lguest: update comments

Also removes a long-unused #define and an extraneous semicolon.

Signed-off-by: Rusty Russell <[email protected]>

drivers/lguest/core.c

@@ -117,7 +117,7 @@ static __init int map_switcher(void)
 
 	/*
 	 * Now the Switcher is mapped at the right address, we can't fail!
-	 * Copy in the compiled-in Switcher code (from <arch>_switcher.S).
+	 * Copy in the compiled-in Switcher code (from x86/switcher_32.S).
 	 */
 	memcpy(switcher_vma->addr, start_switcher_text,
 	       end_switcher_text - start_switcher_text);

drivers/lguest/interrupts_and_traps.c

@@ -427,8 +427,8 @@ void pin_stack_pages(struct lg_cpu *cpu)
 
 /*
  * Direct traps also mean that we need to know whenever the Guest wants to use
- * a different kernel stack, so we can change the IDT entries to use that
- * stack.  The IDT entries expect a virtual address, so unlike most addresses
+ * a different kernel stack, so we can change the guest TSS to use that
+ * stack.  The TSS entries expect a virtual address, so unlike most addresses
  * the Guest gives us, the "esp" (stack pointer) value here is virtual, not
  * physical.
  *

drivers/lguest/lguest_user.c

@@ -1,8 +1,10 @@
-/*P:200 This contains all the /dev/lguest code, whereby the userspace launcher
- * controls and communicates with the Guest.  For example, the first write will
- * tell us the Guest's memory layout and entry point.  A read will run the
- * Guest until something happens, such as a signal or the Guest doing a NOTIFY
- * out to the Launcher.
+/*P:200 This contains all the /dev/lguest code, whereby the userspace
+ * launcher controls and communicates with the Guest.  For example,
+ * the first write will tell us the Guest's memory layout and entry
+ * point.  A read will run the Guest until something happens, such as
+ * a signal or the Guest doing a NOTIFY out to the Launcher.  There is
+ * also a way for the Launcher to attach eventfds to particular NOTIFY
+ * values instead of returning from the read() call.
 :*/
 #include <linux/uaccess.h>
 #include <linux/miscdevice.h>
@@ -357,8 +359,8 @@ static int initialize(struct file *file, const unsigned long __user *input)
 		goto free_eventfds;
 
 	/*
-	 * Initialize the Guest's shadow page tables, using the toplevel
-	 * address the Launcher gave us.  This allocates memory, so can fail.
+	 * Initialize the Guest's shadow page tables.  This allocates
+	 * memory, so can fail.
 	 */
 	err = init_guest_pagetable(lg);
 	if (err)
@@ -516,6 +518,7 @@ static const struct file_operations lguest_fops = {
 	.read	 = read,
 	.llseek  = default_llseek,
 };
+/*:*/
 
 /*
  * This is a textbook example of a "misc" character device.  Populate a "struct

drivers/lguest/page_tables.c

@@ -155,7 +155,7 @@ static pte_t *spte_addr(struct lg_cpu *cpu, pgd_t spgd, unsigned long vaddr)
 }
 
 /*
- * These functions are just like the above two, except they access the Guest
+ * These functions are just like the above, except they access the Guest
  * page tables.  Hence they return a Guest address.
  */
 static unsigned long gpgd_addr(struct lg_cpu *cpu, unsigned long vaddr)
@@ -195,7 +195,7 @@ static unsigned long gpte_addr(struct lg_cpu *cpu,
 #endif
 /*:*/
 
-/*M:014
+/*M:007
  * get_pfn is slow: we could probably try to grab batches of pages here as
  * an optimization (ie. pre-faulting).
 :*/

drivers/lguest/x86/core.c

@@ -272,7 +272,7 @@ static int emulate_insn(struct lg_cpu *cpu)
 	unsigned int insnlen = 0, in = 0, shift = 0;
 	/*
 	 * The eip contains the *virtual* address of the Guest's instruction:
-	 * guest_pa just subtracts the Guest's page_offset.
+	 * walk the Guest's page tables to find the "physical" address.
 	 */
 	unsigned long physaddr = guest_pa(cpu, cpu->regs->eip);
 
@@ -409,7 +409,7 @@ void lguest_arch_handle_trap(struct lg_cpu *cpu)
 		 * These values mean a real interrupt occurred, in which case
 		 * the Host handler has already been run. We just do a
 		 * friendly check if another process should now be run, then
-		 * return to run the Guest again
+		 * return to run the Guest again.
 		 */
 		cond_resched();
 		return;
@@ -459,7 +459,7 @@ void __init lguest_arch_host_init(void)
 	int i;
 
 	/*
-	 * Most of the i386/switcher.S doesn't care that it's been moved; on
+	 * Most of the x86/switcher_32.S doesn't care that it's been moved; on
 	 * Intel, jumps are relative, and it doesn't access any references to
 	 * external code or data.
 	 *
@@ -587,7 +587,7 @@ void __init lguest_arch_host_init(void)
 		clear_cpu_cap(&boot_cpu_data, X86_FEATURE_PGE);
 	}
 	put_online_cpus();
-};
+}
 /*:*/
 
 void __exit lguest_arch_host_fini(void)
@@ -670,8 +670,6 @@ int lguest_arch_init_hypercalls(struct lg_cpu *cpu)
 /*:*/
 
 /*L:030
- * lguest_arch_setup_regs()
- *
  * Most of the Guest's registers are left alone: we used get_zeroed_page() to
  * allocate the structure, so they will be 0.
  */