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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v3 5/8] dm_op: convert HVMOP_modified_memory
This patch introduces code to handle DMOP continuations.
NOTE: This patch also modifies the type of the 'nr' argument of
xc_hvm_modified_memory() from uint64_t to uint32_t. In practice the
value passed was always truncated to 32 bits.
Suggested-by: Jan Beulich <jbeulich@xxxxxxxx>
Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
---
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Acked-by: Wei Liu <wei.liu2@xxxxxxxxxx>
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Cc: Daniel De Graaf <dgdegra@xxxxxxxxxxxxx>
v3:
- Addressed more comments from Jan.
v2:
- Addressed several comments from Jan, including...
- Added explanatory note on continuation handling
---
tools/libxc/include/xenctrl.h | 2 +-
tools/libxc/xc_misc.c | 27 +++++--------
xen/arch/x86/hvm/dm.c | 78 ++++++++++++++++++++++++++++++++++++-
xen/arch/x86/hvm/hvm.c | 60 ----------------------------
xen/include/public/hvm/dm_op.h | 19 +++++++++
xen/include/public/hvm/hvm_op.h | 13 -------
xen/xsm/flask/policy/access_vectors | 2 +-
7 files changed, 107 insertions(+), 94 deletions(-)
diff --git a/tools/libxc/include/xenctrl.h b/tools/libxc/include/xenctrl.h
index f819bf2..a5c234f 100644
--- a/tools/libxc/include/xenctrl.h
+++ b/tools/libxc/include/xenctrl.h
@@ -1627,7 +1627,7 @@ int xc_hvm_track_dirty_vram(
* Notify that some pages got modified by the Device Model
*/
int xc_hvm_modified_memory(
- xc_interface *xch, domid_t dom, uint64_t first_pfn, uint64_t nr);
+ xc_interface *xch, domid_t dom, uint64_t first_pfn, uint32_t nr);
/*
* Set a range of memory to a specific type.
diff --git a/tools/libxc/xc_misc.c b/tools/libxc/xc_misc.c
index ddea2bb..597df99 100644
--- a/tools/libxc/xc_misc.c
+++ b/tools/libxc/xc_misc.c
@@ -573,29 +573,20 @@ int xc_hvm_track_dirty_vram(
}
int xc_hvm_modified_memory(
- xc_interface *xch, domid_t dom, uint64_t first_pfn, uint64_t nr)
+ xc_interface *xch, domid_t dom, uint64_t first_pfn, uint32_t nr)
{
- DECLARE_HYPERCALL_BUFFER(struct xen_hvm_modified_memory, arg);
- int rc;
-
- arg = xc_hypercall_buffer_alloc(xch, arg, sizeof(*arg));
- if ( arg == NULL )
- {
- PERROR("Could not allocate memory for xc_hvm_modified_memory
hypercall");
- return -1;
- }
+ struct xen_dm_op op;
+ struct xen_dm_op_modified_memory *data;
- arg->domid = dom;
- arg->first_pfn = first_pfn;
- arg->nr = nr;
+ memset(&op, 0, sizeof(op));
- rc = xencall2(xch->xcall, __HYPERVISOR_hvm_op,
- HVMOP_modified_memory,
- HYPERCALL_BUFFER_AS_ARG(arg));
+ op.op = XEN_DMOP_modified_memory;
+ data = &op.u.modified_memory;
- xc_hypercall_buffer_free(xch, arg);
+ data->first_pfn = first_pfn;
+ data->nr = nr;
- return rc;
+ return do_dm_op(xch, dom, 1, &op, sizeof(op));
}
int xc_hvm_set_mem_type(
diff --git a/xen/arch/x86/hvm/dm.c b/xen/arch/x86/hvm/dm.c
index bcd9ea6..1a7c913 100644
--- a/xen/arch/x86/hvm/dm.c
+++ b/xen/arch/x86/hvm/dm.c
@@ -14,6 +14,7 @@
* this program; If not, see <http://www.gnu.org/licenses/>.
