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lguest: get rid of lg variable assignments

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We can save some lines of code by getting rid of
*lg = cpu... lines of code spread everywhere by now.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
Glauber de Oliveira Costa 2008-01-17 19:19:42 -02:00 committed by Rusty Russell
parent 934faab464
commit 382ac6b3fb
7 changed files with 149 additions and 159 deletions
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24
drivers/lguest/core.c
View file

@ -151,23 +151,23 @@ int lguest_address_ok(const struct lguest *lg,
/* This routine copies memory from the Guest. Here we can see how useful the
* kill_lguest() routine we met in the Launcher can be: we return a random
* value (all zeroes) instead of needing to return an error. */
void __lgread(struct lguest *lg, void *b, unsigned long addr, unsigned bytes)
void __lgread(struct lg_cpu *cpu, void *b, unsigned long addr, unsigned bytes)
{
if (!lguest_address_ok(lg, addr, bytes)
|| copy_from_user(b, lg->mem_base + addr, bytes) != 0) {
if (!lguest_address_ok(cpu->lg, addr, bytes)
|| copy_from_user(b, cpu->lg->mem_base + addr, bytes) != 0) {
/* copy_from_user should do this, but as we rely on it... */
memset(b, 0, bytes);
kill_guest(lg, "bad read address %#lx len %u", addr, bytes);
kill_guest(cpu, "bad read address %#lx len %u", addr, bytes);
}
}
/* This is the write (copy into guest) version. */
void __lgwrite(struct lguest *lg, unsigned long addr, const void *b,
void __lgwrite(struct lg_cpu *cpu, unsigned long addr, const void *b,
unsigned bytes)
{
if (!lguest_address_ok(lg, addr, bytes)
|| copy_to_user(lg->mem_base + addr, b, bytes) != 0)
kill_guest(lg, "bad write address %#lx len %u", addr, bytes);
if (!lguest_address_ok(cpu->lg, addr, bytes)
|| copy_to_user(cpu->lg->mem_base + addr, b, bytes) != 0)
kill_guest(cpu, "bad write address %#lx len %u", addr, bytes);
}
/*:*/
@ -176,10 +176,8 @@ void __lgwrite(struct lguest *lg, unsigned long addr, const void *b,
* going around and around until something interesting happens. */
int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
{
struct lguest *lg = cpu->lg;
/* We stop running once the Guest is dead. */
while (!lg->dead) {
while (!cpu->lg->dead) {
/* First we run any hypercalls the Guest wants done. */
if (cpu->hcall)
do_hypercalls(cpu);
@ -212,7 +210,7 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
/* Just make absolutely sure the Guest is still alive. One of
* those hypercalls could have been fatal, for example. */
if (lg->dead)
if (cpu->lg->dead)
break;
/* If the Guest asked to be stopped, we sleep. The Guest's
@ -237,7 +235,7 @@ int run_guest(struct lg_cpu *cpu, unsigned long __user *user)
lguest_arch_handle_trap(cpu);
}
if (lg->dead == ERR_PTR(-ERESTART))
if (cpu->lg->dead == ERR_PTR(-ERESTART))
return -ERESTART;
/* The Guest is dead => "No such file or directory" */
return -ENOENT;

49
drivers/lguest/hypercalls.c
View file

@ -31,8 +31,6 @@
* Or gets killed. Or, in the case of LHCALL_CRASH, both. */
static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
{
struct lguest *lg = cpu->lg;
switch (args->arg0) {
case LHCALL_FLUSH_ASYNC:
/* This call does nothing, except by breaking out of the Guest
@ -41,7 +39,7 @@ static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
case LHCALL_LGUEST_INIT:
/* You can't get here unless you're already initialized. Don't
* do that. */
kill_guest(lg, "already have lguest_data");
kill_guest(cpu, "already have lguest_data");
break;
case LHCALL_SHUTDOWN: {
/* Shutdown is such a trivial hypercall that we do it in four
@ -49,11 +47,11 @@ static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
char msg[128];
/* If the lgread fails, it will call kill_guest() itself; the
* kill_guest() with the message will be ignored. */
__lgread(lg, msg, args->arg1, sizeof(msg));
__lgread(cpu, msg, args->arg1, sizeof(msg));
msg[sizeof(msg)-1] = '\0';
kill_guest(lg, "CRASH: %s", msg);
kill_guest(cpu, "CRASH: %s", msg);
if (args->arg2 == LGUEST_SHUTDOWN_RESTART)
lg->dead = ERR_PTR(-ERESTART);
cpu->lg->dead = ERR_PTR(-ERESTART);
break;
}
case LHCALL_FLUSH_TLB:
@ -74,10 +72,10 @@ static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
guest_set_stack(cpu, args->arg1, args->arg2, args->arg3);
break;
case LHCALL_SET_PTE:
guest_set_pte(lg, args->arg1, args->arg2, __pte(args->arg3));
guest_set_pte(cpu, args->arg1, args->arg2, __pte(args->arg3));
break;
case LHCALL_SET_PMD:
guest_set_pmd(lg, args->arg1, args->arg2);
guest_set_pmd(cpu->lg, args->arg1, args->arg2);
break;
case LHCALL_SET_CLOCKEVENT:
guest_set_clockevent(cpu, args->arg1);
@ -96,7 +94,7 @@ static void do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
default:
/* It should be an architecture-specific hypercall. */
if (lguest_arch_do_hcall(cpu, args))
kill_guest(lg, "Bad hypercall %li\n", args->arg0);
kill_guest(cpu, "Bad hypercall %li\n", args->arg0);
}
}
/*:*/
@ -112,10 +110,9 @@ static void do_async_hcalls(struct lg_cpu *cpu)
{
unsigned int i;
u8 st[LHCALL_RING_SIZE];
struct lguest *lg = cpu->lg;
/* For simplicity, we copy the entire call status array in at once. */
if (copy_from_user(&st, &lg->lguest_data->hcall_status, sizeof(st)))
if (copy_from_user(&st, &cpu->lg->lguest_data->hcall_status, sizeof(st)))
return;
