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authorJanis Schoetterl-Glausch <scgl@linux.ibm.com>2022-05-12 15:10:17 +0200
committerJanosch Frank <frankja@linux.ibm.com>2022-05-20 16:38:42 +0200
commitc783631b0bffe6060113ff0aafe5fdbd71bea793 (patch)
tree829a501a12d49df12159fc39f1ea5220160a8473 /Documentation/virt
parentselftests: drivers/s390x: Add uvdevice tests (diff)
downloadlinux-dev-c783631b0bffe6060113ff0aafe5fdbd71bea793.tar.xz
linux-dev-c783631b0bffe6060113ff0aafe5fdbd71bea793.zip
KVM: s390: Don't indicate suppression on dirtying, failing memop
If user space uses a memop to emulate an instruction and that memop fails, the execution of the instruction ends. Instruction execution can end in different ways, one of which is suppression, which requires that the instruction execute like a no-op. A writing memop that spans multiple pages and fails due to key protection may have modified guest memory, as a result, the likely correct ending is termination. Therefore, do not indicate a suppressing instruction ending in this case. Signed-off-by: Janis Schoetterl-Glausch <scgl@linux.ibm.com> Reviewed-by: Christian Borntraeger <borntraeger@linux.ibm.com> Reviewed-by: Claudio Imbrenda <imbrenda@linux.ibm.com> Link: https://lore.kernel.org/r/20220512131019.2594948-2-scgl@linux.ibm.com Signed-off-by: Christian Borntraeger <borntraeger@linux.ibm.com> Signed-off-by: Janosch Frank <frankja@linux.ibm.com>
Diffstat (limited to 'Documentation/virt')
-rw-r--r--Documentation/virt/kvm/api.rst6
1 files changed, 6 insertions, 0 deletions
diff --git a/Documentation/virt/kvm/api.rst b/Documentation/virt/kvm/api.rst
index d13fa6600467..09353e27bdbc 100644
--- a/Documentation/virt/kvm/api.rst
+++ b/Documentation/virt/kvm/api.rst
@@ -3754,12 +3754,18 @@ in case of KVM_S390_MEMOP_F_CHECK_ONLY), the ioctl returns a positive
error number indicating the type of exception. This exception is also
raised directly at the corresponding VCPU if the flag
KVM_S390_MEMOP_F_INJECT_EXCEPTION is set.
+On protection exceptions, unless specified otherwise, the injected
+translation-exception identifier (TEID) indicates suppression.
If the KVM_S390_MEMOP_F_SKEY_PROTECTION flag is set, storage key
protection is also in effect and may cause exceptions if accesses are
prohibited given the access key designated by "key"; the valid range is 0..15.
KVM_S390_MEMOP_F_SKEY_PROTECTION is available if KVM_CAP_S390_MEM_OP_EXTENSION
is > 0.
+Since the accessed memory may span multiple pages and those pages might have
+different storage keys, it is possible that a protection exception occurs
+after memory has been modified. In this case, if the exception is injected,
+the TEID does not indicate suppression.
Absolute read/write:
^^^^^^^^^^^^^^^^^^^^