For clarity this patch breaks the code to set/get memory types out
of do_hvm_op() into dedicated functions: hvmop_set/get_mem_type().
Also, for clarity, checks for whether a memory type change is allowed
are broken out into a separate function called by hvmop_set_mem_type().
There is no intentional functional change in this patch.
changes in v3:
- Add Andrew's Acked-by and George's Reviewed-by.
changes in v2:
- According to George Dunlap's comments, follow the "set rc /
do something / goto out" pattern in hvmop_get_mem_type().
Signed-off-by: Paul Durrant <paul.durr...@citrix.com>
Signed-off-by: Yu Zhang <yu.c.zh...@linux.intel.com>
Reviewed-by: George Dunlap <george.dun...@citrix.com>
Acked-by: Andrew Cooper <andrew.coop...@citrix.com>
Cc: Keir Fraser <k...@xen.org>
Cc: Jan Beulich <jbeul...@suse.com>
Cc: Andrew Cooper <andrew.coop...@citrix.com>
---
xen/arch/x86/hvm/hvm.c | 288 +++++++++++++++++++++++++++----------------------
1 file changed, 161 insertions(+), 127 deletions(-)
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 874cb0f..607546c 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -5279,6 +5279,61 @@ static int do_altp2m_op(
return rc;
}
+static int hvmop_get_mem_type(
+ XEN_GUEST_HANDLE_PARAM(xen_hvm_get_mem_type_t) arg)
+{
+ struct xen_hvm_get_mem_type a;
+ struct domain *d;
+ p2m_type_t t;
+ int rc;
+
+ if ( copy_from_guest(&a, arg, 1) )
+ return -EFAULT;
+
+ d = rcu_lock_domain_by_any_id(a.domid);
+ if ( d == NULL )
+ return -ESRCH;
+
+ rc = xsm_hvm_param(XSM_TARGET, d, HVMOP_get_mem_type);
+ if ( rc )
+ goto out;
+
+ rc = -EINVAL;
+ if ( !is_hvm_domain(d) )
+ goto out;
+
+ /*
+ * Use get_gfn query as we are interested in the current
+ * type, not in allocating or unsharing. That'll happen
+ * on access.
+ */
+ get_gfn_query_unlocked(d, a.pfn, &t);
+ if ( p2m_is_mmio(t) )
+ a.mem_type = HVMMEM_mmio_dm;
+ else if ( t == p2m_ioreq_server )
+ a.mem_type = HVMMEM_ioreq_server;
+ else if ( p2m_is_readonly(t) )
+ a.mem_type = HVMMEM_ram_ro;
+ else if ( p2m_is_ram(t) )
+ a.mem_type = HVMMEM_ram_rw;
+ else if ( p2m_is_pod(t) )
+ a.mem_type = HVMMEM_ram_rw;
+ else if ( p2m_is_grant(t) )
+ a.mem_type = HVMMEM_ram_rw;
+ else
+ a.mem_type = HVMMEM_mmio_dm;
+
+ rc = -EFAULT;
+ if ( __copy_to_guest(arg, &a, 1) )
+ goto out;
+ rc = 0;
+
+ out:
+ rcu_unlock_domain(d);
+
+ return rc;
+}
+
/*
* Note that this value is effectively part of the ABI, even if we don't need
* to make it a formal part of it: A guest suspended for migration in the
@@ -5287,6 +5342,107 @@ static int do_altp2m_op(
*/
#define HVMOP_op_mask 0xff
+static bool_t hvm_allow_p2m_type_change(p2m_type_t old, p2m_type_t new)
+{
+ if ( p2m_is_ram(old) ||
