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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen master] x86/HVM: correct page dirty marking in hvm_map_guest_frame_rw()
commit 5c23c760a8ef4cec4aaef11575b85fd17e82986c
Author: Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Tue Oct 27 11:42:04 2015 +0100
Commit: Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Tue Oct 27 11:42:04 2015 +0100
x86/HVM: correct page dirty marking in hvm_map_guest_frame_rw()
Rather than dirtying a page when establishing a (permanent) mapping,
dirty it when the page gets unmapped, or - if still mapped - on the
final iteration of a save operation (or in other cases where the guest
is paused or already shut down). (Transient mappings continue to get
dirtied upon getting mapped, to avoid the overhead of tracking.)
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Reviewed-by: Wei Liu <wei.liu2@xxxxxxxxxx>
Acked-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx>
---
tools/libxc/xc_sr_save.c | 3 +-
xen/arch/x86/hvm/hvm.c | 57 +++++++++++++++++++++++++++++++++++--
xen/arch/x86/mm/paging.c | 10 ++++++
xen/include/asm-x86/hvm/domain.h | 6 ++++
xen/include/asm-x86/hvm/hvm.h | 1 +
xen/include/public/domctl.h | 12 ++++++-
6 files changed, 82 insertions(+), 7 deletions(-)
diff --git a/tools/libxc/xc_sr_save.c b/tools/libxc/xc_sr_save.c
index 7dc3a48..d1bdf72 100644
--- a/tools/libxc/xc_sr_save.c
+++ b/tools/libxc/xc_sr_save.c
@@ -537,7 +537,8 @@ static int suspend_and_send_dirty(struct xc_sr_context *ctx)
if ( xc_shadow_control(
xch, ctx->domid, XEN_DOMCTL_SHADOW_OP_CLEAN,
HYPERCALL_BUFFER(dirty_bitmap), ctx->save.p2m_size,
- NULL, 0, &stats) != ctx->save.p2m_size )
+ NULL, XEN_DOMCTL_SHADOW_LOGDIRTY_FINAL, &stats) !=
+ ctx->save.p2m_size )
{
PERROR("Failed to retrieve logdirty bitmap");
rc = -1;
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 965bfbf..21f42a7 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -1565,6 +1565,8 @@ int hvm_domain_initialise(struct domain *d)
INIT_LIST_HEAD(&d->arch.hvm_domain.ioreq_server.list);
spin_lock_init(&d->arch.hvm_domain.irq_lock);
spin_lock_init(&d->arch.hvm_domain.uc_lock);
+ spin_lock_init(&d->arch.hvm_domain.write_map.lock);
+ INIT_LIST_HEAD(&d->arch.hvm_domain.write_map.list);
hvm_init_cacheattr_region_list(d);
@@ -3677,6 +3679,11 @@ int hvm_virtual_to_linear_addr(
return 1;
}
+struct hvm_write_map {
+ struct list_head list;
+ struct page_info *page;
+};
+
/* On non-NULL return, we leave this function holding an additional
* ref on the underlying mfn, if any */
static void *_hvm_map_guest_frame(unsigned long gfn, bool_t permanent,
@@ -3704,15 +3711,30 @@ static void *_hvm_map_guest_frame(unsigned long gfn,
bool_t permanent,
if ( writable )
{
- if ( !p2m_is_discard_write(p2mt) )
- paging_mark_dirty(d, page_to_mfn(page));
- else
+ if ( unlikely(p2m_is_discard_write(p2mt)) )
*writable = 0;
+ else if ( !permanent )
+ paging_mark_dirty(d, page_to_mfn(page));
}
if ( !permanent )
return __map_domain_page(page);
+ if ( writable && *writable )
+ {
+ struct hvm_write_map *track = xmalloc(struct hvm_write_map);
+
+ if ( !track )
+ {
+ put_page(page);
+ return NULL;
+ }
+ track->page = page;
+ spin_lock(&d->arch.hvm_domain.write_map.lock);
+ list_add_tail(&track->list, &d->arch.hvm_domain.write_map.list);
+ spin_unlock(&d->arch.hvm_domain.write_map.lock);
+ }
+
map = __map_domain_page_global(page);
if ( !map )
put_page(page);
@@ -3735,18 +3757,45 @@ void *hvm_map_guest_frame_ro(unsigned long gfn, bool_t
permanent)
void hvm_unmap_guest_frame(void *p, bool_t permanent)
{
unsigned long mfn;
+ struct page_info *page;
if ( !p )
return;
mfn = domain_page_map_to_mfn(p);
+ page = mfn_to_page(mfn);
if ( !permanent )
unmap_domain_page(p);
else
+ {
+ struct domain *d = page_get_owner(page);
+ struct hvm_write_map *track;
+
unmap_domain_page_global(p);
+ spin_lock(&d->arch.hvm_domain.write_map.lock);
+ list_for_each_entry(track, &d->arch.hvm_domain.write_map.list, list)
+ if ( track->page == page )
+ {
+ paging_mark_dirty(d, mfn);
+ list_del(&track->list);
+ xfree(track);
+ break;
+ }
+ spin_unlock(&d->arch.hvm_domain.write_map.lock);
+ }
+
+ put_page(page);
+}
+
+void hvm_mapped_guest_frames_mark_dirty(struct domain *d)
+{
+ struct hvm_write_map *track;
- put_page(mfn_to_page(mfn));
+ spin_lock(&d->arch.hvm_domain.write_map.lock);
+ list_for_each_entry(track, &d->arch.hvm_domain.write_map.list, list)
+ paging_mark_dirty(d, page_to_mfn(track->page));
+ spin_unlock(&d->arch.hvm_domain.write_map.lock);
}
static void *hvm_map_entry(unsigned long va, bool_t *writable)
diff --git a/xen/arch/x86/mm/paging.c b/xen/arch/x86/mm/paging.c
index ba1d528..42648df 100644
--- a/xen/arch/x86/mm/paging.c
+++ b/xen/arch/x86/mm/paging.c
@@ -29,6 +29,7 @@
#include <asm/hvm/nestedhvm.h>
#include <xen/numa.h>
#include <xsm/xsm.h>
+#include <public/sched.h> /* SHUTDOWN_suspend */
#include "mm-locks.h"
@@ -422,6 +423,13 @@ static int paging_log_dirty_op(struct domain *d,
if ( !resuming )
{
+ /*
+ * Mark dirty all currently write-mapped pages on e.g. the
+ * final iteration of a save operation.
