diff mbox series

[v4,07/14] iommu: make map, unmap and flush all take both an order and a count

Message ID 20200804134209.8717-8-paul@xen.org
State Superseded
Headers show
Series IOMMU cleanup | expand

Commit Message

Paul Durrant Aug. 4, 2020, 1:42 p.m. UTC
From: Paul Durrant <pdurrant@amazon.com>

At the moment iommu_map() and iommu_unmap() take a page order but not a
count, whereas iommu_iotlb_flush() takes a count but not a page order.
This patch simply makes them consistent with each other.

Signed-off-by: Paul Durrant <pdurrant@amazon.com>
---
Cc: Jun Nakajima <jun.nakajima@intel.com>
Cc: Kevin Tian <kevin.tian@intel.com>
Cc: Jan Beulich <jbeulich@suse.com>
Cc: Andrew Cooper <andrew.cooper3@citrix.com>
Cc: George Dunlap <george.dunlap@citrix.com>
Cc: Wei Liu <wl@xen.org>
Cc: "Roger Pau Monné" <roger.pau@citrix.com>
Cc: Ian Jackson <ian.jackson@eu.citrix.com>
Cc: Julien Grall <julien@xen.org>
Cc: Stefano Stabellini <sstabellini@kernel.org>
Cc: Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>

v2:
 - New in v2
---
 xen/arch/arm/p2m.c                       |  2 +-
 xen/arch/x86/mm/p2m-ept.c                |  2 +-
 xen/common/memory.c                      |  4 +--
 xen/drivers/passthrough/amd/iommu.h      |  2 +-
 xen/drivers/passthrough/amd/iommu_map.c  |  4 +--
 xen/drivers/passthrough/arm/ipmmu-vmsa.c |  2 +-
 xen/drivers/passthrough/arm/smmu.c       |  2 +-
 xen/drivers/passthrough/iommu.c          | 31 ++++++++++++------------
 xen/drivers/passthrough/vtd/iommu.c      |  4 +--
 xen/drivers/passthrough/x86/iommu.c      |  2 +-
 xen/include/xen/iommu.h                  |  9 ++++---
 11 files changed, 33 insertions(+), 31 deletions(-)

Comments

Jan Beulich Aug. 6, 2020, 9:57 a.m. UTC | #1
On 04.08.2020 15:42, Paul Durrant wrote:
> From: Paul Durrant <pdurrant@amazon.com>
> 
> At the moment iommu_map() and iommu_unmap() take a page order but not a
> count, whereas iommu_iotlb_flush() takes a count but not a page order.
> This patch simply makes them consistent with each other.

Why can't we do with just a count, where order gets worked out by
functions knowing how to / wanting to deal with higher order pages?

> --- a/xen/arch/x86/mm/p2m-ept.c
> +++ b/xen/arch/x86/mm/p2m-ept.c
> @@ -843,7 +843,7 @@ out:
>           need_modify_vtd_table )
>      {
>          if ( iommu_use_hap_pt(d) )
> -            rc = iommu_iotlb_flush(d, _dfn(gfn), (1u << order),
> +            rc = iommu_iotlb_flush(d, _dfn(gfn), (1u << order), 1,

Forgot to drop the "1 << "? (There are then I think two more instances
further down.)

> --- a/xen/common/memory.c
> +++ b/xen/common/memory.c
> @@ -851,12 +851,12 @@ int xenmem_add_to_physmap(struct domain *d, struct xen_add_to_physmap *xatp,
>  
>          this_cpu(iommu_dont_flush_iotlb) = 0;
>  
> -        ret = iommu_iotlb_flush(d, _dfn(xatp->idx - done), done,
> +        ret = iommu_iotlb_flush(d, _dfn(xatp->idx - done), 0, done,

Arguments wrong way round? (This risk of inverting their order is
one of the primary reasons why I think we want just a count.) I'm
also uncertain about the use of 0 vs PAGE_ORDER_4K here.

>                                  IOMMU_FLUSHF_added | IOMMU_FLUSHF_modified);
>          if ( unlikely(ret) && rc >= 0 )
>              rc = ret;
>  
> -        ret = iommu_iotlb_flush(d, _dfn(xatp->gpfn - done), done,
> +        ret = iommu_iotlb_flush(d, _dfn(xatp->gpfn - done), 0, done,

Same here then.

