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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen-unstable] hvm: Clean up treatment of is_dying per-domain boolean. All critical
# HG changeset patch
# User Keir Fraser <keir@xxxxxxxxxxxxx>
# Date 1176472746 -3600
# Node ID 76f9a8e730ea9e4152e441a081e2aa560bd23d5d
# Parent d51b3bc40ca54d8690080e661e250f21ad0fc23b
hvm: Clean up treatment of is_dying per-domain boolean. All critical
checks are done under an appropriate lock, allowing the lock-free
protocols surrounding this boolean to be removed.
Also simplification and fixes to code for setting/zapping the ioreq
and buf_ioreq shared pages.
Signed-off-by: Keir Fraser <keir@xxxxxxxxxxxxx>
---
xen/arch/x86/hvm/hvm.c | 130 ++++++++++++++++++++++----------------
xen/arch/x86/hvm/intercept.c | 46 +++++--------
xen/arch/x86/hvm/io.c | 2
xen/arch/x86/hvm/platform.c | 6 -
xen/arch/x86/mm.c | 22 +++---
xen/arch/x86/x86_32/domain_page.c | 21 ------
xen/common/domain.c | 3
xen/include/asm-x86/hvm/domain.h | 12 ++-
xen/include/asm-x86/hvm/support.h | 15 ++--
xen/include/xen/domain_page.h | 9 --
10 files changed, 128 insertions(+), 138 deletions(-)
diff -r d51b3bc40ca5 -r 76f9a8e730ea xen/arch/x86/hvm/hvm.c
--- a/xen/arch/x86/hvm/hvm.c Fri Apr 13 13:55:10 2007 +0100
+++ b/xen/arch/x86/hvm/hvm.c Fri Apr 13 14:59:06 2007 +0100
@@ -101,7 +101,7 @@ void hvm_set_guest_time(struct vcpu *v,
u64 hvm_get_guest_time(struct vcpu *v)
{
- u64 host_tsc;
+ u64 host_tsc;
rdtscll(host_tsc);
return host_tsc + v->arch.hvm_vcpu.cache_tsc_offset;
@@ -125,7 +125,7 @@ void hvm_do_resume(struct vcpu *v)
pt_thaw_time(v);
/* NB. Optimised for common case (p->state == STATE_IOREQ_NONE). */
- p = &get_vio(v->domain, v->vcpu_id)->vp_ioreq;
+ p = &get_ioreq(v)->vp_ioreq;
while ( p->state != STATE_IOREQ_NONE )
{
switch ( p->state )
@@ -146,54 +146,68 @@ void hvm_do_resume(struct vcpu *v)
}
}
-static void hvm_clear_ioreq_pfn(
- struct domain *d, unsigned long *pva)
-{
- unsigned long va, mfn;
-
- BUG_ON(!d->is_dying);
-
- if ( (va = xchg(pva, 0UL)) == 0UL )
- return;
-
- mfn = mfn_from_mapped_domain_page((void *)va);
- unmap_domain_page_global((void *)va);
- put_page_and_type(mfn_to_page(mfn));
-}
-
-static int hvm_set_ioreq_pfn(
- struct domain *d, unsigned long *pva, unsigned long gmfn)
-{
+static void hvm_init_ioreq_page(
+ struct domain *d, struct hvm_ioreq_page *iorp)
+{
+ memset(iorp, 0, sizeof(*iorp));
+ spin_lock_init(&iorp->lock);
+ domain_pause(d);
+}
+
+static void hvm_destroy_ioreq_page(
+ struct domain *d, struct hvm_ioreq_page *iorp)
+{
+ spin_lock(&iorp->lock);
+
+ ASSERT(d->is_dying);
+
+ if ( iorp->va != NULL )
+ {
+ unmap_domain_page_global(iorp->va);
+ put_page_and_type(iorp->page);
+ iorp->va = NULL;
+ }
+
+ spin_unlock(&iorp->lock);
+}
+
+static int hvm_set_ioreq_page(
+ struct domain *d, struct hvm_ioreq_page *iorp, unsigned long gmfn)
+{
+ struct page_info *page;
unsigned long mfn;
void *va;
mfn = gmfn_to_mfn(d, gmfn);
- if ( !mfn_valid(mfn) ||
- !get_page_and_type(mfn_to_page(mfn), d, PGT_writable_page) )
+ if ( !mfn_valid(mfn) )
+ return -EINVAL;
+
+ page = mfn_to_page(mfn);
+ if ( !get_page_and_type(page, d, PGT_writable_page) )
return -EINVAL;
va = map_domain_page_global(mfn);
if ( va == NULL )
{
- put_page_and_type(mfn_to_page(mfn));
+ put_page_and_type(page);
return -ENOMEM;
}
- if ( cmpxchg(pva, 0UL, (unsigned long)va) != 0UL )
- {
+ spin_lock(&iorp->lock);
+
+ if ( (iorp->va != NULL) || d->is_dying )
+ {
+ spin_unlock(&iorp->lock);
unmap_domain_page_global(va);
put_page_and_type(mfn_to_page(mfn));
return -EINVAL;
}
- /*
- * Check dying status /after/ setting *pva. cmpxchg() is a barrier.
