lguest: get rid of lg variable assignments
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>
diff --git a/drivers/lguest/page_tables.c b/drivers/lguest/page_tables.c
index c9acafc..983e902 100644
--- a/drivers/lguest/page_tables.c
+++ b/drivers/lguest/page_tables.c
@@ -68,17 +68,17 @@
* 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 @@
* 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 @@
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 @@
* 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 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 @@
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 @@
/* 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 @@
/* 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 @@
/* 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 @@
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 @@
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 @@
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 @@
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 @@
*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 @@
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 @@
* _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 @@
* 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 @@
*
* 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 @@
}
/* 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. */