Jan
Durrant, Paul Aug. 11, 2020, 11 a.m. UTC | #2
> -----Original Message-----
> From: Jan Beulich <jbeulich@suse.com>
> Sent: 06 August 2020 10:57
> To: Paul Durrant <paul@xen.org>
> Cc: xen-devel@lists.xenproject.org; Durrant, Paul <pdurrant@amazon.co.uk>; Jun Nakajima
> <jun.nakajima@intel.com>; Kevin Tian <kevin.tian@intel.com>; Andrew Cooper
> <andrew.cooper3@citrix.com>; George Dunlap <george.dunlap@citrix.com>; Wei Liu <wl@xen.org>; Roger Pau
> Monné <roger.pau@citrix.com>; Ian Jackson <ian.jackson@eu.citrix.com>; Julien Grall <julien@xen.org>;
> Stefano Stabellini <sstabellini@kernel.org>; Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>
> Subject: RE: [EXTERNAL] [PATCH v4 07/14] iommu: make map, unmap and flush all take both an order and a
> count
> 
> CAUTION: This email originated from outside of the organization. Do not click links or open
> attachments unless you can confirm the sender and know the content is safe.
> 
> 
> 
> On 04.08.2020 15:42, Paul Durrant wrote:
> > From: Paul Durrant <pdurrant@amazon.com>
> >
> > At the moment iommu_map() and iommu_unmap() take a page order but not a
> > count, whereas iommu_iotlb_flush() takes a count but not a page order.
> > This patch simply makes them consistent with each other.
> 
> Why can't we do with just a count, where order gets worked out by
> functions knowing how to / wanting to deal with higher order pages?
> 

Yes, that may well be better. The order of the CPU mappings isn't really relevant cases where the IOMMU uses different page orders. I'll just move everything over to a page count.

  Paul

> > --- a/xen/arch/x86/mm/p2m-ept.c
> > +++ b/xen/arch/x86/mm/p2m-ept.c
> > @@ -843,7 +843,7 @@ out:
> >           need_modify_vtd_table )
> >      {
> >          if ( iommu_use_hap_pt(d) )
> > -            rc = iommu_iotlb_flush(d, _dfn(gfn), (1u << order),
> > +            rc = iommu_iotlb_flush(d, _dfn(gfn), (1u << order), 1,
> 
> Forgot to drop the "1 << "? (There are then I think two more instances
> further down.)
> 
> > --- a/xen/common/memory.c
> > +++ b/xen/common/memory.c
> > @@ -851,12 +851,12 @@ int xenmem_add_to_physmap(struct domain *d, struct xen_add_to_physmap *xatp,
> >
> >          this_cpu(iommu_dont_flush_iotlb) = 0;
> >
> > -        ret = iommu_iotlb_flush(d, _dfn(xatp->idx - done), done,
> > +        ret = iommu_iotlb_flush(d, _dfn(xatp->idx - done), 0, done,
> 
> Arguments wrong way round? (This risk of inverting their order is
> one of the primary reasons why I think we want just a count.) I'm
> also uncertain about the use of 0 vs PAGE_ORDER_4K here.
> 
> >                                  IOMMU_FLUSHF_added | IOMMU_FLUSHF_modified);
> >          if ( unlikely(ret) && rc >= 0 )
> >              rc = ret;
> >
> > -        ret = iommu_iotlb_flush(d, _dfn(xatp->gpfn - done), done,
> > +        ret = iommu_iotlb_flush(d, _dfn(xatp->gpfn - done), 0, done,
> 
> Same here then.
> 
> Jan
Tian, Kevin Aug. 14, 2020, 6:57 a.m. UTC | #3
> From: Jan Beulich <jbeulich@suse.com>
> Sent: Thursday, August 6, 2020 5:57 PM
> 
> On 04.08.2020 15:42, Paul Durrant wrote:
> > From: Paul Durrant <pdurrant@amazon.com>
> >
> > At the moment iommu_map() and iommu_unmap() take a page order but
> not a
> > count, whereas iommu_iotlb_flush() takes a count but not a page order.
> > This patch simply makes them consistent with each other.
> 
> Why can't we do with just a count, where order gets worked out by
> functions knowing how to / wanting to deal with higher order pages?

