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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [xen staging] IOMMU/x86: perform PV Dom0 mappings in batches
commit f3185c165d28901c3222becfc8be547263c53745
Author: Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Wed Jun 8 17:03:32 2022 +0200
Commit: Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Wed Jun 8 17:03:32 2022 +0200
IOMMU/x86: perform PV Dom0 mappings in batches
For large page mappings to be easily usable (i.e. in particular without
un-shattering of smaller page mappings) and for mapping operations to
then also be more efficient, pass batches of Dom0 memory to iommu_map().
In dom0_construct_pv() and its helpers (covering strict mode) this
additionally requires establishing the type of those pages (albeit with
zero type references).
The earlier establishing of PGT_writable_page | PGT_validated requires
the existing places where this gets done (through get_page_and_type())
to be updated: For pages which actually have a mapping, the type
refcount needs to be 1.
There is actually a related bug that gets fixed here as a side effect:
Typically the last L1 table would get marked as such only after
get_page_and_type(..., PGT_writable_page). While this is fine as far as
refcounting goes, the page did remain mapped in the IOMMU in this case
(when "iommu=dom0-strict").
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Acked-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
---
xen/arch/x86/pv/dom0_build.c | 84 +++++++++++++++++++++++++++++++++----
xen/drivers/passthrough/x86/iommu.c | 41 +++++++++++++-----
2 files changed, 108 insertions(+), 17 deletions(-)
diff --git a/xen/arch/x86/pv/dom0_build.c b/xen/arch/x86/pv/dom0_build.c
index e501979a86..04a4ea3c18 100644
--- a/xen/arch/x86/pv/dom0_build.c
+++ b/xen/arch/x86/pv/dom0_build.c
@@ -46,7 +46,8 @@ void __init dom0_update_physmap(bool compat, unsigned long
pfn,
static __init void mark_pv_pt_pages_rdonly(struct domain *d,
l4_pgentry_t *l4start,
unsigned long vpt_start,
- unsigned long nr_pt_pages)
+ unsigned long nr_pt_pages,
+ unsigned int *flush_flags)
{
unsigned long count;
struct page_info *page;
@@ -71,6 +72,14 @@ static __init void mark_pv_pt_pages_rdonly(struct domain *d,
ASSERT((page->u.inuse.type_info & PGT_type_mask) <=
PGT_root_page_table);
ASSERT(!(page->u.inuse.type_info & ~(PGT_type_mask | PGT_pae_xen_l2)));
+ /*
+ * Page table pages need to be removed from the IOMMU again in case
+ * iommu_memory_setup() ended up mapping them.
+ */
+ if ( need_iommu_pt_sync(d) &&
+ iommu_unmap(d, _dfn(mfn_x(page_to_mfn(page))), 1, flush_flags) )
+ BUG();
+
/* Read-only mapping + PGC_allocated + page-table page. */
page->count_info = PGC_allocated | 3;
page->u.inuse.type_info |= PGT_validated | 1;
@@ -107,11 +116,43 @@ static __init void mark_pv_pt_pages_rdonly(struct domain
*d,
unmap_domain_page(pl3e);
}
+static void __init iommu_memory_setup(struct domain *d, const char *what,
+ struct page_info *page, unsigned long nr,
+ unsigned int *flush_flags)
+{
+ int rc;
+ mfn_t mfn = page_to_mfn(page);
+
+ if ( !need_iommu_pt_sync(d) )
+ return;
+
+ rc = iommu_map(d, _dfn(mfn_x(mfn)), mfn, nr,
+ IOMMUF_readable | IOMMUF_writable, flush_flags);
+ if ( rc )
+ {
+ printk(XENLOG_ERR "pre-mapping %s MFN [%lx,%lx) into IOMMU failed:
%d\n",
+ what, mfn_x(mfn), mfn_x(mfn) + nr, rc);
+ return;
+ }
+
+ /*
+ * For successfully established IOMMU mappings the type of the page(s)
+ * needs to match (for _get_page_type() to unmap upon type change). Set
+ * the page(s) to writable with no type ref.