/* We process "struct lguest_data"s hcalls[] ring once. */
@ -137,9 +134,9 @@ static void do_async_hcalls(struct lg_cpu *cpu)
/* Copy the hypercall arguments into a local copy of
* the hcall_args struct. */
if (copy_from_user(&args, &lg->lguest_data->hcalls[n],
if (copy_from_user(&args, &cpu->lg->lguest_data->hcalls[n],
sizeof(struct hcall_args))) {
kill_guest(lg, "Fetching async hypercalls");
kill_guest(cpu, "Fetching async hypercalls");
break;
}
@ -147,8 +144,8 @@ static void do_async_hcalls(struct lg_cpu *cpu)
do_hcall(cpu, &args);
/* Mark the hypercall done. */
if (put_user(0xFF, &lg->lguest_data->hcall_status[n])) {
kill_guest(lg, "Writing result for async hypercall");
if (put_user(0xFF, &cpu->lg->lguest_data->hcall_status[n])) {
kill_guest(cpu, "Writing result for async hypercall");
break;
}
@ -163,29 +160,28 @@ static void do_async_hcalls(struct lg_cpu *cpu)
* Guest makes a hypercall, we end up here to set things up: */
static void initialize(struct lg_cpu *cpu)
{
struct lguest *lg = cpu->lg;
/* You can't do anything until you're initialized. The Guest knows the
* rules, so we're unforgiving here. */
if (cpu->hcall->arg0 != LHCALL_LGUEST_INIT) {
kill_guest(lg, "hypercall %li before INIT", cpu->hcall->arg0);
kill_guest(cpu, "hypercall %li before INIT", cpu->hcall->arg0);
return;
}
if (lguest_arch_init_hypercalls(cpu))
kill_guest(lg, "bad guest page %p", lg->lguest_data);
kill_guest(cpu, "bad guest page %p", cpu->lg->lguest_data);
/* The Guest tells us where we're not to deliver interrupts by putting
* the range of addresses into "struct lguest_data". */
if (get_user(lg->noirq_start, &lg->lguest_data->noirq_start)
|| get_user(lg->noirq_end, &lg->lguest_data->noirq_end))
kill_guest(lg, "bad guest page %p", lg->lguest_data);
if (get_user(cpu->lg->noirq_start, &cpu->lg->lguest_data->noirq_start)
|| get_user(cpu->lg->noirq_end, &cpu->lg->lguest_data->noirq_end))
kill_guest(cpu, "bad guest page %p", cpu->lg->lguest_data);
/* We write the current time into the Guest's data page once so it can
* set its clock. */
write_timestamp(lg);
write_timestamp(cpu);
/* page_tables.c will also do some setup. */
page_table_guest_data_init(lg);
page_table_guest_data_init(cpu);
/* This is the one case where the above accesses might have been the
* first write to a Guest page. This may have caused a copy-on-write
@ -237,10 +233,11 @@ void do_hypercalls(struct lg_cpu *cpu)
/* This routine supplies the Guest with time: it's used for wallclock time at
* initial boot and as a rough time source if the TSC isn't available. */
void write_timestamp(struct lguest *lg)
void write_timestamp(struct lg_cpu *cpu)
{
struct timespec now;
ktime_get_real_ts(&now);
if (copy_to_user(&lg->lguest_data->time, &now, sizeof(struct timespec)))
kill_guest(lg, "Writing timestamp");
if (copy_to_user(&cpu->lg->lguest_data->time,
&now, sizeof(struct timespec)))
kill_guest(cpu, "Writing timestamp");
}

54
drivers/lguest/interrupts_and_traps.c
View file

@ -41,11 +41,11 @@ static int idt_present(u32 lo, u32 hi)
/* We need a helper to "push" a value onto the Guest's stack, since that's a
* big part of what delivering an interrupt does. */
static void push_guest_stack(struct lguest *lg, unsigned long *gstack, u32 val)
static void push_guest_stack(struct lg_cpu *cpu, unsigned long *gstack, u32 val)
{
/* Stack grows upwards: move stack then write value. */
*gstack -= 4;
lgwrite(lg, *gstack, u32, val);
lgwrite(cpu, *gstack, u32, val);
}
/*H:210 The set_guest_interrupt() routine actually delivers the interrupt or
@ -65,7 +65,6 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err)
unsigned long gstack, origstack;
u32 eflags, ss, irq_enable;
unsigned long virtstack;
struct lguest *lg = cpu->lg;
/* There are two cases for interrupts: one where the Guest is already
* in the kernel, and a more complex one where the Guest is in
@ -81,8 +80,8 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err)
* stack: when the Guest does an "iret" back from the interrupt
* handler the CPU will notice they're dropping privilege
* levels and expect these here. */
push_guest_stack(lg, &gstack, cpu->regs->ss);
push_guest_stack(lg, &gstack, cpu->regs->esp);
push_guest_stack(cpu, &gstack, cpu->regs->ss);
push_guest_stack(cpu, &gstack, cpu->regs->esp);
} else {
/* We're staying on the same Guest (kernel) stack. */
virtstack = cpu->regs->esp;
@ -96,20 +95,20 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err)
* Guest's "irq_enabled" field into the eflags word: we saw the Guest
* copy it back in "lguest_iret". */
eflags = cpu->regs->eflags;
if (get_user(irq_enable, &lg->lguest_data->irq_enabled) == 0
if (get_user(irq_enable, &cpu->lg->lguest_data->irq_enabled) == 0
&& !(irq_enable & X86_EFLAGS_IF))
eflags &= ~X86_EFLAGS_IF;
/* An interrupt is expected to push three things on the stack: the old
* "eflags" word, the old code segment, and the old instruction
* pointer. */
push_guest_stack(lg, &gstack, eflags);
push_guest_stack(lg, &gstack, cpu->regs->cs);
push_guest_stack(lg, &gstack, cpu->regs->eip);
push_guest_stack(cpu, &gstack, eflags);
push_guest_stack(cpu, &gstack, cpu->regs->cs);
push_guest_stack(cpu, &gstack, cpu->regs->eip);
/* For the six traps which supply an error code, we push that, too. */
if (has_err)
push_guest_stack(lg, &gstack, cpu->regs->errcode);
push_guest_stack(cpu, &gstack, cpu->regs->errcode);