- * We race against hvm_domain_relinquish_resources().
- */
- if ( d->is_dying )
- hvm_clear_ioreq_pfn(d, pva);
-
- /* Balance the domain_pause() in hvm_domain_initialise(). */
+ iorp->va = va;
+ iorp->page = page;
+
+ spin_unlock(&iorp->lock);
+
domain_unpause(d);
return 0;
@@ -211,7 +225,6 @@ int hvm_domain_initialise(struct domain
}
spin_lock_init(&d->arch.hvm_domain.pbuf_lock);
- spin_lock_init(&d->arch.hvm_domain.buffered_io_lock);
spin_lock_init(&d->arch.hvm_domain.irq_lock);
rc = paging_enable(d, PG_refcounts|PG_translate|PG_external);
@@ -221,17 +234,16 @@ int hvm_domain_initialise(struct domain
vpic_init(d);
vioapic_init(d);
- /* Do not allow domain to run until it has ioreq shared pages. */
- domain_pause(d); /* HVM_PARAM_IOREQ_PFN */
- domain_pause(d); /* HVM_PARAM_BUFIOREQ_PFN */
+ hvm_init_ioreq_page(d, &d->arch.hvm_domain.ioreq);
+ hvm_init_ioreq_page(d, &d->arch.hvm_domain.buf_ioreq);
return 0;
}
void hvm_domain_relinquish_resources(struct domain *d)
{
- hvm_clear_ioreq_pfn(d, &d->arch.hvm_domain.shared_page_va);
- hvm_clear_ioreq_pfn(d, &d->arch.hvm_domain.buffered_io_va);
+ hvm_destroy_ioreq_page(d, &d->arch.hvm_domain.ioreq);
+ hvm_destroy_ioreq_page(d, &d->arch.hvm_domain.buf_ioreq);
}
void hvm_domain_destroy(struct domain *d)
@@ -379,10 +391,20 @@ int hvm_vcpu_initialise(struct vcpu *v)
}
/* Create ioreq event channel. */
- v->arch.hvm_vcpu.xen_port = alloc_unbound_xen_event_channel(v, 0);
- if ( get_sp(v->domain) && get_vio(v->domain, v->vcpu_id) )
- get_vio(v->domain, v->vcpu_id)->vp_eport =
- v->arch.hvm_vcpu.xen_port;
+ rc = alloc_unbound_xen_event_channel(v, 0);
+ if ( rc < 0 )
+ {
+ hvm_funcs.vcpu_destroy(v);
+ vlapic_destroy(v);
+ return rc;
+ }
+
+ /* Register ioreq event channel. */
+ v->arch.hvm_vcpu.xen_port = rc;
+ spin_lock(&v->domain->arch.hvm_domain.ioreq.lock);
+ if ( v->domain->arch.hvm_domain.ioreq.va != NULL )
+ get_ioreq(v)->vp_eport = v->arch.hvm_vcpu.xen_port;
+ spin_unlock(&v->domain->arch.hvm_domain.ioreq.lock);
INIT_LIST_HEAD(&v->arch.hvm_vcpu.tm_list);
@@ -463,7 +485,7 @@ void hvm_send_assist_req(struct vcpu *v)
if ( unlikely(!vcpu_start_shutdown_deferral(v)) )
return; /* implicitly bins the i/o operation */
- p = &get_vio(v->domain, v->vcpu_id)->vp_ioreq;
+ p = &get_ioreq(v)->vp_ioreq;
if ( unlikely(p->state != STATE_IOREQ_NONE) )
{
/* This indicates a bug in the device model. Crash the domain. */
@@ -981,6 +1003,7 @@ long do_hvm_op(unsigned long op, XEN_GUE
case HVMOP_get_param:
{
struct xen_hvm_param a;
+ struct hvm_ioreq_page *iorp;
struct domain *d;
struct vcpu *v;
@@ -1009,19 +1032,18 @@ long do_hvm_op(unsigned long op, XEN_GUE
switch ( a.index )
{
case HVM_PARAM_IOREQ_PFN:
- rc = hvm_set_ioreq_pfn(
- d, &d->arch.hvm_domain.shared_page_va, a.value);
- if ( rc == 0 )
- {
+ iorp = &d->arch.hvm_domain.ioreq;
+ rc = hvm_set_ioreq_page(d, iorp, a.value);
+ spin_lock(&iorp->lock);
