[PATCH 1/6] Add GHCB with setters and getters

Peter Gonda
2024-04-09T13:40:17Z

Move the GHCB definitions from svm.h to the tools/ copy. This allows the
SEV-ES selftest to use GHCBs which are required for non-trival VMs to
paravirtualize NonAutomaticExits (NAEs) when SEV-ES is enabled. GHCB
getters/setters have a warning with address-of-packed-member, so removed
this using the CFLAGS.

Cc: Vishal Annapurve <vannapurve@google.com>
Cc: Ackerley Tng <ackerleytng@google.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Claudio Imbrenda <imbrenda@linux.ibm.com>
Cc: Sean Christopherson <seanjc@google.com>
Cc: Carlos Bilbao <carlos.bilbao@amd.com>
Cc: Tom Lendacky <thomas.lendacky@amd.com>
Cc: Michael Roth <michael.roth@amd.com>
Cc: kvm@vger.kernel.org
Cc: linux-kselftest@vger.kernel.org
Signed-off-by: Peter Gonda <pgonda@google.com>
---
tools/testing/selftests/kvm/Makefile | 2 +-
.../selftests/kvm/include/x86_64/svm.h | 106 ++++++++++++++++++
2 files changed, 107 insertions(+), 1 deletion(-)

diff --git a/tools/testing/selftests/kvm/Makefile b/tools/testing/selftests/kvm/Makefile
index c75251d5c97c..95fa0cead256 100644
--- a/tools/testing/selftests/kvm/Makefile
+++ b/tools/testing/selftests/kvm/Makefile
@@ -221,7 +221,7 @@ endif
CFLAGS += -Wall -Wstrict-prototypes -Wuninitialized -O2 -g -std=gnu99 \
-Wno-gnu-variable-sized-type-not-at-end -MD -MP \
-fno-builtin-memcmp -fno-builtin-memcpy -fno-builtin-memset \
- -fno-builtin-strnlen \
+ -fno-builtin-strnlen -Wno-address-of-packed-member \
-fno-stack-protector -fno-PIE -I$(LINUX_TOOL_INCLUDE) \
-I$(LINUX_TOOL_ARCH_INCLUDE) -I$(LINUX_HDR_PATH) -Iinclude \
-I$(<D) -Iinclude/$(ARCH_DIR) -I ../rseq -I.. $(EXTRA_CFLAGS) \
diff --git a/tools/testing/selftests/kvm/include/x86_64/svm.h b/tools/testing/selftests/kvm/include/x86_64/svm.h
index 4803e1056055..fbd8d29c15a8 100644
--- a/tools/testing/selftests/kvm/include/x86_64/svm.h
+++ b/tools/testing/selftests/kvm/include/x86_64/svm.h
@@ -323,4 +323,110 @@ struct __attribute__ ((__packed__)) vmcb {

#define SVM_CR0_SELECTIVE_MASK (X86_CR0_TS | X86_CR0_MP)

+struct ghcb_save_area {
+ u8 reserved_0x0[203];
+ u8 cpl;
+ u8 reserved_0xcc[116];
+ u64 xss;
+ u8 reserved_0x148[24];
+ u64 dr7;
+ u8 reserved_0x168[16];
+ u64 rip;
+ u8 reserved_0x180[88];
+ u64 rsp;
+ u8 reserved_0x1e0[24];
+ u64 rax;
+ u8 reserved_0x200[264];
+ u64 rcx;
+ u64 rdx;
+ u64 rbx;
+ u8 reserved_0x320[8];
+ u64 rbp;
+ u64 rsi;
+ u64 rdi;
+ u64 r8;
+ u64 r9;
+ u64 r10;
+ u64 r11;
+ u64 r12;
+ u64 r13;
+ u64 r14;
+ u64 r15;
+ u8 reserved_0x380[16];
+ u64 sw_exit_code;
+ u64 sw_exit_info_1;
+ u64 sw_exit_info_2;
+ u64 sw_scratch;
+ u8 reserved_0x3b0[56];
+ u64 xcr0;
+ u8 valid_bitmap[16];
+ u64 x87_state_gpa;
+} __packed;
+
+#define GHCB_SHARED_BUF_SIZE 2032
+
+struct ghcb {
+ struct ghcb_save_area save;
+ u8 reserved_save[2048 - sizeof(struct ghcb_save_area)];
+
+ u8 shared_buffer[GHCB_SHARED_BUF_SIZE];
+
+ u8 reserved_0xff0[10];
+ u16 protocol_version; /* negotiated SEV-ES/GHCB protocol version */
+ u32 ghcb_usage;
+} __packed;
+
+/* GHCB Accessor functions */
+
+#define GHCB_BITMAP_IDX(field) \
+ (offsetof(struct ghcb_save_area, field) / sizeof(u64))
+
+#define DEFINE_GHCB_ACCESSORS(field) \
+ static __always_inline bool ghcb_##field##_is_valid(const struct ghcb *ghcb) \
+ { \
+ return test_bit(GHCB_BITMAP_IDX(field), \
+ (unsigned long *)&ghcb->save.valid_bitmap); \
+ } \
+ \
+ static __always_inline u64 ghcb_get_##field(struct ghcb *ghcb) \
+ { \
+ return ghcb->save.field; \
+ } \
+ \
+ static __always_inline u64 ghcb_get_##field##_if_valid(struct ghcb *ghcb) \
+ { \
+ return ghcb_##field##_is_valid(ghcb) ? ghcb->save.field : 0; \
+ } \
+ \
+ static __always_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 /* SELFTEST_KVM_SVM_H */
--
2.44.0.478.gd926399ef9-goog