Agree. especially the new map/unmap code looks weird when having both 
order and count in parameters.

Thanks
Kevin

> 
> > --- a/xen/arch/x86/mm/p2m-ept.c
> > +++ b/xen/arch/x86/mm/p2m-ept.c
> > @@ -843,7 +843,7 @@ out:
> >           need_modify_vtd_table )
> >      {
> >          if ( iommu_use_hap_pt(d) )
> > -            rc = iommu_iotlb_flush(d, _dfn(gfn), (1u << order),
> > +            rc = iommu_iotlb_flush(d, _dfn(gfn), (1u << order), 1,
> 
> Forgot to drop the "1 << "? (There are then I think two more instances
> further down.)
> 
> > --- a/xen/common/memory.c
> > +++ b/xen/common/memory.c
> > @@ -851,12 +851,12 @@ int xenmem_add_to_physmap(struct domain *d,
> struct xen_add_to_physmap *xatp,
> >
> >          this_cpu(iommu_dont_flush_iotlb) = 0;
> >
> > -        ret = iommu_iotlb_flush(d, _dfn(xatp->idx - done), done,
> > +        ret = iommu_iotlb_flush(d, _dfn(xatp->idx - done), 0, done,
> 
> Arguments wrong way round? (This risk of inverting their order is
> one of the primary reasons why I think we want just a count.) I'm
> also uncertain about the use of 0 vs PAGE_ORDER_4K here.
> 
> >                                  IOMMU_FLUSHF_added | IOMMU_FLUSHF_modified);
> >          if ( unlikely(ret) && rc >= 0 )
> >              rc = ret;
> >
> > -        ret = iommu_iotlb_flush(d, _dfn(xatp->gpfn - done), done,
> > +        ret = iommu_iotlb_flush(d, _dfn(xatp->gpfn - done), 0, done,
> 
> Same here then.
> 
> Jan
diff mbox series

Patch

diff --git a/xen/arch/arm/p2m.c b/xen/arch/arm/p2m.c
index ce59f2b503..71f4a78425 100644
--- a/xen/arch/arm/p2m.c
+++ b/xen/arch/arm/p2m.c
@@ -1061,7 +1061,7 @@  static int __p2m_set_entry(struct p2m_domain *p2m,
             flush_flags |= IOMMU_FLUSHF_added;
 
         rc = iommu_iotlb_flush(p2m->domain, _dfn(gfn_x(sgfn)),
-                               1UL << page_order, flush_flags);
+                               page_order, 1, flush_flags);
     }
     else
         rc = 0;
diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c
index b8154a7ecc..b2ac912cde 100644
--- a/xen/arch/x86/mm/p2m-ept.c
+++ b/xen/arch/x86/mm/p2m-ept.c
@@ -843,7 +843,7 @@  out:
          need_modify_vtd_table )
     {
         if ( iommu_use_hap_pt(d) )
-            rc = iommu_iotlb_flush(d, _dfn(gfn), (1u << order),
+            rc = iommu_iotlb_flush(d, _dfn(gfn), (1u << order), 1,
                                    (iommu_flags ? IOMMU_FLUSHF_added : 0) |
                                    (vtd_pte_present ? IOMMU_FLUSHF_modified
                                                     : 0));
diff --git a/xen/common/memory.c b/xen/common/memory.c
index 714077c1e5..8de334ff10 100644
--- a/xen/common/memory.c
+++ b/xen/common/memory.c
@@ -851,12 +851,12 @@  int xenmem_add_to_physmap(struct domain *d, struct xen_add_to_physmap *xatp,
 
         this_cpu(iommu_dont_flush_iotlb) = 0;
 
-        ret = iommu_iotlb_flush(d, _dfn(xatp->idx - done), done,
+        ret = iommu_iotlb_flush(d, _dfn(xatp->idx - done), 0, done,
                                 IOMMU_FLUSHF_added | IOMMU_FLUSHF_modified);
         if ( unlikely(ret) && rc >= 0 )
             rc = ret;
 
