[PATCH v3] x86/altp2m: Added xc_altp2m_set_mem_access_multi()

[Petre Pircalabu <ppircalabu@bitdefender.com>]

From: Razvan Cojocaru <rcojocaru@bitdefender.com>

For the default EPT view we have xc_set_mem_access_multi(), which
is able to set an array of pages to an array of access rights with
a single hypercall. However, this functionality was lacking for the
altp2m subsystem, which could only set page restrictions for one
page at a time. This patch addresses the gap.

Signed-off-by: Razvan Cojocaru <rcojocaru@bitdefender.com>
Signed-off-by: Petre Pircalabu <ppircalabu@bitdefender.com>

---

Changed since v2:
    * Added support for compat arguments translation
---
 tools/libxc/include/xenctrl.h    |  3 ++
 tools/libxc/xc_altp2m.c          | 41 ++++++++++++++++++++++
 xen/arch/x86/hvm/hvm.c           | 76 +++++++++++++++++++++++++++++++++++++++-
 xen/include/Makefile             |  1 +
 xen/include/public/hvm/hvm_op.h  | 30 +++++++++++++---
 xen/include/xlat.lst             |  1 +
 xen/tools/compat-build-header.py |  1 +
 7 files changed, 147 insertions(+), 6 deletions(-)

diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
index 3bcab3c..4e2ce64 100644
--- a/tools/libxc/include/xenctrl.h
+++ b/tools/libxc/include/xenctrl.h
@@ -1971,6 +1971,9 @@ int xc_altp2m_switch_to_view(xc_interface *handle, domid_t domid,
 int xc_altp2m_set_mem_access(xc_interface *handle, domid_t domid,
                              uint16_t view_id, xen_pfn_t gfn,
                              xenmem_access_t access);
+int xc_altp2m_set_mem_access_multi(xc_interface *handle, domid_t domid,
+                                   uint16_t view_id, uint8_t *access,
+                                   uint64_t *pages, uint32_t nr);
 int xc_altp2m_change_gfn(xc_interface *handle, domid_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 0639632..f202ca1 100644
--- a/tools/libxc/xc_altp2m.c
+++ b/tools/libxc/xc_altp2m.c
@@ -188,6 +188,47 @@ int xc_altp2m_set_mem_access(xc_interface *handle, domid_t domid,
     return rc;
 }
 
+int xc_altp2m_set_mem_access_multi(xc_interface *xch, domid_t domid,
+                                   uint16_t view_id, uint8_t *access,
+                                   uint64_t *pages, uint32_t nr)
+{
+    int rc;
+
+    DECLARE_HYPERCALL_BUFFER(xen_hvm_altp2m_op_t, arg);
+    DECLARE_HYPERCALL_BOUNCE(access, nr, XC_HYPERCALL_BUFFER_BOUNCE_IN);
+    DECLARE_HYPERCALL_BOUNCE(pages, nr * sizeof(uint64_t),
+                             XC_HYPERCALL_BUFFER_BOUNCE_IN);
+
+    arg = xc_hypercall_buffer_alloc(xch, arg, sizeof(*arg));
+    if ( arg == NULL )
+        return -1;
+
+    arg->version = HVMOP_ALTP2M_INTERFACE_VERSION;
+    arg->cmd = HVMOP_altp2m_set_mem_access_multi;
+    arg->domain = domid;
+    arg->u.set_mem_access_multi.view = view_id;
+    arg->u.set_mem_access_multi.nr = nr;
+
+    if ( xc_hypercall_bounce_pre(xch, pages) ||
+         xc_hypercall_bounce_pre(xch, access) )
+    {
+        PERROR("Could not bounce memory for HVMOP_altp2m_set_mem_access_multi");
+        return -1;
+    }
+
+    set_xen_guest_handle(arg->u.set_mem_access_multi.pfn_list, pages);
+    set_xen_guest_handle(arg->u.set_mem_access_multi.access_list, access);
+
+    rc = xencall2(xch->xcall, __HYPERVISOR_hvm_op, HVMOP_altp2m,
+		  HYPERCALL_BUFFER_AS_ARG(arg));
+
+    xc_hypercall_buffer_free(xch, arg);
+    xc_hypercall_bounce_post(xch, access);
+    xc_hypercall_bounce_post(xch, pages);
+
+    return rc;
+}
+
 int xc_altp2m_change_gfn(xc_interface *handle, domid_t domid,
                          uint16_t view_id, xen_pfn_t old_gfn,
                          xen_pfn_t new_gfn)
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 205b4cb..1f4358c 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -73,6 +73,8 @@
 #include <public/arch-x86/cpuid.h>
 #include <asm/cpuid.h>
 