+ if ( (rc == 0) && (iorp->va != NULL) )
/* Initialise evtchn port info if VCPUs already created. */
for_each_vcpu ( d, v )
- get_vio(d, v->vcpu_id)->vp_eport =
- v->arch.hvm_vcpu.xen_port;
- }
+ get_ioreq(v)->vp_eport = v->arch.hvm_vcpu.xen_port;
+ spin_unlock(&iorp->lock);
break;
- case HVM_PARAM_BUFIOREQ_PFN:
- rc = hvm_set_ioreq_pfn(
- d, &d->arch.hvm_domain.buffered_io_va, a.value);
+ case HVM_PARAM_BUFIOREQ_PFN:
+ iorp = &d->arch.hvm_domain.buf_ioreq;
+ rc = hvm_set_ioreq_page(d, iorp, a.value);
break;
case HVM_PARAM_CALLBACK_IRQ:
hvm_set_callback_via(d, a.value);
diff -r d51b3bc40ca5 -r 76f9a8e730ea xen/arch/x86/hvm/intercept.c
--- a/xen/arch/x86/hvm/intercept.c Fri Apr 13 13:55:10 2007 +0100
+++ b/xen/arch/x86/hvm/intercept.c Fri Apr 13 14:59:06 2007 +0100
@@ -158,34 +158,26 @@ int hvm_buffered_io_send(ioreq_t *p)
int hvm_buffered_io_send(ioreq_t *p)
{
struct vcpu *v = current;
- spinlock_t *buffered_io_lock;
- buffered_iopage_t *buffered_iopage =
- (buffered_iopage_t *)(v->domain->arch.hvm_domain.buffered_io_va);
- unsigned long tmp_write_pointer = 0;
-
- buffered_io_lock = &v->domain->arch.hvm_domain.buffered_io_lock;
- spin_lock(buffered_io_lock);
-
- if ( buffered_iopage->write_pointer - buffered_iopage->read_pointer ==
- (unsigned int)IOREQ_BUFFER_SLOT_NUM ) {
- /* the queue is full.
- * send the iopacket through the normal path.
- * NOTE: The arithimetic operation could handle the situation for
- * write_pointer overflow.
- */
- spin_unlock(buffered_io_lock);
- return 0;
- }
-
- tmp_write_pointer = buffered_iopage->write_pointer % IOREQ_BUFFER_SLOT_NUM;
-
- memcpy(&buffered_iopage->ioreq[tmp_write_pointer], p, sizeof(ioreq_t));
-
- /*make the ioreq_t visible before write_pointer*/
+ struct hvm_ioreq_page *iorp = &v->domain->arch.hvm_domain.buf_ioreq;
+ buffered_iopage_t *pg = iorp->va;
+
+ spin_lock(&iorp->lock);
+
+ if ( (pg->write_pointer - pg->read_pointer) == IOREQ_BUFFER_SLOT_NUM )
+ {
+ /* The queue is full: send the iopacket through the normal path. */
+ spin_unlock(&iorp->lock);
+ return 0;
+ }
+
+ memcpy(&pg->ioreq[pg->write_pointer % IOREQ_BUFFER_SLOT_NUM],
+ p, sizeof(ioreq_t));
+
+ /* Make the ioreq_t visible /before/ write_pointer. */
wmb();
- buffered_iopage->write_pointer++;
-
- spin_unlock(buffered_io_lock);
+ pg->write_pointer++;
+
+ spin_unlock(&iorp->lock);
return 1;
}
diff -r d51b3bc40ca5 -r 76f9a8e730ea xen/arch/x86/hvm/io.c
--- a/xen/arch/x86/hvm/io.c Fri Apr 13 13:55:10 2007 +0100
+++ b/xen/arch/x86/hvm/io.c Fri Apr 13 14:59:06 2007 +0100
@@ -832,7 +832,7 @@ void hvm_io_assist(void)
io_opp = &v->arch.hvm_vcpu.io_op;
regs = &io_opp->io_context;
- vio = get_vio(d, v->vcpu_id);
+ vio = get_ioreq(v);
p = &vio->vp_ioreq;
if ( p->state != STATE_IORESP_READY )
diff -r d51b3bc40ca5 -r 76f9a8e730ea xen/arch/x86/hvm/platform.c
--- a/xen/arch/x86/hvm/platform.c Fri Apr 13 13:55:10 2007 +0100
