[PATCH v2 0/2] Add an altp2m subop for obtaining the page mem access

[PATCH v2 0/2] Add an altp2m subop for obtaining the page mem access

[Adrian Pop]

Currently there is a subop for setting the memaccess of a page, but not
for consulting it.  The new HVMOP_altp2m_get_mem_access adds this
functionality.

Changes in v2:
- use the _p2m_get_mem_access helper from p2m_get_mem_access
- minor Arm adjustments
- move out the addition of a memaccess helper function to a separate
  patch in the attempts of making the diff clearer

Adrian Pop (2):
  x86/mem_access: Add a helper function for memaccess conversion
  x86/altp2m: Add a subop for obtaining the mem access of a page

 tools/libxc/include/xenctrl.h   |  3 ++
 tools/libxc/xc_altp2m.c         | 33 +++++++++++++--
 xen/arch/arm/mem_access.c       |  8 +++-
 xen/arch/x86/hvm/hvm.c          | 26 ++++++++++--
 xen/arch/x86/mm/mem_access.c    | 73 +++++++++++++++++++++++----------
 xen/common/mem_access.c         |  2 +-
 xen/include/public/hvm/hvm_op.h | 10 +++--
 xen/include/xen/mem_access.h    |  3 +-
 8 files changed, 121 insertions(+), 37 deletions(-)

-- 
2.17.0


_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

[PATCH v2 1/2] x86/mem_access: Add a helper function for memaccess conversion

[Adrian Pop]

The p2m_access_to_xenmem_access() converts a p2m_access_t to a
xenmem_access_t.  It is complementary to xenmem_access_to_p2m_access().
It is currently only used by _p2m_get_mem_access().

Signed-off-by: Adrian Pop <apop@bitdefender.com>
---
 xen/arch/x86/mm/mem_access.c | 41 +++++++++++++++++++++---------------
 1 file changed, 24 insertions(+), 17 deletions(-)

diff --git a/xen/arch/x86/mm/mem_access.c b/xen/arch/x86/mm/mem_access.c
index c0cd0174cf..e75ff0c735 100644
--- a/xen/arch/x86/mm/mem_access.c
+++ b/xen/arch/x86/mm/mem_access.c
@@ -33,16 +33,12 @@
 #include "mm-locks.h"
 
 /*
- * Get access type for a gfn.
- * If gfn == INVALID_GFN, gets the default access type.
+ * Convert a p2m_access_t to a xenmem_access_t.
  */
-static int _p2m_get_mem_access(struct p2m_domain *p2m, gfn_t gfn,
-                               xenmem_access_t *access)
+static int p2m_access_to_xenmem_access(struct p2m_domain *p2m,
+                                       p2m_access_t paccess,
+                                       xenmem_access_t *xaccess)
 {
-    p2m_type_t t;
-    p2m_access_t a;
-    mfn_t mfn;
-
     static const xenmem_access_t memaccess[] = {
 #define ACCESS(ac) [p2m_access_##ac] = XENMEM_access_##ac
             ACCESS(n),
@@ -58,12 +54,27 @@ static int _p2m_get_mem_access(struct p2m_domain *p2m, gfn_t gfn,
 #undef ACCESS
     };
 
+    if ( (unsigned int)paccess >= ARRAY_SIZE(memaccess) )
+        return -ERANGE;
+
+    *xaccess = memaccess[paccess];
+    return 0;
+}
+
+/*
+ * Get access type for a gfn.
+ * If gfn == INVALID_GFN, gets the default access type.
+ */
+static int _p2m_get_mem_access(struct p2m_domain *p2m, gfn_t gfn,
+                               xenmem_access_t *access)
+{
+    p2m_type_t t;
+    p2m_access_t a;
+    mfn_t mfn;
+
     /* If request to get default access. */
     if ( gfn_eq(gfn, INVALID_GFN) )
-    {
-        *access = memaccess[p2m->default_access];
-        return 0;
-    }
+        return p2m_access_to_xenmem_access(p2m, p2m->default_access, access);
 
     gfn_lock(p2m, gfn, 0);
     mfn = p2m->get_entry(p2m, gfn, &t, &a, 0, NULL, NULL);
@@ -72,11 +83,7 @@ static int _p2m_get_mem_access(struct p2m_domain *p2m, gfn_t gfn,
     if ( mfn_eq(mfn, INVALID_MFN) )
         return -ESRCH;
 
