KVM: SVM: Add GHCB Accessor functions

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 and to check the valid bitmap
in KVM.

Signed-off-by: Joerg Roedel <jroedel@suse.de>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/20200907131613.12703-4-joro@8bytes.org

diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index acac55d6f941f441ac76e91785b69bed0f8e3b02..06e52585aed3995757b2d657ed86acadcd5dfba3 100644 (file)
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -345,4 +345,47 @@ struct __attribute__ ((__packed__)) vmcb {
 
 #define SVM_CR0_SELECTIVE_MASK (X86_CR0_TS | X86_CR0_MP)
 
+/* GHCB Accessor functions */
+
+#define GHCB_BITMAP_IDX(field)                                                 \
+       (offsetof(struct vmcb_save_area, field) / sizeof(u64))
+
+#define DEFINE_GHCB_ACCESSORS(field)                                           \
+       static inline bool ghcb_##field##_is_valid(const struct ghcb *ghcb)     \
+       {                                                                       \
+               return test_bit(GHCB_BITMAP_IDX(field),                         \
+                               (unsigned long *)&ghcb->save.valid_bitmap);     \
+       }                                                                       \
+                                                                               \
+       static inline void ghcb_set_##field(struct ghcb *ghcb, u64 value)       \
+       {                                                                       \
+               __set_bit(GHCB_BITMAP_IDX(field),                               \
+                         (unsigned long *)&ghcb->save.valid_bitmap);           \
+               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