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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v8 02/11] x86/hvm/ioreq: simplify code and use consistent naming
This patch re-works much of the ioreq server initialization and teardown
code:
- The hvm_map/unmap_ioreq_gfn() functions are expanded to call through
to hvm_alloc/free_ioreq_gfn() rather than expecting them to be called
separately by outer functions.
- Several functions now test the validity of the hvm_ioreq_page gfn value
to determine whether they need to act. This means can be safely called
for the bufioreq page even when it is not used.
- hvm_add/remove_ioreq_gfn() simply return in the case of the default
IOREQ server so callers no longer need to test before calling.
- hvm_ioreq_server_setup_pages() is renamed to hvm_ioreq_server_map_pages()
to mirror the existing hvm_ioreq_server_unmap_pages().
All of this significantly shortens the code.
Signed-off-by: Paul Durrant <paul.durrant@xxxxxxxxxx>
Reviewed-by: Roger Pau Monné <roger.pau@xxxxxxxxxx>
Reviewed-by: Wei Liu <wei.liu2@xxxxxxxxxx>
Acked-by: Jan Beulich <jbeulich@xxxxxxxx>
---
Cc: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
v3:
- Rebased on top of 's->is_default' to 'IS_DEFAULT(s)' changes.
- Minor updates in response to review comments from Roger.
---
xen/arch/x86/hvm/ioreq.c | 182 ++++++++++++++++++-----------------------------
1 file changed, 69 insertions(+), 113 deletions(-)
diff --git a/xen/arch/x86/hvm/ioreq.c b/xen/arch/x86/hvm/ioreq.c
index e655d2eab3..6ac4ba20ff 100644
--- a/xen/arch/x86/hvm/ioreq.c
+++ b/xen/arch/x86/hvm/ioreq.c
@@ -220,63 +220,75 @@ bool handle_hvm_io_completion(struct vcpu *v)
return true;
}
-static int hvm_alloc_ioreq_gfn(struct domain *d, unsigned long *gfn)
+static unsigned long hvm_alloc_ioreq_gfn(struct hvm_ioreq_server *s)
{
+ struct domain *d = s->domain;
unsigned int i;
- int rc;
- rc = -ENOMEM;
+ ASSERT(!IS_DEFAULT(s));
+
for ( i = 0; i < sizeof(d->arch.hvm_domain.ioreq_gfn.mask) * 8; i++ )
{
if ( test_and_clear_bit(i, &d->arch.hvm_domain.ioreq_gfn.mask) )
- {
- *gfn = d->arch.hvm_domain.ioreq_gfn.base + i;
- rc = 0;
- break;
- }
+ return d->arch.hvm_domain.ioreq_gfn.base + i;
}
- return rc;
+ return gfn_x(INVALID_GFN);
}
-static void hvm_free_ioreq_gfn(struct domain *d, unsigned long gfn)
+static void hvm_free_ioreq_gfn(struct hvm_ioreq_server *s,
+ unsigned long gfn)
{
+ struct domain *d = s->domain;
unsigned int i = gfn - d->arch.hvm_domain.ioreq_gfn.base;
- if ( gfn != gfn_x(INVALID_GFN) )
- set_bit(i, &d->arch.hvm_domain.ioreq_gfn.mask);
+ ASSERT(!IS_DEFAULT(s));
+ ASSERT(gfn != gfn_x(INVALID_GFN));
+
+ set_bit(i, &d->arch.hvm_domain.ioreq_gfn.mask);
}
-static void hvm_unmap_ioreq_page(struct hvm_ioreq_server *s, bool buf)
+static void hvm_unmap_ioreq_gfn(struct hvm_ioreq_server *s, bool buf)
{
struct hvm_ioreq_page *iorp = buf ? &s->bufioreq : &s->ioreq;
+ if ( iorp->gfn == gfn_x(INVALID_GFN) )
+ return;
+
destroy_ring_for_helper(&iorp->va, iorp->page);
+ iorp->page = NULL;
+
+ if ( !IS_DEFAULT(s) )
+ hvm_free_ioreq_gfn(s, iorp->gfn);
+
+ iorp->gfn = gfn_x(INVALID_GFN);
}
-static int hvm_map_ioreq_page(
- struct hvm_ioreq_server *s, bool buf, unsigned long gfn)
+static int hvm_map_ioreq_gfn(struct hvm_ioreq_server *s, bool buf)
{
struct domain *d = s->domain;
struct hvm_ioreq_page *iorp = buf ? &s->bufioreq : &s->ioreq;
- struct page_info *page;
- void *va;
int rc;
- if ( (rc = prepare_ring_for_helper(d, gfn, &page, &va)) )
- return rc;
-
- if ( (iorp->va != NULL) || d->is_dying )
- {
- destroy_ring_for_helper(&va, page);
+ if ( d->is_dying )
return -EINVAL;
- }
- iorp->va = va;
- iorp->page = page;
- iorp->gfn = gfn;
+ if ( IS_DEFAULT(s) )
+ iorp->gfn = buf ?
