[Xen-devel] [PATCH 01/11] public / x86: introduce hvmctl hypercall

["Jan Beulich" <JBeulich@xxxxxxxx>]

... as a means to replace all HVMOP_* which a domain can't issue on
itself (i.e. intended for use by only the control domain or device
model).

Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>

--- a/xen/arch/x86/hvm/Makefile
+++ b/xen/arch/x86/hvm/Makefile
@@ -2,6 +2,7 @@ subdir-y += svm
 subdir-y += vmx
 
 obj-y += asid.o
+obj-y += control.o
 obj-y += emulate.o
 obj-y += event.o
 obj-y += hpet.o
--- /dev/null
+++ b/xen/arch/x86/hvm/control.c
@@ -0,0 +1,96 @@
+/*
+ * control.c: Hardware virtual machine control operations.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms and conditions of the GNU General Public License,
+ * version 2, as published by the Free Software Foundation.
+ *
+ * This program is distributed in the hope it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include <xen/hypercall.h>
+#include <xen/guest_access.h>
+#include <xen/sched.h>
+#include <xsm/xsm.h>
+
+/*
+ * Note that this value is effectively part of the ABI, even if we don't need
+ * to make it a formal part of it.  Hence this value may only be changed if
+ * accompanied by a suitable interface version increase.
+ */
+#define HVMCTL_iter_shift 8
+#define HVMCTL_iter_mask  ((1U << HVMCTL_iter_shift) - 1)
+#define HVMCTL_iter_max   (1U << (16 + HVMCTL_iter_shift))
+
+long do_hvmctl(XEN_GUEST_HANDLE_PARAM(xen_hvmctl_t) u_hvmctl)
+{
+    xen_hvmctl_t op;
+    struct domain *d;
+    unsigned int iter;
+    int rc;
+
+    BUILD_BUG_ON(sizeof(op.u) > sizeof(op.u.pad));
+
+    if ( copy_from_guest(&op, u_hvmctl, 1) )
+        return -EFAULT;
+
+    if ( op.interface_version != XEN_HVMCTL_INTERFACE_VERSION )
+        return -EACCES;
+
+    rc = rcu_lock_remote_domain_by_id(op.domain, &d);
+    if ( rc )
+        return rc;
+
+    if ( !has_hvm_container_domain(d) )
+    {
+        rcu_unlock_domain(d);
+        return -EINVAL;
+    }
+
+    rc = xsm_hvm_control(XSM_DM_PRIV, d, op.cmd);
+    if ( rc )
+    {
+        rcu_unlock_domain(d);
+        return rc;
+    }
+
+    iter = op.opaque << HVMCTL_iter_shift;
+
+    switch ( op.cmd )
+    {
+    default:
+        rc = -EOPNOTSUPP;
+        break;
+    }
+
+    rcu_unlock_domain(d);
+
+    if ( rc == -ERESTART )
+    {
+        ASSERT(!(iter & HVMCTL_iter_mask));
+        op.opaque = iter >> HVMCTL_iter_shift;
+        if ( unlikely(copy_field_to_guest(u_hvmctl, &op, opaque)) )
+            rc = -EFAULT;
+        else
+            rc = hypercall_create_continuation(__HYPERVISOR_hvmctl, "h",
+                                               u_hvmctl);
+    }
+
+    return rc;
+}
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -4113,6 +4113,7 @@ static const struct {
     COMPAT_CALL(platform_op),
     COMPAT_CALL(mmuext_op),
     HYPERCALL(xenpmu_op),
+    HYPERCALL(hvmctl),
     HYPERCALL(arch_1)
 };
 
--- a/xen/arch/x86/x86_64/compat/entry.S
+++ b/xen/arch/x86/x86_64/compat/entry.S
@@ -469,6 +469,7 @@ ENTRY(compat_hypercall_table)
         .quad do_tmem_op
         .quad do_ni_hypercall           /* reserved for XenClient */
         .quad do_xenpmu_op              /* 40 */
+        .quad do_hvmctl
         .rept __HYPERVISOR_arch_0-((.-compat_hypercall_table)/8)
         .quad compat_ni_hypercall
         .endr
@@ -520,6 +521,7 @@ ENTRY(compat_hypercall_args_table)
         .byte 1 /* do_tmem_op               */
         .byte 0 /* reserved for XenClient   */
         .byte 2 /* do_xenpmu_op             */  /* 40 */
+        .byte 1 /* do_hvmctl                */
         .rept __HYPERVISOR_arch_0-(.-compat_hypercall_args_table)
         .byte 0 /* compat_ni_hypercall      */
         .endr
--- a/xen/arch/x86/x86_64/entry.S
+++ b/xen/arch/x86/x86_64/entry.S
@@ -791,6 +791,7 @@ ENTRY(hypercall_table)
         .quad do_tmem_op
         .quad do_ni_hypercall       /* reserved for XenClient */
         .quad do_xenpmu_op          /* 40 */
+        .quad do_hvmctl
         .rept __HYPERVISOR_arch_0-((.-hypercall_table)/8)
         .quad do_ni_hypercall
         .endr
@@ -842,6 +843,7 @@ ENTRY(hypercall_args_table)
         .byte 1 /* do_tmem_op           */
         .byte 0 /* reserved for XenClient */
         .byte 2 /* do_xenpmu_op         */  /* 40 */
+        .byte 1 /* do_hvmctl            */
         .rept __HYPERVISOR_arch_0-(.-hypercall_args_table)
         .byte 0 /* do_ni_hypercall      */
         .endr
--- a/xen/include/Makefile
+++ b/xen/include/Makefile
@@ -93,7 +93,7 @@ all: headers.chk headers++.chk
 
