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Diffstat (limited to 'arch/x86/kvm/svm/sev.c')
-rw-r--r--arch/x86/kvm/svm/sev.c269
1 files changed, 151 insertions, 118 deletions
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 902c52a8dd0c..be2883141220 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -237,7 +237,6 @@ static void sev_unbind_asid(struct kvm *kvm, unsigned int handle)
static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
{
struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
- bool es_active = argp->id == KVM_SEV_ES_INIT;
int asid, ret;
if (kvm->created_vcpus)
@@ -247,7 +246,8 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
if (unlikely(sev->active))
return ret;
- sev->es_active = es_active;
+ sev->active = true;
+ sev->es_active = argp->id == KVM_SEV_ES_INIT;
asid = sev_asid_new(sev);
if (asid < 0)
goto e_no_asid;
@@ -257,8 +257,6 @@ static int sev_guest_init(struct kvm *kvm, struct kvm_sev_cmd *argp)
if (ret)
goto e_free;
- sev->active = true;
- sev->asid = asid;
INIT_LIST_HEAD(&sev->regions_list);
return 0;
@@ -268,6 +266,7 @@ e_free:
sev->asid = 0;
e_no_asid:
sev->es_active = false;
+ sev->active = false;
return ret;
}
@@ -1530,7 +1529,7 @@ static int sev_receive_finish(struct kvm *kvm, struct kvm_sev_cmd *argp)
return sev_issue_cmd(kvm, SEV_CMD_RECEIVE_FINISH, &data, &argp->error);
}
-static bool cmd_allowed_from_miror(u32 cmd_id)
+static bool is_cmd_allowed_from_mirror(u32 cmd_id)
{
/*
* Allow mirrors VM to call KVM_SEV_LAUNCH_UPDATE_VMSA to enable SEV-ES
@@ -1544,28 +1543,50 @@ static bool cmd_allowed_from_miror(u32 cmd_id)
return false;
}
-static int sev_lock_for_migration(struct kvm *kvm)
+static int sev_lock_two_vms(struct kvm *dst_kvm, struct kvm *src_kvm)
{
- struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
+ struct kvm_sev_info *dst_sev = &to_kvm_svm(dst_kvm)->sev_info;
+ struct kvm_sev_info *src_sev = &to_kvm_svm(src_kvm)->sev_info;
+ int r = -EBUSY;
+
+ if (dst_kvm == src_kvm)
+ return -EINVAL;
/*
- * Bail if this VM is already involved in a migration to avoid deadlock
- * between two VMs trying to migrate to/from each other.
+ * Bail if these VMs are already involved in a migration to avoid
+ * deadlock between two VMs trying to migrate to/from each other.
*/
- if (atomic_cmpxchg_acquire(&sev->migration_in_progress, 0, 1))
+ if (atomic_cmpxchg_acquire(&dst_sev->migration_in_progress, 0, 1))
return -EBUSY;
- mutex_lock(&kvm->lock);
+ if (atomic_cmpxchg_acquire(&src_sev->migration_in_progress, 0, 1))
+ goto release_dst;
+ r = -EINTR;
+ if (mutex_lock_killable(&dst_kvm->lock))
+ goto release_src;
+ if (mutex_lock_killable_nested(&src_kvm->lock, SINGLE_DEPTH_NESTING))
+ goto unlock_dst;
return 0;
+
+unlock_dst:
