Or really, in the case of ->map_page(), accommodate it in the existing
"flags" parameter. All call sites will pass 0 for now.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Reviewed-by: Kevin Tian <kevin.tian@intel.com>
---
v2: Re-base over change earlier in the series.

--- a/xen/drivers/passthrough/amd/iommu.h
+++ b/xen/drivers/passthrough/amd/iommu.h
@@ -230,6 +230,7 @@ int __must_check amd_iommu_map_page(stru
                                     mfn_t mfn, unsigned int flags,
                                     unsigned int *flush_flags);
 int __must_check amd_iommu_unmap_page(struct domain *d, dfn_t dfn,
+                                      unsigned int order,
                                       unsigned int *flush_flags);
 int __must_check amd_iommu_alloc_root(struct domain *d);
 int amd_iommu_reserve_domain_unity_map(struct domain *domain,
--- a/xen/drivers/passthrough/amd/iommu_map.c
+++ b/xen/drivers/passthrough/amd/iommu_map.c
@@ -328,7 +328,7 @@ int amd_iommu_map_page(struct domain *d,
     return 0;
 }
 
-int amd_iommu_unmap_page(struct domain *d, dfn_t dfn,
+int amd_iommu_unmap_page(struct domain *d, dfn_t dfn, unsigned int order,
                          unsigned int *flush_flags)
 {
     unsigned long pt_mfn = 0;
--- a/xen/drivers/passthrough/arm/iommu_helpers.c
+++ b/xen/drivers/passthrough/arm/iommu_helpers.c
@@ -57,11 +57,13 @@ int __must_check arm_iommu_map_page(stru
      * The function guest_physmap_add_entry replaces the current mapping
      * if there is already one...
      */
-    return guest_physmap_add_entry(d, _gfn(dfn_x(dfn)), _mfn(dfn_x(dfn)), 0, t);
+    return guest_physmap_add_entry(d, _gfn(dfn_x(dfn)), _mfn(dfn_x(dfn)),
+                                   IOMMUF_order(flags), t);
 }
 
 /* Should only be used if P2M Table is shared between the CPU and the IOMMU. */
 int __must_check arm_iommu_unmap_page(struct domain *d, dfn_t dfn,
+                                      unsigned int order,
                                       unsigned int *flush_flags)
 {
     /*
@@ -71,7 +73,8 @@ int __must_check arm_iommu_unmap_page(st
     if ( !is_domain_direct_mapped(d) )
         return -EINVAL;
 
-    return guest_physmap_remove_page(d, _gfn(dfn_x(dfn)), _mfn(dfn_x(dfn)), 0);
+    return guest_physmap_remove_page(d, _gfn(dfn_x(dfn)), _mfn(dfn_x(dfn)),
+                                     order);
 }
 
 /*
--- a/xen/drivers/passthrough/iommu.c
+++ b/xen/drivers/passthrough/iommu.c
@@ -271,6 +271,8 @@ int iommu_map(struct domain *d, dfn_t df
     if ( !is_iommu_enabled(d) )
         return 0;
 
+    ASSERT(!IOMMUF_order(flags));
+
     for ( i = 0; i < page_count; i++ )
     {
         rc = iommu_call(hd->platform_ops, map_page, d, dfn_add(dfn, i),
@@ -288,7 +290,7 @@ int iommu_map(struct domain *d, dfn_t df
         while ( i-- )
             /* if statement to satisfy __must_check */
             if ( iommu_call(hd->platform_ops, unmap_page, d, dfn_add(dfn, i),
-                            flush_flags) )
+                            0, flush_flags) )
                 continue;
 
         if ( !is_hardware_domain(d) )
@@ -333,7 +335,7 @@ int iommu_unmap(struct domain *d, dfn_t
     for ( i = 0; i < page_count; i++ )
     {
         int err = iommu_call(hd->platform_ops, unmap_page, d, dfn_add(dfn, i),
-                             flush_flags);
+                             0, flush_flags);
 
         if ( likely(!err) )
             continue;
--- a/xen/drivers/passthrough/vtd/iommu.c
+++ b/xen/drivers/passthrough/vtd/iommu.c
@@ -1934,6 +1934,7 @@ static int __must_check intel_iommu_map_
 }
 
 static int __must_check intel_iommu_unmap_page(struct domain *d, dfn_t dfn,
+                                               unsigned int order,
                                                unsigned int *flush_flags)
 {
     /* Do nothing if VT-d shares EPT page table */
@@ -1944,7 +1945,7 @@ static int __must_check intel_iommu_unma
     if ( iommu_hwdom_passthrough && is_hardware_domain(d) )
         return 0;
 