+ */
+ for ( ; nr--; ++page )
+ {
+ ASSERT(!page->u.inuse.type_info);
+ page->u.inuse.type_info = PGT_writable_page | PGT_validated;
+ }
+}
+
static __init void setup_pv_physmap(struct domain *d, unsigned long pgtbl_pfn,
unsigned long v_start, unsigned long v_end,
unsigned long vphysmap_start,
unsigned long vphysmap_end,
- unsigned long nr_pages)
+ unsigned long nr_pages,
+ unsigned int *flush_flags)
{
struct page_info *page = NULL;
l4_pgentry_t *pl4e, *l4start = map_domain_page(_mfn(pgtbl_pfn));
@@ -177,6 +218,10 @@ static __init void setup_pv_physmap(struct domain *d,
unsigned long pgtbl_pfn,
L3_PAGETABLE_SHIFT - PAGE_SHIFT,
MEMF_no_scrub)) != NULL )
{
+ iommu_memory_setup(d, "P2M 1G", page,
+ SUPERPAGE_PAGES * SUPERPAGE_PAGES,
+ flush_flags);
+
*pl3e = l3e_from_page(page, L1_PROT|_PAGE_DIRTY|_PAGE_PSE);
vphysmap_start += 1UL << L3_PAGETABLE_SHIFT;
continue;
@@ -203,6 +248,9 @@ static __init void setup_pv_physmap(struct domain *d,
unsigned long pgtbl_pfn,
L2_PAGETABLE_SHIFT - PAGE_SHIFT,
MEMF_no_scrub)) != NULL )
{
+ iommu_memory_setup(d, "P2M 2M", page, SUPERPAGE_PAGES,
+ flush_flags);
+
*pl2e = l2e_from_page(page, L1_PROT|_PAGE_DIRTY|_PAGE_PSE);
vphysmap_start += 1UL << L2_PAGETABLE_SHIFT;
continue;
@@ -311,6 +359,7 @@ int __init dom0_construct_pv(struct domain *d,
unsigned long initrd_pfn = -1, initrd_mfn = 0;
unsigned long count;
struct page_info *page = NULL;
+ unsigned int flush_flags = 0;
start_info_t *si;
struct vcpu *v = d->vcpu[0];
void *image_base = bootstrap_map(image);
@@ -573,6 +622,9 @@ int __init dom0_construct_pv(struct domain *d,
BUG();
}
initrd->mod_end = 0;
+
+ iommu_memory_setup(d, "initrd", mfn_to_page(_mfn(initrd_mfn)),
+ PFN_UP(initrd_len), &flush_flags);
}
printk("PHYSICAL MEMORY ARRANGEMENT:\n"
@@ -606,6 +658,13 @@ int __init dom0_construct_pv(struct domain *d,
process_pending_softirqs();
+ /*
+ * Map the full range here and then punch holes for page tables
+ * alongside marking them as such in mark_pv_pt_pages_rdonly().
+ */
+ iommu_memory_setup(d, "init-alloc", mfn_to_page(_mfn(alloc_spfn)),
+ alloc_epfn - alloc_spfn, &flush_flags);
+
mpt_alloc = (vpt_start - v_start) + pfn_to_paddr(alloc_spfn);
if ( vinitrd_start )
mpt_alloc -= PAGE_ALIGN(initrd_len);
@@ -690,7 +749,8 @@ int __init dom0_construct_pv(struct domain *d,
l1tab++;
page = mfn_to_page(_mfn(mfn));
- if ( !page->u.inuse.type_info &&
+ if ( (!page->u.inuse.type_info ||
+ page->u.inuse.type_info == (PGT_writable_page | PGT_validated))
&&
!get_page_and_type(page, d, PGT_writable_page) )
BUG();
}
@@ -719,7 +779,7 @@ int __init dom0_construct_pv(struct domain *d,
}
/* Pages that are part of page tables must be read only. */
- mark_pv_pt_pages_rdonly(d, l4start, vpt_start, nr_pt_pages);
+ mark_pv_pt_pages_rdonly(d, l4start, vpt_start, nr_pt_pages, &flush_flags);
/* Mask all upcalls... */
for ( i = 0; i < XEN_LEGACY_MAX_VCPUS; i++ )
@@ -794,7 +854,7 @@ int __init dom0_construct_pv(struct domain *d,
{
pfn = pagetable_get_pfn(v->arch.guest_table);
setup_pv_physmap(d, pfn, v_start, v_end, vphysmap_start, vphysmap_end,
- nr_pages);
+ nr_pages, &flush_flags);
}
/* Write the phys->machine and machine->phys table entries. */
@@ -825,7 +885,9 @@ int __init dom0_construct_pv(struct domain *d,
