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x86/xen: map foreign pfns for autotranslated guests

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When running as a dom0 in PVH mode, foreign pfns that are accessed
must be added to our p2m which is managed by xen. This is done via
XENMEM_add_to_physmap_range hypercall. This is needed for toolstack
building guests and mapping guest memory, xentrace mapping xen pages,
etc.

Signed-off-by: Mukesh Rathor <mukesh.rathor@oracle.com>
Signed-off-by: David Vrabel <david.vrabel@citrix.com>
This commit is contained in:
Mukesh Rathor 2014-05-23 19:33:44 -07:00 committed by David Vrabel
parent 1a4b50f674
commit 77945ca73e
1 changed files with 118 additions and 3 deletions
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121
arch/x86/xen/mmu.c
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@ -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);