2023-08-07 23:44:54

by Ackerley Tng

[permalink] [raw]
Subject: [RFC PATCH 05/11] KVM: x86: Refactor sev's flag migration_in_progress to kvm struct

The migration_in_progress flag will also be needed for migration of
non-sev VMs.

Co-developed-by: Sagi Shahar <[email protected]>
Signed-off-by: Sagi Shahar <[email protected]>
Co-developed-by: Vishal Annapurve <[email protected]>
Signed-off-by: Vishal Annapurve <[email protected]>
Signed-off-by: Ackerley Tng <[email protected]>
---
arch/x86/kvm/svm/sev.c | 17 ++++++-----------
arch/x86/kvm/svm/svm.h | 1 -
include/linux/kvm_host.h | 1 +
3 files changed, 7 insertions(+), 12 deletions(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index 07756b7348ae..725289b523c7 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -1556,8 +1556,6 @@ static bool is_cmd_allowed_from_mirror(u32 cmd_id)

static int sev_lock_two_vms(struct kvm *dst_kvm, struct kvm *src_kvm)
{
- 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)
@@ -1567,10 +1565,10 @@ static int sev_lock_two_vms(struct kvm *dst_kvm, struct kvm *src_kvm)
* 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(&dst_sev->migration_in_progress, 0, 1))
+ if (atomic_cmpxchg_acquire(&dst_kvm->migration_in_progress, 0, 1))
return -EBUSY;

- if (atomic_cmpxchg_acquire(&src_sev->migration_in_progress, 0, 1))
+ if (atomic_cmpxchg_acquire(&src_kvm->migration_in_progress, 0, 1))
goto release_dst;

r = -EINTR;
@@ -1583,21 +1581,18 @@ static int sev_lock_two_vms(struct kvm *dst_kvm, struct kvm *src_kvm)
unlock_dst:
mutex_unlock(&dst_kvm->lock);
release_src:
- atomic_set_release(&src_sev->migration_in_progress, 0);
+ atomic_set_release(&src_kvm->migration_in_progress, 0);
release_dst:
- atomic_set_release(&dst_sev->migration_in_progress, 0);
+ atomic_set_release(&dst_kvm->migration_in_progress, 0);
return r;
}

static void sev_unlock_two_vms(struct kvm *dst_kvm, struct kvm *src_kvm)
{
- 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(&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);
+ atomic_set_release(&dst_kvm->migration_in_progress, 0);
+ atomic_set_release(&src_kvm->migration_in_progress, 0);
}

/* vCPU mutex subclasses. */
diff --git a/arch/x86/kvm/svm/svm.h b/arch/x86/kvm/svm/svm.h
index 18af7e712a5a..d306e2312b53 100644
--- a/arch/x86/kvm/svm/svm.h
+++ b/arch/x86/kvm/svm/svm.h
@@ -87,7 +87,6 @@ struct kvm_sev_info {
struct list_head mirror_vms; /* List of VMs mirroring */
struct list_head mirror_entry; /* Use as a list entry of mirrors */
struct misc_cg *misc_cg; /* For misc cgroup accounting */
- atomic_t migration_in_progress;
};

struct kvm_svm {
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 091bc89ae805..3e03eeca279f 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -842,6 +842,7 @@ struct kvm {
#ifdef CONFIG_KVM_GENERIC_MEMORY_ATTRIBUTES
struct xarray mem_attr_array;
#endif
+ atomic_t migration_in_progress;
char stats_id[KVM_STATS_NAME_SIZE];
};

--
2.41.0.640.ga95def55d0-goog