if ( get_gpfn_from_mfn(mfn) >= count )
{
BUG_ON(compat);
- if ( !page->u.inuse.type_info &&
+ if ( (!page->u.inuse.type_info ||
+ page->u.inuse.type_info == (PGT_writable_page |
+ PGT_validated)) &&
!get_page_and_type(page, d, PGT_writable_page) )
BUG();
@@ -841,8 +903,12 @@ int __init dom0_construct_pv(struct domain *d,
#endif
while ( pfn < nr_pages )
{
- if ( (page = alloc_chunk(d, nr_pages - domain_tot_pages(d))) == NULL )
+ count = domain_tot_pages(d);
+ if ( (page = alloc_chunk(d, nr_pages - count)) == NULL )
panic("Not enough RAM for DOM0 reservation\n");
+
+ iommu_memory_setup(d, "chunk", page, domain_tot_pages(d) - count,
+ &flush_flags);
while ( pfn < domain_tot_pages(d) )
{
mfn = mfn_x(page_to_mfn(page));
@@ -857,6 +923,10 @@ int __init dom0_construct_pv(struct domain *d,
}
}
+ /* Use while() to avoid compiler warning. */
+ while ( iommu_iotlb_flush_all(d, flush_flags) )
+ break;
+
if ( initrd_len != 0 )
{
si->mod_start = vinitrd_start ?: initrd_pfn;
diff --git a/xen/drivers/passthrough/x86/iommu.c
b/xen/drivers/passthrough/x86/iommu.c
index 0ba95473c9..11a4f244e4 100644
--- a/xen/drivers/passthrough/x86/iommu.c
+++ b/xen/drivers/passthrough/x86/iommu.c
@@ -348,8 +348,8 @@ static unsigned int __hwdom_init hwdom_iommu_map(const
struct domain *d,
void __hwdom_init arch_iommu_hwdom_init(struct domain *d)
{
- unsigned long i, top, max_pfn;
- unsigned int flush_flags = 0;
+ unsigned long i, top, max_pfn, start, count;
+ unsigned int flush_flags = 0, start_perms = 0;
BUG_ON(!is_hardware_domain(d));
@@ -380,9 +380,9 @@ void __hwdom_init arch_iommu_hwdom_init(struct domain *d)
* First Mb will get mapped in one go by pvh_populate_p2m(). Avoid
* setting up potentially conflicting mappings here.
*/
- i = paging_mode_translate(d) ? PFN_DOWN(MB(1)) : 0;
+ start = paging_mode_translate(d) ? PFN_DOWN(MB(1)) : 0;
- for ( ; i < top; i++ )
+ for ( i = start, count = 0; i < top; )
{
unsigned long pfn = pdx_to_pfn(i);
unsigned int perms = hwdom_iommu_map(d, pfn, max_pfn);
@@ -391,20 +391,41 @@ void __hwdom_init arch_iommu_hwdom_init(struct domain *d)
if ( !perms )
rc = 0;
else if ( paging_mode_translate(d) )
+ {
rc = p2m_add_identity_entry(d, pfn,
perms & IOMMUF_writable ? p2m_access_rw
: p2m_access_r,
0);
+ if ( rc )
+ printk(XENLOG_WARNING
+ "%pd: identity mapping of %lx failed: %d\n",
+ d, pfn, rc);
+ }
+ else if ( pfn != start + count || perms != start_perms )
+ {
+ commit:
+ rc = iommu_map(d, _dfn(start), _mfn(start), count, start_perms,
+ &flush_flags);
+ if ( rc )
+ printk(XENLOG_WARNING
+ "%pd: IOMMU identity mapping of [%lx,%lx) failed: %d\n",
+ d, pfn, pfn + count, rc);
+ SWAP(start, pfn);
+ start_perms = perms;
+ count = 1;
+ }
else
- rc = iommu_map(d, _dfn(pfn), _mfn(pfn), 1ul << PAGE_ORDER_4K,
- perms, &flush_flags);
+ {
+ ++count;
+ rc = 0;
+ }
- if ( rc )
- printk(XENLOG_WARNING "%pd: identity %smapping of %lx failed:
%d\n",
- d, !paging_mode_translate(d) ? "IOMMU " : "", pfn, rc);
- if (!(i & 0xfffff))
+ if ( !(++i & 0xfffff) )
process_pending_softirqs();
+
+ if ( i == top && count )
+ goto commit;
}
/* Use if to avoid compiler warning */
--
generated by git-patchbot for /home/xen/git/xen.git#staging
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