diff mbox

[v3,2/2] x86/altp2m: Add a hvmop for setting the suppress #VE bit

Message ID 20170718152547.14006-3-apop@bitdefender.com (mailing list archive)
State New, archived
Headers show

Commit Message

Adrian Pop July 18, 2017, 3:25 p.m. UTC
Introduce a new hvmop, HVMOP_altp2m_set_suppress_ve, which allows a
privileged domain to change the value of the #VE suppress bit for a
page.

Add a libxc wrapper for invoking this hvmop.

Signed-off-by: Adrian Pop <apop@bitdefender.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
---
changes in v3:
- fix indentation (Wei Liu)
- use return values other than EINVAL where appropriate (Ian Beulich)
- remove the irrelevant comments from the
  xen_hvm_altp2m_set_suppress_ve struct (Ian Beulich)
- add comment for the suppress_ve field in the struct above (Ian
  Beulich)
- remove the typedef and DEFINE_XEN_GUEST_HANDLE for
  xen_hvm_altp2m_set_suppress_ve (Ian Beulich)
- use XSM_DM_PRIV check instead of domain->is_privileged (Ian Beulich)

changes in v2:
- check if #VE has been enabled on the target domain (Tamas K Lengyel)
- check if the cpu has the #VE feature
- make the suppress_ve argument boolean (Jan Beulich)
- initialize only local variables that need initializing (Jan Beulich)
- use fewer local variables (Jan Beulich)
- fix indentation (Jan Beulich)
- remove unnecessary braces (Jan Beulich)
- use gfn_lock() instead of p2m_lock() in the non-altp2m case (Jan
  Beulich)
- allow only privileged domains to use this hvmop
- merge patch #2 and patch #3 (Jan Beulich)
---
 tools/libxc/include/xenctrl.h   |  2 ++
 tools/libxc/xc_altp2m.c         | 24 +++++++++++++++++++
 xen/arch/x86/hvm/hvm.c          | 14 +++++++++++
 xen/arch/x86/mm/mem_access.c    | 53 +++++++++++++++++++++++++++++++++++++++++
 xen/include/public/hvm/hvm_op.h | 11 +++++++++
 xen/include/xen/mem_access.h    |  3 +++
 6 files changed, 107 insertions(+)

Comments

Tamas K Lengyel July 18, 2017, 5:19 p.m. UTC | #1
On Tue, Jul 18, 2017 at 9:25 AM, Adrian Pop <apop@bitdefender.com> wrote:
> Introduce a new hvmop, HVMOP_altp2m_set_suppress_ve, which allows a
> privileged domain to change the value of the #VE suppress bit for a
> page.
>
> Add a libxc wrapper for invoking this hvmop.
>
> Signed-off-by: Adrian Pop <apop@bitdefender.com>
> Acked-by: Wei Liu <wei.liu2@citrix.com>

Acked-by: Tamas K Lengyel <tamas@tklengyel.com>
Adrian Pop July 19, 2017, 11:47 a.m. UTC | #2
On Tue, Jul 18, 2017 at 11:19:07AM -0600, Tamas K Lengyel wrote:
> On Tue, Jul 18, 2017 at 9:25 AM, Adrian Pop <apop@bitdefender.com> wrote:
> > Introduce a new hvmop, HVMOP_altp2m_set_suppress_ve, which allows a
> > privileged domain to change the value of the #VE suppress bit for a
> > page.
> >
> > Add a libxc wrapper for invoking this hvmop.
> >
> > Signed-off-by: Adrian Pop <apop@bitdefender.com>
> > Acked-by: Wei Liu <wei.liu2@citrix.com>
> 
> Acked-by: Tamas K Lengyel <tamas@tklengyel.com>

Thanks!
diff mbox

Patch

diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
index 552a4fd47d..ea985696e4 100644
--- a/tools/libxc/include/xenctrl.h
+++ b/tools/libxc/include/xenctrl.h
@@ -1938,6 +1938,8 @@  int xc_altp2m_destroy_view(xc_interface *handle, domid_t domid,
 /* Switch all vCPUs of the domain to the specified altp2m view */
 int xc_altp2m_switch_to_view(xc_interface *handle, domid_t domid,
                              uint16_t view_id);
+int xc_altp2m_set_suppress_ve(xc_interface *handle, domid_t domid,
+                              uint16_t view_id, xen_pfn_t gfn, bool sve);
 int xc_altp2m_set_mem_access(xc_interface *handle, domid_t domid,
                              uint16_t view_id, xen_pfn_t gfn,
                              xenmem_access_t access);
diff --git a/tools/libxc/xc_altp2m.c b/tools/libxc/xc_altp2m.c
index 0639632477..26e3a56fb1 100644
--- a/tools/libxc/xc_altp2m.c
+++ b/tools/libxc/xc_altp2m.c
@@ -163,6 +163,30 @@  int xc_altp2m_switch_to_view(xc_interface *handle, domid_t domid,
     return rc;
 }
 
+int xc_altp2m_set_suppress_ve(xc_interface *handle, domid_t domid,
+                              uint16_t view_id, xen_pfn_t gfn, bool sve)
+{
+    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_set_suppress_ve;
+    arg->domain = domid;
+    arg->u.set_suppress_ve.view = view_id;
+    arg->u.set_suppress_ve.gfn = gfn;
+    arg->u.set_suppress_ve.suppress_ve = sve;
+
+    rc = xencall2(handle->xcall, __HYPERVISOR_hvm_op, HVMOP_altp2m,
+                  HYPERCALL_BUFFER_AS_ARG(arg));
+
+    xc_hypercall_buffer_free(handle, arg);
+    return rc;
+}
+
 int xc_altp2m_set_mem_access(xc_interface *handle, domid_t domid,
                              uint16_t view_id, xen_pfn_t gfn,
                              xenmem_access_t access)
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 8145385747..b7ea945f78 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -4413,6 +4413,7 @@  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_suppress_ve:
     case HVMOP_altp2m_change_gfn:
         break;
     default:
@@ -4530,6 +4531,19 @@  static int do_altp2m_op(
                                     a.u.set_mem_access.view);
         break;
 