/* Now we've pushed all the old state, we change the stack, the code
* segment and the address to execute. */
@ -121,8 +120,8 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err)
/* There are two kinds of interrupt handlers: 0xE is an "interrupt
* gate" which expects interrupts to be disabled on entry. */
if (idt_type(lo, hi) == 0xE)
if (put_user(0, &lg->lguest_data->irq_enabled))
kill_guest(lg, "Disabling interrupts");
if (put_user(0, &cpu->lg->lguest_data->irq_enabled))
kill_guest(cpu, "Disabling interrupts");
}
/*H:205
@ -133,17 +132,16 @@ static void set_guest_interrupt(struct lg_cpu *cpu, u32 lo, u32 hi, int has_err)
void maybe_do_interrupt(struct lg_cpu *cpu)
{
unsigned int irq;
struct lguest *lg = cpu->lg;
DECLARE_BITMAP(blk, LGUEST_IRQS);
struct desc_struct *idt;
/* If the Guest hasn't even initialized yet, we can do nothing. */
if (!lg->lguest_data)
if (!cpu->lg->lguest_data)
return;
/* Take our "irqs_pending" array and remove any interrupts the Guest
* wants blocked: the result ends up in "blk". */
if (copy_from_user(&blk, lg->lguest_data->blocked_interrupts,
if (copy_from_user(&blk, cpu->lg->lguest_data->blocked_interrupts,
sizeof(blk)))
return;
@ -157,19 +155,20 @@ void maybe_do_interrupt(struct lg_cpu *cpu)
/* They may be in the middle of an iret, where they asked us never to
* deliver interrupts. */
if (cpu->regs->eip >= lg->noirq_start && cpu->regs->eip < lg->noirq_end)
if (cpu->regs->eip >= cpu->lg->noirq_start &&
(cpu->regs->eip < cpu->lg->noirq_end))
return;
/* If they're halted, interrupts restart them. */
if (cpu->halted) {
/* Re-enable interrupts. */
if (put_user(X86_EFLAGS_IF, &lg->lguest_data->irq_enabled))
kill_guest(lg, "Re-enabling interrupts");
if (put_user(X86_EFLAGS_IF, &cpu->lg->lguest_data->irq_enabled))
kill_guest(cpu, "Re-enabling interrupts");
cpu->halted = 0;
} else {
/* Otherwise we check if they have interrupts disabled. */
u32 irq_enabled;
if (get_user(irq_enabled, &lg->lguest_data->irq_enabled))
if (get_user(irq_enabled, &cpu->lg->lguest_data->irq_enabled))
irq_enabled = 0;
if (!irq_enabled)
return;
@ -194,7 +193,7 @@ void maybe_do_interrupt(struct lg_cpu *cpu)
* did this more often, but it can actually be quite slow: doing it
* here is a compromise which means at least it gets updated every
* timer interrupt. */
write_timestamp(lg);
write_timestamp(cpu);
}
/*:*/
@ -315,10 +314,9 @@ void pin_stack_pages(struct lg_cpu *cpu)
{
unsigned int i;
struct lguest *lg = cpu->lg;
/* Depending on the CONFIG_4KSTACKS option, the Guest can have one or
* two pages of stack space. */
for (i = 0; i < lg->stack_pages; i++)
for (i = 0; i < cpu->lg->stack_pages; i++)
/* The stack grows *upwards*, so the address we're given is the
* start of the page after the kernel stack. Subtract one to
* get back onto the first stack page, and keep subtracting to
@ -339,10 +337,10 @@ void guest_set_stack(struct lg_cpu *cpu, u32 seg, u32 esp, unsigned int pages)
/* You are not allowed have a stack segment with privilege level 0: bad
* Guest! */
if ((seg & 0x3) != GUEST_PL)
kill_guest(cpu->lg, "bad stack segment %i", seg);
kill_guest(cpu, "bad stack segment %i", seg);
/* We only expect one or two stack pages. */
if (pages > 2)
kill_guest(cpu->lg, "bad stack pages %u", pages);
kill_guest(cpu, "bad stack pages %u", pages);
/* Save where the stack is, and how many pages */
cpu->ss1 = seg;
cpu->esp1 = esp;
@ -356,7 +354,7 @@ void guest_set_stack(struct lg_cpu *cpu, u32 seg, u32 esp, unsigned int pages)
/*H:235 This is the routine which actually checks the Guest's IDT entry and
* transfers it into the entry in "struct lguest": */
static void set_trap(struct lguest *lg, struct desc_struct *trap,
static void set_trap(struct lg_cpu *cpu, struct desc_struct *trap,
unsigned int num, u32 lo, u32 hi)
{
u8 type = idt_type(lo, hi);
@ -369,7 +367,7 @@ static void set_trap(struct lguest *lg, struct desc_struct *trap,
/* We only support interrupt and trap gates. */
if (type != 0xE && type != 0xF)
kill_guest(lg, "bad IDT type %i", type);
kill_guest(cpu, "bad IDT type %i", type);
/* We only copy the handler address, present bit, privilege level and
* type. The privilege level controls where the trap can be triggered
@ -399,9 +397,9 @@ void load_guest_idt_entry(struct lg_cpu *cpu, unsigned int num, u32 lo, u32 hi)
/* Check that the Guest doesn't try to step outside the bounds. */
if (num >= ARRAY_SIZE(cpu->arch.idt))
kill_guest(cpu->lg, "Setting idt entry %u", num);
kill_guest(cpu, "Setting idt entry %u", num);
else
set_trap(cpu->lg, &cpu->arch.idt[num], num, lo, hi);
set_trap(cpu, &cpu->arch.idt[num], num, lo, hi);
}
/* The default entry for each interrupt points into the Switcher routines which

28
drivers/lguest/lg.h
View file

@ -111,22 +111,22 @@ extern struct mutex lguest_lock;
/* core.c: */
int lguest_address_ok(const struct lguest *lg,
unsigned long addr, unsigned long len);
void __lgread(struct lguest *, void *, unsigned long, unsigned);
void __lgwrite(struct lguest *, unsigned long, const void *, unsigned);
void __lgread(struct lg_cpu *, void *, unsigned long, unsigned);
void __lgwrite(struct lg_cpu *, unsigned long, const void *, unsigned);
/*H:035 Using memory-copy operations like that is usually inconvient, so we
* have the following helper macros which read and write a specific type (often
* an unsigned long).