+ d->arch.hvm_domain.params[HVM_PARAM_BUFIOREQ_PFN] :
+ d->arch.hvm_domain.params[HVM_PARAM_IOREQ_PFN];
+ else
+ iorp->gfn = hvm_alloc_ioreq_gfn(s);
- return 0;
+ if ( iorp->gfn == gfn_x(INVALID_GFN) )
+ return -ENOMEM;
+
+ rc = prepare_ring_for_helper(d, iorp->gfn, &iorp->page, &iorp->va);
+
+ if ( rc )
+ hvm_unmap_ioreq_gfn(s, buf);
+
+ return rc;
}
bool is_ioreq_server_page(struct domain *d, const struct page_info *page)
@@ -292,8 +304,7 @@ bool is_ioreq_server_page(struct domain *d, const struct
page_info *page)
if ( !s )
continue;
- if ( (s->ioreq.va && s->ioreq.page == page) ||
- (s->bufioreq.va && s->bufioreq.page == page) )
+ if ( (s->ioreq.page == page) || (s->bufioreq.page == page) )
{
found = true;
break;
@@ -305,20 +316,30 @@ bool is_ioreq_server_page(struct domain *d, const struct
page_info *page)
return found;
}
-static void hvm_remove_ioreq_gfn(
- struct domain *d, struct hvm_ioreq_page *iorp)
+static void hvm_remove_ioreq_gfn(struct hvm_ioreq_server *s, bool buf)
+
{
+ struct domain *d = s->domain;
+ struct hvm_ioreq_page *iorp = buf ? &s->bufioreq : &s->ioreq;
+
+ if ( IS_DEFAULT(s) || iorp->gfn == gfn_x(INVALID_GFN) )
+ return;
+
if ( guest_physmap_remove_page(d, _gfn(iorp->gfn),
_mfn(page_to_mfn(iorp->page)), 0) )
domain_crash(d);
clear_page(iorp->va);
}
-static int hvm_add_ioreq_gfn(
- struct domain *d, struct hvm_ioreq_page *iorp)
+static int hvm_add_ioreq_gfn(struct hvm_ioreq_server *s, bool buf)
{
+ struct domain *d = s->domain;
+ struct hvm_ioreq_page *iorp = buf ? &s->bufioreq : &s->ioreq;
int rc;
+ if ( IS_DEFAULT(s) || iorp->gfn == gfn_x(INVALID_GFN) )
+ return 0;
+
clear_page(iorp->va);
rc = guest_physmap_add_page(d, _gfn(iorp->gfn),
@@ -453,78 +474,25 @@ static void hvm_ioreq_server_remove_all_vcpus(struct
hvm_ioreq_server *s)
}
static int hvm_ioreq_server_map_pages(struct hvm_ioreq_server *s,
- unsigned long ioreq_gfn,
- unsigned long bufioreq_gfn)
+ bool handle_bufioreq)
{
int rc;
- rc = hvm_map_ioreq_page(s, false, ioreq_gfn);
- if ( rc )
- return rc;
-
- if ( bufioreq_gfn != gfn_x(INVALID_GFN) )
- rc = hvm_map_ioreq_page(s, true, bufioreq_gfn);
-
- if ( rc )
- hvm_unmap_ioreq_page(s, false);
-
- return rc;
-}
-
-static int hvm_ioreq_server_setup_pages(struct hvm_ioreq_server *s,
- bool handle_bufioreq)
-{
- struct domain *d = s->domain;
- unsigned long ioreq_gfn = gfn_x(INVALID_GFN);
- unsigned long bufioreq_gfn = gfn_x(INVALID_GFN);
- int rc;
-
- if ( IS_DEFAULT(s) )
- {
- /*
- * The default ioreq server must handle buffered ioreqs, for
- * backwards compatibility.