-    if ( (unsigned int)a >= ARRAY_SIZE(memaccess) )
-        return -ERANGE;
-
-    *access =  memaccess[a];
-    return 0;
+    return access_to_xenmem_access(p2m, a, access);
 }
 
 bool p2m_mem_access_emulate_check(struct vcpu *v,
-- 
2.17.0


_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

Re: [PATCH v2 1/2] x86/mem_access: Add a helper function for memaccess conversion

[Tamas K Lengyel]

On Thu, Jul 5, 2018 at 4:44 AM Adrian Pop <apop@bitdefender.com> wrote:
>
> The p2m_access_to_xenmem_access() converts a p2m_access_t to a
> xenmem_access_t.  It is complementary to xenmem_access_to_p2m_access().
> It is currently only used by _p2m_get_mem_access().
>
> Signed-off-by: Adrian Pop <apop@bitdefender.com>
> ---
>  xen/arch/x86/mm/mem_access.c | 41 +++++++++++++++++++++---------------
>  1 file changed, 24 insertions(+), 17 deletions(-)
>
> diff --git a/xen/arch/x86/mm/mem_access.c b/xen/arch/x86/mm/mem_access.c
> index c0cd0174cf..e75ff0c735 100644
> --- a/xen/arch/x86/mm/mem_access.c
> +++ b/xen/arch/x86/mm/mem_access.c
> @@ -33,16 +33,12 @@
>  #include "mm-locks.h"
>
>  /*
> - * Get access type for a gfn.
> - * If gfn == INVALID_GFN, gets the default access type.
> + * Convert a p2m_access_t to a xenmem_access_t.
>   */
> -static int _p2m_get_mem_access(struct p2m_domain *p2m, gfn_t gfn,
> -                               xenmem_access_t *access)
> +static int p2m_access_to_xenmem_access(struct p2m_domain *p2m,
> +                                       p2m_access_t paccess,
> +                                       xenmem_access_t *xaccess)
>  {
> -    p2m_type_t t;
> -    p2m_access_t a;
> -    mfn_t mfn;
> -
>      static const xenmem_access_t memaccess[] = {
>  #define ACCESS(ac) [p2m_access_##ac] = XENMEM_access_##ac
>              ACCESS(n),
> @@ -58,12 +54,27 @@ static int _p2m_get_mem_access(struct p2m_domain *p2m, gfn_t gfn,
>  #undef ACCESS
>      };
>
> +    if ( (unsigned int)paccess >= ARRAY_SIZE(memaccess) )
> +        return -ERANGE;
> +
> +    *xaccess = memaccess[paccess];
> +    return 0;
> +}
> +
> +/*
> + * Get access type for a gfn.
> + * If gfn == INVALID_GFN, gets the default access type.
> + */
> +static int _p2m_get_mem_access(struct p2m_domain *p2m, gfn_t gfn,
> +                               xenmem_access_t *access)
> +{
> +    p2m_type_t t;
> +    p2m_access_t a;
> +    mfn_t mfn;
> +
>      /* If request to get default access. */
>      if ( gfn_eq(gfn, INVALID_GFN) )
> -    {
> -        *access = memaccess[p2m->default_access];
> -        return 0;
> -    }
> +        return p2m_access_to_xenmem_access(p2m, p2m->default_access, access);
>
>      gfn_lock(p2m, gfn, 0);
>      mfn = p2m->get_entry(p2m, gfn, &t, &a, 0, NULL, NULL);
> @@ -72,11 +83,7 @@ static int _p2m_get_mem_access(struct p2m_domain *p2m, gfn_t gfn,
>      if ( mfn_eq(mfn, INVALID_MFN) )
>          return -ESRCH;
>
> -    if ( (unsigned int)a >= ARRAY_SIZE(memaccess) )
> -        return -ERANGE;
> -
> -    *access =  memaccess[a];
> -    return 0;
> +    return access_to_xenmem_access(p2m, a, access);

Shouldn't this be p2m_access_to_xenmem_access? Did you compile check
this patch before sending?

