[PATCH] KVM: SVM: Name and check reserved fields with structs offset
From: Carlos Bilbao
Date: Mon Oct 24 2022 - 14:32:45 EST
Rename reserved fields on all structs in arch/x86/include/asm/svm.h
following their offset within the structs. Include compile time checks for
this in the same place where other BUILD_BUG_ON for the structs are.
This also solves that fields of struct sev_es_save_area are named by their
order of appearance, but right now they jump from reserved_5 to reserved_7.
Link: https://lkml.org/lkml/2022/10/22/376
Signed-off-by: Carlos Bilbao <carlos.bilbao@xxxxxxx>
---
arch/x86/include/asm/svm.h | 94 ++++++++++++++++++++++++++------------
1 file changed, 66 insertions(+), 28 deletions(-)
diff --git a/arch/x86/include/asm/svm.h b/arch/x86/include/asm/svm.h
index 0361626841bc..41d5188bf91a 100644
--- a/arch/x86/include/asm/svm.h
+++ b/arch/x86/include/asm/svm.h
@@ -293,12 +293,13 @@ struct vmcb_save_area {
struct vmcb_seg ldtr;
struct vmcb_seg idtr;
struct vmcb_seg tr;
- u8 reserved_1[42];
+ /* Reserved fields are named following their struct offset */
+ u8 reserved_0xa0[42];
u8 vmpl;
u8 cpl;
- u8 reserved_2[4];
+ u8 reserved_0xcc[4];
u64 efer;
- u8 reserved_3[112];
+ u8 reserved_0xd8[112];
u64 cr4;
u64 cr3;
u64 cr0;
@@ -306,7 +307,7 @@ struct vmcb_save_area {
u64 dr6;
u64 rflags;
u64 rip;
- u8 reserved_4[88];
+ u8 reserved_0x180[88];
u64 rsp;
u64 s_cet;
u64 ssp;
@@ -321,14 +322,14 @@ struct vmcb_save_area {
u64 sysenter_esp;
u64 sysenter_eip;
u64 cr2;
- u8 reserved_5[32];
+ u8 reserved_0x248[32];
u64 g_pat;
u64 dbgctl;
u64 br_from;
u64 br_to;
u64 last_excp_from;
u64 last_excp_to;
- u8 reserved_6[72];
+ u8 reserved_0x298[72];
u32 spec_ctrl; /* Guest version of SPEC_CTRL at 0x2E0 */
} __packed;
@@ -349,12 +350,12 @@ struct sev_es_save_area {
u64 vmpl2_ssp;
u64 vmpl3_ssp;
u64 u_cet;
- u8 reserved_1[2];
+ u8 reserved_0xc8[2];
u8 vmpl;
u8 cpl;
- u8 reserved_2[4];
+ u8 reserved_0xcc[4];
u64 efer;
- u8 reserved_3[104];
+ u8 reserved_0xd8[104];
u64 xss;
u64 cr4;
u64 cr3;
@@ -371,7 +372,7 @@ struct sev_es_save_area {
u64 dr1_addr_mask;
u64 dr2_addr_mask;
u64 dr3_addr_mask;
- u8 reserved_4[24];
+ u8 reserved_0x1c0[24];
u64 rsp;
u64 s_cet;
u64 ssp;
@@ -386,21 +387,21 @@ struct sev_es_save_area {
u64 sysenter_esp;
u64 sysenter_eip;
u64 cr2;
- u8 reserved_5[32];
+ u8 reserved_0x248[32];
u64 g_pat;
u64 dbgctl;
u64 br_from;
u64 br_to;
u64 last_excp_from;
u64 last_excp_to;
- u8 reserved_7[80];
+ u8 reserved_0x2e4[80];
u32 pkru;
- u8 reserved_8[20];
- u64 reserved_9; /* rax already available at 0x01f8 */
+ u8 reserved_0x2ec[20];
+ u64 reserved_0x300; /* rax already available at 0x01f8 */
u64 rcx;
u64 rdx;
u64 rbx;
- u64 reserved_10; /* rsp already available at 0x01d8 */
+ u64 reserved_0x320; /* rsp already available at 0x01d8 */
u64 rbp;
u64 rsi;
u64 rdi;
@@ -412,7 +413,7 @@ struct sev_es_save_area {
u64 r13;
u64 r14;
u64 r15;
- u8 reserved_11[16];
+ u8 reserved_0x380[16];
u64 guest_exit_info_1;
u64 guest_exit_info_2;
u64 guest_exit_int_info;
@@ -425,7 +426,7 @@ struct sev_es_save_area {
u64 pcpu_id;
u64 event_inj;
u64 xcr0;
- u8 reserved_12[16];
+ u8 reserved_0x3f0[16];
/* Floating point area */
u64 x87_dp;
@@ -443,23 +444,23 @@ struct sev_es_save_area {