-        ret = iommu_iotlb_flush(d, _dfn(xatp->gpfn - done), done,
+        ret = iommu_iotlb_flush(d, _dfn(xatp->gpfn - done), 0, done,
                                 IOMMU_FLUSHF_added | IOMMU_FLUSHF_modified);
         if ( unlikely(ret) && rc >= 0 )
             rc = ret;
diff --git a/xen/drivers/passthrough/amd/iommu.h b/xen/drivers/passthrough/amd/iommu.h
index e2d174f3b4..f1f0415469 100644
--- a/xen/drivers/passthrough/amd/iommu.h
+++ b/xen/drivers/passthrough/amd/iommu.h
@@ -231,7 +231,7 @@  int amd_iommu_reserve_domain_unity_map(struct domain *domain,
                                        paddr_t phys_addr, unsigned long size,
                                        int iw, int ir);
 int __must_check amd_iommu_flush_iotlb_pages(struct domain *d, dfn_t dfn,
-                                             unsigned int page_count,
+                                             unsigned long page_count,
                                              unsigned int flush_flags);
 int __must_check amd_iommu_flush_iotlb_all(struct domain *d);
 
diff --git a/xen/drivers/passthrough/amd/iommu_map.c b/xen/drivers/passthrough/amd/iommu_map.c
index 54b991294a..0cb948d114 100644
--- a/xen/drivers/passthrough/amd/iommu_map.c
+++ b/xen/drivers/passthrough/amd/iommu_map.c
@@ -351,7 +351,7 @@  int amd_iommu_unmap_page(struct domain *d, dfn_t dfn,
     return 0;
 }
 
-static unsigned long flush_count(unsigned long dfn, unsigned int page_count,
+static unsigned long flush_count(unsigned long dfn, unsigned long page_count,
                                  unsigned int order)
 {
     unsigned long start = dfn >> order;
@@ -362,7 +362,7 @@  static unsigned long flush_count(unsigned long dfn, unsigned int page_count,
 }
 
 int amd_iommu_flush_iotlb_pages(struct domain *d, dfn_t dfn,
-                                unsigned int page_count,
+                                unsigned long page_count,
                                 unsigned int flush_flags)
 {
     unsigned long dfn_l = dfn_x(dfn);
diff --git a/xen/drivers/passthrough/arm/ipmmu-vmsa.c b/xen/drivers/passthrough/arm/ipmmu-vmsa.c
index b2a65dfaaf..346165c3fa 100644
--- a/xen/drivers/passthrough/arm/ipmmu-vmsa.c
+++ b/xen/drivers/passthrough/arm/ipmmu-vmsa.c
@@ -945,7 +945,7 @@  static int __must_check ipmmu_iotlb_flush_all(struct domain *d)
 }
 
 static int __must_check ipmmu_iotlb_flush(struct domain *d, dfn_t dfn,
-                                          unsigned int page_count,
+                                          unsigned long page_count,
                                           unsigned int flush_flags)
 {
     ASSERT(flush_flags);
diff --git a/xen/drivers/passthrough/arm/smmu.c b/xen/drivers/passthrough/arm/smmu.c
index 94662a8501..06f9bda47d 100644
--- a/xen/drivers/passthrough/arm/smmu.c
+++ b/xen/drivers/passthrough/arm/smmu.c
@@ -2534,7 +2534,7 @@  static int __must_check arm_smmu_iotlb_flush_all(struct domain *d)
 }
 
 static int __must_check arm_smmu_iotlb_flush(struct domain *d, dfn_t dfn,
-					     unsigned int page_count,
+					     unsigned long page_count,
 					     unsigned int flush_flags)
 {
 	ASSERT(flush_flags);
diff --git a/xen/drivers/passthrough/iommu.c b/xen/drivers/passthrough/iommu.c
index e2c0193a09..568a4a5661 100644
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -235,8 +235,8 @@  void iommu_domain_destroy(struct domain *d)
 }
 
 int iommu_map(struct domain *d, dfn_t dfn, mfn_t mfn,
-              unsigned int page_order, unsigned int flags,
-              unsigned int *flush_flags)
+              unsigned int page_order, unsigned int page_count,
+              unsigned int flags, unsigned int *flush_flags)
 {
     const struct domain_iommu *hd = dom_iommu(d);
     unsigned long i;
@@ -248,7 +248,7 @@  int iommu_map(struct domain *d, dfn_t dfn, mfn_t mfn,
     ASSERT(IS_ALIGNED(dfn_x(dfn), (1ul << page_order)));
     ASSERT(IS_ALIGNED(mfn_x(mfn), (1ul << page_order)));
 