+#include <compat/hvm/hvm_op.h>
+
 bool_t __read_mostly hvm_enabled;
 
 #ifdef DBG_LEVEL_0
@@ -4451,6 +4453,7 @@ static int do_altp2m_op(
     case HVMOP_altp2m_destroy_p2m:
     case HVMOP_altp2m_switch_p2m:
     case HVMOP_altp2m_set_mem_access:
+    case HVMOP_altp2m_set_mem_access_multi:
     case HVMOP_altp2m_change_gfn:
         break;
     default:
@@ -4568,6 +4571,30 @@ static int do_altp2m_op(
                                     a.u.set_mem_access.view);
         break;
 
+    case HVMOP_altp2m_set_mem_access_multi:
+        if ( a.u.set_mem_access_multi.pad ||
+             a.u.set_mem_access_multi.opaque >= a.u.set_mem_access_multi.nr )
+        {
+            rc = -EINVAL;
+            break;
+        }
+        rc = p2m_set_mem_access_multi(d, a.u.set_mem_access_multi.pfn_list,
+                                      a.u.set_mem_access_multi.access_list,
+                                      a.u.set_mem_access_multi.nr,
+                                      a.u.set_mem_access_multi.opaque,
+                                      MEMOP_CMD_MASK,
+                                      a.u.set_mem_access_multi.view);
+        if ( rc > 0 )
+        {
+            a.u.set_mem_access_multi.opaque = rc;
+            if ( __copy_to_guest(arg, &a, 1) )
+                rc = -EFAULT;
+            else
+                rc = hypercall_create_continuation(__HYPERVISOR_hvm_op, "lh",
+                                                   HVMOP_altp2m, arg);
+        }
+        break;
+
     case HVMOP_altp2m_change_gfn:
         if ( a.u.change_gfn.pad1 || a.u.change_gfn.pad2 )
             rc = -EINVAL;
@@ -4586,6 +4613,53 @@ static int do_altp2m_op(
     return rc;
 }
 
+static int compat_altp2m_op(
+    XEN_GUEST_HANDLE_PARAM(void) arg)
+{
+    struct compat_hvm_altp2m_op a;
+    union
+    {
+        XEN_GUEST_HANDLE_PARAM(void) hnd;
+        struct xen_hvm_altp2m_op *altp2m_op;
+    } nat;
+
+    if ( !hvm_altp2m_supported() )
+        return -EOPNOTSUPP;
+
+    if ( copy_from_guest(&a, arg, 1) )
+        return -EFAULT;
+
+    if ( a.pad1 || a.pad2 ||
+         (a.version != HVMOP_ALTP2M_INTERFACE_VERSION) )
+        return -EINVAL;
+
+    set_xen_guest_handle(nat.hnd, COMPAT_ARG_XLAT_VIRT_BASE);
+
+    switch ( a.cmd )
+    {
+        case HVMOP_altp2m_set_mem_access_multi:
+#define XLAT_hvm_altp2m_set_mem_access_multi_HNDL_pfn_list(_d_, _s_); \
+            guest_from_compat_handle((_d_)->pfn_list, (_s_)->pfn_list)
+#define XLAT_hvm_altp2m_set_mem_access_multi_HNDL_access_list(_d_, _s_); \
+            guest_from_compat_handle((_d_)->access_list, (_s_)->access_list)
+            XLAT_hvm_altp2m_set_mem_access_multi(&nat.altp2m_op->u.set_mem_access_multi,
+                    &a.u.set_mem_access_multi);
+#undef XLAT_hvm_altp2m_set_mem_access_multi_HNDL_pfn_list
+#undef XLAT_hvm_altp2m_set_mem_access_multi_HNDL_access_list
+            break;
+        default:
+            return do_altp2m_op(arg);
+    }
+
+    nat.altp2m_op->version  = a.version;
+    nat.altp2m_op->cmd      = a.cmd;
+    nat.altp2m_op->domain   = a.domain;
+    nat.altp2m_op->pad1     = a.pad1;
+    nat.altp2m_op->pad2     = a.pad2;
+
+    return do_altp2m_op(nat.hnd);
+}
+
 static int hvmop_get_mem_type(
     XEN_GUEST_HANDLE_PARAM(xen_hvm_get_mem_type_t) arg)
 {
@@ -4733,7 +4807,7 @@ long do_hvm_op(unsigned long op, XEN_GUEST_HANDLE_PARAM(void) arg)
         break;
 
