[PATCH v2 07/11] KVM: x86: emulator/smm: add structs for KVM's smram layout

Maxim Levitsky
2022-06-21T15:09:52Z

Those structs will be used to read/write the smram state image.

Also document the differences between KVM's SMRAM layout and SMRAM
layout that is used by real Intel/AMD cpus.

Signed-off-by: Maxim Levitsky <mlevitsk@redhat.com>
---
arch/x86/kvm/kvm_emulate.h | 139 +++++++++++++++++++++++++++++++++++++
1 file changed, 139 insertions(+)

diff --git a/arch/x86/kvm/kvm_emulate.h b/arch/x86/kvm/kvm_emulate.h
index 89246446d6aa9d..7015728da36d5f 100644
--- a/arch/x86/kvm/kvm_emulate.h
+++ b/arch/x86/kvm/kvm_emulate.h
@@ -503,6 +503,145 @@ enum x86_intercept {
nr_x86_intercepts
};

+
+/*
+ * 32 bit KVM's emulated SMM layout
+ * Loosely based on Intel's layout
+ */
+
+struct kvm_smm_seg_state_32 {
+ u32 flags;
+ u32 limit;
+ u32 base;
+} __packed;
+
+struct kvm_smram_state_32 {
+
+ u32 reserved1[62]; /* FE00 - FEF7 */
+ u32 smbase; /* FEF8 */
+ u32 smm_revision; /* FEFC */
+ u32 reserved2[5]; /* FF00-FF13 */
+ /* CR4 is not present in Intel/AMD SMRAM image*/
+ u32 cr4; /* FF14 */
+ u32 reserved3[5]; /* FF18 */
+
+ /*
+ * Segment state is not present/documented in the
+ * Intel/AMD SMRAM image
+ */
+ struct kvm_smm_seg_state_32 ds; /* FF2C */
+ struct kvm_smm_seg_state_32 fs; /* FF38 */
+ struct kvm_smm_seg_state_32 gs; /* FF44 */
+ /* idtr has only base and limit*/
+ struct kvm_smm_seg_state_32 idtr; /* FF50 */
+ struct kvm_smm_seg_state_32 tr; /* FF5C */
+ u32 reserved; /* FF68 */
+ /* gdtr has only base and limit*/
+ struct kvm_smm_seg_state_32 gdtr; /* FF6C */
+ struct kvm_smm_seg_state_32 ldtr; /* FF78 */
+ struct kvm_smm_seg_state_32 es; /* FF84 */
+ struct kvm_smm_seg_state_32 cs; /* FF90 */
+ struct kvm_smm_seg_state_32 ss; /* FF9C */
+
+ u32 es_sel; /* FFA8 */
+ u32 cs_sel; /* FFAC */
+ u32 ss_sel; /* FFB0 */
+ u32 ds_sel; /* FFB4 */
+ u32 fs_sel; /* FFB8 */
+ u32 gs_sel; /* FFBC */
+ u32 ldtr_sel; /* FFC0 */
+ u32 tr_sel; /* FFC4 */
+
+ u32 dr7; /* FFC8 */
+ u32 dr6; /* FFCC */
+
+ /* GPRS in the "natural" X86 order (RAX/RCX/RDX.../RDI)*/
+ u32 gprs[8]; /* FFD0-FFEC */
+
+ u32 eip; /* FFF0 */
+ u32 eflags; /* FFF4 */
+ u32 cr3; /* FFF8 */
+ u32 cr0; /* FFFC */
+} __packed;
+
+/*
+ * 64 bit KVM's emulated SMM layout
+ * Based on AMD64 layout
+ */
+
+struct kvm_smm_seg_state_64 {
+ u16 selector;
+ u16 attributes;
+ u32 limit;
+ u64 base;
+};
+
+struct kvm_smram_state_64 {
+ struct kvm_smm_seg_state_64 es; /* FE00 (R/O) */
+ struct kvm_smm_seg_state_64 cs; /* FE10 (R/O) */
+ struct kvm_smm_seg_state_64 ss; /* FE20 (R/O) */
+ struct kvm_smm_seg_state_64 ds; /* FE30 (R/O) */
+ struct kvm_smm_seg_state_64 fs; /* FE40 (R/O) */
+ struct kvm_smm_seg_state_64 gs; /* FE50 (R/O) */
+
+ /* gdtr has only base and limit*/
+ struct kvm_smm_seg_state_64 gdtr; /* FE60 (R/O) */
+ struct kvm_smm_seg_state_64 ldtr; /* FE70 (R/O) */
+
+ /* idtr has only base and limit*/
+ struct kvm_smm_seg_state_64 idtr; /* FE80 (R/O) */
+ struct kvm_smm_seg_state_64 tr; /* FE90 (R/O) */
+
+ /* I/O restart and auto halt restart are not implemented by KVM */
+ u64 io_restart_rip; /* FEA0 (R/O) */
+ u64 io_restart_rcx; /* FEA8 (R/O) */
+ u64 io_restart_rsi; /* FEB0 (R/O) */
+ u64 io_restart_rdi; /* FEB8 (R/O) */
+ u32 io_restart_dword; /* FEC0 (R/O) */
+ u32 reserved1; /* FEC4 */
+ u8 io_instruction_restart; /* FEC8 (R/W) */
+ u8 auto_halt_restart; /* FEC9 (R/W) */
+ u8 reserved2[6]; /* FECA-FECF */
+
+ u64 efer; /* FED0 (R/O) */
+
+ /*
+ * Implemented on AMD only, to store current SVM guest address.
+ * svm_guest_virtual_int has unknown purpose, not implemented.
+ */
+
+ u64 svm_guest_flag; /* FED8 (R/O) */
+ u64 svm_guest_vmcb_gpa; /* FEE0 (R/O) */
+ u64 svm_guest_virtual_int; /* FEE8 (R/O) */
+
+ u32 reserved3[3]; /* FEF0-FEFB */
+ u32 smm_revison; /* FEFC (R/O) */
+ u32 smbase; /* FFF0 (R/W) */
+ u32 reserved4[5]; /* FF04-FF17 */
+
+ /* SSP and SVM fields below are not implemented by KVM */
+ u64 ssp; /* FF18 (R/W) */
+ u64 svm_guest_pat; /* FF20 (R/O) */
+ u64 svm_host_efer; /* FF28 (R/O) */
+ u64 svm_host_cr4; /* FF30 (R/O) */
+ u64 svm_host_cr3; /* FF38 (R/O) */
+ u64 svm_host_cr0; /* FF40 (R/O) */
+
+ u64 cr4; /* FF48 (R/O) */
+ u64 cr3; /* FF50 (R/O) */
+ u64 cr0; /* FF58 (R/O) */
+
+ u64 dr7; /* FF60 (R/O) */
+ u64 dr6; /* FF68 (R/O) */
+
+ u64 rflags; /* FF70 (R/W) */
+ u64 rip; /* FF78 (R/W) */
+
+ /* GPRS in a reversed "natural" X86 order (R15/R14/../RCX/RAX.) */
+ u64 gprs[16]; /* FF80-FFFF (R/W) */
+};
+
+
/* Host execution mode. */
#if defined(CONFIG_X86_32)
#define X86EMUL_MODE_HOST X86EMUL_MODE_PROT32
--
2.26.3