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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v4 4/8] ioreq-server: on-demand creation of ioreq server
This patch only creates the ioreq server when the legacy HVM parameters
are read (by an emulator).
A lock is introduced to protect access to the ioreq server by multiple
emulator/tool invocations should such an eventuality arise. The guest is
protected by creation of the ioreq server only being done whilst the
domain is paused.
Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
Cc: Keir Fraser <keir@xxxxxxx>
Cc: Jan Beulich <jbeulich@xxxxxxxx>
---
xen/arch/x86/hvm/hvm.c | 262 +++++++++++++++++++++++++++++++-------
xen/include/asm-x86/hvm/domain.h | 1 +
2 files changed, 215 insertions(+), 48 deletions(-)
diff --git a/xen/arch/x86/hvm/hvm.c b/xen/arch/x86/hvm/hvm.c
index 5f131c4..4ecbede 100644
--- a/xen/arch/x86/hvm/hvm.c
+++ b/xen/arch/x86/hvm/hvm.c
@@ -383,40 +383,38 @@ void hvm_do_resume(struct vcpu *v)
{
struct domain *d = v->domain;
struct hvm_ioreq_server *s = d->arch.hvm_domain.ioreq_server;
- ioreq_t *p;
check_wakeup_from_wait();
if ( is_hvm_vcpu(v) )
pt_restore_timer(v);
- if ( !s )
- goto check_inject_trap;
-
- /* NB. Optimised for common case (p->state == STATE_IOREQ_NONE). */
- p = get_ioreq(s, v);
- while ( p->state != STATE_IOREQ_NONE )
+ if ( s )
{
- switch ( p->state )
+ ioreq_t *p = get_ioreq(s, v);
+
+ while ( p->state != STATE_IOREQ_NONE )
{
- case STATE_IORESP_READY: /* IORESP_READY -> NONE */
- rmb(); /* see IORESP_READY /then/ read contents of ioreq */
- hvm_io_assist(p);
- break;
- case STATE_IOREQ_READY: /* IOREQ_{READY,INPROCESS} -> IORESP_READY */
- case STATE_IOREQ_INPROCESS:
- wait_on_xen_event_channel(p->vp_eport,
- (p->state != STATE_IOREQ_READY) &&
- (p->state != STATE_IOREQ_INPROCESS));
- break;
- default:
- gdprintk(XENLOG_ERR, "Weird HVM iorequest state %d.\n", p->state);
- domain_crash(v->domain);
- return; /* bail */
+ switch ( p->state )
+ {
+ case STATE_IORESP_READY: /* IORESP_READY -> NONE */
+ rmb(); /* see IORESP_READY /then/ read contents of ioreq */
+ hvm_io_assist(p);
+ break;
+ case STATE_IOREQ_READY: /* IOREQ_{READY,INPROCESS} ->
IORESP_READY */
+ case STATE_IOREQ_INPROCESS:
+ wait_on_xen_event_channel(p->vp_eport,
+ (p->state != STATE_IOREQ_READY) &&
+ (p->state != STATE_IOREQ_INPROCESS));
+ break;
+ default:
+ gdprintk(XENLOG_ERR, "Weird HVM iorequest state %d.\n",
p->state);
+ domain_crash(d);
+ return; /* bail */
+ }
}
}
- check_inject_trap:
/* Inject pending hw/sw trap */
if ( v->arch.hvm_vcpu.inject_trap.vector != -1 )
{
@@ -645,13 +643,68 @@ static void hvm_ioreq_server_remove_vcpu(struct