     case HVMOP_altp2m:
-        rc = do_altp2m_op(arg);
+        rc = ( current->hcall_compat ) ? compat_altp2m_op(arg) : do_altp2m_op(arg);
         break;
 
     default:
diff --git a/xen/include/Makefile b/xen/include/Makefile
index c90fdee..814b0a8 100644
--- a/xen/include/Makefile
+++ b/xen/include/Makefile
@@ -28,6 +28,7 @@ headers-$(CONFIG_X86)     += compat/arch-x86/xen.h
 headers-$(CONFIG_X86)     += compat/arch-x86/xen-$(compat-arch-y).h
 headers-$(CONFIG_X86)     += compat/hvm/hvm_vcpu.h
 headers-$(CONFIG_X86)     += compat/hvm/dm_op.h
+headers-$(CONFIG_X86)     += compat/hvm/hvm_op.h
 headers-y                 += compat/arch-$(compat-arch-y).h compat/pmu.h compat/xlat.h
 headers-$(CONFIG_FLASK)   += compat/xsm/flask_op.h
 
diff --git a/xen/include/public/hvm/hvm_op.h b/xen/include/public/hvm/hvm_op.h
index 0bdafdf..bedce71 100644
--- a/xen/include/public/hvm/hvm_op.h
+++ b/xen/include/public/hvm/hvm_op.h
@@ -237,6 +237,23 @@ struct xen_hvm_altp2m_set_mem_access {
 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);
 
+struct xen_hvm_altp2m_set_mem_access_multi {
+    /* view */
+    uint16_t view;
+    uint16_t pad;
+    /* Number of pages */
+    uint32_t nr;
+    /* Used for continuation purposes */
+    uint64_t opaque;
+    /* List of pfns to set access for */
+    XEN_GUEST_HANDLE(const_uint64) pfn_list;
+    /* Corresponding list of access settings for pfn_list */
+    XEN_GUEST_HANDLE(const_uint8) access_list;
+};
+typedef struct xen_hvm_altp2m_set_mem_access_multi
+    xen_hvm_altp2m_set_mem_access_multi_t;
+DEFINE_XEN_GUEST_HANDLE(xen_hvm_altp2m_set_mem_access_multi_t);
+
 struct xen_hvm_altp2m_change_gfn {
     /* view */
     uint16_t view;
@@ -268,15 +285,18 @@ struct xen_hvm_altp2m_op {
 #define HVMOP_altp2m_set_mem_access       7
 /* Change a p2m entry to have a different gfn->mfn mapping */
 #define HVMOP_altp2m_change_gfn           8
+/* Set access for an array of pages */
+#define HVMOP_altp2m_set_mem_access_multi 9
     domid_t domain;
     uint16_t pad1;
     uint32_t pad2;
     union {
-        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_change_gfn         change_gfn;
+        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_change_gfn           change_gfn;
+        struct xen_hvm_altp2m_set_mem_access_multi set_mem_access_multi;
         uint8_t pad[64];
     } u;
 };
diff --git a/xen/include/xlat.lst b/xen/include/xlat.lst
index 0f17000..750d199 100644
--- a/xen/include/xlat.lst
+++ b/xen/include/xlat.lst
@@ -73,6 +73,7 @@
 ?	vcpu_hvm_context		hvm/hvm_vcpu.h
 ?	vcpu_hvm_x86_32			hvm/hvm_vcpu.h
 ?	vcpu_hvm_x86_64			hvm/hvm_vcpu.h
+!	hvm_altp2m_set_mem_access_multi	hvm/hvm_op.h
 ?	kexec_exec			kexec.h
 !	kexec_image			kexec.h
 !	kexec_range			kexec.h
diff --git a/xen/tools/compat-build-header.py b/xen/tools/compat-build-header.py
index 32421b6..12b7a6c 100755
--- a/xen/tools/compat-build-header.py
+++ b/xen/tools/compat-build-header.py
@@ -16,6 +16,7 @@ pats = [
  [ r"(8|16|32|64)_compat_t([^\w]|$)", r"\1_t\2" ],
  [ r"(^|[^\w])xen_?(\w*)_compat_t([^\w]|$$)", r"\1compat_\2_t\3" ],
  [ r"(^|[^\w])XEN_?", r"\1COMPAT_" ],
+ [ r"(^|[^\w])HVMMEM_?", r"\1COMPAT_HVMMEM_" ],
  [ r"(^|[^\w])Xen_?", r"\1Compat_" ],
  [ r"(^|[^\w])long([^\w]|$$)", r"\1int\2" ]
 ];
-- 
2.7.4


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