cc) { - if (uvcb.header.rc & UVC_RC_NEED_DESTROY) + if (uvcb.header.rc & UVC_RC_NEED_DESTROY) { kvm_s390_pv_deinit_vm(kvm, &dummy, &dummy); - else + } else { + atomic_dec(&kvm->mm->context.protected_count); kvm_s390_pv_dealloc_vm(kvm); + } return -EIO; } kvm->arch.gmap->guest_handle = uvcb.guest_handle; + /* Add the notifier only once. No races because we hold kvm->lock */ + if (kvm->arch.pv.mmu_notifier.ops != &kvm_s390_pv_mmu_notifier_ops) { + kvm->arch.pv.mmu_notifier.ops = &kvm_s390_pv_mmu_notifier_ops; + mmu_notifier_register(&kvm->arch.pv.mmu_notifier, kvm->mm); + } return 0; } @@ -224,8 +623,6 @@ int kvm_s390_pv_set_sec_parms(struct kvm *kvm, void *hdr, u64 length, u16 *rc, *rrc = uvcb.header.rrc; KVM_UV_EVENT(kvm, 3, "PROTVIRT VM SET PARMS: rc %x rrc %x", *rc, *rrc); - if (!cc) - atomic_set(&kvm->mm->context.is_protected, 1); return cc ? -EINVAL : 0; } @@ -298,3 +695,200 @@ int kvm_s390_pv_set_cpu_state(struct kvm_vcpu *vcpu, u8 state) return -EINVAL; return 0; } + +int kvm_s390_pv_dump_cpu(struct kvm_vcpu *vcpu, void *buff, u16 *rc, u16 *rrc) +{ + struct uv_cb_dump_cpu uvcb = { + .header.cmd = UVC_CMD_DUMP_CPU, + .header.len = sizeof(uvcb), + .cpu_handle = vcpu->arch.pv.handle, + .dump_area_origin = (u64)buff, + }; + int cc; + + cc = uv_call_sched(0, (u64)&uvcb); + *rc = uvcb.header.rc; + *rrc = uvcb.header.rrc; + return cc; +} + +/* Size of the cache for the storage state dump data. 1MB for now */ +#define DUMP_BUFF_LEN HPAGE_SIZE + +/** + * kvm_s390_pv_dump_stor_state + * + * @kvm: pointer to the guest's KVM struct + * @buff_user: Userspace pointer where we will write the results to + * @gaddr: Starting absolute guest address for which the storage state + * is requested. + * @buff_user_len: Length of the buff_user buffer + * @rc: Pointer to where the uvcb return code is stored + * @rrc: Pointer to where the uvcb return reason code is stored + * + * Stores buff_len bytes of tweak component values to buff_user + * starting with the 1MB block specified by the absolute guest address + * (gaddr). The gaddr pointer will be updated with the last address + * for which data was written when returning to userspace. buff_user + * might be written to even if an error rc is returned. For instance + * if we encounter a fault after writing the first page of data. + * + * Context: kvm->lock needs to be held + * + * Return: + * 0 on success + * -ENOMEM if allocating the cache fails + * -EINVAL if gaddr is not aligned to 1MB + * -EINVAL if buff_user_len is not aligned to uv_info.conf_dump_storage_state_len + * -EINVAL if the UV call fails, rc and rrc will be set in this case + * -EFAULT if copying the result to buff_user failed + */ +int kvm_s390_pv_dump_stor_state(struct kvm *kvm, void __user *buff_user, + u64 *gaddr, u64 buff_user_len, u16 *rc, u16 *rrc) +{ + struct uv_cb_dump_stor_state uvcb = { + .header.cmd = UVC_CMD_DUMP_CONF_STOR_STATE, + .header.len = sizeof(uvcb), + .config_handle = kvm->arch.pv.handle, + .gaddr = *gaddr, + .dump_area_origin = 0, + }; + const u64 increment_len = uv_info.conf_dump_storage_state_len; + size_t buff_kvm_size; + size_t size_done = 0; + u8 *buff_kvm = NULL; + int cc, ret; + + ret = -EINVAL; + /* UV call processes 1MB guest storage chunks at a time */ + if (!IS_ALIGNED(*gaddr, HPAGE_SIZE)) + goto out; + + /* + * We provide the storage state for 1MB chunks of guest + * storage. The