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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v7 4/5] ix86/ioreq server: Asynchronously reset outstanding p2m_ioreq_server entries.
After an ioreq server has unmapped, the remaining p2m_ioreq_server
entries need to be reset back to p2m_ram_rw. This patch does this
asynchronously with the current p2m_change_entry_type_global()
interface.
This patch also disallows live migration, when there's still any
outstanding p2m_ioreq_server entry left. The core reason is our
current implementation of p2m_change_entry_type_global() can not
tell the state of p2m_ioreq_server entries(can not decide if an
entry is to be emulated or to be resynced).
Signed-off-by: Yu Zhang <yu.c.zhang@xxxxxxxxxxxxxxx>
---
Cc: Paul Durrant <paul.durrant@xxxxxxxxxx>
Cc: Jan Beulich <jbeulich@xxxxxxxx>
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Cc: George Dunlap <george.dunlap@xxxxxxxxxxxxx>
Cc: Jun Nakajima <jun.nakajima@xxxxxxxxx>
Cc: Kevin Tian <kevin.tian@xxxxxxxxx>
changes in v3:
- Move the synchronously resetting logic into patch 5.
- According to comments from Jan: introduce p2m_check_changeable()
to clarify the p2m type change code.
- According to comments from George: use locks in the same order
to avoid deadlock, call p2m_change_entry_type_global() after unmap
of the ioreq server is finished.
changes in v2:
- Move the calculation of ioreq server page entry_cout into
p2m_change_type_one() so that we do not need a seperate lock.
Note: entry_count is also calculated in resolve_misconfig()/
do_recalc(), fortunately callers of both routines have p2m
lock protected already.
- Simplify logic in hvmop_set_mem_type().
- Introduce routine p2m_finish_type_change() to walk the p2m
table and do the p2m reset.
---
xen/arch/x86/hvm/ioreq.c | 8 ++++++++
xen/arch/x86/mm/hap/hap.c | 9 +++++++++
xen/arch/x86/mm/p2m-ept.c | 8 +++++++-
xen/arch/x86/mm/p2m-pt.c | 13 +++++++++++--
xen/arch/x86/mm/p2m.c | 20 ++++++++++++++++++++
xen/include/asm-x86/p2m.h | 9 ++++++++-
6 files changed, 63 insertions(+), 4 deletions(-)
diff --git a/xen/arch/x86/hvm/ioreq.c b/xen/arch/x86/hvm/ioreq.c
index fcb9f38..c129eb4 100644
--- a/xen/arch/x86/hvm/ioreq.c
+++ b/xen/arch/x86/hvm/ioreq.c
@@ -949,6 +949,14 @@ int hvm_map_mem_type_to_ioreq_server(struct domain *d,
ioservid_t id,
spin_unlock_recursive(&d->arch.hvm_domain.ioreq_server.lock);
+ if ( rc == 0 && flags == 0 )
+ {
+ struct p2m_domain *p2m = p2m_get_hostp2m(d);
+
+ if ( read_atomic(&p2m->ioreq.entry_count) )
+ p2m_change_entry_type_global(d, p2m_ioreq_server, p2m_ram_rw);
+ }
+
return rc;
}
diff --git a/xen/arch/x86/mm/hap/hap.c b/xen/arch/x86/mm/hap/hap.c
index a57b385..f27a56f 100644
--- a/xen/arch/x86/mm/hap/hap.c
+++ b/xen/arch/x86/mm/hap/hap.c
@@ -187,6 +187,15 @@ out:
*/
static int hap_enable_log_dirty(struct domain *d, bool_t log_global)
{
+ struct p2m_domain *p2m = p2m_get_hostp2m(d);
+
+ /*
+ * Refuse to turn on global log-dirty mode if
+ * there's outstanding p2m_ioreq_server pages.
+ */
+ if ( log_global && read_atomic(&p2m->ioreq.entry_count) )
+ return -EBUSY;
+
/* turn on PG_log_dirty bit in paging mode */
paging_lock(d);
d->arch.paging.mode |= PG_log_dirty;
diff --git a/xen/arch/x86/mm/p2m-ept.c b/xen/arch/x86/mm/p2m-ept.c
index cc1eb21..1df3d09 100644
--- a/xen/arch/x86/mm/p2m-ept.c
+++ b/xen/arch/x86/mm/p2m-ept.c
@@ -544,6 +544,12 @@ static int resolve_misconfig(struct p2m_domain *p2m,
unsigned long gfn)
e.ipat = ipat;
if ( e.recalc && p2m_is_changeable(e.sa_p2mt) )
{
+ if ( e.sa_p2mt == p2m_ioreq_server )
+ {
+ p2m->ioreq.entry_count--;
+ ASSERT(p2m->ioreq.entry_count >= 0);
+ }
+
e.sa_p2mt = p2m_is_logdirty_range(p2m, gfn + i, gfn +
i)
? p2m_ram_logdirty : p2m_ram_rw;
ept_p2m_type_to_flags(p2m, &e, e.sa_p2mt, e.access);
