diff mbox series

[1/6] Add GHCB with setters and getters

Message ID 20240409133959.2888018-2-pgonda@google.com (mailing list archive)
State New
Headers show
Series Add initial GHCB support for SEV-ES selftests | expand

Commit Message

Peter Gonda April 9, 2024, 1:39 p.m. UTC 
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(-)

Comments

Sean Christopherson April 23, 2024, 11:07 p.m. UTC | #1 
On Tue, Apr 09, 2024, Peter Gonda wrote:
> 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.

Just for paranoia, I would put the -Wno-address-of-packed-member in a separate
patch.  And to make life easier for us paranoid folks, call out that the kernel
builds with -Wno-address-of-packed-member by default for *all* architectures,
thanks to this line in scripts/Makefile.extrawarn:

  KBUILD_CFLAGS += $(call cc-disable-warning, address-of-packed-member)

And for good reason, that's a darn stupid warning for the kernel.
diff mbox series

Patch

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 */