*/
+#include <xen/event.h>
#include <xen/guest_access.h>
#include <xen/hypercall.h>
#include <xen/sched.h>
@@ -142,12 +143,68 @@ static int set_isa_irq_level(struct domain *d, uint8_t
isa_irq,
return 0;
}
+static int modified_memory(struct domain *d, xen_pfn_t *first_pfn,
+ unsigned int *nr)
+{
+ xen_pfn_t last_pfn = *first_pfn + *nr - 1;
+ unsigned int iter;
+ int rc;
+
+ if ( (*first_pfn > last_pfn) ||
+ (last_pfn > domain_get_maximum_gpfn(d)) )
+ return -EINVAL;
+
+ if ( !paging_mode_log_dirty(d) )
+ return 0;
+
+ iter = 0;
+ rc = 0;
+ while ( iter < *nr )
+ {
+ unsigned long pfn = *first_pfn + iter;
+ struct page_info *page;
+
+ page = get_page_from_gfn(d, pfn, NULL, P2M_UNSHARE);
+ if ( page )
+ {
+ mfn_t gmfn = _mfn(page_to_mfn(page));
+
+ paging_mark_dirty(d, gmfn);
+ /*
+ * These are most probably not page tables any more
+ * don't take a long time and don't die either.
+ */
+ sh_remove_shadows(d, gmfn, 1, 0);
+ put_page(page);
+ }
+
+ iter++;
+
+ /*
+ * Check for continuation every 256th iteration and if the
+ * iteration is not the last.
+ */
+ if ( (iter < *nr) && ((iter & 0xff) == 0) &&
+ hypercall_preempt_check() )
+ {
+ *first_pfn += iter;
+ *nr -= iter;
+
+ rc = -ERESTART;
+ break;
+ }
+ }
+
+ return rc;
+}
+
long do_dm_op(domid_t domid,
unsigned int nr_bufs,
XEN_GUEST_HANDLE_PARAM(xen_dm_op_buf_t) bufs)
{
struct domain *d;
struct xen_dm_op op;
+ bool restart = false;
long rc;
rc = rcu_lock_remote_domain_by_id(domid, &d);
@@ -299,17 +356,36 @@ long do_dm_op(domid_t domid,
break;
}
+ case XEN_DMOP_modified_memory:
+ {
+ struct xen_dm_op_modified_memory *data =
+ &op.u.modified_memory;
+
+ rc = -EINVAL;
+ if ( data->pad )
+ break;
+
+ rc = modified_memory(d, &data->first_pfn, &data->nr);
+ break;
+ }
+
default:
rc = -EOPNOTSUPP;
break;
}
- if ( !rc )
+ if ( rc == -ERESTART )
+ restart = true;
+
+ if ( !rc || restart )
rc = copy_buf_to_guest(bufs, nr_bufs, 0, &op, sizeof(op));
out:
rcu_unlock_domain(d);
+ if ( !rc && restart )
+ rc = hypercall_create_continuation(__HYPERVISOR_dm_op, "iih",
+ domid, nr_bufs, bufs);
return rc;
}
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 30d5d72..b4dacae 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -5347,7 +5347,6 @@ long do_hvm_op(unsigned long op,
XEN_GUEST_HANDLE_PARAM(void) arg)
default:
mask = ~0UL;
break;
- case HVMOP_modified_memory:
case HVMOP_set_mem_type:
mask = HVMOP_op_mask;
break;
@@ -5380,65 +5379,6 @@ long do_hvm_op(unsigned long op,
XEN_GUEST_HANDLE_PARAM(void) arg)
rc = guest_handle_is_null(arg) ? hvmop_flush_tlb_all() : -EINVAL;
break;
- case HVMOP_modified_memory:
- {
- struct xen_hvm_modified_memory a;
- struct domain *d;
-
- 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 modmem_fail;
-
- rc = xsm_hvm_control(XSM_DM_PRIV, d, op);
- if ( rc )
- goto modmem_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 modmem_fail;
-
- rc = 0;
- if ( !paging_mode_log_dirty(d) )
- goto modmem_fail;
-
- while ( a.nr > start_iter )
- {
- unsigned long pfn = a.first_pfn + start_iter;
- struct page_info *page;