+ (p2m_is_hole(old) && new == p2m_mmio_dm) ||
+ (old == p2m_ioreq_server && new == p2m_ram_rw) )
+ return 1;
+
+ return 0;
+}
+
+static int hvmop_set_mem_type(
+ XEN_GUEST_HANDLE_PARAM(xen_hvm_set_mem_type_t) arg,
+ unsigned long *iter)
+{
+ unsigned long start_iter = *iter;
+ struct xen_hvm_set_mem_type a;
+ struct domain *d;
+ int rc;
+
+ /* Interface types to internal p2m types */
+ static const p2m_type_t memtype[] = {
+ [HVMMEM_ram_rw] = p2m_ram_rw,
+ [HVMMEM_ram_ro] = p2m_ram_ro,
+ [HVMMEM_mmio_dm] = p2m_mmio_dm,
+ [HVMMEM_unused] = p2m_invalid,
+ [HVMMEM_ioreq_server] = p2m_ioreq_server
+ };
+
+ if ( copy_from_guest(&a, arg, 1) )
+ return -EFAULT;
+
+ rc = rcu_lock_remote_domain_by_id(a.domid, &d);
+ if ( rc != 0 )
+ return rc;
+
+ rc = -EINVAL;
+ if ( !is_hvm_domain(d) )
+ goto out;
+
+ rc = xsm_hvm_control(XSM_DM_PRIV, d, HVMOP_set_mem_type);
+ if ( rc )
+ goto out;
+
+ rc = -EINVAL;
+ if ( a.nr < start_iter ||
+ ((a.first_pfn + a.nr - 1) < a.first_pfn) ||
+ ((a.first_pfn + a.nr - 1) > domain_get_maximum_gpfn(d)) )
+ goto out;
+
+ if ( a.hvmmem_type >= ARRAY_SIZE(memtype) ||
+ unlikely(a.hvmmem_type == HVMMEM_unused) )
+ goto out;
+
+ while ( a.nr > start_iter )
+ {
+ unsigned long pfn = a.first_pfn + start_iter;
+ p2m_type_t t;
+
+ get_gfn_unshare(d, pfn, &t);
+ if ( p2m_is_paging(t) )
+ {
+ put_gfn(d, pfn);
+ p2m_mem_paging_populate(d, pfn);
+ rc = -EAGAIN;
+ goto out;
+ }
+ if ( p2m_is_shared(t) )
+ {
+ put_gfn(d, pfn);
+ rc = -EAGAIN;
+ goto out;
+ }
+ if ( !hvm_allow_p2m_type_change(t, memtype[a.hvmmem_type]) )
+ {
+ put_gfn(d, pfn);
+ goto out;
+ }
+
+ rc = p2m_change_type_one(d, pfn, t, memtype[a.hvmmem_type]);
+ put_gfn(d, pfn);
+
+ if ( rc )
+ goto out;
+
+ /* Check for continuation if it's not the last interation */
+ if ( a.nr > ++start_iter && !(start_iter & HVMOP_op_mask) &&
+ hypercall_preempt_check() )
+ {
+ rc = -ERESTART;
+ goto out;
+ }
+ }
+ rc = 0;
+
+ out:
+ rcu_unlock_domain(d);
+ *iter = start_iter;
+
+ return rc;
+}
+
long do_hvm_op(unsigned long op, XEN_GUEST_HANDLE_PARAM(void) arg)
{
unsigned long start_iter, mask;
@@ -5476,137 +5632,15 @@ long do_hvm_op(unsigned long op,
XEN_GUEST_HANDLE_PARAM(void) arg)
}
case HVMOP_get_mem_type:
- {
- struct xen_hvm_get_mem_type a;
- struct domain *d;
- p2m_type_t t;
-
- if ( copy_from_guest(&a, arg, 1) )
- return -EFAULT;
-
- d = rcu_lock_domain_by_any_id(a.domid);
- if ( d == NULL )
- return -ESRCH;
-
- rc = xsm_hvm_param(XSM_TARGET, d, op);
- if ( unlikely(rc) )
- /* nothing */;
- else if ( likely(is_hvm_domain(d)) )
- {
- /* Use get_gfn query as we are interested in the current
- * type, not in allocating or unsharing. That'll happen
- * on access. */
- get_gfn_query_unlocked(d, a.pfn, &t);