-    for ( i = 0; i < (1ul << page_order); i++ )
+    for ( i = 0; i < ((unsigned long)page_count << page_order); i++ )
     {
         rc = iommu_call(hd->platform_ops, map_page, d, dfn_add(dfn, i),
                         mfn_add(mfn, i), flags, flush_flags);
@@ -285,16 +285,16 @@  int iommu_legacy_map(struct domain *d, dfn_t dfn, mfn_t mfn,
                      unsigned int page_order, unsigned int flags)
 {
     unsigned int flush_flags = 0;
-    int rc = iommu_map(d, dfn, mfn, page_order, flags, &flush_flags);
+    int rc = iommu_map(d, dfn, mfn, page_order, 1, flags, &flush_flags);
 
     if ( !this_cpu(iommu_dont_flush_iotlb) && !rc )
-        rc = iommu_iotlb_flush(d, dfn, (1u << page_order), flush_flags);
+        rc = iommu_iotlb_flush(d, dfn, (1u << page_order), 1, flush_flags);
 
     return rc;
 }
 
 int iommu_unmap(struct domain *d, dfn_t dfn, unsigned int page_order,
-                unsigned int *flush_flags)
+                unsigned int page_count, unsigned int *flush_flags)
 {
     const struct domain_iommu *hd = dom_iommu(d);
     unsigned long i;
@@ -305,7 +305,7 @@  int iommu_unmap(struct domain *d, dfn_t dfn, unsigned int page_order,
 
     ASSERT(IS_ALIGNED(dfn_x(dfn), (1ul << page_order)));
 
-    for ( i = 0; i < (1ul << page_order); i++ )
+    for ( i = 0; i < ((unsigned long)page_count << page_order); i++ )
     {
         int err = iommu_call(hd->platform_ops, unmap_page, d, dfn_add(dfn, i),
                              flush_flags);
@@ -338,10 +338,10 @@  int iommu_unmap(struct domain *d, dfn_t dfn, unsigned int page_order,
 int iommu_legacy_unmap(struct domain *d, dfn_t dfn, unsigned int page_order)
 {
     unsigned int flush_flags = 0;
-    int rc = iommu_unmap(d, dfn, page_order, &flush_flags);
+    int rc = iommu_unmap(d, dfn, page_order, 1, &flush_flags);
 
     if ( !this_cpu(iommu_dont_flush_iotlb) && ! rc )
-        rc = iommu_iotlb_flush(d, dfn, (1u << page_order), flush_flags);
+        rc = iommu_iotlb_flush(d, dfn, (1u << page_order), 1, flush_flags);
 
     return rc;
 }
@@ -357,8 +357,8 @@  int iommu_lookup_page(struct domain *d, dfn_t dfn, mfn_t *mfn,
     return iommu_call(hd->platform_ops, lookup_page, d, dfn, mfn, flags);
 }
 
-int iommu_iotlb_flush(struct domain *d, dfn_t dfn, unsigned int page_count,
-                      unsigned int flush_flags)
+int iommu_iotlb_flush(struct domain *d, dfn_t dfn, unsigned int page_order,
+                      unsigned int page_count, unsigned int flush_flags)
 {
     const struct domain_iommu *hd = dom_iommu(d);
     int rc;
@@ -370,14 +370,15 @@  int iommu_iotlb_flush(struct domain *d, dfn_t dfn, unsigned int page_count,
     if ( dfn_eq(dfn, INVALID_DFN) )
         return -EINVAL;
 
