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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v4] dm_op: Add xendevicemodel_modified_memory_bulk.
From: Jennifer Herbert <Jennifer.Herbert@xxxxxxxxxx>
This new lib devicemodel call allows multiple extents of pages to be
marked as modified in a single call. This is something needed for a
usecase I'm working on.
The xen side of the modified_memory call has been modified to accept
an array of extents. The devicemodle library either provides an array
of length 1, to support the original library function, or a second
function allows an array to be provided.
Signed-off-by: Jennifer Herbert <Jennifer.Herbert@xxxxxxxxxx>
---
Changes as discussed on V3.
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
Cc: Wei Liu <wei.liu2@xxxxxxxxxx>
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Cc: Paul Durrant <paul.durrant@xxxxxxxxxx>
---
tools/libs/devicemodel/core.c | 30 ++++--
tools/libs/devicemodel/include/xendevicemodel.h | 19 +++-
xen/arch/x86/hvm/dm.c | 124 ++++++++++++++++-------
xen/include/public/hvm/dm_op.h | 19 +++-
4 files changed, 140 insertions(+), 52 deletions(-)
diff --git a/tools/libs/devicemodel/core.c b/tools/libs/devicemodel/core.c
index a85cb49..f9e37a5 100644
--- a/tools/libs/devicemodel/core.c
+++ b/tools/libs/devicemodel/core.c
@@ -434,22 +434,36 @@ int xendevicemodel_track_dirty_vram(
dirty_bitmap, (size_t)(nr + 7) / 8);
}
-int xendevicemodel_modified_memory(
- xendevicemodel_handle *dmod, domid_t domid, uint64_t first_pfn,
- uint32_t nr)
+int xendevicemodel_modified_memory_bulk(
+ xendevicemodel_handle *dmod, domid_t domid,
+ struct xen_dm_op_modified_memory_extent *extents, uint32_t nr)
{
struct xen_dm_op op;
- struct xen_dm_op_modified_memory *data;
+ struct xen_dm_op_modified_memory *header;
+ size_t extents_size = nr * sizeof(struct xen_dm_op_modified_memory_extent);
memset(&op, 0, sizeof(op));
op.op = XEN_DMOP_modified_memory;
- data = &op.u.modified_memory;
+ header = &op.u.modified_memory;
- data->first_pfn = first_pfn;
- data->nr = nr;
+ header->nr_extents = nr;
+ header->pfns_processed = 0;
- return xendevicemodel_op(dmod, domid, 1, &op, sizeof(op));
+ return xendevicemodel_op(dmod, domid, 2, &op, sizeof(op),
+ extents, extents_size);
+}
+
+int xendevicemodel_modified_memory(
+ xendevicemodel_handle *dmod, domid_t domid, uint64_t first_pfn,
+ uint32_t nr)
+{
+ struct xen_dm_op_modified_memory_extent extent;
+
+ extent.first_pfn = first_pfn;
+ extent.nr = nr;
+
+ return xendevicemodel_modified_memory_bulk(dmod, domid, &extent, 1);
}
int xendevicemodel_set_mem_type(
diff --git a/tools/libs/devicemodel/include/xendevicemodel.h
b/tools/libs/devicemodel/include/xendevicemodel.h
index b3f600e..9c62bf9 100644
--- a/tools/libs/devicemodel/include/xendevicemodel.h
+++ b/tools/libs/devicemodel/include/xendevicemodel.h
@@ -236,8 +236,8 @@ int xendevicemodel_track_dirty_vram(
uint32_t nr, unsigned long *dirty_bitmap);
/**
- * This function notifies the hypervisor that a set of domain pages
- * have been modified.
+ * This function notifies the hypervisor that a set of contiguous
+ * domain pages have been modified.
*
* @parm dmod a handle to an open devicemodel interface.
* @parm domid the domain id to be serviced
@@ -250,6 +250,21 @@ int xendevicemodel_modified_memory(
uint32_t nr);
/**
+ * This function notifies the hypervisor that a set of discontiguous
+ * domain pages have been modified.
+ *
+ * @parm dmod a handle to an open devicemodel interface.
+ * @parm domid the domain id to be serviced
+ * @parm extents an array of extent structs, which each hold
+ a start_pfn and nr (number of pfns).
+ * @parm nr the number of extents in the array
+ * @return 0 on success, -1 on failure.
+ */
+int xendevicemodel_modified_memory_bulk(
+ xendevicemodel_handle *dmod, domid_t domid,
+ struct xen_dm_op_modified_memory_extent extents[], uint32_t nr);
+
+/**
* This function notifies the hypervisor that a set of domain pages
* are to be treated in a specific way. (See the definition of
* hvmmem_type_t).