@@ -965,7 +971,7 @@ static mfn_t ept_get_entry(struct p2m_domain *p2m,
if ( is_epte_valid(ept_entry) )
{
if ( (recalc || ept_entry->recalc) &&
- p2m_is_changeable(ept_entry->sa_p2mt) )
+ p2m_check_changeable(ept_entry->sa_p2mt) )
*t = p2m_is_logdirty_range(p2m, gfn, gfn) ? p2m_ram_logdirty
: p2m_ram_rw;
else
diff --git a/xen/arch/x86/mm/p2m-pt.c b/xen/arch/x86/mm/p2m-pt.c
index 97dc25d..d9a7b76 100644
--- a/xen/arch/x86/mm/p2m-pt.c
+++ b/xen/arch/x86/mm/p2m-pt.c
@@ -437,11 +437,13 @@ static int do_recalc(struct p2m_domain *p2m, unsigned
long gfn)
needs_recalc(l1, *pent) )
{
l1_pgentry_t e = *pent;
+ p2m_type_t p2mt_old;
if ( !valid_recalc(l1, e) )
P2M_DEBUG("bogus recalc leaf at d%d:%lx:%u\n",
p2m->domain->domain_id, gfn, level);
- if ( p2m_is_changeable(p2m_flags_to_type(l1e_get_flags(e))) )
+ p2mt_old = p2m_flags_to_type(l1e_get_flags(e));
+ if ( p2m_is_changeable(p2mt_old) )
{
unsigned long mask = ~0UL << (level * PAGETABLE_ORDER);
p2m_type_t p2mt = p2m_is_logdirty_range(p2m, gfn & mask, gfn |
~mask)
@@ -461,6 +463,13 @@ static int do_recalc(struct p2m_domain *p2m, unsigned long
gfn)
mfn &= ~(_PAGE_PSE_PAT >> PAGE_SHIFT);
flags |= _PAGE_PSE;
}
+
+ if ( p2mt_old == p2m_ioreq_server )
+ {
+ p2m->ioreq.entry_count--;
+ ASSERT(p2m->ioreq.entry_count >= 0);
+ }
+
e = l1e_from_pfn(mfn, flags);
p2m_add_iommu_flags(&e, level,
(p2mt == p2m_ram_rw)
@@ -730,7 +739,7 @@ p2m_pt_set_entry(struct p2m_domain *p2m, unsigned long gfn,
mfn_t mfn,
static inline p2m_type_t recalc_type(bool_t recalc, p2m_type_t t,
struct p2m_domain *p2m, unsigned long gfn)
{
- if ( !recalc || !p2m_is_changeable(t) )
+ if ( !recalc || !p2m_check_changeable(t) )
return t;
return p2m_is_logdirty_range(p2m, gfn, gfn) ? p2m_ram_logdirty
: p2m_ram_rw;
diff --git a/xen/arch/x86/mm/p2m.c b/xen/arch/x86/mm/p2m.c
index 0edfc61..94d7141 100644
--- a/xen/arch/x86/mm/p2m.c
+++ b/xen/arch/x86/mm/p2m.c
@@ -954,6 +954,26 @@ int p2m_change_type_one(struct domain *d, unsigned long
gfn,
p2m->default_access)
: -EBUSY;
+ if ( !rc )
+ {
+ switch ( nt )
+ {
+ case p2m_ram_rw:
+ if ( ot == p2m_ioreq_server )
+ {
+ p2m->ioreq.entry_count--;
+ ASSERT(p2m->ioreq.entry_count >= 0);
+ }
+ break;
+ case p2m_ioreq_server:
+ if ( ot == p2m_ram_rw )
+ p2m->ioreq.entry_count++;
+ break;
+ default:
+ break;
+ }
+ }
+
gfn_unlock(p2m, gfn, 0);
return rc;
diff --git a/xen/include/asm-x86/p2m.h b/xen/include/asm-x86/p2m.h
index 3786680..395f125 100644
--- a/xen/include/asm-x86/p2m.h
+++ b/xen/include/asm-x86/p2m.h
@@ -120,7 +120,10 @@ typedef unsigned int p2m_query_t;
/* Types that can be subject to bulk transitions. */
#define P2M_CHANGEABLE_TYPES (p2m_to_mask(p2m_ram_rw) \
- | p2m_to_mask(p2m_ram_logdirty) )
+ | p2m_to_mask(p2m_ram_logdirty) \
+ | p2m_to_mask(p2m_ioreq_server) )
+
+#define P2M_IOREQ_TYPES (p2m_to_mask(p2m_ioreq_server))
#define P2M_POD_TYPES (p2m_to_mask(p2m_populate_on_demand))
@@ -157,6 +160,7 @@ typedef unsigned int p2m_query_t;
#define p2m_is_readonly(_t) (p2m_to_mask(_t) & P2M_RO_TYPES)
#define p2m_is_discard_write(_t) (p2m_to_mask(_t) & P2M_DISCARD_WRITE_TYPES)
#define p2m_is_changeable(_t) (p2m_to_mask(_t) & P2M_CHANGEABLE_TYPES)
+#define p2m_is_ioreq(_t) (p2m_to_mask(_t) & P2M_IOREQ_TYPES)
#define p2m_is_pod(_t) (p2m_to_mask(_t) & P2M_POD_TYPES)
#define p2m_is_grant(_t) (p2m_to_mask(_t) & P2M_GRANT_TYPES)
/* Grant types are *not* considered valid, because they can be
@@ -178,6 +182,8 @@ typedef unsigned int p2m_query_t;
#define p2m_allows_invalid_mfn(t) (p2m_to_mask(t) & P2M_INVALID_MFN_TYPES)
+#define p2m_check_changeable(t) (p2m_is_changeable(t) && !p2m_is_ioreq(t))
+
typedef enum {
p2m_host,
p2m_nested,
@@ -349,6 +355,7 @@ struct p2m_domain {
* are to be emulated by an ioreq server.
*/
unsigned int flags;
+ long entry_count;
} ioreq;
};
--
1.9.1
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