-    rc = iommu_call(hd->platform_ops, iotlb_flush, d, dfn, page_count,
-                    flush_flags);
+    rc = iommu_call(hd->platform_ops, iotlb_flush, d, dfn,
+                    (unsigned long)page_count << page_order, flush_flags);
     if ( unlikely(rc) )
     {
         if ( !d->is_shutting_down && printk_ratelimit() )
             printk(XENLOG_ERR
-                   "d%d: IOMMU IOTLB flush failed: %d, dfn %"PRI_dfn", page count %u flags %x\n",
-                   d->domain_id, rc, dfn_x(dfn), page_count, flush_flags);
+                   "d%d: IOMMU IOTLB flush failed: %d, dfn %"PRI_dfn", page order %u, page count %u flags %x\n",
+                   d->domain_id, rc, dfn_x(dfn), page_order, page_count,
+                   flush_flags);
 
         if ( !is_hardware_domain(d) )
             domain_crash(d);
diff --git a/xen/drivers/passthrough/vtd/iommu.c b/xen/drivers/passthrough/vtd/iommu.c
index 607e8b5e65..68cf0e535a 100644
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -584,7 +584,7 @@  static int __must_check iommu_flush_all(void)
 
 static int __must_check iommu_flush_iotlb(struct domain *d, dfn_t dfn,
                                           bool_t dma_old_pte_present,
-                                          unsigned int page_count)
+                                          unsigned long page_count)
 {
     struct domain_iommu *hd = dom_iommu(d);
     struct acpi_drhd_unit *drhd;
@@ -632,7 +632,7 @@  static int __must_check iommu_flush_iotlb(struct domain *d, dfn_t dfn,
 
 static int __must_check iommu_flush_iotlb_pages(struct domain *d,
                                                 dfn_t dfn,
-                                                unsigned int page_count,
+                                                unsigned long page_count,
                                                 unsigned int flush_flags)
 {
     ASSERT(page_count && !dfn_eq(dfn, INVALID_DFN));
diff --git a/xen/drivers/passthrough/x86/iommu.c b/xen/drivers/passthrough/x86/iommu.c
index aea07e47c4..dba6c9d642 100644
--- a/xen/drivers/passthrough/x86/iommu.c
+++ b/xen/drivers/passthrough/x86/iommu.c
@@ -244,7 +244,7 @@  void __hwdom_init arch_iommu_hwdom_init(struct domain *d)
         else if ( paging_mode_translate(d) )
             rc = set_identity_p2m_entry(d, pfn, p2m_access_rw, 0);
         else
-            rc = iommu_map(d, _dfn(pfn), _mfn(pfn), PAGE_ORDER_4K,
+            rc = iommu_map(d, _dfn(pfn), _mfn(pfn), PAGE_ORDER_4K, 1,
                            IOMMUF_readable | IOMMUF_writable, &flush_flags);
 
         if ( rc )
diff --git a/xen/include/xen/iommu.h b/xen/include/xen/iommu.h
index 1831dc66b0..d9c2e764aa 100644
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -146,10 +146,10 @@  enum
 #define IOMMU_FLUSHF_modified (1u << _IOMMU_FLUSHF_modified)
 
 int __must_check iommu_map(struct domain *d, dfn_t dfn, mfn_t mfn,
-                           unsigned int page_order, unsigned int flags,
-                           unsigned int *flush_flags);
+                           unsigned int page_order, unsigned int page_count,
+                           unsigned int flags, unsigned int *flush_flags);
 int __must_check iommu_unmap(struct domain *d, dfn_t dfn,
-                             unsigned int page_order,
+                             unsigned int page_order, unsigned int page_count,
                              unsigned int *flush_flags);
 
 int __must_check iommu_legacy_map(struct domain *d, dfn_t dfn, mfn_t mfn,
@@ -162,6 +162,7 @@  int __must_check iommu_lookup_page(struct domain *d, dfn_t dfn, mfn_t *mfn,
                                    unsigned int *flags);
 
 int __must_check iommu_iotlb_flush(struct domain *d, dfn_t dfn,
+                                   unsigned int page_order,
                                    unsigned int page_count,
                                    unsigned int flush_flags);
 int __must_check iommu_iotlb_flush_all(struct domain *d,
@@ -281,7 +282,7 @@  struct iommu_ops {
     void (*share_p2m)(struct domain *d);
     void (*crash_shutdown)(void);
     int __must_check (*iotlb_flush)(struct domain *d, dfn_t dfn,
-                                    unsigned int page_count,
+                                    unsigned long page_count,
                                     unsigned int flush_flags);
     int __must_check (*iotlb_flush_all)(struct domain *d);
     int (*get_reserved_device_memory)(iommu_grdm_t *, void *);