+ mutex_unlock(&dst_kvm->lock);
+release_src:
+ atomic_set_release(&src_sev->migration_in_progress, 0);
+release_dst:
+ atomic_set_release(&dst_sev->migration_in_progress, 0);
+ return r;
}
-static void sev_unlock_after_migration(struct kvm *kvm)
+static void sev_unlock_two_vms(struct kvm *dst_kvm, struct kvm *src_kvm)
{
- struct kvm_sev_info *sev = &to_kvm_svm(kvm)->sev_info;
+ struct kvm_sev_info *dst_sev = &to_kvm_svm(dst_kvm)->sev_info;
+ struct kvm_sev_info *src_sev = &to_kvm_svm(src_kvm)->sev_info;
- mutex_unlock(&kvm->lock);
- atomic_set_release(&sev->migration_in_progress, 0);
+ mutex_unlock(&dst_kvm->lock);
+ mutex_unlock(&src_kvm->lock);
+ atomic_set_release(&dst_sev->migration_in_progress, 0);
+ atomic_set_release(&src_sev->migration_in_progress, 0);
}
@@ -1608,14 +1629,15 @@ static void sev_migrate_from(struct kvm_sev_info *dst,
dst->asid = src->asid;
dst->handle = src->handle;
dst->pages_locked = src->pages_locked;
+ dst->enc_context_owner = src->enc_context_owner;
src->asid = 0;
src->active = false;
src->handle = 0;
src->pages_locked = 0;
+ src->enc_context_owner = NULL;
- INIT_LIST_HEAD(&dst->regions_list);
- list_replace_init(&src->regions_list, &dst->regions_list);
+ list_cut_before(&dst->regions_list, &src->regions_list, &src->regions_list);
}
static int sev_es_migrate_from(struct kvm *dst, struct kvm *src)
@@ -1667,15 +1689,6 @@ int svm_vm_migrate_from(struct kvm *kvm, unsigned int source_fd)
bool charged = false;
int ret;
- ret = sev_lock_for_migration(kvm);
- if (ret)
- return ret;
-
- if (sev_guest(kvm)) {
- ret = -EINVAL;
- goto out_unlock;
- }
-
source_kvm_file = fget(source_fd);
if (!file_is_kvm(source_kvm_file)) {
ret = -EBADF;
@@ -1683,16 +1696,26 @@ int svm_vm_migrate_from(struct kvm *kvm, unsigned int source_fd)
}
source_kvm = source_kvm_file->private_data;
- ret = sev_lock_for_migration(source_kvm);
+ ret = sev_lock_two_vms(kvm, source_kvm);
if (ret)
goto out_fput;
- if (!sev_guest(source_kvm)) {
+ if (sev_guest(kvm) || !sev_guest(source_kvm)) {
ret = -EINVAL;
- goto out_source;
+ goto out_unlock;
}
src_sev = &to_kvm_svm(source_kvm)->sev_info;
+
+ /*
+ * VMs mirroring src's encryption context rely on it to keep the
+ * ASID allocated, but below we are clearing src_sev->asid.
+ */
+ if (src_sev->num_mirrored_vms) {
+ ret = -EBUSY;
+ goto out_unlock;
+ }
+
dst_sev->misc_cg = get_current_misc_cg();
cg_cleanup_sev = dst_sev;
if (dst_sev->misc_cg != src_sev->misc_cg) {
@@ -1729,13 +1752,11 @@ out_dst_cgroup:
sev_misc_cg_uncharge(cg_cleanup_sev);
put_misc_cg(cg_cleanup_sev->misc_cg);
cg_cleanup_sev->misc_cg = NULL;
-out_source:
- sev_unlock_after_migration(source_kvm);
+out_unlock:
+ sev_unlock_two_vms(kvm, source_kvm);
out_fput:
if (source_kvm_file)
fput(source_kvm_file);