*
* This reads into a variable of the given type then returns that. */
#define lgread(lg, addr, type) \
({ type _v; __lgread((lg), &_v, (addr), sizeof(_v)); _v; })
#define lgread(cpu, addr, type) \
({ type _v; __lgread((cpu), &_v, (addr), sizeof(_v)); _v; })
/* This checks that the variable is of the given type, then writes it out. */
#define lgwrite(lg, addr, type, val) \
#define lgwrite(cpu, addr, type, val) \
do { \
typecheck(type, val); \
__lgwrite((lg), (addr), &(val), sizeof(val)); \
__lgwrite((cpu), (addr), &(val), sizeof(val)); \
} while(0)
/* (end of memory access helper routines) :*/
@ -171,13 +171,13 @@ void guest_new_pagetable(struct lg_cpu *cpu, unsigned long pgtable);
void guest_set_pmd(struct lguest *lg, unsigned long gpgdir, u32 i);
void guest_pagetable_clear_all(struct lg_cpu *cpu);
void guest_pagetable_flush_user(struct lg_cpu *cpu);
void guest_set_pte(struct lguest *lg, unsigned long gpgdir,
void guest_set_pte(struct lg_cpu *cpu, unsigned long gpgdir,
unsigned long vaddr, pte_t val);
void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages);
int demand_page(struct lg_cpu *cpu, unsigned long cr2, int errcode);
void pin_page(struct lg_cpu *cpu, unsigned long vaddr);
unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr);
void page_table_guest_data_init(struct lguest *lg);
void page_table_guest_data_init(struct lg_cpu *cpu);
/* <arch>/core.c: */
void lguest_arch_host_init(void);
@ -197,7 +197,7 @@ void lguest_device_remove(void);
/* hypercalls.c: */
void do_hypercalls(struct lg_cpu *cpu);
void write_timestamp(struct lguest *lg);
void write_timestamp(struct lg_cpu *cpu);
/*L:035
* Let's step aside for the moment, to study one important routine that's used
@ -223,12 +223,12 @@ void write_timestamp(struct lguest *lg);
* Like any macro which uses an "if", it is safely wrapped in a run-once "do {
* } while(0)".
*/
#define kill_guest(lg, fmt...) \
#define kill_guest(cpu, fmt...) \
do { \
if (!(lg)->dead) { \
(lg)->dead = kasprintf(GFP_ATOMIC, fmt); \
if (!(lg)->dead) \
(lg)->dead = ERR_PTR(-ENOMEM); \
if (!(cpu)->lg->dead) { \
(cpu)->lg->dead = kasprintf(GFP_ATOMIC, fmt); \
if (!(cpu)->lg->dead) \
(cpu)->lg->dead = ERR_PTR(-ENOMEM); \
} \
} while(0)
/* (End of aside) :*/

115
drivers/lguest/page_tables.c
View file

@ -68,17 +68,17 @@ static DEFINE_PER_CPU(pte_t *, switcher_pte_pages);
* page directory entry (PGD) for that address. Since we keep track of several
* page tables, the "i" argument tells us which one we're interested in (it's
* usually the current one). */
static pgd_t *spgd_addr(struct lguest *lg, u32 i, unsigned long vaddr)
static pgd_t *spgd_addr(struct lg_cpu *cpu, u32 i, unsigned long vaddr)
{
unsigned int index = pgd_index(vaddr);
/* We kill any Guest trying to touch the Switcher addresses. */
if (index >= SWITCHER_PGD_INDEX) {
kill_guest(lg, "attempt to access switcher pages");
kill_guest(cpu, "attempt to access switcher pages");
index = 0;
}
/* Return a pointer index'th pgd entry for the i'th page table. */
return &lg->pgdirs[i].pgdir[index];
return &cpu->lg->pgdirs[i].pgdir[index];
}
/* This routine then takes the page directory entry returned above, which
@ -137,7 +137,7 @@ static unsigned long get_pfn(unsigned long virtpfn, int write)
* entry can be a little tricky. The flags are (almost) the same, but the
* Guest PTE contains a virtual page number: the CPU needs the real page
* number. */
static pte_t gpte_to_spte(struct lguest *lg, pte_t gpte, int write)
static pte_t gpte_to_spte(struct lg_cpu *cpu, pte_t gpte, int write)
{
unsigned long pfn, base, flags;
@ -148,7 +148,7 @@ static pte_t gpte_to_spte(struct lguest *lg, pte_t gpte, int write)
flags = (pte_flags(gpte) & ~_PAGE_GLOBAL);
/* The Guest's pages are offset inside the Launcher. */
base = (unsigned long)lg->mem_base / PAGE_SIZE;