>  }
>
>  bool p2m_mem_access_emulate_check(struct vcpu *v,
> --
> 2.17.0

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

Re: [PATCH v2 1/2] x86/mem_access: Add a helper function for memaccess conversion

[Adrian Pop]

On Thu, Jul 05, 2018 at 10:53:22AM -0600, Tamas K Lengyel wrote:
> On Thu, Jul 5, 2018 at 4:44 AM Adrian Pop <apop@bitdefender.com> wrote:
> > @@ -72,11 +83,7 @@ static int _p2m_get_mem_access(struct p2m_domain *p2m, gfn_t gfn,
> >      if ( mfn_eq(mfn, INVALID_MFN) )
> >          return -ESRCH;
> >
> > -    if ( (unsigned int)a >= ARRAY_SIZE(memaccess) )
> > -        return -ERANGE;
> > -
> > -    *access =  memaccess[a];
> > -    return 0;
> > +    return access_to_xenmem_access(p2m, a, access);
> 
> Shouldn't this be p2m_access_to_xenmem_access? Did you compile check
> this patch before sending?

Oh, that's right!  It seems I've mistakenly used an intermediary version
of the patch when testing unfortunately.

Thank you!

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

[PATCH v2 2/2] x86/altp2m: Add a subop for obtaining the memaccess of a page

[Adrian Pop]

Both altp2m get/set memaccess functions use the struct
xen_hvm_altp2m_mem_access which has now dropped the `set' part and has
been renamed from xen_hvm_altp2m_set_mem_access.

Signed-off-by: Adrian Pop <apop@bitdefender.com>
---
 tools/libxc/include/xenctrl.h   |  3 +++
 tools/libxc/xc_altp2m.c         | 33 ++++++++++++++++++++++++++++++---
 xen/arch/arm/mem_access.c       |  8 ++++++--
 xen/arch/x86/hvm/hvm.c          | 26 ++++++++++++++++++++++----
 xen/arch/x86/mm/mem_access.c    | 32 +++++++++++++++++++++++++++-----
 xen/common/mem_access.c         |  2 +-
 xen/include/public/hvm/hvm_op.h | 10 ++++++----
 xen/include/xen/mem_access.h    |  3 ++-
 8 files changed, 97 insertions(+), 20 deletions(-)

diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
index e8285dbb5f..efd196e480 100644
--- a/tools/libxc/include/xenctrl.h
+++ b/tools/libxc/include/xenctrl.h
@@ -1962,6 +1962,9 @@ int xc_altp2m_set_mem_access(xc_interface *handle, uint32_t domid,
 int xc_altp2m_set_mem_access_multi(xc_interface *handle, uint32_t domid,
                                    uint16_t view_id, uint8_t *access,
                                    uint64_t *gfns, uint32_t nr);
+int xc_altp2m_get_mem_access(xc_interface *handle, uint32_t domid,
+                             uint16_t view_id, xen_pfn_t gfn,
+                             xenmem_access_t *access);
 int xc_altp2m_change_gfn(xc_interface *handle, uint32_t domid,
                          uint16_t view_id, xen_pfn_t old_gfn,
                          xen_pfn_t new_gfn);
diff --git a/tools/libxc/xc_altp2m.c b/tools/libxc/xc_altp2m.c
index ce4a1e4d60..0ddb18fa2c 100644
--- a/tools/libxc/xc_altp2m.c
+++ b/tools/libxc/xc_altp2m.c
@@ -177,9 +177,9 @@ int xc_altp2m_set_mem_access(xc_interface *handle, uint32_t domid,
     arg->version = HVMOP_ALTP2M_INTERFACE_VERSION;
     arg->cmd = HVMOP_altp2m_set_mem_access;
     arg->domain = domid;
-    arg->u.set_mem_access.view = view_id;
-    arg->u.set_mem_access.hvmmem_access = access;
-    arg->u.set_mem_access.gfn = gfn;
+    arg->u.mem_access.view = view_id;
+    arg->u.mem_access.hvmmem_access = access;
+    arg->u.mem_access.gfn = gfn;
 
     rc = xencall2(handle->xcall, __HYPERVISOR_hvm_op, HVMOP_altp2m,
 		  HYPERCALL_BUFFER_AS_ARG(arg));
@@ -254,3 +254,30 @@ int xc_altp2m_set_mem_access_multi(xc_interface *xch, uint32_t domid,
 
