[PATCH V6 1/2] xen/arm: Introduce gpaddr_bits field to struct xen_domctl_getdomaininfo

[Oleksandr Tyshchenko <olekstysh@xxxxxxxxx>]

From: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>

We need to pass info about maximum supported guest physical
address space size to the toolstack on Arm in order to properly
calculate the base and size of the extended region (safe range)
for the guest. The extended region is unused address space which
could be safely used by domain for foreign/grant mappings on Arm.
The extended region itself will be handled by the subsequent
patch.

Currently the same guest physical address space size is used
for all guests (p2m_ipa_bits variable on Arm, the x86 equivalent
is hap_paddr_bits).

As we add new field to the structure bump the interface version.

Suggested-by: Julien Grall <jgrall@xxxxxxxxxx>
Signed-off-by: Oleksandr Tyshchenko <oleksandr_tyshchenko@xxxxxxxx>
---
Changes RFC -> V2:
   - update patch subject/description
   - replace arch-specific sub-struct with common gpaddr_bits
     field and update code to reflect that

Changes V2 -> V3:
   - make the field uint8_t and add uint8_t pad[7] after
   - remove leading blanks in libxl.h

Changes V3 -> V4:
   - also print gpaddr_bits from output_physinfo()
   - add Michal's R-b

Changes V4 -> V5:
   - update patch subject and description
   - drop Michal's R-b
   - pass gpaddr_bits via createdomain domctl
     (struct xen_arch_domainconfig)

Changes V5 -> V6:
   - update patch subject and description
   - pass gpaddr_bits via getdomaininfo domctl
     (struct xen_domctl_getdomaininfo)
---
 tools/include/libxl.h            | 8 ++++++++
 tools/include/xenctrl.h          | 1 +
 tools/libs/ctrl/xc_domain.c      | 1 +
 tools/libs/light/libxl_domain.c  | 1 +
 tools/libs/light/libxl_types.idl | 1 +
 xen/arch/arm/domctl.c            | 2 ++
 xen/arch/x86/domctl.c            | 1 +
 xen/include/public/domctl.h      | 3 ++-
 8 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/tools/include/libxl.h b/tools/include/libxl.h
index b9ba16d..deb5022 100644
--- a/tools/include/libxl.h
+++ b/tools/include/libxl.h
@@ -874,6 +874,14 @@ typedef struct libxl__ctx libxl_ctx;
 #define LIBXL_HAVE_DOMINFO_NEVER_STOP 1
 
 /*
+ * LIBXL_HAVE_DOMINFO_GPADDR_BITS
+ *
+ * If this is defined, libxl_dominfo will contain an uint8 field called
+ * gpaddr_bits, containing the guest physical address space size.
+ */
+#define LIBXL_HAVE_DOMINFO_GPADDR_BITS 1
+
+/*
  * LIBXL_HAVE_QXL
  *
  * If defined, then the libxl_vga_interface_type will contain another value:
diff --git a/tools/include/xenctrl.h b/tools/include/xenctrl.h
index a306399..07b96e6 100644
--- a/tools/include/xenctrl.h
+++ b/tools/include/xenctrl.h
@@ -462,6 +462,7 @@ typedef struct xc_dominfo {
     unsigned int  max_vcpu_id;
     xen_domain_handle_t handle;
     unsigned int  cpupool;
+    uint8_t       gpaddr_bits;
     struct xen_arch_domainconfig arch_config;
 } xc_dominfo_t;
 
diff --git a/tools/libs/ctrl/xc_domain.c b/tools/libs/ctrl/xc_domain.c
index 23322b7..b155d6a 100644
--- a/tools/libs/ctrl/xc_domain.c
+++ b/tools/libs/ctrl/xc_domain.c
@@ -396,6 +396,7 @@ int xc_domain_getinfo(xc_interface *xch,
         info->nr_online_vcpus = domctl.u.getdomaininfo.nr_online_vcpus;
         info->max_vcpu_id = domctl.u.getdomaininfo.max_vcpu_id;
         info->cpupool = domctl.u.getdomaininfo.cpupool;
+        info->gpaddr_bits = domctl.u.getdomaininfo.gpaddr_bits;
         info->arch_config = domctl.u.getdomaininfo.arch_config;
 