+ */
+ if ( sc->mode & XEN_DOMCTL_SHADOW_LOGDIRTY_FINAL )
+ hvm_mapped_guest_frames_mark_dirty(d);
+
domain_pause(d);
/*
@@ -744,6 +752,8 @@ int paging_domctl(struct domain *d, xen_domctl_shadow_op_t
*sc,
case XEN_DOMCTL_SHADOW_OP_CLEAN:
case XEN_DOMCTL_SHADOW_OP_PEEK:
+ if ( sc->mode & ~XEN_DOMCTL_SHADOW_LOGDIRTY_FINAL )
+ return -EINVAL;
return paging_log_dirty_op(d, sc, resuming);
}
diff --git a/xen/include/asm-x86/hvm/domain.h b/xen/include/asm-x86/hvm/domain.h
index 992d5d1..a8cc2ad 100644
--- a/xen/include/asm-x86/hvm/domain.h
+++ b/xen/include/asm-x86/hvm/domain.h
@@ -145,6 +145,12 @@ struct hvm_domain {
unsigned long *io_bitmap;
+ /* List of permanently write-mapped pages. */
+ struct {
+ spinlock_t lock;
+ struct list_head list;
+ } write_map;
+
union {
struct vmx_domain vmx;
struct svm_domain svm;
diff --git a/xen/include/asm-x86/hvm/hvm.h b/xen/include/asm-x86/hvm/hvm.h
index 0693706..0cf7da1 100644
--- a/xen/include/asm-x86/hvm/hvm.h
+++ b/xen/include/asm-x86/hvm/hvm.h
@@ -445,6 +445,7 @@ void *hvm_map_guest_frame_rw(unsigned long gfn, bool_t
permanent,
bool_t *writable);
void *hvm_map_guest_frame_ro(unsigned long gfn, bool_t permanent);
void hvm_unmap_guest_frame(void *p, bool_t permanent);
+void hvm_mapped_guest_frames_mark_dirty(struct domain *);
static inline void hvm_set_info_guest(struct vcpu *v)
{
diff --git a/xen/include/public/domctl.h b/xen/include/public/domctl.h
index 86cd0ab..7a56b3f 100644
--- a/xen/include/public/domctl.h
+++ b/xen/include/public/domctl.h
@@ -208,6 +208,13 @@ struct xen_domctl_getpageframeinfo3 {
*/
#define XEN_DOMCTL_SHADOW_ENABLE_EXTERNAL (1 << 4)
+/* Mode flags for XEN_DOMCTL_SHADOW_OP_{CLEAN,PEEK}. */
+ /*
+ * This is the final iteration: Requesting to include pages mapped
+ * writably by the hypervisor in the dirty bitmap.
+ */
+#define XEN_DOMCTL_SHADOW_LOGDIRTY_FINAL (1 << 0)
+
struct xen_domctl_shadow_op_stats {
uint32_t fault_count;
uint32_t dirty_count;
@@ -219,8 +226,9 @@ struct xen_domctl_shadow_op {
/* IN variables. */
uint32_t op; /* XEN_DOMCTL_SHADOW_OP_* */
- /* OP_ENABLE */
- uint32_t mode; /* XEN_DOMCTL_SHADOW_ENABLE_* */
+ /* OP_ENABLE: XEN_DOMCTL_SHADOW_ENABLE_* */
+ /* OP_PEAK / OP_CLEAN: XEN_DOMCTL_SHADOW_LOGDIRTY_* */
+ uint32_t mode;
/* OP_GET_ALLOCATION / OP_SET_ALLOCATION */
uint32_t mb; /* Shadow memory allocation in MB */
--
generated by git-patchbot for /home/xen/git/xen.git#master
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