-out_unlock:
- sev_unlock_after_migration(kvm);
return ret;
}
@@ -1757,7 +1778,7 @@ int svm_mem_enc_op(struct kvm *kvm, void __user *argp)
/* Only the enc_context_owner handles some memory enc operations. */
if (is_mirroring_enc_context(kvm) &&
- !cmd_allowed_from_miror(sev_cmd.id)) {
+ !is_cmd_allowed_from_mirror(sev_cmd.id)) {
r = -EINVAL;
goto out;
}
@@ -1954,71 +1975,60 @@ int svm_vm_copy_asid_from(struct kvm *kvm, unsigned int source_fd)
{
struct file *source_kvm_file;
struct kvm *source_kvm;
- struct kvm_sev_info source_sev, *mirror_sev;
+ struct kvm_sev_info *source_sev, *mirror_sev;
int ret;
source_kvm_file = fget(source_fd);
if (!file_is_kvm(source_kvm_file)) {
ret = -EBADF;
- goto e_source_put;
+ goto e_source_fput;
}
source_kvm = source_kvm_file->private_data;
- mutex_lock(&source_kvm->lock);
-
- if (!sev_guest(source_kvm)) {
- ret = -EINVAL;
- goto e_source_unlock;
- }
+ ret = sev_lock_two_vms(kvm, source_kvm);
+ if (ret)
+ goto e_source_fput;
- /* Mirrors of mirrors should work, but let's not get silly */
- if (is_mirroring_enc_context(source_kvm) || source_kvm == kvm) {
+ /*
+ * Mirrors of mirrors should work, but let's not get silly. Also
+ * disallow out-of-band SEV/SEV-ES init if the target is already an
+ * SEV guest, or if vCPUs have been created. KVM relies on vCPUs being
+ * created after SEV/SEV-ES initialization, e.g. to init intercepts.
+ */
+ if (sev_guest(kvm) || !sev_guest(source_kvm) ||
+ is_mirroring_enc_context(source_kvm) || kvm->created_vcpus) {
ret = -EINVAL;
- goto e_source_unlock;
+ goto e_unlock;
}
- memcpy(&source_sev, &to_kvm_svm(source_kvm)->sev_info,
- sizeof(source_sev));
-
/*
* The mirror kvm holds an enc_context_owner ref so its asid can't
* disappear until we're done with it
*/
+ source_sev = &to_kvm_svm(source_kvm)->sev_info;
kvm_get_kvm(source_kvm);
-
- fput(source_kvm_file);
- mutex_unlock(&source_kvm->lock);
- mutex_lock(&kvm->lock);
-
- if (sev_guest(kvm)) {
- ret = -EINVAL;
- goto e_mirror_unlock;
- }
+ source_sev->num_mirrored_vms++;
/* Set enc_context_owner and copy its encryption context over */
mirror_sev = &to_kvm_svm(kvm)->sev_info;
mirror_sev->enc_context_owner = source_kvm;
mirror_sev->active = true;
- mirror_sev->asid = source_sev.asid;
- mirror_sev->fd = source_sev.fd;
- mirror_sev->es_active = source_sev.es_active;
- mirror_sev->handle = source_sev.handle;
+ mirror_sev->asid = source_sev->asid;
+ mirror_sev->fd = source_sev->fd;
+ mirror_sev->es_active = source_sev->es_active;
+ mirror_sev->handle = source_sev->handle;
+ INIT_LIST_HEAD(&mirror_sev->regions_list);
+ ret = 0;
+
/*
* Do not copy ap_jump_table. Since the mirror does not share the same
* KVM contexts as the original, and they may have different
* memory-views.