     return rc;
 }
+
+int xc_altp2m_get_mem_access(xc_interface *handle, uint32_t domid,
+                             uint16_t view_id, xen_pfn_t gfn,
+                             xenmem_access_t *access)
+{
+    int rc;
+    DECLARE_HYPERCALL_BUFFER(xen_hvm_altp2m_op_t, arg);
+
+    arg = xc_hypercall_buffer_alloc(handle, arg, sizeof(*arg));
+    if ( arg == NULL )
+        return -1;
+
+    arg->version = HVMOP_ALTP2M_INTERFACE_VERSION;
+    arg->cmd = HVMOP_altp2m_get_mem_access;
+    arg->domain = domid;
+    arg->u.mem_access.view = view_id;
+    arg->u.mem_access.gfn = gfn;
+
+    rc = xencall2(handle->xcall, __HYPERVISOR_hvm_op, HVMOP_altp2m,
+                 HYPERCALL_BUFFER_AS_ARG(arg));
+
+    if ( !rc )
+        *access = arg->u.mem_access.hvmmem_access;
+
+    xc_hypercall_buffer_free(handle, arg);
+    return rc;
+}
diff --git a/xen/arch/arm/mem_access.c b/xen/arch/arm/mem_access.c
index ae2686ffa2..1fbf138b12 100644
--- a/xen/arch/arm/mem_access.c
+++ b/xen/arch/arm/mem_access.c
@@ -236,7 +236,7 @@ bool p2m_mem_access_check(paddr_t gpa, vaddr_t gla, const struct npfec npfec)
     if ( !p2m->mem_access_enabled )
         return true;
 
-    rc = p2m_get_mem_access(v->domain, gaddr_to_gfn(gpa), &xma);
+    rc = p2m_get_mem_access(v->domain, gaddr_to_gfn(gpa), &xma, 0);
     if ( rc )
         return true;
 
@@ -441,11 +441,15 @@ long p2m_set_mem_access_multi(struct domain *d,
 }
 
 int p2m_get_mem_access(struct domain *d, gfn_t gfn,
-                       xenmem_access_t *access)
+                       xenmem_access_t *access, unsigned int altp2m_idx)
 {
     int ret;
     struct p2m_domain *p2m = p2m_get_hostp2m(d);
 
+    /* altp2m is not yet implemented on Arm. The altp2m_idx should be 0. */
+    if ( altp2m_idx )
+        return -EINVAL;
+
     p2m_read_lock(p2m);
     ret = __p2m_get_mem_access(d, gfn, access);
     p2m_read_unlock(p2m);
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index c23983cdff..28e1719751 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -4509,6 +4509,7 @@ static int do_altp2m_op(
     case HVMOP_altp2m_switch_p2m:
     case HVMOP_altp2m_set_mem_access:
     case HVMOP_altp2m_set_mem_access_multi:
+    case HVMOP_altp2m_get_mem_access:
     case HVMOP_altp2m_change_gfn:
         break;
 
@@ -4625,12 +4626,12 @@ static int do_altp2m_op(
         break;
 
     case HVMOP_altp2m_set_mem_access:
-        if ( a.u.set_mem_access.pad )
+        if ( a.u.mem_access.pad )
             rc = -EINVAL;
         else
-            rc = p2m_set_mem_access(d, _gfn(a.u.set_mem_access.gfn), 1, 0, 0,
-                                    a.u.set_mem_access.hvmmem_access,
-                                    a.u.set_mem_access.view);
+            rc = p2m_set_mem_access(d, _gfn(a.u.mem_access.gfn), 1, 0, 0,
+                                    a.u.mem_access.hvmmem_access,
+                                    a.u.mem_access.view);
         break;
 
     case HVMOP_altp2m_set_mem_access_multi:
@@ -4666,6 +4667,23 @@ static int do_altp2m_op(
         }
         break;
 
+    case HVMOP_altp2m_get_mem_access:
+        if ( a.u.mem_access.pad )
+            rc = -EINVAL;
+        else
+        {
+            xenmem_access_t access;
+
+            rc = p2m_get_mem_access(d, _gfn(a.u.mem_access.gfn), &access,
+                                    a.u.mem_access.view);
+            if ( !rc )
+            {
+                a.u.mem_access.hvmmem_access = access;
+                rc = __copy_to_guest(arg, &a, 1) ? -EFAULT : 0;
+            }
+        }
+        break;
+
     case HVMOP_altp2m_change_gfn:
         if ( a.u.change_gfn.pad1 || a.u.change_gfn.pad2 )
             rc = -EINVAL;
diff --git a/xen/arch/x86/mm/mem_access.c b/xen/arch/x86/mm/mem_access.c
index e75ff0c735..2767100eb0 100644
--- a/xen/arch/x86/mm/mem_access.c
+++ b/xen/arch/x86/mm/mem_access.c
@@ -76,9 +76,9 @@ static int _p2m_get_mem_access(struct p2m_domain *p2m, gfn_t gfn,
     if ( gfn_eq(gfn, INVALID_GFN) )
         return p2m_access_to_xenmem_access(p2m, p2m->default_access, access);
 
