commentHEADmaster

1 files changed, 119 insertions, 14 deletions

diff --git a/kern/inc/pv.h b/kern/inc/pv.h
index c0708dc..294966c 100644
--- a/kern/inc/pv.h
+++ b/kern/inc/pv.h
@@ -1,3 +1,11 @@
+/** @file pv.h
+ *
+ *  @brief PV functions
+ *
+ *  @author Hanjie Wu (hanjiew)
+ *  @bug No functional bugs
+ */
+
 #ifndef _PV_H_
 #define _PV_H_
 
@@ -14,60 +22,86 @@
 #include <loader.h>
 #include <paging.h>
 
+/** RPL3 means RPL is 3 */
 #define SEGSEL_RPL3 3
 
+/** cs for PV guest */
 #define SEGSEL_PV_CS (SEGSEL_SPARE0 | SEGSEL_RPL3)
+/** cs index for PV guest */
 #define SEGSEL_PV_CS_IDX SEGSEL_SPARE0_IDX
+/** ds for PV guest */
 #define SEGSEL_PV_DS (SEGSEL_SPARE1 | SEGSEL_RPL3)
+/** ds index for PV guest */
 #define SEGSEL_PV_DS_IDX SEGSEL_SPARE1_IDX
+/** fs for PV guest */
 #define SEGSEL_PV_FS (SEGSEL_SPARE3 | SEGSEL_RPL3)
+/** fs index for PV guest */
 #define SEGSEL_PV_FS_IDX SEGSEL_SPARE3_IDX
 
+/** VM limit for a PV guest */
 #define PV_VM_LIMIT (va_t)(~(USER_MEM_START - 1))
 
+/** default memory size (MB) for a PV guest */
 #define PV_DEFAULT_SIZE 24
+/** minimum memory size (MB) for a PV guest */
 #define PV_MINIMUM_SIZE 20
 
+/** shadow page table structure */
 typedef struct pv_pd_s {
     int refcount;
-    queue_t pv_link;
-    pa_t guest_pd;
+    queue_t pv_link; /** in pv_t's shadow_pds */
+    pa_t guest_pd;   /** physical address of original guest page table */
     int wp;
-    pa_t cr3;
-    pa_t user_cr3;
+    pa_t cr3;      /** shadow page table for PV kernel mode */
+    pa_t user_cr3; /** shadow page table for user mode */
 } pv_pd_t;
 
+/** DPL_0 means DPL is 0 */
 #define VIDT_DPL_0 0
+/** DPL_3 means DPL is 3 */
 #define VIDT_DPL_3 3
+/** all bits used in dpl */
 #define VIDT_DPL_MASK 3
 
+/** virtual idt entry structure */
 typedef struct pv_idt_entry_s {
     va_t eip;
-    int desc;
+    int desc; /** currently only contains dpl */
 } pv_idt_entry_t;
 
+/** virtual IRQ table */
 typedef struct pv_irq_s {
     int pending;
     int arg;
 } pv_irq_t;
 
+/** index where fault starts */
 #define PV_FAULT_START 0
+/** index where fault ends */
 #define PV_FAULT_END 20
+/** index where IRQ starts */
 #define PV_IRQ_START 32
+/** index where IRQ ends */
 #define PV_IRQ_END 34
+/** index where syscall area 1 starts */
 #define PV_SYSCALL_1_START 65
+/** index where syscall area 1 ends */
 #define PV_SYSCALL_1_END 117
+/** index where syscall area 2 starts */
 #define PV_SYSCALL_2_START 128
+/** index where syscall area 2 ends */
 #define PV_SYSCALL_2_END 135
 
+/** virtual idt structure */
 typedef struct pv_idt_s {
-    pv_idt_entry_t fault[PV_FAULT_END - PV_FAULT_START];
-    pv_idt_entry_t irq[PV_IRQ_END - PV_IRQ_START];
-    pv_irq_t pending_irq[PV_IRQ_END - PV_IRQ_START];
+    pv_idt_entry_t fault_irq[PV_IRQ_END - PV_FAULT_START];
+    pv_irq_t pending_irq[PV_IRQ_END -
+                         PV_IRQ_START]; /** pending keyboard/timer IRQ */
     pv_idt_entry_t syscall_1[PV_SYSCALL_1_END - PV_SYSCALL_1_START];
     pv_idt_entry_t syscall_2[PV_SYSCALL_2_END - PV_SYSCALL_2_START];
 } pv_idt_t;
 
+/** PV control block structure */
 typedef struct pv_s {
     int n_pages;
     pa_t mem_base;
@@ -76,9 +110,12 @@ typedef struct pv_s {
     queue_t* shadow_pds;
     pv_idt_t vidt;
     va_t vesp0;
-    queue_t pts_link;
+    queue_t pts_link; /** in pts_t's pvs */
 } pv_t;
 