*/
- mutex_unlock(&kvm->lock);
- return 0;
-
-e_mirror_unlock:
- mutex_unlock(&kvm->lock);
- kvm_put_kvm(source_kvm);
- return ret;
-e_source_unlock:
- mutex_unlock(&source_kvm->lock);
-e_source_put:
+e_unlock:
+ sev_unlock_two_vms(kvm, source_kvm);
+e_source_fput:
if (source_kvm_file)
fput(source_kvm_file);
return ret;
@@ -2030,17 +2040,24 @@ void sev_vm_destroy(struct kvm *kvm)
struct list_head *head = &sev->regions_list;
struct list_head *pos, *q;
+ WARN_ON(sev->num_mirrored_vms);
+
if (!sev_guest(kvm))
return;
/* If this is a mirror_kvm release the enc_context_owner and skip sev cleanup */
if (is_mirroring_enc_context(kvm)) {
- kvm_put_kvm(sev->enc_context_owner);
+ struct kvm *owner_kvm = sev->enc_context_owner;
+ struct kvm_sev_info *owner_sev = &to_kvm_svm(owner_kvm)->sev_info;
+
+ mutex_lock(&owner_kvm->lock);
+ if (!WARN_ON(!owner_sev->num_mirrored_vms))
+ owner_sev->num_mirrored_vms--;
+ mutex_unlock(&owner_kvm->lock);
+ kvm_put_kvm(owner_kvm);
return;
}
- mutex_lock(&kvm->lock);
-
/*
* Ensure that all guest tagged cache entries are flushed before
* releasing the pages back to the system for use. CLFLUSH will
@@ -2060,8 +2077,6 @@ void sev_vm_destroy(struct kvm *kvm)
}
}
- mutex_unlock(&kvm->lock);
-
sev_unbind_asid(kvm, sev->handle);
sev_asid_free(sev);
}
@@ -2245,7 +2260,7 @@ void sev_free_vcpu(struct kvm_vcpu *vcpu)
__free_page(virt_to_page(svm->sev_es.vmsa));
if (svm->sev_es.ghcb_sa_free)
- kfree(svm->sev_es.ghcb_sa);
+ kvfree(svm->sev_es.ghcb_sa);
}
static void dump_ghcb(struct vcpu_svm *svm)
@@ -2337,24 +2352,29 @@ static void sev_es_sync_from_ghcb(struct vcpu_svm *svm)
memset(ghcb->save.valid_bitmap, 0, sizeof(ghcb->save.valid_bitmap));
}
-static int sev_es_validate_vmgexit(struct vcpu_svm *svm)
+static bool sev_es_validate_vmgexit(struct vcpu_svm *svm)
{
struct kvm_vcpu *vcpu;
struct ghcb *ghcb;
- u64 exit_code = 0;
+ u64 exit_code;
+ u64 reason;
ghcb = svm->sev_es.ghcb;
- /* Only GHCB Usage code 0 is supported */
- if (ghcb->ghcb_usage)
- goto vmgexit_err;
-
/*
- * Retrieve the exit code now even though is may not be marked valid
+ * Retrieve the exit code now even though it may not be marked valid
* as it could help with debugging.
*/
exit_code = ghcb_get_sw_exit_code(ghcb);
+ /* Only GHCB Usage code 0 is supported */
+ if (ghcb->ghcb_usage) {
+ reason = GHCB_ERR_INVALID_USAGE;
+ goto vmgexit_err;
+ }
+
+ reason = GHCB_ERR_MISSING_INPUT;
+
if (!ghcb_sw_exit_code_is_valid(ghcb) ||
!ghcb_sw_exit_info_1_is_valid(ghcb) ||
!ghcb_sw_exit_info_2_is_valid(ghcb))
@@ -2433,30 +2453,34 @@ static int sev_es_validate_vmgexit(struct vcpu_svm *svm)
case SVM_VMGEXIT_UNSUPPORTED_EVENT:
break;
default:
+ reason = GHCB_ERR_INVALID_EVENT;
goto vmgexit_err;
}
- return 0;
+ return true;
vmgexit_err:
vcpu = &svm->vcpu;
- if (ghcb->ghcb_usage) {
+ if (reason == GHCB_ERR_INVALID_USAGE) {
