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lguest: use set_pte/set_pmd uniformly for real page table entries 

If we're building a pte, we can use simple assigment; only use set_pte
etc. when we're actually going to use that destination as a PTE.  I
don't know that we'll ever run under Xen, but it's neater.

And use set_pte/set_pmd rather than assuming native_ versions, even
though that's probably true for most people.

(Includes compile fix by Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>)
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
Cc: Matias Zabaljauregui <zabaljauregui@gmail.com>
Cc: Kamalesh Babulal <kamalesh@linux.vnet.ibm.com>
This commit is contained in:
Rusty Russell 2009-09-23 22:26:45 -06:00
parent cdae0ad5e8
commit 4c1ea3dd71
1 changed files with 17 additions and 22 deletions
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39
drivers/lguest/page_tables.c
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@ -380,7 +380,7 @@ bool demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
* And we copy the flags to the shadow PMD entry. The page
* number in the shadow PMD is the page we just allocated.
*/
native_set_pmd(spmd, __pmd(__pa(ptepage) | pmd_flags(gpmd)));
set_pmd(spmd, __pmd(__pa(ptepage) | pmd_flags(gpmd)));
}
/*
@ -447,7 +447,7 @@ bool demand_page(struct lg_cpu *cpu, unsigned long vaddr, int errcode)
* we will come back here when a write does actually occur, so
* we can update the Guest's _PAGE_DIRTY flag.
*/
native_set_pte(spte, gpte_to_spte(cpu, pte_wrprotect(gpte), 0));
set_pte(spte, gpte_to_spte(cpu, pte_wrprotect(gpte), 0));
/*
* Finally, we write the Guest PTE entry back: we've set the
@ -528,7 +528,7 @@ static void release_pmd(pmd_t *spmd)
/* Now we can free the page of PTEs */
free_page((long)ptepage);
/* And zero out the PMD entry so we never release it twice. */
native_set_pmd(spmd, __pmd(0));
set_pmd(spmd, __pmd(0));
}
}
@ -833,15 +833,15 @@ static void do_set_pte(struct lg_cpu *cpu, int idx,
*/
if (pte_flags(gpte) & (_PAGE_DIRTY | _PAGE_ACCESSED)) {
check_gpte(cpu, gpte);
native_set_pte(spte,
gpte_to_spte(cpu, gpte,
set_pte(spte,
gpte_to_spte(cpu, gpte,
pte_flags(gpte) & _PAGE_DIRTY));
} else {
/*
* Otherwise kill it and we can demand_page()
* it in later.
*/
native_set_pte(spte, __pte(0));
set_pte(spte, __pte(0));
}
#ifdef CONFIG_X86_PAE
}
@ -983,16 +983,15 @@ static unsigned long setup_pagetables(struct lguest *lg,
*/
for (i = j = 0; i < mapped_pages && j < PTRS_PER_PMD;
i += PTRS_PER_PTE, j++) {
/* FIXME: native_set_pmd is overkill here. */
native_set_pmd(&pmd, __pmd(((unsigned long)(linear + i)
- mem_base) | _PAGE_PRESENT | _PAGE_RW | _PAGE_USER));
pmd = pfn_pmd(((unsigned long)&linear[i] - mem_base)/PAGE_SIZE,
__pgprot(_PAGE_PRESENT | _PAGE_RW | _PAGE_USER));
if (copy_to_user(&pmds[j], &pmd, sizeof(pmd)) != 0)
return -EFAULT;
}
/* One PGD entry, pointing to that PMD page. */
set_pgd(&pgd, __pgd(((u32)pmds - mem_base) | _PAGE_PRESENT));
pgd = __pgd(((unsigned long)pmds - mem_base) | _PAGE_PRESENT);
/* Copy it in as the first PGD entry (ie. addresses 0-1G). */
if (copy_to_user(&pgdir[0], &pgd, sizeof(pgd)) != 0)
return -EFAULT;
@ -1141,15 +1140,13 @@ void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages)
{
pte_t *switcher_pte_page = __get_cpu_var(switcher_pte_pages);
pte_t regs_pte;
unsigned long pfn;
#ifdef CONFIG_X86_PAE
pmd_t switcher_pmd;
pmd_t *pmd_table;
/* FIXME: native_set_pmd is overkill here. */
native_set_pmd(&switcher_pmd, pfn_pmd(__pa(switcher_pte_page) >>
PAGE_SHIFT, PAGE_KERNEL_EXEC));
switcher_pmd = pfn_pmd(__pa(switcher_pte_page) >> PAGE_SHIFT,
PAGE_KERNEL_EXEC);
/* Figure out where the pmd page is, by reading the PGD, and converting
* it to a virtual address. */
@ -1157,7 +1154,7 @@ void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages)
pgdirs[cpu->cpu_pgd].pgdir[SWITCHER_PGD_INDEX])
<< PAGE_SHIFT);
/* Now write it into the shadow page table. */
native_set_pmd(&pmd_table[SWITCHER_PMD_INDEX], switcher_pmd);
set_pmd(&pmd_table[SWITCHER_PMD_INDEX], switcher_pmd);
#else
pgd_t switcher_pgd;
@ -1179,10 +1176,8 @@ void map_switcher_in_guest(struct lg_cpu *cpu, struct lguest_pages *pages)
* page is already mapped there, we don't have to copy them out
* again.
*/
pfn = __pa(cpu->regs_page) >> PAGE_SHIFT;
native_set_pte(&regs_pte, pfn_pte(pfn, PAGE_KERNEL));
native_set_pte(&switcher_pte_page[pte_index((unsigned long)pages)],
regs_pte);
regs_pte = pfn_pte(__pa(cpu->regs_page) >> PAGE_SHIFT, PAGE_KERNEL);
set_pte(&switcher_pte_page[pte_index((unsigned long)pages)], regs_pte);
}
/*:*/
@ -1209,7 +1204,7 @@ static __init void populate_switcher_pte_page(unsigned int cpu,
/* The first entries are easy: they map the Switcher code. */
for (i = 0; i < pages; i++) {
native_set_pte(&pte[i], mk_pte(switcher_page[i],
set_pte(&pte[i], mk_pte(switcher_page[i],
__pgprot(_PAGE_PRESENT|_PAGE_ACCESSED)));
}
@ -1217,14 +1212,14 @@ static __init void populate_switcher_pte_page(unsigned int cpu,
i = pages + cpu*2;
/* First page (Guest registers) is writable from the Guest */
native_set_pte(&pte[i], pfn_pte(page_to_pfn(switcher_page[i]),
set_pte(&pte[i], pfn_pte(page_to_pfn(switcher_page[i]),
__pgprot(_PAGE_PRESENT|_PAGE_ACCESSED|_PAGE_RW)));
/*
* The second page contains the "struct lguest_ro_state", and is
* read-only.
*/
native_set_pte(&pte[i+1], pfn_pte(page_to_pfn(switcher_page[i+1]),
set_pte(&pte[i+1], pfn_pte(page_to_pfn(switcher_page[i+1]),
__pgprot(_PAGE_PRESENT|_PAGE_ACCESSED)));
}