+/**
+ * @brief initialize PV system
+ */
 void pv_init();
 
 struct process_s;
@@ -86,25 +123,44 @@ typedef struct process_s process_t;
 struct thread_s;
 typedef struct thread_s thread_t;
 
+/**
+ * @brief create a PV guest
+ * @param t thread control block
+ * @param elf the guest kernel
+ * @param exe name of guest kernel file
+ * @param mem_size size of guest kernel memory
+ * @return the guest kernel thread, NULL on failure
+ */
 thread_t* create_pv_process(thread_t* t,
                             simple_elf_t* elf,
                             char* exe,
                             va_size_t mem_size);
 
+/**
+ * @brief block interrupt for a PV guest
+ * @param pv PV control block for PV guest
+ */
 static inline void pv_mask_interrupt(pv_t* pv) {
     pv->vif = 0;
 }
 
+/**
+ * @brief unblock interrupt for a PV guest
+ * @param pv PV control block for PV guest
+ */
 static inline void pv_unmask_interrupt(pv_t* pv) {
     pv->vif = EFL_IF;
 }
 
+/**
+ * @brief find a vidt entry for a interrupt index
+ * @param pv PV control block for PV guest
+ * @param index interrupt index
+ * @return vidt entry, NULL on failure
+ */
 static inline pv_idt_entry_t* pv_classify_interrupt(pv_t* pv, int index) {
-    if (index >= PV_FAULT_START && index < PV_FAULT_END) {
-        return &pv->vidt.fault[index - PV_FAULT_START];
-    }
-    if (index >= PV_IRQ_START && index < PV_IRQ_END) {
-        return &pv->vidt.irq[index - PV_IRQ_START];
+    if (index >= PV_FAULT_START && index < PV_IRQ_END) {
+        return &pv->vidt.fault_irq[index - PV_FAULT_START];
     }
     if (index >= PV_SYSCALL_1_START && index < PV_SYSCALL_1_END) {
         return &pv->vidt.syscall_1[index - PV_SYSCALL_1_START];
@@ -115,24 +171,73 @@ static inline pv_idt_entry_t* pv_classify_interrupt(pv_t* pv, int index) {
     return NULL;
 }
 
+/**
+ * @brief destroy a pv control block
+ * @param pv PV control block for PV guest
+ */
 void destroy_pv(pv_t* pv);
 
+/**
+ * @brief kill current PV guest and print a reason
+ * @param reason reason
+ */
 void pv_die(char* reason);
 
+/**
+ * @brief switch PV guest to kernel/user mode
+ * @param p process block of PV guest
+ * @param kernelmode is switching to kernel mode?
+ */
 void pv_switch_mode(process_t* p, int kernelmode);
 
+/**
+ * @brief load a shadow page table
+ * @param p process block of PV guest
+ * @param pv_pd shadow page table
+ */
 void pv_select_pd(process_t* p, pv_pd_t* pv_pd);
 
+/**
+ * @brief handel a fault happened when PV guest is running
+ * @param frame fault frame
+ * @param t PV guest thread
+ */
 void pv_handle_fault(ureg_t* frame, thread_t* t);
 
+/**
+ * @brief Pend an IRQ request to PV guest
+ * @param pv PV control block for PV guest
+ * @param index IRQ index
+ * @param arg a custom arg to push to PV guest kernel stack
+ */
 void pv_pend_irq(pv_t* pv, int index, int arg);
 
 struct stack_frame_s;
 typedef struct stack_frame_s stack_frame_t;
+
+/**
+ * @brief try to inject an IRQ to PV guest, or mark it as pending if the guest
+ * is currently blocking interrupt
+ * @param f stack frame of PV guest
+ * @param index IRQ index
+ * @param arg a custom arg to push to PV guest kernel stack
+ */
 int pv_inject_irq(stack_frame_t* f, int index, int arg);
 
+/**
+ * @brief check if there is a pending IRQ and inject it if one exists
+ * @param f stack frame of PV guest
+ */
 void pv_check_pending_irq(stack_frame_t* f);
 
+/**
+ * @brief arrange the stack layout for injecting an interrupt (fault/IRQ)
+ * @param t PV guest thread
+ * @param pv PV control block for PV guest
+ * @param f stack frame of PV guest
+ * @param arg a custom arg to push to PV guest kernel stack
+ * @param eip guest handler address
+ */
 void pv_inject_interrupt(thread_t* t,
                          pv_t* pv,
                          stack_frame_t* f,