vcpu_unimpl(vcpu, "vmgexit: ghcb usage %#x is not valid\n",
ghcb->ghcb_usage);
+ } else if (reason == GHCB_ERR_INVALID_EVENT) {
+ vcpu_unimpl(vcpu, "vmgexit: exit code %#llx is not valid\n",
+ exit_code);
} else {
- vcpu_unimpl(vcpu, "vmgexit: exit reason %#llx is not valid\n",
+ vcpu_unimpl(vcpu, "vmgexit: exit code %#llx input is not valid\n",
exit_code);
dump_ghcb(svm);
}
- vcpu->run->exit_reason = KVM_EXIT_INTERNAL_ERROR;
- vcpu->run->internal.suberror = KVM_INTERNAL_ERROR_UNEXPECTED_EXIT_REASON;
- vcpu->run->internal.ndata = 2;
- vcpu->run->internal.data[0] = exit_code;
- vcpu->run->internal.data[1] = vcpu->arch.last_vmentry_cpu;
+ /* Clear the valid entries fields */
+ memset(ghcb->save.valid_bitmap, 0, sizeof(ghcb->save.valid_bitmap));
+
+ ghcb_set_sw_exit_info_1(ghcb, 2);
+ ghcb_set_sw_exit_info_2(ghcb, reason);
- return -EINVAL;
+ return false;
}
void sev_es_unmap_ghcb(struct vcpu_svm *svm)
@@ -2478,7 +2502,7 @@ void sev_es_unmap_ghcb(struct vcpu_svm *svm)
svm->sev_es.ghcb_sa_sync = false;
}
- kfree(svm->sev_es.ghcb_sa);
+ kvfree(svm->sev_es.ghcb_sa);
svm->sev_es.ghcb_sa = NULL;
svm->sev_es.ghcb_sa_free = false;
}
@@ -2526,14 +2550,14 @@ static bool setup_vmgexit_scratch(struct vcpu_svm *svm, bool sync, u64 len)
scratch_gpa_beg = ghcb_get_sw_scratch(ghcb);
if (!scratch_gpa_beg) {
pr_err("vmgexit: scratch gpa not provided\n");
- return false;
+ goto e_scratch;
}
scratch_gpa_end = scratch_gpa_beg + len;
if (scratch_gpa_end < scratch_gpa_beg) {
pr_err("vmgexit: scratch length (%#llx) not valid for scratch address (%#llx)\n",
len, scratch_gpa_beg);
- return false;
+ goto e_scratch;
}
if ((scratch_gpa_beg & PAGE_MASK) == control->ghcb_gpa) {
@@ -2551,7 +2575,7 @@ static bool setup_vmgexit_scratch(struct vcpu_svm *svm, bool sync, u64 len)
scratch_gpa_end > ghcb_scratch_end) {
pr_err("vmgexit: scratch area is outside of GHCB shared buffer area (%#llx - %#llx)\n",
scratch_gpa_beg, scratch_gpa_end);
- return false;
+ goto e_scratch;
}
scratch_va = (void *)svm->sev_es.ghcb;
@@ -2564,18 +2588,18 @@ static bool setup_vmgexit_scratch(struct vcpu_svm *svm, bool sync, u64 len)
if (len > GHCB_SCRATCH_AREA_LIMIT) {
pr_err("vmgexit: scratch area exceeds KVM limits (%#llx requested, %#llx limit)\n",
len, GHCB_SCRATCH_AREA_LIMIT);
- return false;
+ goto e_scratch;
}
- scratch_va = kzalloc(len, GFP_KERNEL_ACCOUNT);
+ scratch_va = kvzalloc(len, GFP_KERNEL_ACCOUNT);
if (!scratch_va)
- return false;
+ goto e_scratch;
if (kvm_read_guest(svm->vcpu.kvm, scratch_gpa_beg, scratch_va, len)) {
/* Unable to copy scratch area from guest */
pr_err("vmgexit: kvm_read_guest for scratch area failed\n");
- kfree(scratch_va);
- return false;
+ kvfree(scratch_va);
+ goto e_scratch;
}
/*
@@ -2592,6 +2616,12 @@ static bool setup_vmgexit_scratch(struct vcpu_svm *svm, bool sync, u64 len)
