x86 architectural infrastructure for exception handling

Unlike the GDT which PV guests might have a legitimate interest in, a PV guest
genuinely has no interest in an x86 architectural IDT.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>

diff --git a/arch/x86/desc.c b/arch/x86/desc.c
index 4dd02bfb5b006262a1537f4a02c4327e05f15fa9..9acd62c239e194168118120f0404f765f1cc6f8f 100644 (file)
--- a/arch/x86/desc.c
+++ b/arch/x86/desc.c
@@ -14,6 +14,18 @@ desc_ptr gdt_ptr =
     .base = (unsigned long)&gdt,
 };
 
+#if defined(CONFIG_ENV_hvm)
+
+gate_desc idt[256] = { };
+
+desc_ptr idt_ptr =
+{
+    .limit = sizeof(idt) - 1,
+    .base = (unsigned long)&idt,
+};
+
+#endif
+
 /*
  * Local variables:
  * mode: C

diff --git a/include/arch/x86/desc.h b/include/arch/x86/desc.h
index 6f48754c76cdb1f996c446834bf2dbe6d5df6c4f..d80750cebc7184de8a6bece9302406a5150a0348 100644 (file)
--- a/include/arch/x86/desc.h
+++ b/include/arch/x86/desc.h
@@ -56,6 +56,39 @@ struct __packed seg_desc32 {
     };
 };
 
+/** 8-byte gate - Protected mode IDT entry, GDT task/call gate. */
+struct __packed seg_gate32 {
+    union {
+        struct {
+            uint32_t lo, hi;
+        };
+        struct {
+            uint16_t offset0;
+            uint16_t selector;
+            uint8_t  _r0;
+            unsigned type: 4, s: 1, dpl: 2, p: 1;
+            uint16_t offset1;
+        };
+    };
+};
+
+/** 16-byte gate - Long mode IDT entry. */
+struct __packed seg_gate64 {
+    union {
+        struct {
+            uint64_t lo, hi;
+        };
+        struct {
+            uint16_t offset0;
+            uint16_t selector;
+            unsigned ist: 3, _r0: 5, type: 4, s: 1, dpl: 2, p: 1;
+            uint16_t offset1;
+            uint32_t offset2;
+            uint32_t _r1;
+        };
+    };
+};
+
 /* GDT/LDT attribute flags for user segments */
 
 /* Common */
@@ -128,11 +161,13 @@ struct __packed desc_ptr32 {
 
 typedef struct desc_ptr64 desc_ptr;
 typedef struct seg_desc32 user_desc;
+typedef struct seg_gate64 gate_desc;
 
 #elif defined(__i386__)
 
 typedef struct desc_ptr32 desc_ptr;
 typedef struct seg_desc32 user_desc;
+typedef struct seg_gate32 gate_desc;
 
 #else
 # error Bad architecture for descriptor infrastructure
@@ -141,6 +176,11 @@ typedef struct seg_desc32 user_desc;
 extern user_desc gdt[NR_GDT_ENTRIES];
 extern desc_ptr  gdt_ptr;
 
+#if defined(CONFIG_ENV_hvm)
+extern gate_desc idt[256];
+extern desc_ptr  idt_ptr;
+#endif
+
 #endif /* XTF_X86_DESC_H */
 
 /*

diff --git a/include/arch/x86/processor.h b/include/arch/x86/processor.h
index 3276b7d8e647e5196f6c1b2f84eb662c9f14c201..7e359b5f011a94d3870a1d20dbbeebb243820270 100644 (file)
--- a/include/arch/x86/processor.h
+++ b/include/arch/x86/processor.h
@@ -60,6 +60,58 @@
 #define X86_CR4_SMEP            0x00100000  /* SMEP                           */
 #define X86_CR4_SMAP            0x00200000  /* SMAP                           */
 
+/*
+ * Exception mnemonics.
+ */
+#define X86_EXC_DE             0 /* Divide Error. */
+#define X86_EXC_DB             1 /* Debug Exception. */
+#define X86_EXC_NMI            2 /* NMI. */
+#define X86_EXC_BP             3 /* Breakpoint. */
+#define X86_EXC_OF             4 /* Overflow. */
+#define X86_EXC_BR             5 /* BOUND Range. */
+#define X86_EXC_UD             6 /* Invalid Opcode. */
+#define X86_EXC_NM             7 /* Device Not Available. */
+#define X86_EXC_DF             8 /* Double Fault. */
+#define X86_EXC_CSO            9 /* Coprocessor Segment Overrun. */
+#define X86_EXC_TS            10 /* Invalid TSS. */
+#define X86_EXC_NP            11 /* Segment Not Present. */
+#define X86_EXC_SS            12 /* Stack-Segment Fault. */
+#define X86_EXC_GP            13 /* General Porection Fault. */
+#define X86_EXC_PF            14 /* Page Fault. */
+#define X86_EXC_SPV           15 /* PIC Spurious Interrupt Vector. */
+#define X86_EXC_MF            16 /* Maths fault (x87 FPU). */
+#define X86_EXC_AC            17 /* Alignment Check. */
+#define X86_EXC_MC            18 /* Machine Check. */
+#define X86_EXC_XM            19 /* SIMD Exception. */
+#define X86_EXC_VE            20 /* Virtualisation Exception. */
+
+/* Bitmap of exceptions which have error codes. */
+#define X86_EXC_HAVE_EC ((1 << X86_EXC_DF) | (1 << X86_EXC_TS) |    \
+                         (1 << X86_EXC_NP) | (1 << X86_EXC_SS) |    \
+                         (1 << X86_EXC_GP) | (1 << X86_EXC_PF) |    \
+                         (1 << X86_EXC_AC))
+
+/* Bitmap of exceptions which are classified as faults. */
+#define X86_EXC_FAULTS ((1 << X86_EXC_DE)  | (1 << X86_EXC_BR) |    \
+                        (1 << X86_EXC_UD)  | (1 << X86_EXC_NM) |    \
+                        (1 << X86_EXC_CSO) | (1 << X86_EXC_TS) |    \
+                        (1 << X86_EXC_NP)  | (1 << X86_EXC_SS) |    \
+                        (1 << X86_EXC_GP)  | (1 << X86_EXC_PF) |    \
+                        (1 << X86_EXC_MF)  | (1 << X86_EXC_AC) |    \
+                        (1 << X86_EXC_XM)  | (1 << X86_EXC_VE))
+
+/* Bitmap of exceptions which are classified as interrupts. */
+#define X86_EXC_INTERRUPTS (1 << X86_EXC_NMI)
+
+/* Bitmap of exceptions which are classified as traps. */
+#define X86_EXC_TRAPS ((1 << X86_EXC_BP) | (1 << X86_EXC_OF))
+
+/* Bitmap of exceptions which are classified as aborts. */
+#define X86_EXC_ABORTS ((1 << X86_EXC_DF) | (1 << X86_EXC_MC))
+
+/* Number of reserved vectors for exceptions. */
+#define X86_NR_RESERVED_VECTORS 32
+
 #endif /* XTF_X86_PROCESSOR_H */
 
 /*