 PUBLIC_HEADERS := $(filter-out public/arch-% public/dom0_ops.h, $(wildcard 
public/*.h public/*/*.h) $(public-y))
 
-PUBLIC_ANSI_HEADERS := $(filter-out public/%ctl.h public/xsm/% 
public/%hvm/save.h, $(PUBLIC_HEADERS))
+PUBLIC_ANSI_HEADERS := $(filter-out public/%ctl.h public/hvm/control.h 
public/xsm/% public/%hvm/save.h,$(PUBLIC_HEADERS))
 
 headers.chk: $(PUBLIC_ANSI_HEADERS) Makefile
        for i in $(filter %.h,$^); do \
--- /dev/null
+++ b/xen/include/public/hvm/control.h
@@ -0,0 +1,54 @@
+/*
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to
+ * deal in the Software without restriction, including without limitation the
+ * rights to use, copy, modify, merge, publish, distribute, sublicense, and/or
+ * sell copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
+ * FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
+ * DEALINGS IN THE SOFTWARE.
+ */
+
+#ifndef __XEN_PUBLIC_HVM_CONTROL_H__
+#define __XEN_PUBLIC_HVM_CONTROL_H__
+
+#if !defined(__XEN__) && !defined(__XEN_TOOLS__)
+#error "HVM control operations are intended for use by control tools only"
+#endif
+
+#include "../xen.h"
+
+#define XEN_HVMCTL_INTERFACE_VERSION 0x00000001
+
+struct xen_hvmctl {
+    uint16_t interface_version;    /* XEN_HVMCTL_INTERFACE_VERSION */
+    domid_t domain;
+    uint16_t cmd;
+    uint16_t opaque;               /* Must be zero on initial invocation. */
+    union {
+        uint8_t pad[120];
+    } u;
+};
+typedef struct xen_hvmctl xen_hvmctl_t;
+DEFINE_XEN_GUEST_HANDLE(xen_hvmctl_t);
+
+#endif /* __XEN_PUBLIC_HVM_CONTROL_H__ */
+
+/*
+ * Local variables:
+ * mode: C
+ * c-file-style: "BSD"
+ * c-basic-offset: 4
+ * tab-width: 4
+ * indent-tabs-mode: nil
+ * End:
+ */
--- a/xen/include/public/xen.h
+++ b/xen/include/public/xen.h
@@ -115,6 +115,7 @@ DEFINE_XEN_GUEST_HANDLE(xen_ulong_t);
 #define __HYPERVISOR_tmem_op              38
 #define __HYPERVISOR_xc_reserved_op       39 /* reserved for XenClient */
 #define __HYPERVISOR_xenpmu_op            40
+#define __HYPERVISOR_hvmctl               41
 
 /* Architecture-specific hypercall definitions. */
 #define __HYPERVISOR_arch_0               48
--- a/xen/include/xen/hypercall.h
+++ b/xen/include/xen/hypercall.h
@@ -15,6 +15,7 @@
 #include <public/tmem.h>
 #include <public/version.h>
 #include <public/pmu.h>
+#include <public/hvm/control.h>
 #include <asm/hypercall.h>
 #include <xsm/xsm.h>
 
@@ -46,6 +47,10 @@ arch_do_sysctl(
     XEN_GUEST_HANDLE_PARAM(xen_sysctl_t) u_sysctl);
 
 extern long
+do_hvmctl(
+    XEN_GUEST_HANDLE_PARAM(xen_hvmctl_t) u_hvmctl);
+
+extern long
 do_platform_op(
     XEN_GUEST_HANDLE_PARAM(xen_platform_op_t) u_xenpf_op);
 
--- a/xen/xsm/flask/hooks.c
+++ b/xen/xsm/flask/hooks.c
@@ -1183,6 +1183,20 @@ static int flask_hvm_param(struct domain
     return current_has_perm(d, SECCLASS_HVM, perm);
 }
 
+static int flask_hvm_control(struct domain *d, unsigned long op)
+{
+    u32 perm;
+
+    switch ( op )
+    {
+    default:
+        perm = HVM__HVMCTL;
+        break;
+    }
+
+    return current_has_perm(d, SECCLASS_HVM, perm);
+}
+
 static int flask_hvm_param_nested(struct domain *d)
 {
     return current_has_perm(d, SECCLASS_HVM, HVM__NESTED);
@@ -1745,7 +1759,7 @@ static struct xsm_operations flask_ops =
     .page_offline = flask_page_offline,
     .tmem_op = flask_tmem_op,
     .hvm_param = flask_hvm_param,
-    .hvm_control = flask_hvm_param,
+    .hvm_control = flask_hvm_control,
     .hvm_param_nested = flask_hvm_param_nested,
     .hvm_param_altp2mhvm = flask_hvm_param_altp2mhvm,
     .hvm_altp2mhvm_op = flask_hvm_altp2mhvm_op,

Attachment: hvmctl-intro.patch
Description: Text document

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