-    gfn_lock(p2m, gfn, 0);
+    p2m_read_lock(p2m);
     mfn = p2m->get_entry(p2m, gfn, &t, &a, 0, NULL, NULL);
-    gfn_unlock(p2m, gfn, 0);
+    p2m_read_unlock(p2m);
 
     if ( mfn_eq(mfn, INVALID_MFN) )
         return -ESRCH;
@@ -465,11 +465,33 @@ long p2m_set_mem_access_multi(struct domain *d,
     return rc;
 }
 
-int p2m_get_mem_access(struct domain *d, gfn_t gfn, xenmem_access_t *access)
+int p2m_get_mem_access(struct domain *d, gfn_t gfn, xenmem_access_t *access,
+                       unsigned int altp2m_idx)
 {
-    struct p2m_domain *p2m = p2m_get_hostp2m(d);
+    struct p2m_domain *host_p2m = p2m_get_hostp2m(d);
+    struct p2m_domain *p2m;
+    int rc;
+
+    if ( altp2m_idx )
+    {
+        if ( altp2m_idx >= MAX_ALTP2M ||
+             d->arch.altp2m_eptp[altp2m_idx] == mfn_x(INVALID_MFN) )
+            return -EINVAL;
 
-    return _p2m_get_mem_access(p2m, gfn, access);
+        p2m = d->arch.altp2m_p2m[altp2m_idx];
+    }
+    else
+        p2m = host_p2m;
+
+    if ( altp2m_idx )
+        p2m_read_lock(host_p2m);
+
+    rc = _p2m_get_mem_access(p2m, gfn, access);
+
+    if ( altp2m_idx )
+        p2m_read_unlock(host_p2m);
+
+    return rc;
 }
 
 /*
diff --git a/xen/common/mem_access.c b/xen/common/mem_access.c
index 1bf6824442..010e6f8dbf 100644
--- a/xen/common/mem_access.c
+++ b/xen/common/mem_access.c
@@ -99,7 +99,7 @@ int mem_access_memop(unsigned long cmd,
         if ( (mao.pfn > domain_get_maximum_gpfn(d)) && mao.pfn != ~0ull )
             break;
 
-        rc = p2m_get_mem_access(d, _gfn(mao.pfn), &access);
+        rc = p2m_get_mem_access(d, _gfn(mao.pfn), &access, 0);
         if ( rc != 0 )
             break;
 
diff --git a/xen/include/public/hvm/hvm_op.h b/xen/include/public/hvm/hvm_op.h
index bbba99e5f5..36fd97f329 100644
--- a/xen/include/public/hvm/hvm_op.h
+++ b/xen/include/public/hvm/hvm_op.h
@@ -234,7 +234,7 @@ struct xen_hvm_altp2m_view {
 typedef struct xen_hvm_altp2m_view xen_hvm_altp2m_view_t;
 DEFINE_XEN_GUEST_HANDLE(xen_hvm_altp2m_view_t);
 
-struct xen_hvm_altp2m_set_mem_access {
+struct xen_hvm_altp2m_mem_access {
     /* view */
     uint16_t view;
     /* Memory type */
@@ -243,8 +243,8 @@ struct xen_hvm_altp2m_set_mem_access {
     /* gfn */
     uint64_t gfn;
 };
-typedef struct xen_hvm_altp2m_set_mem_access xen_hvm_altp2m_set_mem_access_t;
-DEFINE_XEN_GUEST_HANDLE(xen_hvm_altp2m_set_mem_access_t);
+typedef struct xen_hvm_altp2m_mem_access xen_hvm_altp2m_mem_access_t;
+DEFINE_XEN_GUEST_HANDLE(xen_hvm_altp2m_mem_access_t);
 