diff --git a/xen/arch/x86/hvm/dm.c b/xen/arch/x86/hvm/dm.c
index 2122c45..c4fa704 100644
--- a/xen/arch/x86/hvm/dm.c
+++ b/xen/arch/x86/hvm/dm.c
@@ -118,57 +118,108 @@ static int set_isa_irq_level(struct domain *d, uint8_t
isa_irq,
return 0;
}
-static int modified_memory(struct domain *d,
- struct xen_dm_op_modified_memory *data)
+
+int copy_extent_from_guest_array(struct xen_dm_op_modified_memory_extent*
extent,
+ xen_dm_op_buf_t* buf, unsigned int index)
+
{
- xen_pfn_t last_pfn = data->first_pfn + data->nr - 1;
- unsigned int iter = 0;
- int rc = 0;
+ if ( (buf->size / sizeof(struct xen_dm_op_modified_memory_extent)) <=
+ index )
+ return -EINVAL;
- if ( (data->first_pfn > last_pfn) ||
- (last_pfn > domain_get_maximum_gpfn(d)) )
+ if ( copy_from_guest_offset(extent, buf->h, index, 1) )
+ return -EFAULT;
+
+ if (extent->pad)
return -EINVAL;
+ return 0;
+}
+
+static int modified_memory(struct domain *d,
+ struct xen_dm_op_modified_memory *header,
+ xen_dm_op_buf_t* buf)
+{
+ /* Process maximum of 256 pfns before checking for continuation */
+ const unsigned int cont_check_interval = 0x100;
+ unsigned int *rem_extents = &header->nr_extents;
+ unsigned int batch_rem_pfns = cont_check_interval;
+ /* Used for continuation */
+ unsigned int *pfns_done = &header->opaque;
+
if ( !paging_mode_log_dirty(d) )
return 0;
- while ( iter < data->nr )
+ while ( *rem_extents > 0)
{
- unsigned long pfn = data->first_pfn + iter;
- struct page_info *page;
+ struct xen_dm_op_modified_memory_extent extent;
+ unsigned int batch_nr;
+ xen_pfn_t pfn;
+ xen_pfn_t end_pfn;
+ int rc;
+
+ if ( (rc = copy_extent_from_guest_array(&extent, buf, *rem_extents -
1)) )
+ return rc;
+
+ end_pfn = extent.first_pfn + extent.nr;
+
+ if ( (end_pfn <= extent.first_pfn) ||
+ (end_pfn > domain_get_maximum_gpfn(d)) )
+ return -EINVAL;
+
+ if (*pfns_done >= extent.nr)
+ return -EINVAL;
+
+ pfn = extent.first_pfn + *pfns_done;
+ batch_nr = extent.nr - *pfns_done;
- page = get_page_from_gfn(d, pfn, NULL, P2M_UNSHARE);
- if ( page )
+ if ( batch_nr > batch_rem_pfns )
{
- 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);
+ batch_nr = batch_rem_pfns;
+ *pfns_done += batch_nr;
+ end_pfn = pfn + batch_nr;
+ }
+ else
+ {
+ (*rem_extents)--;
+ *pfns_done = 0;
}
- iter++;
+ batch_rem_pfns -= batch_nr;
+
+ for ( ; pfn < end_pfn; pfn++)
+ {
+ 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);
+ }
+ }
/*
- * Check for continuation every 256th iteration and if the
- * iteration is not the last.
+ * After a full batch of cont_check_interval pfns
+ * have been processed, and there are still extents
+ * remaining to process, check for contination.
*/
- if ( (iter < data->nr) && ((iter & 0xff) == 0) &&
- hypercall_preempt_check() )
+ if ( (batch_rem_pfns == 0) && (*rem_extents > 0) )
{
- data->first_pfn += iter;
- data->nr -= iter;
+ if ( hypercall_preempt_check() )
+ return -ERESTART;
- rc = -ERESTART;
- break;
+ batch_rem_pfns = cont_check_interval;
}
}
-
- return rc;
+ return 0;
}
static bool allow_p2m_type_change(p2m_type_t old, p2m_type_t new)
@@ -441,13 +492,8 @@ static int dm_op(domid_t domid,
struct xen_dm_op_modified_memory *data =
&op.u.modified_memory;
- const_op = false;
-
- rc = -EINVAL;
- if ( data->pad )
- break;
-
- rc = modified_memory(d, data);
+ rc = modified_memory(d, data, &bufs[1]);
+ const_op = !rc;
break;
}
diff --git a/xen/include/public/hvm/dm_op.h b/xen/include/public/hvm/dm_op.h
index f54cece..a296d6a 100644
--- a/xen/include/public/hvm/dm_op.h
+++ b/xen/include/public/hvm/dm_op.h
@@ -237,13 +237,26 @@ struct xen_dm_op_set_pci_link_route {
* 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.
+ * DMOP buf 1 contains an array of xen_dm_op_modified_memory_extent with
+ * @nr_extents entries.
+ *
+ * On error, @nr_extents will contain the index+1 of the extent that
+ * had the error. It is not defined if or which pages may have been
+ * marked as dirty, in this event.
*/
#define XEN_DMOP_modified_memory 11
struct xen_dm_op_modified_memory {
+ /*
+ * IN - Number of extents to be processed
+ * OUT -returns n+1 for failing extent
+ */
+ uint32_t nr_extents;
+ /* IN/OUT - Must be set to 0 */
+ uint32_t opaque;
+};
+
+struct xen_dm_op_modified_memory_extent {
/* IN - number of contiguous pages modified */
uint32_t nr;
uint32_t pad;
--
1.7.10.4
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