KVM: arm/arm64: VGIC/ITS save/restore: protect kvm_read_guest() calls

commit 711702b57cc3c50b84bd648de0f1ca0a378805be upstream.

kvm_read_guest() will eventually look up in kvm_memslots(), which requires
either to hold the kvm->slots_lock or to be inside a kvm->srcu critical
section.
In contrast to x86 and s390 we don't take the SRCU lock on every guest
exit, so we have to do it individually for each kvm_read_guest() call.
Use the newly introduced wrapper for that.

Cc: Stable <stable@vger.kernel.org> # 4.12+
Reported-by: Jan Glauber <jan.glauber@caviumnetworks.com>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Acked-by: Christoffer Dall <christoffer.dall@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/virt/kvm/arm/vgic/vgic-its.c b/virt/kvm/arm/vgic/vgic-its.c
index 5a11f4d3972cdb992250672f09c8061ccd9c589a..4131560d9f745e65357faddb345455676062fa30 100644 (file)
--- a/virt/kvm/arm/vgic/vgic-its.c
+++ b/virt/kvm/arm/vgic/vgic-its.c
@@ -1830,7 +1830,7 @@ static int scan_its_table(struct vgic_its *its, gpa_t base, int size, int esz,
                int next_offset;
                size_t byte_offset;
 
-               ret = kvm_read_guest(kvm, gpa, entry, esz);
+               ret = kvm_read_guest_lock(kvm, gpa, entry, esz);
                if (ret)
                        return ret;
 
@@ -2191,7 +2191,7 @@ static int vgic_its_restore_cte(struct vgic_its *its, gpa_t gpa, int esz)
        int ret;
 
        BUG_ON(esz > sizeof(val));
-       ret = kvm_read_guest(kvm, gpa, &val, esz);
+       ret = kvm_read_guest_lock(kvm, gpa, &val, esz);
        if (ret)
                return ret;
        val = le64_to_cpu(val);

diff --git a/virt/kvm/arm/vgic/vgic-v3.c b/virt/kvm/arm/vgic/vgic-v3.c
index 9dcc31600a8bd21f50709edf4d7e628c6f303e4d..6b4fcd52f14c86f84e414092a6985e8510a11b0a 100644 (file)
--- a/virt/kvm/arm/vgic/vgic-v3.c
+++ b/virt/kvm/arm/vgic/vgic-v3.c
@@ -297,7 +297,7 @@ retry:
        bit_nr = irq->intid % BITS_PER_BYTE;
        ptr = pendbase + byte_offset;
 
-       ret = kvm_read_guest(kvm, ptr, &val, 1);
+       ret = kvm_read_guest_lock(kvm, ptr, &val, 1);
        if (ret)
                return ret;
 
@@ -350,7 +350,7 @@ int vgic_v3_save_pending_tables(struct kvm *kvm)
                ptr = pendbase + byte_offset;
 
                if (byte_offset != last_byte_offset) {
-                       ret = kvm_read_guest(kvm, ptr, &val, 1);
+                       ret = kvm_read_guest_lock(kvm, ptr, &val, 1);
                        if (ret)
                                return ret;
                        last_byte_offset = byte_offset;