base = (unsigned long)cpu->lg->mem_base / PAGE_SIZE;
/* We need a temporary "unsigned long" variable to hold the answer from
* get_pfn(), because it returns 0xFFFFFFFF on failure, which wouldn't
@ -156,7 +156,7 @@ static pte_t gpte_to_spte(struct lguest *lg, pte_t gpte, int write)
* page, given the virtual number. */
pfn = get_pfn(base + pte_pfn(gpte), write);
if (pfn == -1UL) {
kill_guest(lg, "failed to get page %lu", pte_pfn(gpte));
kill_guest(cpu, "failed to get page %lu", pte_pfn(gpte));
/* When we destroy the Guest, we'll go through the shadow page
* tables and release_pte() them. Make sure we don't think
* this one is valid! */
@ -176,17 +176,18 @@ static void release_pte(pte_t pte)
}
/*:*/
static void check_gpte(struct lguest *lg, pte_t gpte)
static void check_gpte(struct lg_cpu *cpu, pte_t gpte)
{
if ((pte_flags(gpte) & (_PAGE_PWT|_PAGE_PSE))
|| pte_pfn(gpte) >= lg->pfn_limit)
kill_guest(lg, "bad page table entry");
|| pte_pfn(gpte) >= cpu->lg->pfn_limit)
kill_guest(cpu, "bad page table entry");
}
static void check_gpgd(struct lguest *lg, pgd_t gpgd)
static void check_gpgd(struct lg_cpu *cpu, pgd_t gpgd)
{
if ((pgd_flags(gpgd) & ~_PAGE_TABLE) || pgd_pfn(gpgd) >= lg->pfn_limit)
kill_guest(lg, "bad page directory entry");
if ((pgd_flags(gpgd) & ~_PAGE_TABLE) ||
(pgd_pfn(gpgd) >= cpu->lg->pfn_limit))
kill_guest(cpu, "bad page directory entry");
}
/*H:330
@ -206,27 +207,26 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
unsigned long gpte_ptr;
pte_t gpte;
pte_t *spte;
struct lguest *lg = cpu->lg;
/* First step: get the top-level Guest page table entry. */
gpgd = lgread(lg, gpgd_addr(cpu, vaddr), pgd_t);
gpgd = lgread(cpu, gpgd_addr(cpu, vaddr), pgd_t);
/* Toplevel not present? We can't map it in. */
if (!(pgd_flags(gpgd) & _PAGE_PRESENT))
return 0;
/* Now look at the matching shadow entry. */
spgd = spgd_addr(lg, cpu->cpu_pgd, vaddr);
spgd = spgd_addr(cpu, cpu->cpu_pgd, vaddr);
if (!(pgd_flags(*spgd) & _PAGE_PRESENT)) {
/* No shadow entry: allocate a new shadow PTE page. */
unsigned long ptepage = get_zeroed_page(GFP_KERNEL);
/* This is not really the Guest's fault, but killing it is
* simple for this corner case. */
if (!ptepage) {
kill_guest(lg, "out of memory allocating pte page");
kill_guest(cpu, "out of memory allocating pte page");
return 0;
}
/* We check that the Guest pgd is OK. */
check_gpgd(lg, gpgd);
check_gpgd(cpu, gpgd);
/* And we copy the flags to the shadow PGD entry. The page
* number in the shadow PGD is the page we just allocated. */
*spgd = __pgd(__pa(ptepage) | pgd_flags(gpgd));
@ -235,7 +235,7 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
/* OK, now we look at the lower level in the Guest page table: keep its
* address, because we might update it later. */
gpte_ptr = gpte_addr(gpgd, vaddr);
gpte = lgread(lg, gpte_ptr, pte_t);
gpte = lgread(cpu, gpte_ptr, pte_t);
/* If this page isn't in the Guest page tables, we can't page it in. */
if (!(pte_flags(gpte) & _PAGE_PRESENT))
@ -252,7 +252,7 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
/* Check that the Guest PTE flags are OK, and the page number is below
* the pfn_limit (ie. not mapping the Launcher binary). */
check_gpte(lg, gpte);
check_gpte(cpu, gpte);
/* Add the _PAGE_ACCESSED and (for a write) _PAGE_DIRTY flag */
gpte = pte_mkyoung(gpte);
@ -268,17 +268,17 @@ int demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
/* If this is a write, we insist that the Guest page is writable (the
* final arg to gpte_to_spte()). */
if (pte_dirty(gpte))
*spte = gpte_to_spte(lg, gpte, 1);
*spte = gpte_to_spte(cpu, gpte, 1);
else
/* If this is a read, don't set the "writable" bit in the page
* table entry, even if the Guest says it's writable. That way
* we will come back here when a write does actually occur, so
* we can update the Guest's _PAGE_DIRTY flag. */