+    case HVMOP_altp2m_set_suppress_ve:
+        if ( a.u.set_suppress_ve.pad1 || a.u.set_suppress_ve.pad2 )
+            rc = -EINVAL;
+        else
+        {
+            gfn_t gfn = _gfn(a.u.set_mem_access.gfn);
+            unsigned int altp2m_idx = a.u.set_mem_access.view;
+            bool suppress_ve = a.u.set_suppress_ve.suppress_ve;
+
+            rc = p2m_set_suppress_ve(d, gfn, suppress_ve, altp2m_idx);
+        }
+        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 d0b0767855..87a92a632b 100644
--- a/xen/arch/x86/mm/mem_access.c
+++ b/xen/arch/x86/mm/mem_access.c
@@ -29,6 +29,7 @@ 
 #include <asm/p2m.h>
 #include <asm/altp2m.h>
 #include <asm/vm_event.h>
+#include <xsm/xsm.h>
 
 #include "mm-locks.h"
 
@@ -466,6 +467,58 @@  int p2m_get_mem_access(struct domain *d, gfn_t gfn, xenmem_access_t *access)
 }
 
 /*
+ * Set/clear the #VE suppress bit for a page.  Only available on VMX.
+ */
+int p2m_set_suppress_ve(struct domain *d, gfn_t gfn, bool suppress_ve,
+                        unsigned int altp2m_idx)
+{
+    struct p2m_domain *host_p2m = p2m_get_hostp2m(d);
+    struct p2m_domain *ap2m = NULL;
+    struct p2m_domain *p2m;
+    mfn_t mfn;
+    p2m_access_t a;
+    p2m_type_t t;
+    int rc;
+
+    if ( !cpu_has_vmx_virt_exceptions )
+        return -EOPNOTSUPP;
+
+    /* This subop should only be used from a privileged domain. */
+    if ( xsm_dm_op(XSM_DM_PRIV, d) )
+        return -EPERM;
+
+    /* #VE should be enabled for this vcpu. */
+    if ( gfn_eq(vcpu_altp2m(current).veinfo_gfn, INVALID_GFN) )
+        return -ENXIO;
+
+    if ( altp2m_idx > 0 )
+    {
+        if ( altp2m_idx >= MAX_ALTP2M ||
+             d->arch.altp2m_eptp[altp2m_idx] == mfn_x(INVALID_MFN) )
+            return -EINVAL;
+
+        p2m = ap2m = d->arch.altp2m_p2m[altp2m_idx];
+    }
+    else
+        p2m = host_p2m;
+
+    gfn_lock(host_p2m, gfn, 0);
+    if ( ap2m )
+        p2m_lock(ap2m);
+
+    mfn = p2m->get_entry(p2m, gfn_x(gfn), &t, &a, 0, NULL, NULL);
+    if ( !mfn_valid(mfn) )
+        return -ESRCH;
+    rc = p2m->set_entry(p2m, gfn_x(gfn), mfn, PAGE_ORDER_4K, t, a,
+                        suppress_ve);
+    if ( ap2m )
+        p2m_unlock(ap2m);
+    gfn_unlock(host_p2m, gfn, 0);
+
+    return rc;
+}
+
+/*
  * Local variables:
  * mode: C
  * c-file-style: "BSD"
diff --git a/xen/include/public/hvm/hvm_op.h b/xen/include/public/hvm/hvm_op.h
index 0bdafdf59a..16983a8f4e 100644
--- a/xen/include/public/hvm/hvm_op.h
+++ b/xen/include/public/hvm/hvm_op.h
@@ -237,6 +237,14 @@  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_suppress_ve {
+    uint16_t view;
+    uint8_t suppress_ve; /* Boolean type. */
+    uint8_t pad1;
+    uint32_t pad2;
+    uint64_t gfn;
+};
+
 struct xen_hvm_altp2m_change_gfn {
     /* view */
     uint16_t view;
@@ -268,6 +276,8 @@  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 the "Suppress #VE" bit on a page */
+#define HVMOP_altp2m_set_suppress_ve      9
     domid_t domain;
     uint16_t pad1;
     uint32_t pad2;
@@ -276,6 +286,7 @@  struct xen_hvm_altp2m_op {
         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_set_suppress_ve    set_suppress_ve;
         struct xen_hvm_altp2m_change_gfn         change_gfn;
         uint8_t pad[64];
     } u;
diff --git a/xen/include/xen/mem_access.h b/xen/include/xen/mem_access.h
index 5ab34c1553..0c6717d80f 100644
--- a/xen/include/xen/mem_access.h
+++ b/xen/include/xen/mem_access.h
@@ -78,6 +78,9 @@  long p2m_set_mem_access_multi(struct domain *d,
  */
 int p2m_get_mem_access(struct domain *d, gfn_t gfn, xenmem_access_t *access);
 
+int p2m_set_suppress_ve(struct domain *d, gfn_t gfn, bool suppress_ve,
+                        unsigned int altp2m_idx);
+
 #ifdef CONFIG_HAS_MEM_ACCESS
 int mem_access_memop(unsigned long cmd,
                      XEN_GUEST_HANDLE_PARAM(xen_mem_access_op_t) arg);