hvm_ioreq_server *s,
spin_unlock(&s->lock);
}
-static int hvm_create_ioreq_server(struct domain *d, domid_t domid)
+static void hvm_ioreq_server_remove_all_vcpus(struct hvm_ioreq_server *s)
{
- struct hvm_ioreq_server *s;
+ struct list_head *entry, *next;
- s = xzalloc(struct hvm_ioreq_server);
- if ( !s )
- return -ENOMEM;
+ spin_lock(&s->lock);
+
+ list_for_each_safe ( entry, next, &s->ioreq_vcpu_list )
+ {
+ struct hvm_ioreq_vcpu *sv = container_of(entry,
+ struct hvm_ioreq_vcpu,
+ list_entry);
+ struct vcpu *v = sv->vcpu;
+
+ list_del_init(&sv->list_entry);
+
+ if ( v->vcpu_id == 0 )
+ free_xen_event_channel(v, s->bufioreq_evtchn);
+
+ free_xen_event_channel(v, sv->ioreq_evtchn);
+
+ xfree(sv);
+ }
+
+ spin_unlock(&s->lock);
+}
+
+static int hvm_ioreq_server_map_pages(struct hvm_ioreq_server *s)
+{
+ struct domain *d = s->domain;
+ unsigned long pfn;
+ int rc;
+
+ pfn = d->arch.hvm_domain.params[HVM_PARAM_IOREQ_PFN];
+ rc = hvm_map_ioreq_page(d, &s->ioreq, pfn);
+ if ( rc )
+ goto fail1;
+
+ pfn = d->arch.hvm_domain.params[HVM_PARAM_BUFIOREQ_PFN];
+ rc = hvm_map_ioreq_page(d, &s->bufioreq, pfn);
+ if ( rc )
+ goto fail2;
+
+ return 0;
+
+fail2:
+ hvm_unmap_ioreq_page(&s->ioreq);
+
+fail1:
+ return rc;
+}
+
+static void hvm_ioreq_server_unmap_pages(struct hvm_ioreq_server *s)
+{
+ hvm_unmap_ioreq_page(&s->bufioreq);
+ hvm_unmap_ioreq_page(&s->ioreq);
+}
+
+static int hvm_ioreq_server_init(struct hvm_ioreq_server *s, struct domain *d,
+ domid_t domid)
+{
+ struct vcpu *v;
+ int rc;
s->domain = d;
s->domid = domid;
@@ -660,29 +713,112 @@ static int hvm_create_ioreq_server(struct domain *d,
domid_t domid)
INIT_LIST_HEAD(&s->ioreq_vcpu_list);
spin_lock_init(&s->bufioreq_lock);
+ rc = hvm_ioreq_server_map_pages(s);
+ if ( rc )
+ return rc;
+
+ for_each_vcpu ( d, v )
+ {
+ rc = hvm_ioreq_server_add_vcpu(s, v);
+ if ( rc )
+ goto fail;
+ }
+
+ return 0;
+
+ fail:
+ hvm_ioreq_server_remove_all_vcpus(s);
+ hvm_ioreq_server_unmap_pages(s);
+
+ return rc;
+}
+
+static void hvm_ioreq_server_deinit(struct hvm_ioreq_server *s)
+{
+ hvm_ioreq_server_remove_all_vcpus(s);
+ hvm_ioreq_server_unmap_pages(s);
+}
+
+static int hvm_create_ioreq_server(struct domain *d, domid_t domid)
+{
+ struct hvm_ioreq_server *s;
+ int rc;
+
+ spin_lock(&d->arch.hvm_domain.ioreq_server_lock);
+
+ rc = -EEXIST;
+ if ( d->arch.hvm_domain.ioreq_server != NULL )
+ goto fail1;
+
+ rc = -ENOMEM;
+ s = xzalloc(struct hvm_ioreq_server);
+ if ( !s )
+ goto fail2;
+
+ domain_pause(d);
+
+ rc = hvm_ioreq_server_init(s, d, domid);
+ if ( rc )
+ goto fail3;
+
d->arch.hvm_domain.ioreq_server = s;
+
+ domain_unpause(d);
+
