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authorRadim Krčmář <rkrcmar@redhat.com>2017-12-06 17:55:44 +0300
committerRadim Krčmář <rkrcmar@redhat.com>2017-12-06 17:55:44 +0300
commitd29899a30f987de46bcdab3ca4513de2479629e5 (patch)
tree58869cb489ae91c13b77f2b4ff93fda835fd1405 /Documentation
parent2895db67b01cb875457c9c3f30a14723b6b5dfd5 (diff)
parentca76ec9ca871e67d8cd0b6caba24aca3d3ac4546 (diff)
downloadlinux-d29899a30f987de46bcdab3ca4513de2479629e5.tar.xz
Merge tag 'kvm-s390-master-4.15-1' of git://git.kernel.org/pub/scm/linux/kernel/git/kvms390/linux
KVM: s390: Fixes for 4.15 - SPDX tags - Fence storage key accesses from problem state - Make sure that irq_state.flags is not used in the future
Diffstat (limited to 'Documentation')
-rw-r--r--Documentation/virtual/kvm/api.txt15
1 files changed, 12 insertions, 3 deletions
diff --git a/Documentation/virtual/kvm/api.txt b/Documentation/virtual/kvm/api.txt
index f670e4b9e7f3..57d3ee9e4bde 100644
--- a/Documentation/virtual/kvm/api.txt
+++ b/Documentation/virtual/kvm/api.txt
@@ -2901,14 +2901,19 @@ userspace buffer and its length:
struct kvm_s390_irq_state {
__u64 buf;
- __u32 flags;
+ __u32 flags; /* will stay unused for compatibility reasons */
__u32 len;
- __u32 reserved[4];
+ __u32 reserved[4]; /* will stay unused for compatibility reasons */
};
Userspace passes in the above struct and for each pending interrupt a
struct kvm_s390_irq is copied to the provided buffer.
+The structure contains a flags and a reserved field for future extensions. As
+the kernel never checked for flags == 0 and QEMU never pre-zeroed flags and
+reserved, these fields can not be used in the future without breaking
+compatibility.
+
If -ENOBUFS is returned the buffer provided was too small and userspace
may retry with a bigger buffer.
@@ -2932,10 +2937,14 @@ containing a struct kvm_s390_irq_state:
struct kvm_s390_irq_state {
__u64 buf;
+ __u32 flags; /* will stay unused for compatibility reasons */
__u32 len;
- __u32 pad;
+ __u32 reserved[4]; /* will stay unused for compatibility reasons */
};
+The restrictions for flags and reserved apply as well.
+(see KVM_S390_GET_IRQ_STATE)
+
The userspace memory referenced by buf contains a struct kvm_s390_irq
for each interrupt to be injected into the guest.
If one of the interrupts could not be injected for some reason the