+++ b/xen/arch/x86/hvm/platform.c Fri Apr 13 14:59:06 2007 +0100
@@ -866,7 +866,7 @@ void send_pio_req(unsigned long port, un
port, count, size, value, dir, value_is_ptr);
}
- vio = get_vio(v->domain, v->vcpu_id);
+ vio = get_ioreq(v);
if ( vio == NULL ) {
printk("bad shared page: %lx\n", (unsigned long) vio);
domain_crash_synchronous();
@@ -915,7 +915,7 @@ static void send_mmio_req(unsigned char
type, gpa, count, size, value, dir, value_is_ptr);
}
- vio = get_vio(v->domain, v->vcpu_id);
+ vio = get_ioreq(v);
if (vio == NULL) {
printk("bad shared page\n");
domain_crash_synchronous();
@@ -976,7 +976,7 @@ void send_invalidate_req(void)
vcpu_iodata_t *vio;
ioreq_t *p;
- vio = get_vio(v->domain, v->vcpu_id);
+ vio = get_ioreq(v);
if ( vio == NULL )
{
printk("bad shared page: %lx\n", (unsigned long) vio);
diff -r d51b3bc40ca5 -r 76f9a8e730ea xen/arch/x86/mm.c
--- a/xen/arch/x86/mm.c Fri Apr 13 13:55:10 2007 +0100
+++ b/xen/arch/x86/mm.c Fri Apr 13 14:59:06 2007 +0100
@@ -2041,7 +2041,7 @@ int do_mmuext_op(
MEM_LOG("Error while pinning mfn %lx", mfn);
break;
}
-
+
if ( unlikely(test_and_set_bit(_PGT_pinned,
&page->u.inuse.type_info)) )
{
@@ -2054,14 +2054,18 @@ int do_mmuext_op(
/* A page is dirtied when its pin status is set. */
mark_dirty(d, mfn);
- /*
- * We can race domain destruction (domain_relinquish_resources).
- * NB. The dying-flag test must happen /after/ setting PGT_pinned.
- */
- if ( unlikely(this_cpu(percpu_mm_info).foreign != NULL) &&
- this_cpu(percpu_mm_info).foreign->is_dying &&
- test_and_clear_bit(_PGT_pinned, &page->u.inuse.type_info) )
- put_page_and_type(page);
+ /* We can race domain destruction (domain_relinquish_resources). */
+ if ( unlikely(this_cpu(percpu_mm_info).foreign != NULL) )
+ {
+ int drop_ref;
+ spin_lock(&FOREIGNDOM->page_alloc_lock);
+ drop_ref = (FOREIGNDOM->is_dying &&
+ test_and_clear_bit(_PGT_pinned,
+ &page->u.inuse.type_info));
+ spin_unlock(&FOREIGNDOM->page_alloc_lock);
+ if ( drop_ref )
+ put_page_and_type(page);
+ }
break;
diff -r d51b3bc40ca5 -r 76f9a8e730ea xen/arch/x86/x86_32/domain_page.c
--- a/xen/arch/x86/x86_32/domain_page.c Fri Apr 13 13:55:10 2007 +0100
+++ b/xen/arch/x86/x86_32/domain_page.c Fri Apr 13 14:59:06 2007 +0100
@@ -251,24 +251,3 @@ void unmap_domain_page_global(void *va)
idx = (__va - IOREMAP_VIRT_START) >> PAGE_SHIFT;
set_bit(idx, garbage);
}
-
-unsigned long mfn_from_mapped_domain_page(void *va)
-{
- unsigned long __va = (unsigned long)va;
- l2_pgentry_t *pl2e;
- l1_pgentry_t *pl1e;
- unsigned int idx;
- struct mapcache *cache;
-
- if ( (__va >= MAPCACHE_VIRT_START) && (__va < MAPCACHE_VIRT_END) )
- {
- cache = &mapcache_current_vcpu()->domain->arch.mapcache;
- idx = ((unsigned long)va - MAPCACHE_VIRT_START) >> PAGE_SHIFT;
- return l1e_get_pfn(cache->l1tab[idx]);
- }
-
- ASSERT(__va >= IOREMAP_VIRT_START);
- pl2e = virt_to_xen_l2e(__va);
- pl1e = l2e_to_l1e(*pl2e) + l1_table_offset(__va);