 struct xen_hvm_altp2m_set_mem_access_multi {
     /* view */
@@ -296,6 +296,8 @@ struct xen_hvm_altp2m_op {
 #define HVMOP_altp2m_change_gfn           8
 /* Set access for an array of pages */
 #define HVMOP_altp2m_set_mem_access_multi 9
+/* Get the access of a page of memory from a certain view */
+#define HVMOP_altp2m_get_mem_access       10
     domid_t domain;
     uint16_t pad1;
     uint32_t pad2;
@@ -303,7 +305,7 @@ struct xen_hvm_altp2m_op {
         struct xen_hvm_altp2m_domain_state         domain_state;
         struct xen_hvm_altp2m_vcpu_enable_notify   enable_notify;
         struct xen_hvm_altp2m_view                 view;
-        struct xen_hvm_altp2m_set_mem_access       set_mem_access;
+        struct xen_hvm_altp2m_mem_access           mem_access;
         struct xen_hvm_altp2m_change_gfn           change_gfn;
         struct xen_hvm_altp2m_set_mem_access_multi set_mem_access_multi;
         uint8_t pad[64];
diff --git a/xen/include/xen/mem_access.h b/xen/include/xen/mem_access.h
index 5ab34c1553..99fe11f6bc 100644
--- a/xen/include/xen/mem_access.h
+++ b/xen/include/xen/mem_access.h
@@ -76,7 +76,8 @@ long p2m_set_mem_access_multi(struct domain *d,
  * Get access type for a gfn.
  * If gfn == INVALID_GFN, gets the default access type.
  */
-int p2m_get_mem_access(struct domain *d, gfn_t gfn, xenmem_access_t *access);
+int p2m_get_mem_access(struct domain *d, gfn_t gfn, xenmem_access_t *access,
+                       unsigned int altp2m_idx);
 
 #ifdef CONFIG_HAS_MEM_ACCESS
 int mem_access_memop(unsigned long cmd,
-- 
2.17.0


_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

Re: [PATCH v2 2/2] x86/altp2m: Add a subop for obtaining the memaccess of a page

[Jan Beulich]

>>> On 05.07.18 at 12:44, <apop@bitdefender.com> wrote:
> Both altp2m get/set memaccess functions use the struct
> xen_hvm_altp2m_mem_access which has now dropped the `set' part and has
> been renamed from xen_hvm_altp2m_set_mem_access.
> 
> Signed-off-by: Adrian Pop <apop@bitdefender.com>

Looking through this patch - what's the point of patch 1? There's no
further user being introduced here.

Jan



_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

Re: [PATCH v2 2/2] x86/altp2m: Add a subop for obtaining the memaccess of a page

[Razvan Cojocaru]

On 07/09/2018 11:35 AM, Jan Beulich wrote:
>>>> On 05.07.18 at 12:44, <apop@bitdefender.com> wrote:
>> Both altp2m get/set memaccess functions use the struct
>> xen_hvm_altp2m_mem_access which has now dropped the `set' part and has
>> been renamed from xen_hvm_altp2m_set_mem_access.
>>
>> Signed-off-by: Adrian Pop <apop@bitdefender.com>
> 
> Looking through this patch - what's the point of patch 1? There's no
> further user being introduced here.

I think it was meant just as code cleanup for now, probably also to be
used in later patches.


Thanks,
Razvan

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel

Re: [PATCH v2 2/2] x86/altp2m: Add a subop for obtaining the memaccess of a page

[Adrian Pop]

On Mon, Jul 09, 2018 at 02:35:30AM -0600, Jan Beulich wrote:
> >>> On 05.07.18 at 12:44, <apop@bitdefender.com> wrote:
> > Both altp2m get/set memaccess functions use the struct
> > xen_hvm_altp2m_mem_access which has now dropped the `set' part and has
> > been renamed from xen_hvm_altp2m_set_mem_access.
> > 
> > Signed-off-by: Adrian Pop <apop@bitdefender.com>
> 
> Looking through this patch - what's the point of patch 1? There's no
> further user being introduced here.

It's not entirely necessary.  It just cleans up _p2m_get_mem_access()
slightly, which would be the only user of the new function.  I could
drop patch 1 and if it's deemed desirable I could send it separately.

_______________________________________________
Xen-devel mailing list
Xen-devel@lists.xenproject.org
https://lists.xenproject.org/mailman/listinfo/xen-devel