[PATCH v7 02/72] KVM: SVM: Add GHCB definitions

From: Joerg Roedel
Date: Mon Sep 07 2020 - 13:44:35 EST


From: Tom Lendacky <thomas.lendacky@xxxxxxx>

Extend the vmcb_safe_area with SEV-ES fields and add a new
'struct ghcb' which will be used for guest-hypervisor communication.

Signed-off-by: Tom Lendacky <thomas.lendacky@xxxxxxx>
Signed-off-by: Joerg Roedel <jroedel@xxxxxxx>
---
arch/x86/include/asm/svm.h | 51 ++++++++++++++++++++++++++++++++++++--
arch/x86/kvm/svm/svm.c | 2 ++
2 files changed, 51 insertions(+), 2 deletions(-)

diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 8a1f5382a4ea..acac55d6f941 100644
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -200,13 +200,60 @@ struct __attribute__ ((__packed__)) vmcb_save_area {
u64 br_to;
u64 last_excp_from;
u64 last_excp_to;
+
+ /*
+ * The following part of the save area is valid only for
+ * SEV-ES guests when referenced through the GHCB.
+ */
+ u8 reserved_7[104];
+ u64 reserved_8; /* rax already available at 0x01f8 */
+ u64 rcx;
+ u64 rdx;
+ u64 rbx;
+ u64 reserved_9; /* rsp already available at 0x01d8 */
+ u64 rbp;
+ u64 rsi;
+ u64 rdi;
+ u64 r8;
+ u64 r9;
+ u64 r10;
+ u64 r11;
+ u64 r12;
+ u64 r13;
+ u64 r14;
+ u64 r15;
+ u8 reserved_10[16];
+ u64 sw_exit_code;
+ u64 sw_exit_info_1;
+ u64 sw_exit_info_2;
+ u64 sw_scratch;
+ u8 reserved_11[56];
+ u64 xcr0;
+ u8 valid_bitmap[16];
+ u64 x87_state_gpa;
};

+struct ghcb {
+ struct vmcb_save_area save;
+ u8 reserved_save[2048 - sizeof(struct vmcb_save_area)];
+
+ u8 shared_buffer[2032];
+
+ u8 reserved_1[10];
+ u16 protocol_version; /* negotiated SEV-ES/GHCB protocol version */
+ u32 ghcb_usage;
+} __packed;
+
+
+#define EXPECTED_VMCB_SAVE_AREA_SIZE 1032
+#define EXPECTED_VMCB_CONTROL_AREA_SIZE 256
+#define EXPECTED_GHCB_SIZE PAGE_SIZE

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);
+ BUILD_BUG_ON(sizeof(struct vmcb_save_area) != EXPECTED_VMCB_SAVE_AREA_SIZE);
+ BUILD_BUG_ON(sizeof(struct vmcb_control_area) != EXPECTED_VMCB_CONTROL_AREA_SIZE);
+ BUILD_BUG_ON(sizeof(struct ghcb) != EXPECTED_GHCB_SIZE);
}

struct __attribute__ ((__packed__)) vmcb {
diff --git a/arch/x86/kvm/svm/svm.c b/arch/x86/kvm/svm/svm.c
index 0194336b64a4..1db4fdcb4906 100644
--- a/arch/x86/kvm/svm/svm.c
+++ b/arch/x86/kvm/svm/svm.c
@@ -4164,6 +4164,8 @@ static struct kvm_x86_init_ops svm_init_ops __initdata = {

static int __init svm_init(void)
{
+ __unused_size_checks();
+
return kvm_init(&svm_init_ops, sizeof(struct vcpu_svm),
__alignof__(struct vcpu_svm), THIS_MODULE);
}
--
2.28.0