- return l1e_get_pfn(*pl1e);
-}
diff -r d51b3bc40ca5 -r 76f9a8e730ea xen/common/domain.c
--- a/xen/common/domain.c Fri Apr 13 13:55:10 2007 +0100
+++ b/xen/common/domain.c Fri Apr 13 14:59:06 2007 +0100
@@ -313,9 +313,6 @@ void domain_kill(struct domain *d)
return;
}
- /* Tear down state /after/ setting the dying flag. */
- smp_mb();
-
gnttab_release_mappings(d);
domain_relinquish_resources(d);
put_domain(d);
diff -r d51b3bc40ca5 -r 76f9a8e730ea xen/include/asm-x86/hvm/domain.h
--- a/xen/include/asm-x86/hvm/domain.h Fri Apr 13 13:55:10 2007 +0100
+++ b/xen/include/asm-x86/hvm/domain.h Fri Apr 13 14:59:06 2007 +0100
@@ -28,10 +28,16 @@
#include <public/hvm/params.h>
#include <public/hvm/save.h>
+struct hvm_ioreq_page {
+ spinlock_t lock;
+ struct page_info *page;
+ void *va;
+};
+
struct hvm_domain {
- unsigned long shared_page_va;
- unsigned long buffered_io_va;
- spinlock_t buffered_io_lock;
+ struct hvm_ioreq_page ioreq;
+ struct hvm_ioreq_page buf_ioreq;
+
s64 tsc_frequency;
struct pl_time pl_time;
diff -r d51b3bc40ca5 -r 76f9a8e730ea xen/include/asm-x86/hvm/support.h
--- a/xen/include/asm-x86/hvm/support.h Fri Apr 13 13:55:10 2007 +0100
+++ b/xen/include/asm-x86/hvm/support.h Fri Apr 13 14:59:06 2007 +0100
@@ -32,14 +32,13 @@
#define HVM_DEBUG 1
#endif
-static inline shared_iopage_t *get_sp(struct domain *d)
-{
- return (shared_iopage_t *) d->arch.hvm_domain.shared_page_va;
-}
-
-static inline vcpu_iodata_t *get_vio(struct domain *d, unsigned long cpu)
-{
- return &get_sp(d)->vcpu_iodata[cpu];
+static inline vcpu_iodata_t *get_ioreq(struct vcpu *v)
+{
+ struct domain *d = v->domain;
+ shared_iopage_t *p = d->arch.hvm_domain.ioreq.va;
+ ASSERT((v == current) || spin_is_locked(&d->arch.hvm_domain.ioreq.lock));
+ ASSERT(d->arch.hvm_domain.ioreq.va != NULL);
+ return &p->vcpu_iodata[v->vcpu_id];
}
/* XXX these are really VMX specific */
diff -r d51b3bc40ca5 -r 76f9a8e730ea xen/include/xen/domain_page.h
--- a/xen/include/xen/domain_page.h Fri Apr 13 13:55:10 2007 +0100
+++ b/xen/include/xen/domain_page.h Fri Apr 13 14:59:06 2007 +0100
@@ -33,13 +33,6 @@ void unmap_domain_page(void *va);
*/
void *map_domain_page_global(unsigned long mfn);
void unmap_domain_page_global(void *va);
-
-/*
- * Convert a VA (within a page previously mapped in the context of the
- * currently-executing VCPU via a call to map_domain_page(), or via a
- * previous call to map_domain_page_global()) to the mapped page frame.
- */
-unsigned long mfn_from_mapped_domain_page(void *va);
#define DMCACHE_ENTRY_VALID 1U
#define DMCACHE_ENTRY_HELD 2U
@@ -109,8 +102,6 @@ domain_mmap_cache_destroy(struct domain_
#define map_domain_page_global(mfn) mfn_to_virt(mfn)
#define unmap_domain_page_global(va) ((void)(va))
-#define mfn_from_mapped_domain_page(va) virt_to_mfn(va)
-
struct domain_mmap_cache {
};
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