- if ( p2m_is_mmio(t) )
- a.mem_type = HVMMEM_mmio_dm;
- else if ( t == p2m_ioreq_server )
- a.mem_type = HVMMEM_ioreq_server;
- else if ( p2m_is_readonly(t) )
- a.mem_type = HVMMEM_ram_ro;
- else if ( p2m_is_ram(t) )
- a.mem_type = HVMMEM_ram_rw;
- else if ( p2m_is_pod(t) )
- a.mem_type = HVMMEM_ram_rw;
- else if ( p2m_is_grant(t) )
- a.mem_type = HVMMEM_ram_rw;
- else
- a.mem_type = HVMMEM_mmio_dm;
- if ( __copy_to_guest(arg, &a, 1) )
- rc = -EFAULT;
- }
- else
- rc = -EINVAL;
-
- rcu_unlock_domain(d);
+ rc = hvmop_get_mem_type(
+ guest_handle_cast(arg, xen_hvm_get_mem_type_t));
break;
- }
case HVMOP_set_mem_type:
- {
- struct xen_hvm_set_mem_type a;
- struct domain *d;
-
- /* Interface types to internal p2m types */
- static const p2m_type_t memtype[] = {
- [HVMMEM_ram_rw] = p2m_ram_rw,
- [HVMMEM_ram_ro] = p2m_ram_ro,
- [HVMMEM_mmio_dm] = p2m_mmio_dm,
- [HVMMEM_unused] = p2m_invalid,
- [HVMMEM_ioreq_server] = p2m_ioreq_server
- };
-
- if ( copy_from_guest(&a, arg, 1) )
- return -EFAULT;
-
- rc = rcu_lock_remote_domain_by_id(a.domid, &d);
- if ( rc != 0 )
- return rc;
-
- rc = -EINVAL;
- if ( !is_hvm_domain(d) )
- goto setmemtype_fail;
-
- rc = xsm_hvm_control(XSM_DM_PRIV, d, op);
- if ( rc )
- goto setmemtype_fail;
-
- rc = -EINVAL;
- if ( a.nr < start_iter ||
- ((a.first_pfn + a.nr - 1) < a.first_pfn) ||
- ((a.first_pfn + a.nr - 1) > domain_get_maximum_gpfn(d)) )
- goto setmemtype_fail;
-
- if ( a.hvmmem_type >= ARRAY_SIZE(memtype) ||
- unlikely(a.hvmmem_type == HVMMEM_unused) )
- goto setmemtype_fail;
-
- while ( a.nr > start_iter )
- {
- unsigned long pfn = a.first_pfn + start_iter;
- p2m_type_t t;
-
- get_gfn_unshare(d, pfn, &t);
- if ( p2m_is_paging(t) )
- {
- put_gfn(d, pfn);
- p2m_mem_paging_populate(d, pfn);
- rc = -EAGAIN;
- goto setmemtype_fail;
- }
- if ( p2m_is_shared(t) )
- {
- put_gfn(d, pfn);
- rc = -EAGAIN;
- goto setmemtype_fail;
- }
- if ( !p2m_is_ram(t) &&
- (!p2m_is_hole(t) || a.hvmmem_type != HVMMEM_mmio_dm) &&
- (t != p2m_ioreq_server || a.hvmmem_type != HVMMEM_ram_rw) )
- {
- put_gfn(d, pfn);
- goto setmemtype_fail;
- }
-
- rc = p2m_change_type_one(d, pfn, t, memtype[a.hvmmem_type]);
- put_gfn(d, pfn);
- if ( rc )
- goto setmemtype_fail;
-
- /* Check for continuation if it's not the last interation */
- if ( a.nr > ++start_iter && !(start_iter & HVMOP_op_mask) &&
- hypercall_preempt_check() )
- {
- rc = -ERESTART;
- goto setmemtype_fail;
- }
- }
-
- rc = 0;
-
- setmemtype_fail:
- rcu_unlock_domain(d);
+ rc = hvmop_set_mem_type(
+ guest_handle_cast(arg, xen_hvm_set_mem_type_t),
+ &start_iter);
break;
- }
case HVMOP_pagetable_dying:
{
--
1.9.1
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