         memcpy(info->handle, domctl.u.getdomaininfo.handle,
diff --git a/tools/libs/light/libxl_domain.c b/tools/libs/light/libxl_domain.c
index 51a6127..544a9bf 100644
--- a/tools/libs/light/libxl_domain.c
+++ b/tools/libs/light/libxl_domain.c
@@ -306,6 +306,7 @@ void libxl__xcinfo2xlinfo(libxl_ctx *ctx,
     xlinfo->vcpu_max_id = xcinfo->max_vcpu_id;
     xlinfo->vcpu_online = xcinfo->nr_online_vcpus;
     xlinfo->cpupool = xcinfo->cpupool;
+    xlinfo->gpaddr_bits = xcinfo->gpaddr_bits;
     xlinfo->domain_type = (xcinfo->flags & XEN_DOMINF_hvm_guest) ?
         LIBXL_DOMAIN_TYPE_HVM : LIBXL_DOMAIN_TYPE_PV;
 }
diff --git a/tools/libs/light/libxl_types.idl b/tools/libs/light/libxl_types.idl
index 3f9fff6..2df7258 100644
--- a/tools/libs/light/libxl_types.idl
+++ b/tools/libs/light/libxl_types.idl
@@ -357,6 +357,7 @@ libxl_dominfo = Struct("dominfo",[
     ("vcpu_max_id", uint32),
     ("vcpu_online", uint32),
     ("cpupool",     uint32),
+    ("gpaddr_bits", uint8),
     ("domain_type", libxl_domain_type),
     ], dir=DIR_OUT)
 
diff --git a/xen/arch/arm/domctl.c b/xen/arch/arm/domctl.c
index b7d27f3..6245af6 100644
--- a/xen/arch/arm/domctl.c
+++ b/xen/arch/arm/domctl.c
@@ -20,6 +20,8 @@ void arch_get_domain_info(const struct domain *d,
 {
     /* All ARM domains use hardware assisted paging. */
     info->flags |= XEN_DOMINF_hap;
+
+    info->gpaddr_bits = p2m_ipa_bits;
 }
 
 static int handle_vuart_init(struct domain *d, 
diff --git a/xen/arch/x86/domctl.c b/xen/arch/x86/domctl.c
index 26a76d2..7d102e0 100644
--- a/xen/arch/x86/domctl.c
+++ b/xen/arch/x86/domctl.c
@@ -151,6 +151,7 @@ void arch_get_domain_info(const struct domain *d,
         info->flags |= XEN_DOMINF_hap;
 
     info->arch_config.emulation_flags = d->arch.emulation_flags;
+    info->gpaddr_bits = hap_paddr_bits;
 }
 
 static int do_vmtrace_op(struct domain *d, struct xen_domctl_vmtrace_op *op,
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index 4cb3f66..b93f776 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -38,7 +38,7 @@
 #include "hvm/save.h"
 #include "memory.h"
 
-#define XEN_DOMCTL_INTERFACE_VERSION 0x00000014
+#define XEN_DOMCTL_INTERFACE_VERSION 0x00000015
 
 /*
  * NB. xen_domctl.domain is an IN/OUT parameter for this operation.
@@ -150,6 +150,7 @@ struct xen_domctl_getdomaininfo {
     uint32_t ssidref;
     xen_domain_handle_t handle;
     uint32_t cpupool;
+    uint8_t gpaddr_bits; /* Guest physical address space size. */
     struct xen_arch_domainconfig arch_config;
 };
 typedef struct xen_domctl_getdomaininfo xen_domctl_getdomaininfo_t;
-- 
2.7.4