-
- page = get_page_from_gfn(d, pfn, NULL, P2M_UNSHARE);
- if ( page )
- {
- paging_mark_dirty(d, _mfn(page_to_mfn(page)));
- /* These are most probably not page tables any more */
- /* don't take a long time and don't die either */
- sh_remove_shadows(d, _mfn(page_to_mfn(page)), 1, 0);
- put_page(page);
- }
-
- /* 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;
- break;
- }
- }
-
- modmem_fail:
- rcu_unlock_domain(d);
- break;
- }
-
case HVMOP_get_mem_type:
rc = hvmop_get_mem_type(
guest_handle_cast(arg, xen_hvm_get_mem_type_t));
diff --git a/xen/include/public/hvm/dm_op.h b/xen/include/public/hvm/dm_op.h
index 9743453..6a2fb39 100644
--- a/xen/include/public/hvm/dm_op.h
+++ b/xen/include/public/hvm/dm_op.h
@@ -230,6 +230,24 @@ struct xen_dm_op_set_pci_link_route {
uint8_t isa_irq;
};
+/*
+ * XEN_DMOP_modified_memory: Notify that a set of pages were modified by
+ * an emulator.
+ *
+ * NOTE: In the event of a continuation, the @first_pfn is set to the
+ * value of the pfn of the remaining set of pages and @nr reduced
+ * to the size of the remaining set.
+ */
+#define XEN_DMOP_modified_memory 11
+
+struct xen_dm_op_modified_memory {
+ /* IN - number of contiguous pages modified */
+ uint32_t nr;
+ uint32_t pad;
+ /* IN - first pfn modified */
+ uint64_aligned_t first_pfn;
+};
+
struct xen_dm_op {
uint32_t op;
uint32_t pad;
@@ -244,6 +262,7 @@ struct xen_dm_op {
struct xen_dm_op_set_pci_intx_level set_pci_intx_level;
struct xen_dm_op_set_isa_irq_level set_isa_irq_level;
struct xen_dm_op_set_pci_link_route set_pci_link_route;
+ struct xen_dm_op_modified_memory modified_memory;
} u;
};
diff --git a/xen/include/public/hvm/hvm_op.h b/xen/include/public/hvm/hvm_op.h
index 7cf8d4d..76e1b78 100644
--- a/xen/include/public/hvm/hvm_op.h
+++ b/xen/include/public/hvm/hvm_op.h
@@ -99,19 +99,6 @@ typedef enum {
/* Following tools-only interfaces may change in future. */
#if defined(__XEN__) || defined(__XEN_TOOLS__)
-/* Notify that some pages got modified by the Device Model. */
-#define HVMOP_modified_memory 7
-struct xen_hvm_modified_memory {
- /* Domain to be updated. */
- domid_t domid;
- /* Number of pages. */
- uint32_t nr;
- /* First pfn. */
- uint64_aligned_t first_pfn;
-};
-typedef struct xen_hvm_modified_memory xen_hvm_modified_memory_t;
-DEFINE_XEN_GUEST_HANDLE(xen_hvm_modified_memory_t);
-
#define HVMOP_set_mem_type 8
/* Notify that a region of memory is to be treated in a specific way. */
struct xen_hvm_set_mem_type {
diff --git a/xen/xsm/flask/policy/access_vectors
b/xen/xsm/flask/policy/access_vectors
index 2f0ed2d..361e7aa 100644
--- a/xen/xsm/flask/policy/access_vectors
+++ b/xen/xsm/flask/policy/access_vectors
@@ -262,7 +262,7 @@ class hvm
bind_irq
# XEN_DOMCTL_pin_mem_cacheattr
cacheattr
-# HVMOP_modified_memory, HVMOP_get_mem_type, HVMOP_set_mem_type,
+# HVMOP_get_mem_type, HVMOP_set_mem_type,
# HVMOP_set_mem_access, HVMOP_get_mem_access, HVMOP_pagetable_dying,
# HVMOP_inject_trap
hvmctl
--
2.1.4
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