Allow altp2m users to disable #VE/VMFUNC alone. Currently it is
only possible to disable this functionality when we disable altp2m
completely; #VE/VMFUNC can only be enabled once per altp2m session.
In addition to making things complete, disabling #VE is also a
workaround for CFW116 ("When Virtualization Exceptions are Enabled,
EPT Violations May Generate Erroneous Virtualization Exceptions")
on Xeon E-2100 CPUs.
Signed-off-by: Razvan Cojocaru
---
Changes since V1:
- Updated the patch description to specify E-2100.
- Made trying to disable #VE when it's already disabled a no-op.
- Removed leftover uint32_t pad; from struct
xen_hvm_altp2m_vcpu_disable_notify.
---
tools/libxc/include/xenctrl.h | 2 ++
tools/libxc/xc_altp2m.c | 22 ++
xen/arch/x86/hvm/hvm.c | 29 +
xen/include/public/hvm/hvm_op.h | 11 ++-
4 files changed, 63 insertions(+), 1 deletion(-)
diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
index 97ae965..31cdda7 100644
--- a/tools/libxc/include/xenctrl.h
+++ b/tools/libxc/include/xenctrl.h
@@ -1932,6 +1932,8 @@ int xc_altp2m_get_domain_state(xc_interface *handle,
uint32_t dom, bool *state);
int xc_altp2m_set_domain_state(xc_interface *handle, uint32_t dom, bool state);
int xc_altp2m_set_vcpu_enable_notify(xc_interface *handle, uint32_t domid,
uint32_t vcpuid, xen_pfn_t gfn);
+int xc_altp2m_set_vcpu_disable_notify(xc_interface *handle, uint32_t domid,
+ uint32_t vcpuid);
int xc_altp2m_create_view(xc_interface *handle, uint32_t domid,
xenmem_access_t default_access, uint16_t *view_id);
int xc_altp2m_destroy_view(xc_interface *handle, uint32_t domid,
diff --git a/tools/libxc/xc_altp2m.c b/tools/libxc/xc_altp2m.c
index 844b9f1..f8cd603 100644
--- a/tools/libxc/xc_altp2m.c
+++ b/tools/libxc/xc_altp2m.c
@@ -91,6 +91,28 @@ int xc_altp2m_set_vcpu_enable_notify(xc_interface *handle,
uint32_t domid,
return rc;
}
+int xc_altp2m_set_vcpu_disable_notify(xc_interface *handle, uint32_t domid,
+ uint32_t vcpuid)
+{
+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_vcpu_disable_notify;
+arg->domain = domid;
+arg->u.disable_notify.vcpu_id = vcpuid;
+
+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_create_view(xc_interface *handle, uint32_t domid,
xenmem_access_t default_access, uint16_t *view_id)
{
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index d64b6b6..424e4d1 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -4485,6 +4485,7 @@ static int do_altp2m_op(
case HVMOP_altp2m_get_domain_state:
case HVMOP_altp2m_set_domain_state:
case HVMOP_altp2m_vcpu_enable_notify:
+case HVMOP_altp2m_vcpu_disable_notify:
case HVMOP_altp2m_create_p2m:
case HVMOP_altp2m_destroy_p2m:
case HVMOP_altp2m_switch_p2m:
@@ -4602,6 +4603,34 @@ static int do_altp2m_op(
break;
}
+case HVMOP_altp2m_vcpu_disable_notify:
+{
+struct vcpu *v;
+
+if ( a.u.disable_notify.pad ||
+ a.u.disable_notify.vcpu_id >= d->max_vcpus )
+{
+rc = -EINVAL;
+break;
+}
+
+if ( !cpu_has_vmx_virt_exceptions )
+{
+rc = -EOPNOTSUPP;
+break;
+}
+
+v = d->vcpu[a.u.enable_notify.vcpu_id];
+
+/* Already disabled, nothing to do. */
+if ( gfn_eq(vcpu_altp2m(v).veinfo_gfn, INVALID_GFN) )
+break;
+
+vcpu_altp2m(v).veinfo_gfn = INVALID_GFN;
+altp2m_vcpu_update_vmfunc_ve(v);
+break;
+}
+
case HVMOP_altp2m_create_p2m:
if ( !(rc = p2m_init_next_altp2m(d, )) )
rc = __copy_to_guest(arg, , 1) ? -EFAULT : 0;
diff --git a/xen/include/public/hvm/hvm_op.h b/xen/include/public/hvm/hvm_op.h
index 5878a25..c6cd12f 100644
--- a/xen/include/public/hvm/hvm_op.h
+++ b/xen/include/public/hvm/hvm_op.h
@@ -232,6 +232,12 @@ struct xen_hvm_altp2m_vcpu_enable_notify {
typedef struct xen_hvm_altp2m_vcpu_enable_notify
xen_hvm_altp2m_vcpu_enable_notify_t;
DEFINE_XEN_GUEST_HANDLE(xen_hvm_altp2m_vcpu_enable_notify_t);
+struct xen_hvm_altp2m_vcpu_disable_notify {
+uint32_t vcpu_id;
+};
+typedef struct xen_hvm_altp2m_vcpu_disable_notify
xen_hvm_altp2m_vcpu_disable_notify_t;
+DEFINE_XEN_GUEST_HANDLE(xen_hvm_altp2m_vcpu_disable_notify_t);
+
struct xen_hvm_altp2m_view {
/* IN/OUT variable */
uint16_t view;
@@ -304,7 +310,7 @@ struct