svm->sev_es.ghcb_sa_len = len;
return true;
+
+e_scratch:
+ ghcb_set_sw_exit_info_1(ghcb, 2);
+ ghcb_set_sw_exit_info_2(ghcb, GHCB_ERR_INVALID_SCRATCH_AREA);
+
+ return false;
}
static void set_ghcb_msr_bits(struct vcpu_svm *svm, u64 value, u64 mask,
@@ -2642,7 +2672,7 @@ static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm)
ret = svm_invoke_exit_handler(vcpu, SVM_EXIT_CPUID);
if (!ret) {
- ret = -EINVAL;
+ /* Error, keep GHCB MSR value as-is */
break;
}
@@ -2678,10 +2708,13 @@ static int sev_handle_vmgexit_msr_protocol(struct vcpu_svm *svm)
GHCB_MSR_TERM_REASON_POS);
pr_info("SEV-ES guest requested termination: %#llx:%#llx\n",
reason_set, reason_code);
- fallthrough;
+
+ ret = -EINVAL;
+ break;
}
default:
- ret = -EINVAL;
+ /* Error, keep GHCB MSR value as-is */
+ break;
}
trace_kvm_vmgexit_msr_protocol_exit(svm->vcpu.vcpu_id,
@@ -2705,14 +2738,18 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
if (!ghcb_gpa) {
vcpu_unimpl(vcpu, "vmgexit: GHCB gpa is not set\n");
- return -EINVAL;
+
+ /* Without a GHCB, just return right back to the guest */
+ return 1;
}
if (kvm_vcpu_map(vcpu, ghcb_gpa >> PAGE_SHIFT, &svm->sev_es.ghcb_map)) {
/* Unable to map GHCB from guest */
vcpu_unimpl(vcpu, "vmgexit: error mapping GHCB [%#llx] from guest\n",
ghcb_gpa);
- return -EINVAL;
+
+ /* Without a GHCB, just return right back to the guest */
+ return 1;
}
svm->sev_es.ghcb = svm->sev_es.ghcb_map.hva;
@@ -2722,15 +2759,14 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
exit_code = ghcb_get_sw_exit_code(ghcb);
- ret = sev_es_validate_vmgexit(svm);
- if (ret)
- return ret;
+ if (!sev_es_validate_vmgexit(svm))
+ return 1;
sev_es_sync_from_ghcb(svm);
ghcb_set_sw_exit_info_1(ghcb, 0);
ghcb_set_sw_exit_info_2(ghcb, 0);
- ret = -EINVAL;
+ ret = 1;
switch (exit_code) {
case SVM_VMGEXIT_MMIO_READ:
if (!setup_vmgexit_scratch(svm, true, control->exit_info_2))
@@ -2771,20 +2807,17 @@ int sev_handle_vmgexit(struct kvm_vcpu *vcpu)
default:
pr_err("svm: vmgexit: unsupported AP jump table request - exit_info_1=%#llx\n",
control->exit_info_1);
- ghcb_set_sw_exit_info_1(ghcb, 1);
- ghcb_set_sw_exit_info_2(ghcb,
- X86_TRAP_UD |
- SVM_EVTINJ_TYPE_EXEPT |
- SVM_EVTINJ_VALID);
+ ghcb_set_sw_exit_info_1(ghcb, 2);
+ ghcb_set_sw_exit_info_2(ghcb, GHCB_ERR_INVALID_INPUT);
}
- ret = 1;
break;
}
case SVM_VMGEXIT_UNSUPPORTED_EVENT:
vcpu_unimpl(vcpu,
"vmgexit: unsupported event - exit_info_1=%#llx, exit_info_2=%#llx\n",
control->exit_info_1, control->exit_info_2);
+ ret = -EINVAL;
break;
default:
ret = svm_invoke_exit_handler(vcpu, exit_code);
@@ -2806,7 +2839,7 @@ int sev_es_string_io(struct vcpu_svm *svm, int size, unsigned int port, int in)
return -EINVAL;
if (!setup_vmgexit_scratch(svm, in, bytes))
- return -EINVAL;
+ return 1;
return kvm_sev_es_string_io(&svm->vcpu, size, port, svm->sev_es.ghcb_sa,
count, in);