*spte = gpte_to_spte(lg, pte_wrprotect(gpte), 0);
*spte = gpte_to_spte(cpu, pte_wrprotect(gpte), 0);
/* Finally, we write the Guest PTE entry back: we've set the
* _PAGE_ACCESSED and maybe the _PAGE_DIRTY flags. */
lgwrite(lg, gpte_ptr, pte_t, gpte);
lgwrite(cpu, gpte_ptr, pte_t, gpte);
/* The fault is fixed, the page table is populated, the mapping
* manipulated, the result returned and the code complete. A small
@ -303,7 +303,7 @@ static int page_writable(struct lg_cpu *cpu, unsigned long vaddr)
unsigned long flags;
/* Look at the current top level entry: is it present? */
spgd = spgd_addr(cpu->lg, cpu->cpu_pgd, vaddr);
spgd = spgd_addr(cpu, cpu->cpu_pgd, vaddr);
if (!(pgd_flags(*spgd) & _PAGE_PRESENT))
return 0;
@ -320,7 +320,7 @@ static int page_writable(struct lg_cpu *cpu, unsigned long vaddr)
void pin_page(struct lg_cpu *cpu, unsigned long vaddr)
{
if (!page_writable(cpu, vaddr) && !demand_page(cpu, vaddr, 2))
kill_guest(cpu->lg, "bad stack page %#lx", vaddr);
kill_guest(cpu, "bad stack page %#lx", vaddr);
}
/*H:450 If we chase down the release_pgd() code, it looks like this: */
@ -372,14 +372,14 @@ unsigned long guest_pa(struct lg_cpu *cpu, unsigned long vaddr)
pte_t gpte;
/* First step: get the top-level Guest page table entry. */
gpgd = lgread(cpu->lg, gpgd_addr(cpu, vaddr), pgd_t);
gpgd = lgread(cpu, gpgd_addr(cpu, vaddr), pgd_t);
/* Toplevel not present? We can't map it in. */
if (!(pgd_flags(gpgd) & _PAGE_PRESENT))
kill_guest(cpu->lg, "Bad address %#lx", vaddr);
kill_guest(cpu, "Bad address %#lx", vaddr);
gpte = lgread(cpu->lg, gpte_addr(gpgd, vaddr), pte_t);
gpte = lgread(cpu, gpte_addr(gpgd, vaddr), pte_t);
if (!(pte_flags(gpte) & _PAGE_PRESENT))
kill_guest(cpu->lg, "Bad address %#lx", vaddr);
kill_guest(cpu, "Bad address %#lx", vaddr);
return pte_pfn(gpte) * PAGE_SIZE | (vaddr & ~PAGE_MASK);
}
@ -404,16 +404,16 @@ static unsigned int new_pgdir(struct lg_cpu *cpu,
int *blank_pgdir)
{
unsigned int next;
struct lguest *lg = cpu->lg;
/* We pick one entry at random to throw out. Choosing the Least
* Recently Used might be better, but this is easy. */
next = random32() % ARRAY_SIZE(lg->pgdirs);
next = random32() % ARRAY_SIZE(cpu->lg->pgdirs);
/* If it's never been allocated at all before, try now. */
if (!lg->pgdirs[next].pgdir) {
lg->pgdirs[next].pgdir = (pgd_t *)get_zeroed_page(GFP_KERNEL);
if (!cpu->lg->pgdirs[next].pgdir) {
cpu->lg->pgdirs[next].pgdir =
(pgd_t *)get_zeroed_page(GFP_KERNEL);
/* If the allocation fails, just keep using the one we have */
if (!lg->pgdirs[next].pgdir)
if (!cpu->lg->pgdirs[next].pgdir)
next = cpu->cpu_pgd;
else
/* This is a blank page, so there are no kernel
@ -421,9 +421,9 @@ static unsigned int new_pgdir(struct lg_cpu *cpu,
*blank_pgdir = 1;
}
/* Record which Guest toplevel this shadows. */
lg->pgdirs[next].gpgdir = gpgdir;
cpu->lg->pgdirs[next].gpgdir = gpgdir;
/* Release all the non-kernel mappings. */
flush_user_mappings(lg, next);
flush_user_mappings(cpu->lg, next);
return next;
}
@ -436,13 +436,12 @@ static unsigned int new_pgdir(struct lg_cpu *cpu,
void guest_new_pagetable(struct lg_cpu *cpu, unsigned long pgtable)
{
int newpgdir, repin = 0;
struct lguest *lg = cpu->lg;
/* Look to see if we have this one already. */
newpgdir = find_pgdir(lg, pgtable);
newpgdir = find_pgdir(cpu->lg, pgtable);
/* If not, we allocate or mug an existing one: if it's a fresh one,
* repin gets set to 1. */
if (newpgdir == ARRAY_SIZE(lg->pgdirs))
if (newpgdir == ARRAY_SIZE(cpu->lg->pgdirs))
newpgdir = new_pgdir(cpu, pgtable, &repin);
/* Change the current pgd index to the new one. */
cpu->cpu_pgd = newpgdir;
@ -499,11 +498,11 @@ void guest_pagetable_clear_all(struct lg_cpu *cpu)
* _PAGE_ACCESSED then we can put a read-only PTE entry in immediately, and if
* they set _PAGE_DIRTY then we can put a writable PTE entry in immediately.