+ spin_unlock(&d->arch.hvm_domain.ioreq_server_lock);
return 0;
+
+ fail3:
+ domain_unpause(d);
+
+ xfree(s);
+
+ fail2:
+ fail1:
+ spin_unlock(&d->arch.hvm_domain.ioreq_server_lock);
+ return rc;
}
static void hvm_destroy_ioreq_server(struct domain *d)
{
- struct hvm_ioreq_server *s = d->arch.hvm_domain.ioreq_server;
+ struct hvm_ioreq_server *s;
- hvm_unmap_ioreq_page(&s->bufioreq);
- hvm_unmap_ioreq_page(&s->ioreq);
+ spin_lock(&d->arch.hvm_domain.ioreq_server_lock);
+
+ s = d->arch.hvm_domain.ioreq_server;
+ if ( !s )
+ goto done;
+
+ d->arch.hvm_domain.ioreq_server = NULL;
+
+ domain_pause(d);
+
+ hvm_ioreq_server_deinit(s);
+
+ domain_unpause(d);
xfree(s);
+
+ done:
+ spin_unlock(&d->arch.hvm_domain.ioreq_server_lock);
}
static int hvm_set_ioreq_pfn(struct domain *d, bool_t buf,
unsigned long pfn)
{
- struct hvm_ioreq_server *s = d->arch.hvm_domain.ioreq_server;
- struct hvm_ioreq_page *iorp = buf ? &s->bufioreq : &s->ioreq;
+ struct hvm_ioreq_server *s;
+ struct hvm_ioreq_page *iorp;
int rc;
+ spin_lock(&d->arch.hvm_domain.ioreq_server_lock);
+
+ s = d->arch.hvm_domain.ioreq_server;
+ if ( !s )
+ goto done;
+
spin_lock(&s->lock);
+ iorp = buf ? &s->bufioreq : &s->ioreq;
rc = hvm_map_ioreq_page(d, iorp, pfn);
if ( rc )
goto fail;
@@ -701,10 +837,14 @@ static int hvm_set_ioreq_pfn(struct domain *d, bool_t buf,
}
spin_unlock(&s->lock);
+
+ done:
+ spin_unlock(&d->arch.hvm_domain.ioreq_server_lock);
return 0;
fail:
spin_unlock(&s->lock);
+ spin_unlock(&d->arch.hvm_domain.ioreq_server_lock);
return rc;
}
@@ -725,9 +865,15 @@ static int hvm_replace_event_channel(struct vcpu *v,
domid_t remote_domid,
static int hvm_set_dm_domain(struct domain *d, domid_t domid)
{
- struct hvm_ioreq_server *s = d->arch.hvm_domain.ioreq_server;
+ struct hvm_ioreq_server *s;
int rc = 0;
+ spin_lock(&d->arch.hvm_domain.ioreq_server_lock);
+
+ s = d->arch.hvm_domain.ioreq_server;
+ if ( !s )
+ goto done;
+
spin_lock(&s->lock);
domain_pause(d);
@@ -764,12 +910,13 @@ static int hvm_set_dm_domain(struct domain *d, domid_t
domid)
domain_unpause(d);
spin_unlock(&s->lock);
+ done:
+ spin_unlock(&d->arch.hvm_domain.ioreq_server_lock);
return rc;
}
int hvm_domain_initialise(struct domain *d)
{
- domid_t domid;
int rc;
if ( !hvm_enabled )
@@ -795,6 +942,7 @@ int hvm_domain_initialise(struct domain *d)
}
+ spin_lock_init(&d->arch.hvm_domain.ioreq_server_lock);
spin_lock_init(&d->arch.hvm_domain.irq_lock);
spin_lock_init(&d->arch.hvm_domain.uc_lock);
@@ -835,21 +983,14 @@ int hvm_domain_initialise(struct domain *d)
rtc_init(d);
- domid = d->arch.hvm_domain.params[HVM_PARAM_DM_DOMAIN];
- rc = hvm_create_ioreq_server(d, domid);
- if ( rc != 0 )
