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lguest: documentation update

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Went through the documentation doing typo and content fixes.  This
patch contains only comment and whitespace changes.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Rusty Russell
2007-10-25 15:02:50 +10:00
parent 568a17ffce
commit e1e72965ec
16 changed files with 414 additions and 266 deletions
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48
arch/x86/lguest/boot.c
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@@ -99,7 +99,7 @@ static cycle_t clock_base;
* When lazy_mode is set, it means we're allowed to defer all hypercalls and do
* them as a batch when lazy_mode is eventually turned off. Because hypercalls
* are reasonably expensive, batching them up makes sense. For example, a
* large mmap might update dozens of page table entries: that code calls
* large munmap might update dozens of page table entries: that code calls
* paravirt_enter_lazy_mmu(), does the dozen updates, then calls
* lguest_leave_lazy_mode().
*
@@ -164,8 +164,8 @@ void async_hcall(unsigned long call,
/*:*/
/*G:033
* Here are our first native-instruction replacements: four functions for
* interrupt control.
* After that diversion we return to our first native-instruction
* replacements: four functions for interrupt control.
*
* The simplest way of implementing these would be to have "turn interrupts
* off" and "turn interrupts on" hypercalls. Unfortunately, this is too slow:
@@ -184,7 +184,7 @@ static unsigned long save_fl(void)
return lguest_data.irq_enabled;
}
/* "restore_flags" just sets the flags back to the value given. */
/* restore_flags() just sets the flags back to the value given. */
static void restore_fl(unsigned long flags)
{
lguest_data.irq_enabled = flags;
@@ -357,7 +357,7 @@ static void lguest_cpuid(unsigned int *eax, unsigned int *ebx,
* it. The Host needs to know when the Guest wants to change them, so we have
* a whole series of functions like read_cr0() and write_cr0().
*
* We start with CR0. CR0 allows you to turn on and off all kinds of basic
* We start with cr0. cr0 allows you to turn on and off all kinds of basic
* features, but Linux only really cares about one: the horrifically-named Task
* Switched (TS) bit at bit 3 (ie. 8)
*
@@ -390,7 +390,7 @@ static void lguest_clts(void)
current_cr0 &= ~X86_CR0_TS;
}
/* CR2 is the virtual address of the last page fault, which the Guest only ever
/* cr2 is the virtual address of the last page fault, which the Guest only ever
* reads. The Host kindly writes this into our "struct lguest_data", so we
* just read it out of there. */
static unsigned long lguest_read_cr2(void)
@@ -398,7 +398,7 @@ static unsigned long lguest_read_cr2(void)
return lguest_data.cr2;
}
/* CR3 is the current toplevel pagetable page: the principle is the same as
/* cr3 is the current toplevel pagetable page: the principle is the same as
* cr0. Keep a local copy, and tell the Host when it changes. */
static void lguest_write_cr3(unsigned long cr3)
{
@@ -411,7 +411,7 @@ static unsigned long lguest_read_cr3(void)
return current_cr3;
}
/* CR4 is used to enable and disable PGE, but we don't care. */
/* cr4 is used to enable and disable PGE, but we don't care. */
static unsigned long lguest_read_cr4(void)
{
return 0;
@@ -432,7 +432,7 @@ static void lguest_write_cr4(unsigned long val)
* maps virtual addresses to physical addresses using "page tables". We could
* use one huge index of 1 million entries: each address is 4 bytes, so that's
* 1024 pages just to hold the page tables. But since most virtual addresses
* are unused, we use a two level index which saves space. The CR3 register
* are unused, we use a two level index which saves space. The cr3 register
* contains the physical address of the top level "page directory" page, which
* contains physical addresses of up to 1024 second-level pages. Each of these
* second level pages contains up to 1024 physical addresses of actual pages,
@@ -440,7 +440,7 @@ static void lguest_write_cr4(unsigned long val)
*
* Here's a diagram, where arrows indicate physical addresses:
*
* CR3 ---> +---------+
* cr3 ---> +---------+
* | --------->+---------+
* | | | PADDR1 |
* Top-level | | PADDR2 |
@@ -498,8 +498,7 @@ static void lguest_set_pmd(pmd_t *pmdp, pmd_t pmdval)
*
* ... except in early boot when the kernel sets up the initial pagetables,
* which makes booting astonishingly slow. So we don't even tell the Host
* anything changed until we've done the first page table switch.