*/
static void do_set_pte(struct lguest *lg, int idx,
static void do_set_pte(struct lg_cpu *cpu, int idx,
unsigned long vaddr, pte_t gpte)
{
/* Look up the matching shadow page directory entry. */
pgd_t *spgd = spgd_addr(lg, idx, vaddr);
pgd_t *spgd = spgd_addr(cpu, idx, vaddr);
/* If the top level isn't present, there's no entry to update. */
if (pgd_flags(*spgd) & _PAGE_PRESENT) {
@ -515,8 +514,8 @@ static void do_set_pte(struct lguest *lg, int idx,
* as well put that entry they've given us in now. This shaves
* 10% off a copy-on-write micro-benchmark. */
if (pte_flags(gpte) & (_PAGE_DIRTY | _PAGE_ACCESSED)) {
check_gpte(lg, gpte);
*spte = gpte_to_spte(lg, gpte,
check_gpte(cpu, gpte);
*spte = gpte_to_spte(cpu, gpte,
pte_flags(gpte) & _PAGE_DIRTY);
} else
/* Otherwise kill it and we can demand_page() it in
@ -535,22 +534,22 @@ static void do_set_pte(struct lguest *lg, int idx,
*
* The benefit is that when we have to track a new page table, we can copy keep
* all the kernel mappings. This speeds up context switch immensely. */
void guest_set_pte(struct lguest *lg,
void guest_set_pte(struct lg_cpu *cpu,
unsigned long gpgdir, unsigned long vaddr, pte_t gpte)
{
/* Kernel mappings must be changed on all top levels. Slow, but
* doesn't happen often. */
if (vaddr >= lg->kernel_address) {
if (vaddr >= cpu->lg->kernel_address) {
unsigned int i;
for (i = 0; i < ARRAY_SIZE(lg->pgdirs); i++)
if (lg->pgdirs[i].pgdir)
do_set_pte(lg, i, vaddr, gpte);
for (i = 0; i < ARRAY_SIZE(cpu->lg->pgdirs); i++)
if (cpu->lg->pgdirs[i].pgdir)
do_set_pte(cpu, i, vaddr, gpte);
} else {
/* Is this page table one we have a shadow for? */
int pgdir = find_pgdir(lg, gpgdir);
if (pgdir != ARRAY_SIZE(lg->pgdirs))
int pgdir = find_pgdir(cpu->lg, gpgdir);
if (pgdir != ARRAY_SIZE(cpu->lg->pgdirs))
/* If so, do the update. */
do_set_pte(lg, pgdir, vaddr, gpte);
do_set_pte(cpu, pgdir, vaddr, gpte);
}
}
@ -601,21 +600,23 @@ int init_guest_pagetable(struct lguest *lg, unsigned long pgtable)
}
/* When the Guest calls LHCALL_LGUEST_INIT we do more setup. */
void page_table_guest_data_init(struct lguest *lg)
void page_table_guest_data_init(struct lg_cpu *cpu)
{
/* We get the kernel address: above this is all kernel memory. */
if (get_user(lg->kernel_address, &lg->lguest_data->kernel_address)
if (get_user(cpu->lg->kernel_address,
&cpu->lg->lguest_data->kernel_address)
/* We tell the Guest that it can't use the top 4MB of virtual
* addresses used by the Switcher. */
|| put_user(4U*1024*1024, &lg->lguest_data->reserve_mem)
|| put_user(lg->pgdirs[0].gpgdir, &lg->lguest_data->pgdir))
kill_guest(lg, "bad guest page %p", lg->lguest_data);
|| put_user(4U*1024*1024, &cpu->lg->lguest_data->reserve_mem)
|| put_user(cpu->lg->pgdirs[0].gpgdir, &cpu->lg->lguest_data->pgdir))
kill_guest(cpu, "bad guest page %p", cpu->lg->lguest_data);
/* In flush_user_mappings() we loop from 0 to
* "pgd_index(lg->kernel_address)". This assumes it won't hit the
* Switcher mappings, so check that now. */
if (pgd_index(lg->kernel_address) >= SWITCHER_PGD_INDEX)
kill_guest(lg, "bad kernel address %#lx", lg->kernel_address);
if (pgd_index(cpu->lg->kernel_address) >= SWITCHER_PGD_INDEX)
kill_guest(cpu, "bad kernel address %#lx",
cpu->lg->kernel_address);
}
/* When a Guest dies, our cleanup is fairly simple. */

8
drivers/lguest/segments.c
View file

@ -148,14 +148,13 @@ void copy_gdt(const struct lg_cpu *cpu, struct desc_struct *gdt)
* We copy it from the Guest and tweak the entries. */
void load_guest_gdt(struct lg_cpu *cpu, unsigned long table, u32 num)
{
struct lguest *lg = cpu->lg;
/* We assume the Guest has the same number of GDT entries as the
* Host, otherwise we'd have to dynamically allocate the Guest GDT. */
if (num > ARRAY_SIZE(cpu->arch.gdt))
kill_guest(lg, "too many gdt entries %i", num);
kill_guest(cpu, "too many gdt entries %i", num);
/* We read the whole thing in, then fix it up. */
__lgread(lg, cpu->arch.gdt, table, num * sizeof(cpu->arch.gdt[0]));
__lgread(cpu, cpu->arch.gdt, table, num * sizeof(cpu->arch.gdt[0]));
fixup_gdt_table(cpu, 0, ARRAY_SIZE(cpu->arch.gdt));
/* Mark that the GDT changed so the core knows it has to copy it again,
* even if the Guest is run on the same CPU. */
@ -169,9 +168,8 @@ void load_guest_gdt(struct lg_cpu *cpu, unsigned long table, u32 num)
void guest_load_tls(struct lg_cpu *cpu, unsigned long gtls)
{
struct desc_struct *tls = &cpu->arch.gdt[GDT_ENTRY_TLS_MIN];
struct lguest *lg = cpu->lg;
__lgread(lg, tls, gtls, sizeof(*tls)*GDT_ENTRY_TLS_ENTRIES);
__lgread(cpu, tls, gtls, sizeof(*tls)*GDT_ENTRY_TLS_ENTRIES);
fixup_gdt_table(cpu, GDT_ENTRY_TLS_MIN, GDT_ENTRY_TLS_MAX+1);
