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authorPaolo Bonzini <pbonzini@redhat.com>2021-11-22 19:50:36 -0500
committerPaolo Bonzini <pbonzini@redhat.com>2021-11-30 03:54:15 -0500
commitc9d61dcb0bc26a761dc84a87bd8a0d3b3c432f10 (patch)
treec58760947e78c0658a2222eefdeff70d7baab596 /arch
parent10a37929efeb4c51a0069afdd537c4fa3831f6e5 (diff)
KVM: SEV: accept signals in sev_lock_two_vms
Generally, kvm->lock is not taken for a long time, but sev_lock_two_vms is different: it takes vCPU locks inside, so userspace can hold it back just by calling a vCPU ioctl. Play it safe and use mutex_lock_killable. Message-Id: <20211123005036.2954379-13-pbonzini@redhat.com> Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Diffstat (limited to 'arch')
-rw-r--r--arch/x86/kvm/svm/sev.c22
1 files changed, 16 insertions, 6 deletions
diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index bbbf980c7e40..59727a966f90 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -1547,6 +1547,7 @@ 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)
return -EINVAL;
@@ -1558,14 +1559,23 @@ static int sev_lock_two_vms(struct kvm *dst_kvm, struct kvm *src_kvm)
if (atomic_cmpxchg_acquire(&dst_sev->migration_in_progress, 0, 1))
return -EBUSY;
- if (atomic_cmpxchg_acquire(&src_sev->migration_in_progress, 0, 1)) {
- atomic_set_release(&dst_sev->migration_in_progress, 0);
- return -EBUSY;
- }
+ if (atomic_cmpxchg_acquire(&src_sev->migration_in_progress, 0, 1))
+ goto release_dst;
- mutex_lock(&dst_kvm->lock);
- mutex_lock(&src_kvm->lock);
+ r = -EINTR;
+ if (mutex_lock_killable(&dst_kvm->lock))
+ goto release_src;
+ if (mutex_lock_killable(&src_kvm->lock))
+ 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_two_vms(struct kvm *dst_kvm, struct kvm *src_kvm)