x86/xen: map foreign pfns for autotranslated guests (77945ca7) · Commits · 戴 / test

arch/x86/xen/mmu.c

+118 −3

Original line number	Diff line number	Diff line
		@@ -2510,6 +2510,95 @@ void __init xen_hvm_init_mmu_ops(void)
		}
		#endif

		#ifdef CONFIG_XEN_PVH
		/*
		* Map foreign gfn (fgfn), to local pfn (lpfn). This for the user
		* space creating new guest on pvh dom0 and needing to map domU pages.
		*/
		static int xlate_add_to_p2m(unsigned long lpfn, unsigned long fgfn,
		unsigned int domid)
		{
		int rc, err = 0;
		xen_pfn_t gpfn = lpfn;
		xen_ulong_t idx = fgfn;

		struct xen_add_to_physmap_range xatp = {
		.domid = DOMID_SELF,
		.foreign_domid = domid,
		.size = 1,
		.space = XENMAPSPACE_gmfn_foreign,
		};
		set_xen_guest_handle(xatp.idxs, &idx);
		set_xen_guest_handle(xatp.gpfns, &gpfn);
		set_xen_guest_handle(xatp.errs, &err);

		rc = HYPERVISOR_memory_op(XENMEM_add_to_physmap_range, &xatp);
		if (rc < 0)
		return rc;
		return err;
		}

		static int xlate_remove_from_p2m(unsigned long spfn, int count)
		{
		struct xen_remove_from_physmap xrp;
		int i, rc;

		for (i = 0; i < count; i++) {
		xrp.domid = DOMID_SELF;
		xrp.gpfn = spfn+i;
		rc = HYPERVISOR_memory_op(XENMEM_remove_from_physmap, &xrp);
		if (rc)
		break;
		}
		return rc;
		}

		struct xlate_remap_data {
		unsigned long fgfn; /* foreign domain's gfn */
		pgprot_t prot;
		domid_t domid;
		int index;
		struct page **pages;
		};

		static int xlate_map_pte_fn(pte_t *ptep, pgtable_t token, unsigned long addr,
		void *data)
		{
		int rc;
		struct xlate_remap_data *remap = data;
		unsigned long pfn = page_to_pfn(remap->pages[remap->index++]);
		pte_t pteval = pte_mkspecial(pfn_pte(pfn, remap->prot));

		rc = xlate_add_to_p2m(pfn, remap->fgfn, remap->domid);
		if (rc)
		return rc;
		native_set_pte(ptep, pteval);

		return 0;
		}

		static int xlate_remap_gfn_range(struct vm_area_struct *vma,
		unsigned long addr, unsigned long mfn,
		int nr, pgprot_t prot, unsigned domid,
		struct page **pages)
		{
		int err;
		struct xlate_remap_data pvhdata;

		BUG_ON(!pages);

		pvhdata.fgfn = mfn;
		pvhdata.prot = prot;
		pvhdata.domid = domid;
		pvhdata.index = 0;
		pvhdata.pages = pages;
		err = apply_to_page_range(vma->vm_mm, addr, nr << PAGE_SHIFT,
		xlate_map_pte_fn, &pvhdata);
		flush_tlb_all();
		return err;
		}
		#endif

		#define REMAP_BATCH_SIZE 16

		struct remap_data {
		@@ -2544,11 +2633,18 @@ int xen_remap_domain_mfn_range(struct vm_area_struct *vma,
		unsigned long range;
		int err = 0;

		if (xen_feature(XENFEAT_auto_translated_physmap))
		return -EINVAL;

		BUG_ON(!((vma->vm_flags & (VM_PFNMAP \| VM_IO)) == (VM_PFNMAP \| VM_IO)));

		if (xen_feature(XENFEAT_auto_translated_physmap)) {
		#ifdef CONFIG_XEN_PVH
		/* We need to update the local page tables and the xen HAP */
		return xlate_remap_gfn_range(vma, addr, mfn, nr, prot,
		domid, pages);
		#else
		return -EINVAL;
		#endif
		}

		rmd.mfn = mfn;
		rmd.prot = prot;

		@@ -2586,6 +2682,25 @@ int xen_unmap_domain_mfn_range(struct vm_area_struct *vma,
		if (!pages \|\| !xen_feature(XENFEAT_auto_translated_physmap))
		return 0;

		#ifdef CONFIG_XEN_PVH
		while (numpgs--) {
		/*
		* The mmu has already cleaned up the process mmu
		* resources at this point (lookup_address will return
		* NULL).
		*/
		unsigned long pfn = page_to_pfn(pages[numpgs]);

		xlate_remove_from_p2m(pfn, 1);
		}
		/*
		* We don't need to flush tlbs because as part of
		* xlate_remove_from_p2m, the hypervisor will do tlb flushes
		* after removing the p2m entries from the EPT/NPT
		*/
		return 0;
		#else
		return -EINVAL;
		#endif
		}
		EXPORT_SYMBOL_GPL(xen_unmap_domain_mfn_range);

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