-    return dma_pte_clear_one(d, dfn_to_daddr(dfn), 0, flush_flags);
+    return dma_pte_clear_one(d, dfn_to_daddr(dfn), order, flush_flags);
 }
 
 static int intel_iommu_lookup_page(struct domain *d, dfn_t dfn, mfn_t *mfn,
--- a/xen/include/asm-arm/iommu.h
+++ b/xen/include/asm-arm/iommu.h
@@ -31,6 +31,7 @@ int __must_check arm_iommu_map_page(stru
                                     unsigned int flags,
                                     unsigned int *flush_flags);
 int __must_check arm_iommu_unmap_page(struct domain *d, dfn_t dfn,
+                                      unsigned int order,
                                       unsigned int *flush_flags);
 
 #endif /* __ARCH_ARM_IOMMU_H__ */
--- a/xen/include/xen/iommu.h
+++ b/xen/include/xen/iommu.h
@@ -127,9 +127,10 @@ void arch_iommu_hwdom_init(struct domain
  * The following flags are passed to map operations and passed by lookup
  * operations.
  */
-#define _IOMMUF_readable 0
+#define IOMMUF_order(n)  ((n) & 0x3f)
+#define _IOMMUF_readable 6
 #define IOMMUF_readable  (1u<<_IOMMUF_readable)
-#define _IOMMUF_writable 1
+#define _IOMMUF_writable 7
 #define IOMMUF_writable  (1u<<_IOMMUF_writable)
 
 /*
@@ -255,6 +256,7 @@ struct iommu_ops {
                                  unsigned int flags,
                                  unsigned int *flush_flags);
     int __must_check (*unmap_page)(struct domain *d, dfn_t dfn,
+                                   unsigned int order,
                                    unsigned int *flush_flags);
     int __must_check (*lookup_page)(struct domain *d, dfn_t dfn, mfn_t *mfn,
                                     unsigned int *flags);

On Fri, Sep 24, 2021 at 11:44:50AM +0200, Jan Beulich wrote:
> Or really, in the case of ->map_page(), accommodate it in the existing
> "flags" parameter. All call sites will pass 0 for now.

It feels slightly weird from an interface PoV that the map handler
takes the order from the flags parameter, while the unmap one has a
function parameter for it.

> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> Reviewed-by: Kevin Tian <kevin.tian@intel.com>

Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>

Thanks, Roger.

On 30.11.2021 14:49, Roger Pau Monné wrote:
> On Fri, Sep 24, 2021 at 11:44:50AM +0200, Jan Beulich wrote:
>> Or really, in the case of ->map_page(), accommodate it in the existing
>> "flags" parameter. All call sites will pass 0 for now.
> 
> It feels slightly weird from an interface PoV that the map handler
> takes the order from the flags parameter, while the unmap one has a
> function parameter for it.

Well, I wouldn't want to call the unmap parameter "flags" just for
consistency. If there ever is a flag to be passed, I guess that's
going to be the natural course of action.

>> Signed-off-by: Jan Beulich <jbeulich@suse.com>
>> Reviewed-by: Kevin Tian <kevin.tian@intel.com>
> 
> Reviewed-by: Roger Pau Monné <roger.pau@citrix.com>

Thanks.

Jan

Hi Jan,

On 24/09/2021 10:44, Jan Beulich wrote:
> Or really, in the case of ->map_page(), accommodate it in the existing
> "flags" parameter. All call sites will pass 0 for now.
> 
> Signed-off-by: Jan Beulich <jbeulich@suse.com>
> Reviewed-by: Kevin Tian <kevin.tian@intel.com>

For the Arm bits:

Acked-by: Julien Grall <jgrall@amazon.com>

Cheers,

-- 
Julien Grall