Commit 1327138e authored Aug 06, 2008 by Adrian Bunk Committed by Avi Kivity Aug 25, 2008

KVM: fix userspace ABI breakage



The following part of commit 9ef621d3
(KVM: Support mixed endian machines) changed on the size of a struct
that is exported to userspace:

include/linux/kvm.h:

@@ -318,14 +318,14 @@ struct kvm_trace_rec {
 	__u32 vcpu_id;
 	union {
 		struct {
-			__u32 cycle_lo, cycle_hi;
+			__u64 cycle_u64;
 			__u32 extra_u32[KVM_TRC_EXTRA_MAX];
 		} cycle;
 		struct {
 			__u32 extra_u32[KVM_TRC_EXTRA_MAX];
 		} nocycle;
 	} u;
-};
+} __attribute__((packed));

Packing a struct was the correct idea, but it packed the wrong struct.

Signed-off-by: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Avi Kivity <avi@qumranet.com>

parent cd5998eb

include/linux/kvm.h

+2 −2

Original line number	Diff line number	Diff line
		@@ -320,12 +320,12 @@ struct kvm_trace_rec {
		struct {
		__u64 cycle_u64;
		__u32 extra_u32[KVM_TRC_EXTRA_MAX];
		} cycle;
		} __attribute__((packed)) cycle;
		struct {
		__u32 extra_u32[KVM_TRC_EXTRA_MAX];
		} nocycle;
		} u;
		} __attribute__((packed));
		};

		#define KVMIO 0xAE

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