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Subject[PATCH 14/28] KVM: nSVM: remove trailing padding for struct vmcb_control_area
Date
Allow placing the VMCB structs on the stack or in other structs without
wasting too much space. Add BUILD_BUG_ON as a quick safeguard against typos.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
arch/x86/include/asm/svm.h | 9 ++++++++-
1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 6ece8561ba66..8a1f5382a4ea 100644
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -96,7 +96,6 @@ struct __attribute__ ((__packed__)) vmcb_control_area {
u8 reserved_6[8]; /* Offset 0xe8 */
u64 avic_logical_id; /* Offset 0xf0 */
u64 avic_physical_id; /* Offset 0xf8 */
- u8 reserved_7[768];
};


@@ -203,8 +202,16 @@ struct __attribute__ ((__packed__)) vmcb_save_area {
u64 last_excp_to;
};

+
+static inline void __unused_size_checks(void)
+{
+ BUILD_BUG_ON(sizeof(struct vmcb_save_area) != 0x298);
+ BUILD_BUG_ON(sizeof(struct vmcb_control_area) != 256);
+}
+
struct __attribute__ ((__packed__)) vmcb {
struct vmcb_control_area control;
+ u8 reserved_control[1024 - sizeof(struct vmcb_control_area)];
struct vmcb_save_area save;
};

--
2.26.2

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