/* Note that just the TLS entries have changed. */
cpu->changed |= CHANGED_GDT_TLS;

30
drivers/lguest/x86/core.c
View file

@ -117,7 +117,6 @@ static void run_guest_once(struct lg_cpu *cpu, struct lguest_pages *pages)
{
/* This is a dummy value we need for GCC's sake. */
unsigned int clobber;
struct lguest *lg = cpu->lg;
/* Copy the guest-specific information into this CPU's "struct
* lguest_pages". */
@ -144,7 +143,7 @@ static void run_guest_once(struct lg_cpu *cpu, struct lguest_pages *pages)
* 0-th argument above, ie "a"). %ebx contains the
* physical address of the Guest's top-level page
* directory. */
: "0"(pages), "1"(__pa(lg->pgdirs[cpu->cpu_pgd].pgdir))
: "0"(pages), "1"(__pa(cpu->lg->pgdirs[cpu->cpu_pgd].pgdir))
/* We tell gcc that all these registers could change,
* which means we don't have to save and restore them in
* the Switcher. */
@ -217,7 +216,6 @@ void lguest_arch_run_guest(struct lg_cpu *cpu)
* instructions and skip over it. We return true if we did. */
static int emulate_insn(struct lg_cpu *cpu)
{
struct lguest *lg = cpu->lg;
u8 insn;
unsigned int insnlen = 0, in = 0, shift = 0;
/* The eip contains the *virtual* address of the Guest's instruction:
@ -231,7 +229,7 @@ static int emulate_insn(struct lg_cpu *cpu)
return 0;
/* Decoding x86 instructions is icky. */
insn = lgread(lg, physaddr, u8);
insn = lgread(cpu, physaddr, u8);
/* 0x66 is an "operand prefix". It means it's using the upper 16 bits
of the eax register. */
@ -239,7 +237,7 @@ static int emulate_insn(struct lg_cpu *cpu)
shift = 16;
/* The instruction is 1 byte so far, read the next byte. */
insnlen = 1;
insn = lgread(lg, physaddr + insnlen, u8);
insn = lgread(cpu, physaddr + insnlen, u8);
}
/* We can ignore the lower bit for the moment and decode the 4 opcodes
@ -283,7 +281,6 @@ static int emulate_insn(struct lg_cpu *cpu)
/*H:050 Once we've re-enabled interrupts, we look at why the Guest exited. */
void lguest_arch_handle_trap(struct lg_cpu *cpu)
{
struct lguest *lg = cpu->lg;
switch (cpu->regs->trapnum) {
case 13: /* We've intercepted a General Protection Fault. */
/* Check if this was one of those annoying IN or OUT
@ -315,9 +312,10 @@ void lguest_arch_handle_trap(struct lg_cpu *cpu)
* Note that if the Guest were really messed up, this could
* happen before it's done the LHCALL_LGUEST_INIT hypercall, so
* lg->lguest_data could be NULL */
if (lg->lguest_data &&
put_user(cpu->arch.last_pagefault, &lg->lguest_data->cr2))
kill_guest(lg, "Writing cr2");
if (cpu->lg->lguest_data &&
put_user(cpu->arch.last_pagefault,
&cpu->lg->lguest_data->cr2))
kill_guest(cpu, "Writing cr2");
break;
case 7: /* We've intercepted a Device Not Available fault. */
/* If the Guest doesn't want to know, we already restored the
@ -345,7 +343,7 @@ void lguest_arch_handle_trap(struct lg_cpu *cpu)
/* If the Guest doesn't have a handler (either it hasn't
* registered any yet, or it's one of the faults we don't let
* it handle), it dies with a cryptic error message. */
kill_guest(lg, "unhandled trap %li at %#lx (%#lx)",
kill_guest(cpu, "unhandled trap %li at %#lx (%#lx)",
cpu->regs->trapnum, cpu->regs->eip,
cpu->regs->trapnum == 14 ? cpu->arch.last_pagefault
: cpu->regs->errcode);
@ -514,11 +512,11 @@ int lguest_arch_do_hcall(struct lg_cpu *cpu, struct hcall_args *args)
int lguest_arch_init_hypercalls(struct lg_cpu *cpu)
{
u32 tsc_speed;
struct lguest *lg = cpu->lg;
/* The pointer to the Guest's "struct lguest_data" is the only
* argument. We check that address now. */
if (!lguest_address_ok(lg, cpu->hcall->arg1, sizeof(*lg->lguest_data)))
if (!lguest_address_ok(cpu->lg, cpu->hcall->arg1,
sizeof(*cpu->lg->lguest_data)))
return -EFAULT;
/* Having checked it, we simply set lg->lguest_data to point straight
@ -526,7 +524,7 @@ int lguest_arch_init_hypercalls(struct lg_cpu *cpu)
* copy_to_user/from_user from now on, instead of lgread/write. I put
* this in to show that I'm not immune to writing stupid
* optimizations. */
lg->lguest_data = lg->mem_base + cpu->hcall->arg1;
cpu->lg->lguest_data = cpu->lg->mem_base + cpu->hcall->arg1;
/* We insist that the Time Stamp Counter exist and doesn't change with
* cpu frequency. Some devious chip manufacturers decided that TSC
@ -539,12 +537,12 @@ int lguest_arch_init_hypercalls(struct lg_cpu *cpu)
tsc_speed = tsc_khz;
else
tsc_speed = 0;
if (put_user(tsc_speed, &lg->lguest_data->tsc_khz))
if (put_user(tsc_speed, &cpu->lg->lguest_data->tsc_khz))
return -EFAULT;
/* The interrupt code might not like the system call vector. */
if (!check_syscall_vector(lg))
kill_guest(lg, "bad syscall vector");
if (!check_syscall_vector(cpu->lg))
kill_guest(cpu, "bad syscall vector");
return 0;
}