- goto fail2;
-
register_portio_handler(d, 0xe9, 1, hvm_print_line);
rc = hvm_funcs.domain_initialise(d);
if ( rc != 0 )
- goto fail3;
+ goto fail2;
return 0;
- fail3:
- hvm_destroy_ioreq_server(d);
fail2:
rtc_deinit(d);
stdvga_deinit(d);
@@ -1506,7 +1647,7 @@ int hvm_vcpu_initialise(struct vcpu *v)
{
int rc;
struct domain *d = v->domain;
- struct hvm_ioreq_server *s = d->arch.hvm_domain.ioreq_server;
+ struct hvm_ioreq_server *s;
hvm_asid_flush_vcpu(v);
@@ -1549,7 +1690,14 @@ int hvm_vcpu_initialise(struct vcpu *v)
&& (rc = nestedhvm_vcpu_initialise(v)) < 0 ) /* teardown:
nestedhvm_vcpu_destroy */
goto fail5;
- rc = hvm_ioreq_server_add_vcpu(s, v);
+ spin_lock(&d->arch.hvm_domain.ioreq_server_lock);
+
+ s = d->arch.hvm_domain.ioreq_server;
+ if ( s )
+ rc = hvm_ioreq_server_add_vcpu(s, v);
+
+ spin_unlock(&d->arch.hvm_domain.ioreq_server_lock);
+
if ( rc != 0 )
goto fail6;
@@ -1586,9 +1734,15 @@ int hvm_vcpu_initialise(struct vcpu *v)
void hvm_vcpu_destroy(struct vcpu *v)
{
struct domain *d = v->domain;
- struct hvm_ioreq_server *s = d->arch.hvm_domain.ioreq_server;
+ struct hvm_ioreq_server *s;
+
+ spin_lock(&d->arch.hvm_domain.ioreq_server_lock);
+
+ s = d->arch.hvm_domain.ioreq_server;
+ if ( s )
+ hvm_ioreq_server_remove_vcpu(s, v);
- hvm_ioreq_server_remove_vcpu(s, v);
+ spin_unlock(&d->arch.hvm_domain.ioreq_server_lock);
nestedhvm_vcpu_destroy(v);
@@ -4464,7 +4618,7 @@ long do_hvm_op(unsigned long op,
XEN_GUEST_HANDLE_PARAM(void) arg)
domctl_lock_release();
break;
case HVM_PARAM_DM_DOMAIN:
- /* Not reflexive, as we must domain_pause(). */
+ /* Not reflexive, as we may need to domain_pause(). */
rc = -EPERM;
if ( curr_d == d )
break;
@@ -4570,6 +4724,18 @@ long do_hvm_op(unsigned long op,
XEN_GUEST_HANDLE_PARAM(void) arg)
case HVM_PARAM_ACPI_S_STATE:
a.value = d->arch.hvm_domain.is_s3_suspended ? 3 : 0;
break;
+ case HVM_PARAM_IOREQ_PFN:
+ case HVM_PARAM_BUFIOREQ_PFN:
+ case HVM_PARAM_BUFIOREQ_EVTCHN: {
+ domid_t domid;
+
+ /* May need to create server */
+ domid = d->arch.hvm_domain.params[HVM_PARAM_DM_DOMAIN];
+ rc = hvm_create_ioreq_server(d, domid);
+ if ( rc != 0 && rc != -EEXIST )
+ goto param_fail;
+ /*FALLTHRU*/
+ }
default:
a.value = d->arch.hvm_domain.params[a.index];
break;
diff --git a/xen/include/asm-x86/hvm/domain.h b/xen/include/asm-x86/hvm/domain.h
index 1f6eaec..b6911f9 100644
--- a/xen/include/asm-x86/hvm/domain.h
+++ b/xen/include/asm-x86/hvm/domain.h
@@ -63,6 +63,7 @@ struct hvm_ioreq_server {
};
struct hvm_domain {
+ spinlock_t ioreq_server_lock;
struct hvm_ioreq_server *ioreq_server;
struct pl_time pl_time;
--
1.7.10.4
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