*/
* anything changed until we've done the first page table switch. */
static void lguest_set_pte(pte_t *ptep, pte_t pteval)
{
*ptep = pteval;
@@ -720,10 +719,10 @@ static void lguest_time_init(void)
/* Set up the timer interrupt (0) to go to our simple timer routine */
set_irq_handler(0, lguest_time_irq);
/* Our clock structure look like arch/i386/kernel/tsc.c if we can use
* the TSC, otherwise it's a dumb nanosecond-resolution clock. Either
* way, the "rating" is initialized so high that it's always chosen
* over any other clocksource. */
/* Our clock structure looks like arch/x86/kernel/tsc_32.c if we can
* use the TSC, otherwise it's a dumb nanosecond-resolution clock.
* Either way, the "rating" is set so high that it's always chosen over
* any other clocksource. */
if (lguest_data.tsc_khz)
lguest_clock.mult = clocksource_khz2mult(lguest_data.tsc_khz,
lguest_clock.shift);
@@ -749,7 +748,7 @@ static void lguest_time_init(void)
* to work. They're pretty simple.
*/
/* The Guest needs to tell the host what stack it expects traps to use. For
/* The Guest needs to tell the Host what stack it expects traps to use. For
* native hardware, this is part of the Task State Segment mentioned above in
* lguest_load_tr_desc(), but to help hypervisors there's this special call.
*
@@ -850,13 +849,16 @@ static __init char *lguest_memory_setup(void)
return "LGUEST";
}
/* Before virtqueues are set up, we use LHCALL_NOTIFY on normal memory to
* produce console output. */
/* We will eventually use the virtio console device to produce console output,
* but before that is set up we use LHCALL_NOTIFY on normal memory to produce
* console output. */
static __init int early_put_chars(u32 vtermno, const char *buf, int count)
{
char scratch[17];
unsigned int len = count;
/* We use a nul-terminated string, so we have to make a copy. Icky,
* huh? */
if (len > sizeof(scratch) - 1)
len = sizeof(scratch) - 1;
scratch[len] = '\0';
@@ -883,7 +885,7 @@ static __init int early_put_chars(u32 vtermno, const char *buf, int count)
* Our current solution is to allow the paravirt back end to optionally patch
* over the indirect calls to replace them with something more efficient. We
* patch the four most commonly called functions: disable interrupts, enable
* interrupts, restore interrupts and save interrupts. We usually have 10
* interrupts, restore interrupts and save interrupts. We usually have 6 or 10
* bytes to patch into: the Guest versions of these operations are small enough
* that we can fit comfortably.
*
@@ -1015,7 +1017,7 @@ __init void lguest_init(void)
asm volatile ("mov %0, %%fs" : : "r" (__KERNEL_DS) : "memory");
/* The Host uses the top of the Guest's virtual address space for the
* Host<->Guest Switcher, and it tells us how much it needs in
* Host<->Guest Switcher, and it tells us how big that is in
* lguest_data.reserve_mem, set up on the LGUEST_INIT hypercall. */
reserve_top_address(lguest_data.reserve_mem);
@@ -1065,6 +1067,6 @@ __init void lguest_init(void)
/*
* This marks the end of stage II of our journey, The Guest.
*
* It is now time for us to explore the nooks and crannies of the three Guest
* devices and complete our understanding of the Guest in "make Drivers".
* It is now time for us to explore the layer of virtual drivers and complete
* our understanding of the Guest in "make Drivers".
*/