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Commit bc7fe1d9 authored by Jeremy Fitzhardinge's avatar Jeremy Fitzhardinge
Browse files

xen/mmu: tune pgtable alloc/release 



Make sure the fastpath code is inlined.  Batch the page permission change
and the pin/unpin, and make sure that it can be batched with any
adjacent set_pte/pmd/etc operations.

Signed-off-by: default avatarJeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
parent dcf7435c

arch/x86/xen/mmu.c

+44 −9
Original line number Diff line number Diff line
@@ -1497,22 +1497,52 @@ static void __init xen_release_pmd_init(unsigned long pfn) 
	make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));

}



static inline void __pin_pagetable_pfn(unsigned cmd, unsigned long pfn)

{

	struct multicall_space mcs;

	struct mmuext_op *op;



	mcs = __xen_mc_entry(sizeof(*op));

	op = mcs.args;

	op->cmd = cmd;

	op->arg1.mfn = pfn_to_mfn(pfn);



	MULTI_mmuext_op(mcs.mc, mcs.args, 1, NULL, DOMID_SELF);

}



static inline void __set_pfn_prot(unsigned long pfn, pgprot_t prot)

{

	struct multicall_space mcs;

	unsigned long addr = (unsigned long)__va(pfn << PAGE_SHIFT);



	mcs = __xen_mc_entry(0);

	MULTI_update_va_mapping(mcs.mc, (unsigned long)addr,

				pfn_pte(pfn, prot), 0);

}



/* This needs to make sure the new pte page is pinned iff its being

   attached to a pinned pagetable. */

static void xen_alloc_ptpage(struct mm_struct *mm, unsigned long pfn, unsigned level)

static inline void xen_alloc_ptpage(struct mm_struct *mm, unsigned long pfn,

				    unsigned level)

{

	struct page *page = pfn_to_page(pfn);

	int pinned = PagePinned(virt_to_page(mm->pgd));

	bool pinned = PagePinned(virt_to_page(mm->pgd));



	trace_xen_mmu_alloc_ptpage(mm, pfn, level, pinned);



	if (pinned) {

		struct page *page = pfn_to_page(pfn);



		SetPagePinned(page);



		if (!PageHighMem(page)) {

			make_lowmem_page_readonly(__va(PFN_PHYS((unsigned long)pfn)));

			xen_mc_batch();



			__set_pfn_prot(pfn, PAGE_KERNEL_RO);



			if (level == PT_PTE && USE_SPLIT_PTLOCKS)

				pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn);

				__pin_pagetable_pfn(MMUEXT_PIN_L1_TABLE, pfn);



			xen_mc_issue(PARAVIRT_LAZY_MMU);

		} else {

			/* make sure there are no stray mappings of

			   this page */
@@ -1532,7 +1562,7 @@ static void xen_alloc_pmd(struct mm_struct *mm, unsigned long pfn) 
}



/* This should never happen until we're OK to use struct page */

static void xen_release_ptpage(unsigned long pfn, unsigned level)

static inline void xen_release_ptpage(unsigned long pfn, unsigned level)

{

	struct page *page = pfn_to_page(pfn);

	bool pinned = PagePinned(page);
@@ -1541,9 +1571,14 @@ static void xen_release_ptpage(unsigned long pfn, unsigned level) 


	if (pinned) {

		if (!PageHighMem(page)) {

			xen_mc_batch();



			if (level == PT_PTE && USE_SPLIT_PTLOCKS)

				pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn);

			make_lowmem_page_readwrite(__va(PFN_PHYS(pfn)));

				__pin_pagetable_pfn(MMUEXT_UNPIN_TABLE, pfn);



			__set_pfn_prot(pfn, PAGE_KERNEL);



			xen_mc_issue(PARAVIRT_LAZY_MMU);

		}

		ClearPagePinned(page);

	}