[PATCH v4 02/75] KVM: SVM: Add GHCB Accessor functions

Joerg Roedel
Tue, 14 Jul 2020 12:08:04 -0000

Building a correct GHCB for the hypervisor requires setting valid bits
in the GHCB. Simplify that process by providing accessor functions to
set values and to update the valid bitmap.

Signed-off-by: Joerg Roedel <jroedel at suse.de>
---
 arch/x86/include/asm/svm.h | 61 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 61 insertions(+)

diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 9a3e0b802716..0420250b008b 100644
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -341,4 +341,65 @@ struct __attribute__ ((__packed__)) vmcb {

 #define SVM_CR0_SELECTIVE_MASK (X86_CR0_TS | X86_CR0_MP)

+/* GHCB Accessor functions */
+
+#define DEFINE_GHCB_INDICES(field)					\
+	u16 idx = offsetof(struct vmcb_save_area, field) / 8;		\
+	u16 byte_idx  = idx / 8;					\
+	u16 bit_idx   = idx % 8;					\
+	BUILD_BUG_ON(byte_idx > ARRAY_SIZE(ghcb->save.valid_bitmap));
+
+#define GHCB_SET_VALID(ghcb, field)					\
+	{								\
+		DEFINE_GHCB_INDICES(field)				\
+		(ghcb)->save.valid_bitmap[byte_idx] |= BIT(bit_idx);	\
+	}
+
+#define DEFINE_GHCB_SETTER(field)					\
+	static inline void						\
+	ghcb_set_##field(struct ghcb *ghcb, u64 value)			\
+	{								\
+		GHCB_SET_VALID(ghcb, field)				\
+		(ghcb)->save.field = value;				\
+	}
+
+#define DEFINE_GHCB_ACCESSORS(field)					\
+	static inline bool ghcb_is_valid_##field(const struct ghcb *ghcb)	\
+	{								\
+		DEFINE_GHCB_INDICES(field)				\
+		return !!((ghcb)->save.valid_bitmap[byte_idx]		\
+						& BIT(bit_idx));	\
+	}								\
+									\
+	static inline void						\
+	ghcb_set_##field(struct ghcb *ghcb, u64 value)			\
+	{								\
+		GHCB_SET_VALID(ghcb, field)				\
+		(ghcb)->save.field = value;				\
+	}
+
+DEFINE_GHCB_ACCESSORS(cpl)
+DEFINE_GHCB_ACCESSORS(rip)
+DEFINE_GHCB_ACCESSORS(rsp)
+DEFINE_GHCB_ACCESSORS(rax)
+DEFINE_GHCB_ACCESSORS(rcx)
+DEFINE_GHCB_ACCESSORS(rdx)
+DEFINE_GHCB_ACCESSORS(rbx)
+DEFINE_GHCB_ACCESSORS(rbp)
+DEFINE_GHCB_ACCESSORS(rsi)
+DEFINE_GHCB_ACCESSORS(rdi)
+DEFINE_GHCB_ACCESSORS(r8)
+DEFINE_GHCB_ACCESSORS(r9)
+DEFINE_GHCB_ACCESSORS(r10)
+DEFINE_GHCB_ACCESSORS(r11)
+DEFINE_GHCB_ACCESSORS(r12)
+DEFINE_GHCB_ACCESSORS(r13)
+DEFINE_GHCB_ACCESSORS(r14)
+DEFINE_GHCB_ACCESSORS(r15)
+DEFINE_GHCB_ACCESSORS(sw_exit_code)
+DEFINE_GHCB_ACCESSORS(sw_exit_info_1)
+DEFINE_GHCB_ACCESSORS(sw_exit_info_2)
+DEFINE_GHCB_ACCESSORS(sw_scratch)
+DEFINE_GHCB_ACCESSORS(xcr0)
+
 #endif
--
2.27.0