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-rw-r--r--arch/s390/kvm/pv.c545
1 files changed, 545 insertions, 0 deletions
diff --git a/arch/s390/kvm/pv.c b/arch/s390/kvm/pv.c
new file mode 100644
index 000000000..7cb7799a0
--- /dev/null
+++ b/arch/s390/kvm/pv.c
@@ -0,0 +1,545 @@
+// SPDX-License-Identifier: GPL-2.0
+/*
+ * Hosting Protected Virtual Machines
+ *
+ * Copyright IBM Corp. 2019, 2020
+ * Author(s): Janosch Frank <frankja@linux.ibm.com>
+ */
+#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"
+
+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;
+
+ if (!kvm_s390_pv_cpu_get_handle(vcpu))
+ return 0;
+
+ cc = uv_cmd_nodata(kvm_s390_pv_cpu_get_handle(vcpu), UVC_CMD_DESTROY_SEC_CPU, rc, rrc);
+
+ KVM_UV_EVENT(vcpu->kvm, 3, "PROTVIRT DESTROY VCPU %d: rc %x rrc %x",
+ vcpu->vcpu_id, *rc, *rrc);
+ WARN_ONCE(cc, "protvirt destroy cpu failed rc %x rrc %x", *rc, *rrc);
+
+ /* Intended memory leak for something that should never happen. */
+ if (!cc)
+ free_pages(vcpu->arch.pv.stor_base,
+ get_order(uv_info.guest_cpu_stor_len));
+
+ free_page(sida_origin(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));
+ vcpu->arch.sie_block->sdf = 0;
+ /*
+ * The sidad field (for sdf == 2) is now the gbea field (for sdf == 0).
+ * Use the reset value of gbea to avoid leaking the kernel pointer of
+ * the just freed sida.
+ */
+ vcpu->arch.sie_block->gbea = 1;
+ kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
+
+ return cc ? EIO : 0;
+}
+
+int kvm_s390_pv_create_cpu(struct kvm_vcpu *vcpu, u16 *rc, u16 *rrc)
+{
+ struct uv_cb_csc uvcb = {
+ .header.cmd = UVC_CMD_CREATE_SEC_CPU,
+ .header.len = sizeof(uvcb),
+ };
+ int cc;
+
+ if (kvm_s390_pv_cpu_get_handle(vcpu))
+ return -EINVAL;
+
+ vcpu->arch.pv.stor_base = __get_free_pages(GFP_KERNEL_ACCOUNT,
+ get_order(uv_info.guest_cpu_stor_len));
+ if (!vcpu->arch.pv.stor_base)
+ return -ENOMEM;
+
+ /* 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;
+
+ /* 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) {
+ free_pages(vcpu->arch.pv.stor_base,
+ get_order(uv_info.guest_cpu_stor_len));
+ return -ENOMEM;
+ }
+
+ cc = uv_call(0, (u64)&uvcb);
+ *rc = uvcb.header.rc;
+ *rrc = uvcb.header.rrc;
+ KVM_UV_EVENT(vcpu->kvm, 3,
+ "PROTVIRT CREATE VCPU: cpu %d handle %llx rc %x rrc %x",
+ vcpu->vcpu_id, uvcb.cpu_handle, uvcb.header.rc,
+ uvcb.header.rrc);
+
+ if (cc) {
+ u16 dummy;
+
+ kvm_s390_pv_destroy_cpu(vcpu, &dummy, &dummy);
+ return -EIO;
+ }
+
+ /* Output */
+ vcpu->arch.pv.handle = uvcb.cpu_handle;
+ vcpu->arch.sie_block->pv_handle_cpu = uvcb.cpu_handle;
+ vcpu->arch.sie_block->pv_handle_config = kvm_s390_pv_get_handle(vcpu->kvm);
+ vcpu->arch.sie_block->sdf = 2;
+ kvm_make_request(KVM_REQ_TLB_FLUSH, vcpu);
+ return 0;
+}
+
+/* only free resources when the destroy was successful */
+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));
+ kvm_s390_clear_pv_state(kvm);
+}
+
+static int kvm_s390_pv_alloc_vm(struct kvm *kvm)
+{
+ unsigned long base = uv_info.guest_base_stor_len;
+ unsigned long virt = uv_info.guest_virt_var_stor_len;
+ unsigned long npages = 0, vlen = 0;
+
+ kvm->arch.pv.stor_var = NULL;
+ kvm->arch.pv.stor_base = __get_free_pages(GFP_KERNEL_ACCOUNT, get_order(base));
+ if (!kvm->arch.pv.stor_base)
+ return -ENOMEM;
+
+ /*
+ * Calculate current guest storage for allocation of the
+ * variable storage, which is based on the length in MB.
