Introduce a new field in struct xen_dom_flags to store arch-specific
flags.

Add an ARM-specific flag to specify that the domain should be directly
mapped (guest physical addresses == physical addresses).

Also, add a direct_map flag under struct arch_domain and use it to
implement is_domain_direct_mapped.

Signed-off-by: Stefano Stabellini <stefano.stabellini@xilinx.com>
CC: andrew.cooper3@citrix.com
CC: jbeulich@suse.com
CC: George Dunlap <George.Dunlap@eu.citrix.com>
CC: Ian Jackson <ian.jackson@eu.citrix.com>
CC: Wei Liu <wl@xen.org>
CC: "Roger Pau Monné" <roger.pau@citrix.com>
---
 xen/arch/arm/domain.c        | 1 +
 xen/arch/arm/domain_build.c  | 1 +
 xen/arch/arm/setup.c         | 2 +-
 xen/include/asm-arm/domain.h | 9 ++++++++-
 xen/include/asm-x86/domain.h | 2 ++
 xen/include/xen/domain.h     | 1 +
 6 files changed, 14 insertions(+), 2 deletions(-)

diff --git a/xen/arch/arm/domain.c b/xen/arch/arm/domain.c
index b906a38b6b..59eae36de7 100644
--- a/xen/arch/arm/domain.c
+++ b/xen/arch/arm/domain.c
@@ -682,6 +682,7 @@ int arch_domain_create(struct domain *d,
         return 0;
 
     ASSERT(config != NULL);
+    d->arch.direct_map = flags != NULL ? flags->arch.is_direct_map : false;
 
     /* p2m_init relies on some value initialized by the IOMMU subsystem */
     if ( (rc = iommu_domain_init(d, config->iommu_opts)) != 0 )
diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
index 20e62a9fc4..2ec7453aa3 100644
--- a/xen/arch/arm/domain_build.c
+++ b/xen/arch/arm/domain_build.c
@@ -2527,6 +2527,7 @@ int __init construct_dom0(struct domain *d)
 
     iommu_hwdom_init(d);
 
+    d->arch.direct_map = true;
     d->max_pages = ~0U;
 
     kinfo.unassigned_mem = dom0_mem;
diff --git a/xen/arch/arm/setup.c b/xen/arch/arm/setup.c
index 9ccb3f7385..5434548e7b 100644
--- a/xen/arch/arm/setup.c
+++ b/xen/arch/arm/setup.c
@@ -787,7 +787,7 @@ void __init start_xen(unsigned long boot_phys_offset,
         .max_maptrack_frames = -1,
     };
     int rc;
-    struct xen_dom_flags flags = { true };
+    struct xen_dom_flags flags = { true, .arch.is_direct_map = true };
 
     dcache_line_bytes = read_dcache_line_bytes();
 
diff --git a/xen/include/asm-arm/domain.h b/xen/include/asm-arm/domain.h
index d39477a939..7a498921bf 100644
--- a/xen/include/asm-arm/domain.h
+++ b/xen/include/asm-arm/domain.h
@@ -32,7 +32,7 @@ enum domain_type {
 #endif
 
 /* The hardware domain has always its memory direct mapped. */
-#define is_domain_direct_mapped(d) ((d) == hardware_domain)
+#define is_domain_direct_mapped(d) ((d)->arch.direct_map != false)
 
 struct vtimer {
     struct vcpu *v;
@@ -98,8 +98,15 @@ struct arch_domain
 #ifdef CONFIG_TEE
     void *tee;
 #endif
+
+    bool direct_map;
 }  __cacheline_aligned;
 
+struct arch_xen_dom_flags
+{
+    bool is_direct_map;
+};
+
 struct arch_vcpu
 {
     struct {
diff --git a/xen/include/asm-x86/domain.h b/xen/include/asm-x86/domain.h
index 105adf96eb..52199ed5b9 100644
--- a/xen/include/asm-x86/domain.h
+++ b/xen/include/asm-x86/domain.h
@@ -418,6 +418,8 @@ struct arch_domain
     uint32_t emulation_flags;
 } __cacheline_aligned;
 
+struct arch_xen_dom_flags {};
+
 #ifdef CONFIG_HVM
 #define X86_EMU_LAPIC    XEN_X86_EMU_LAPIC
 #define X86_EMU_HPET     XEN_X86_EMU_HPET
diff --git a/xen/include/xen/domain.h b/xen/include/xen/domain.h
index 4423e34500..7227e6ca98 100644
--- a/xen/include/xen/domain.h
+++ b/xen/include/xen/domain.h
@@ -65,6 +65,7 @@ void unmap_vcpu_info(struct vcpu *v);
 
 struct xen_dom_flags {
     bool is_priv;
+    struct arch_xen_dom_flags arch;
 };
 
 int arch_domain_create(struct domain *d,
-- 
2.17.1

On 15.04.2020 03:02, Stefano Stabellini wrote:
> --- a/xen/arch/arm/domain.c
> +++ b/xen/arch/arm/domain.c
> @@ -682,6 +682,7 @@ int arch_domain_create(struct domain *d,
>          return 0;
>  
>      ASSERT(config != NULL);
> +    d->arch.direct_map = flags != NULL ? flags->arch.is_direct_map : false;

Shouldn't "true" here imply ->disable_migrate also getting
set to true? Or is this already the case anyway for domains
created right at boot?

> --- a/xen/arch/arm/domain_build.c
> +++ b/xen/arch/arm/domain_build.c
> @@ -2527,6 +2527,7 @@ int __init construct_dom0(struct domain *d)
>  
>      iommu_hwdom_init(d);
>  
> +    d->arch.direct_map = true;

Shouldn't this get set via arch_domain_create() instead?

> --- a/xen/include/asm-x86/domain.h
> +++ b/xen/include/asm-x86/domain.h
> @@ -418,6 +418,8 @@ struct arch_domain
>      uint32_t emulation_flags;
>  } __cacheline_aligned;
>  
> +struct arch_xen_dom_flags {};

This trivial x86 change
Acked-by: Jan Beulich <jbeulich@suse.com>

Jan

On 15/04/2020 11:27, Jan Beulich wrote:
> On 15.04.2020 03:02, Stefano Stabellini wrote:
>> --- a/xen/arch/arm/domain.c
>> +++ b/xen/arch/arm/domain.c
>> @@ -682,6 +682,7 @@ int arch_domain_create(struct domain *d,
>>          return 0;
>>  
>>      ASSERT(config != NULL);
>> +    d->arch.direct_map = flags != NULL ? flags->arch.is_direct_map : false;
> Shouldn't "true" here imply ->disable_migrate also getting
> set to true? Or is this already the case anyway for domains
> created right at boot?

Please don't introduce any more uses for disable_migrate.  It is
fundamentally broken and won't survive to 4.14 (assuming that the 30 odd
patches of prereq fixes on xen-devel start unblocking themselves in time)

~Andrew

On Wed, 15 Apr 2020, Jan Beulich wrote:
> > --- a/xen/arch/arm/domain_build.c
> > +++ b/xen/arch/arm/domain_build.c
> > @@ -2527,6 +2527,7 @@ int __init construct_dom0(struct domain *d)
> >  
> >      iommu_hwdom_init(d);
> >  
> > +    d->arch.direct_map = true;
> 
> Shouldn't this get set via arch_domain_create() instead?

Yes you are right, this is unnecessary and I can remove it.