} __packed;
struct ghcb_save_area {
- u8 reserved_1[203];
+ u8 reserved_0x0[203];
u8 cpl;
- u8 reserved_2[116];
+ u8 reserved_0xcc[116];
u64 xss;
- u8 reserved_3[24];
+ u8 reserved_0x148[24];
u64 dr7;
- u8 reserved_4[16];
+ u8 reserved_0x168[16];
u64 rip;
- u8 reserved_5[88];
+ u8 reserved_0x180[88];
u64 rsp;
- u8 reserved_6[24];
+ u8 reserved_0x1e0[24];
u64 rax;
- u8 reserved_7[264];
+ u8 reserved_0x200[264];
u64 rcx;
u64 rdx;
u64 rbx;
- u8 reserved_8[8];
+ u8 reserved_0x320[8];
u64 rbp;
u64 rsi;
u64 rdi;
@@ -471,12 +472,12 @@ struct ghcb_save_area {
u64 r13;
u64 r14;
u64 r15;
- u8 reserved_9[16];
+ u8 reserved_0x380[16];
u64 sw_exit_code;
u64 sw_exit_info_1;
u64 sw_exit_info_2;
u64 sw_scratch;
- u8 reserved_10[56];
+ u8 reserved_0x3b0[56];
u64 xcr0;
u8 valid_bitmap[16];
u64 x87_state_gpa;
@@ -490,7 +491,7 @@ struct ghcb {
u8 shared_buffer[GHCB_SHARED_BUF_SIZE];
- u8 reserved_1[10];
+ u8 reserved_0xff0[10];
u16 protocol_version; /* negotiated SEV-ES/GHCB protocol version */
u32 ghcb_usage;
} __packed;
@@ -502,6 +503,9 @@ struct ghcb {
#define EXPECTED_VMCB_CONTROL_AREA_SIZE 1024
#define EXPECTED_GHCB_SIZE PAGE_SIZE
+#define BUILD_BUG_RESERVED_OFFSET(x, y) \
+ BUILD_BUG_ON(offsetof(struct x, reserved ## _ ## y) != y)
+
static inline void __unused_size_checks(void)
{
BUILD_BUG_ON(sizeof(struct vmcb_save_area) != EXPECTED_VMCB_SAVE_AREA_SIZE);
@@ -509,6 +513,40 @@ static inline void __unused_size_checks(void)
BUILD_BUG_ON(sizeof(struct sev_es_save_area) != EXPECTED_SEV_ES_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);
+
+ /* Check offsets of reserved fields */
+
+ BUILD_BUG_RESERVED_OFFSET(vmcb_save_area, 0xa0);
+ BUILD_BUG_RESERVED_OFFSET(vmcb_save_area, 0xcc);
+ BUILD_BUG_RESERVED_OFFSET(vmcb_save_area, 0xd8);
+ BUILD_BUG_RESERVED_OFFSET(vmcb_save_area, 0x180);
+ BUILD_BUG_RESERVED_OFFSET(vmcb_save_area, 0x248);
+ BUILD_BUG_RESERVED_OFFSET(vmcb_save_area, 0x298);
+
+ BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0xc8);
+ BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0xcc);
+ BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0xd8);
+ BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0x1c0);
+ BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0x248);
+ BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0x2e4);
+ BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0x2ec);
+ BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0x300);
+ BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0x320);
+ BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0x380);
+ BUILD_BUG_RESERVED_OFFSET(sev_es_save_area, 0x3f0);
+
+ BUILD_BUG_RESERVED_OFFSET(ghcb_save_area, 0x0);
+ BUILD_BUG_RESERVED_OFFSET(ghcb_save_area, 0xcc);
+ BUILD_BUG_RESERVED_OFFSET(ghcb_save_area, 0x148);
+ BUILD_BUG_RESERVED_OFFSET(ghcb_save_area, 0x168);
+ BUILD_BUG_RESERVED_OFFSET(ghcb_save_area, 0x180);
+ BUILD_BUG_RESERVED_OFFSET(ghcb_save_area, 0x1e0);
+ BUILD_BUG_RESERVED_OFFSET(ghcb_save_area, 0x200);
+ BUILD_BUG_RESERVED_OFFSET(ghcb_save_area, 0x320);
+ BUILD_BUG_RESERVED_OFFSET(ghcb_save_area, 0x380);
+ BUILD_BUG_RESERVED_OFFSET(ghcb_save_area, 0x3b0);
+
+ BUILD_BUG_RESERVED_OFFSET(ghcb, 0xff0);
}
struct vmcb {
--
2.34.1