buffer will need to be aligned to + * conf_dump_storage_state_len so we don't end on a partial + * chunk. + */ + if (!buff_user_len || + !IS_ALIGNED(buff_user_len, increment_len)) + goto out; + + /* + * Allocate a buffer from which we will later copy to the user + * process. We don't want userspace to dictate our buffer size + * so we limit it to DUMP_BUFF_LEN. + */ + ret = -ENOMEM; + buff_kvm_size = min_t(u64, buff_user_len, DUMP_BUFF_LEN); + buff_kvm = vzalloc(buff_kvm_size); + if (!buff_kvm) + goto out; + + ret = 0; + uvcb.dump_area_origin = (u64)buff_kvm; + /* We will loop until the user buffer is filled or an error occurs */ + do { + /* Get 1MB worth of guest storage state data */ + cc = uv_call_sched(0, (u64)&uvcb); + + /* All or nothing */ + if (cc) { + ret = -EINVAL; + break; + } + + size_done += increment_len; + uvcb.dump_area_origin += increment_len; + buff_user_len -= increment_len; + uvcb.gaddr += HPAGE_SIZE; + + /* KVM Buffer full, time to copy to the process */ + if (!buff_user_len || size_done == DUMP_BUFF_LEN) { + if (copy_to_user(buff_user, buff_kvm, size_done)) { + ret = -EFAULT; + break; + } + + buff_user += size_done; + size_done = 0; + uvcb.dump_area_origin = (u64)buff_kvm; + } + } while (buff_user_len); + + /* Report back where we ended dumping */ + *gaddr = uvcb.gaddr; + + /* Lets only log errors, we don't want to spam */ +out: + if (ret) + KVM_UV_EVENT(kvm, 3, + "PROTVIRT DUMP STORAGE STATE: addr %llx ret %d, uvcb rc %x rrc %x", + uvcb.gaddr, ret, uvcb.header.rc, uvcb.header.rrc); + *rc = uvcb.header.rc; + *rrc = uvcb.header.rrc; + vfree(buff_kvm); + + return ret; +} + +/** + * kvm_s390_pv_dump_complete + * + * @kvm: pointer to the guest's KVM struct + * @buff_user: Userspace pointer where we will write the results to + * @rc: Pointer to where the uvcb return code is stored + * @rrc: Pointer to where the uvcb return reason code is stored + * + * Completes the dumping operation and writes the completion data to + * user space. + * + * Context: kvm->lock needs to be held + * + * Return: + * 0 on success + * -ENOMEM if allocating the completion buffer fails + * -EINVAL if the UV call fails, rc and rrc will be set in this case + * -EFAULT if copying the result to buff_user failed + */ +int kvm_s390_pv_dump_complete(struct kvm *kvm, void __user *buff_user, + u16 *rc, u16 *rrc) +{ + struct uv_cb_dump_complete complete = { + .header.len = sizeof(complete), + .header.cmd = UVC_CMD_DUMP_COMPLETE, + .config_handle = kvm_s390_pv_get_handle(kvm), + }; + u64 *compl_data; + int ret; + + /* Allocate dump area */ + compl_data = vzalloc(uv_info.conf_dump_finalize_len); + if (!compl_data) + return -ENOMEM; + complete.dump_area_origin = (u64)compl_data; + + ret = uv_call_sched(0, (u64)&complete); + *rc = complete.header.rc; + *rrc = complete.header.rrc; + KVM_UV_EVENT(kvm, 3, "PROTVIRT DUMP COMPLETE: rc %x rrc %x", + complete.header.rc, complete.header.rrc); + + if (!ret) { + /* + * kvm_s390_pv_dealloc_vm() will also (mem)set + * this to false on a reboot or other destroy + * operation for this vm. + */ + kvm->arch.pv.dumping = false; + kvm_s390_vcpu_unblock_all(kvm); + ret = copy_to_user(buff_user, compl_data, uv_info.conf_dump_finalize_len); + if (ret) + ret = -EFAULT; + } + vfree(compl_data); + /* If the UVC returned an error, translate it to -EINVAL */ + if (ret > 0) + ret = -EINVAL; + return ret; +} |