+ *
+ * Slots are sorted by GFN
+ */
+ mutex_lock(&kvm->slots_lock);
+ npages = kvm_s390_get_gfn_end(kvm_memslots(kvm));
+ mutex_unlock(&kvm->slots_lock);
+
+ kvm->arch.pv.guest_len = npages * PAGE_SIZE;
+
+ /* Allocate variable storage */
+ vlen = ALIGN(virt * ((npages * PAGE_SIZE) / HPAGE_SIZE), PAGE_SIZE);
+ vlen += uv_info.guest_virt_base_stor_len;
+ kvm->arch.pv.stor_var = vzalloc(vlen);
+ if (!kvm->arch.pv.stor_var)
+ goto out_err;
+ return 0;
+
+out_err:
+ kvm_s390_pv_dealloc_vm(kvm);
+ 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)
+{
+ 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);
+ /*
+ * if the mm still has a mapping, make all its pages accessible
+ * before destroying the guest
+ */
+ if (mmget_not_zero(kvm->mm)) {
+ s390_uv_destroy_range(kvm->mm, 0, TASK_SIZE);
+ mmput(kvm->mm);
+ }
+
+ 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);
+
+ return cc ? -EIO : 0;
+}
+
+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;
+
+ /*
+ * 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.
+ */
+ kvm_s390_cpus_from_pv(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 = {
+ .header.cmd = UVC_CMD_CREATE_SEC_CONF,
+ .header.len = sizeof(uvcb)
+ };
+ int cc, ret;
+ u16 dummy;
+
+ ret = kvm_s390_pv_alloc_vm(kvm);
+ if (ret)
+ return ret;
+
+ /* Inputs */
+ 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.conf_virt_stor_origin = (u64)kvm->arch.pv.stor_var;
+
+ 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);
+
+ /* 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) {
+ kvm_s390_pv_deinit_vm(kvm, &dummy, &dummy);
+ } 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;
+}
+
+int kvm_s390_pv_set_sec_parms(struct kvm *kvm, void *hdr, u64 length, u16 *rc,
+ u16 *rrc)
+{
+ struct uv_cb_ssc uvcb = {
+ .header.cmd = UVC_CMD_SET_SEC_CONF_PARAMS,
+ .header.len = sizeof(uvcb),
+ .sec_header_origin = (u64)hdr,
+ .sec_header_len = length,
+ .guest_handle = kvm_s390_pv_get_handle(kvm),
+ };
+ int cc = uv_call(0, (u64)&uvcb);
+
+ *rc = uvcb.header.rc;
+ *rrc = uvcb.header.rrc;
+ KVM_UV_EVENT(kvm, 3, "PROTVIRT VM SET PARMS: rc %x rrc %x",
+ *rc, *rrc);
+ return cc ? -EINVAL : 0;
+}
+
+static int unpack_one(struct kvm *kvm, unsigned long addr, u64 tweak,
+ u64 offset, u16 *rc, u16 *rrc)
+{
+ struct uv_cb_unp uvcb = {
+ .header.cmd = UVC_CMD_UNPACK_IMG,
+ .header.len = sizeof(uvcb),
+ .guest_handle = kvm_s390_pv_get_handle(kvm),
+ .gaddr = addr,
+ .tweak[0] = tweak,
+ .tweak[1] = offset,
+ };
+ int ret = gmap_make_secure(kvm->arch.gmap, addr, &uvcb);
+
+ *rc = uvcb.header.rc;
+ *rrc = uvcb.header.rrc;
+
+ if (ret && ret != -EAGAIN)
+ KVM_UV_EVENT(kvm, 3, "PROTVIRT VM UNPACK: failed addr %llx with rc %x rrc %x",
+ uvcb.gaddr, *rc, *rrc);
+ return ret;
+}
+
+int kvm_s390_pv_unpack(struct kvm *kvm, unsigned long addr, unsigned long size,
+ unsigned long tweak, u16 *rc, u16 *rrc)
+{
+ u64 offset = 0;
+ int ret = 0;
+
+ if (addr & ~PAGE_MASK || !size || size & ~PAGE_MASK)
+ return -EINVAL;
+
+ KVM_UV_EVENT(kvm, 3, "PROTVIRT VM UNPACK: start addr %lx size %lx",
+ addr, size);
+
+ while (offset < size) {
+ ret = unpack_one(kvm, addr, tweak, offset, rc, rrc);
+ if (ret == -EAGAIN) {
+ cond_resched();
+ if (fatal_signal_pending(current))
+ break;
+ continue;
+ }
+ if (ret)
+ break;
+ addr += PAGE_SIZE;
+ offset += PAGE_SIZE;
+ }
+ if (!ret)
+ KVM_UV_EVENT(kvm, 3, "%s", "PROTVIRT VM UNPACK: successful");
+ return ret;
+}
+
+int kvm_s390_pv_set_cpu_state(struct kvm_vcpu *vcpu, u8 state)
+{
+ struct uv_cb_cpu_set_state uvcb = {
+ .header.cmd = UVC_CMD_CPU_SET_STATE,
+ .header.len = sizeof(uvcb),
+ .cpu_handle = kvm_s390_pv_cpu_get_handle(vcpu),
+ .state = state,
+ };
+ int cc;
+
+ cc = uv_call(0, (u64)&uvcb);
+ KVM_UV_EVENT(vcpu->kvm, 3, "PROTVIRT SET CPU %d STATE %d rc %x rrc %x",
+ vcpu->vcpu_id, state, uvcb.header.rc, uvcb.header.rrc);
+ if (cc)
+ 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;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-08 04:51:55 +0000