- */
- ASSERT(handle_bufioreq);
- return hvm_ioreq_server_map_pages(s,
- d->arch.hvm_domain.params[HVM_PARAM_IOREQ_PFN],
- d->arch.hvm_domain.params[HVM_PARAM_BUFIOREQ_PFN]);
- }
-
- rc = hvm_alloc_ioreq_gfn(d, &ioreq_gfn);
+ rc = hvm_map_ioreq_gfn(s, false);
if ( !rc && handle_bufioreq )
- rc = hvm_alloc_ioreq_gfn(d, &bufioreq_gfn);
-
- if ( !rc )
- rc = hvm_ioreq_server_map_pages(s, ioreq_gfn, bufioreq_gfn);
+ rc = hvm_map_ioreq_gfn(s, true);
if ( rc )
- {
- hvm_free_ioreq_gfn(d, ioreq_gfn);
- hvm_free_ioreq_gfn(d, bufioreq_gfn);
- }
+ hvm_unmap_ioreq_gfn(s, false);
return rc;
}
static void hvm_ioreq_server_unmap_pages(struct hvm_ioreq_server *s)
{
- struct domain *d = s->domain;
- bool handle_bufioreq = !!s->bufioreq.va;
-
- if ( handle_bufioreq )
- hvm_unmap_ioreq_page(s, true);
-
- hvm_unmap_ioreq_page(s, false);
-
- if ( !IS_DEFAULT(s) )
- {
- if ( handle_bufioreq )
- hvm_free_ioreq_gfn(d, s->bufioreq.gfn);
-
- hvm_free_ioreq_gfn(d, s->ioreq.gfn);
- }
+ hvm_unmap_ioreq_gfn(s, true);
+ hvm_unmap_ioreq_gfn(s, false);
}
static void hvm_ioreq_server_free_rangesets(struct hvm_ioreq_server *s)
@@ -584,22 +552,15 @@ static int hvm_ioreq_server_alloc_rangesets(struct
hvm_ioreq_server *s,
static void hvm_ioreq_server_enable(struct hvm_ioreq_server *s)
{
- struct domain *d = s->domain;
struct hvm_ioreq_vcpu *sv;
- bool handle_bufioreq = !!s->bufioreq.va;
spin_lock(&s->lock);
if ( s->enabled )
goto done;
- if ( !IS_DEFAULT(s) )
- {
- hvm_remove_ioreq_gfn(d, &s->ioreq);
-
- if ( handle_bufioreq )
- hvm_remove_ioreq_gfn(d, &s->bufioreq);
- }
+ hvm_remove_ioreq_gfn(s, false);
+ hvm_remove_ioreq_gfn(s, true);
s->enabled = true;
@@ -614,21 +575,13 @@ static void hvm_ioreq_server_enable(struct
hvm_ioreq_server *s)
static void hvm_ioreq_server_disable(struct hvm_ioreq_server *s)
{
- struct domain *d = s->domain;
- bool handle_bufioreq = !!s->bufioreq.va;
-
spin_lock(&s->lock);
if ( !s->enabled )
goto done;
- if ( !IS_DEFAULT(s) )
- {
- if ( handle_bufioreq )
- hvm_add_ioreq_gfn(d, &s->bufioreq);
-
- hvm_add_ioreq_gfn(d, &s->ioreq);
- }
+ hvm_add_ioreq_gfn(s, true);
+ hvm_add_ioreq_gfn(s, false);
s->enabled = false;
@@ -650,6 +603,9 @@ static int hvm_ioreq_server_init(struct hvm_ioreq_server *s,
INIT_LIST_HEAD(&s->ioreq_vcpu_list);
spin_lock_init(&s->bufioreq_lock);
+ s->ioreq.gfn = gfn_x(INVALID_GFN);
+ s->bufioreq.gfn = gfn_x(INVALID_GFN);
+
rc = hvm_ioreq_server_alloc_rangesets(s, id);
if ( rc )
return rc;
@@ -657,7 +613,7 @@ static int hvm_ioreq_server_init(struct hvm_ioreq_server *s,
if ( bufioreq_handling == HVM_IOREQSRV_BUFIOREQ_ATOMIC )
s->bufioreq_atomic = true;
- rc = hvm_ioreq_server_setup_pages(
+ rc = hvm_ioreq_server_map_pages(
s, bufioreq_handling != HVM_IOREQSRV_BUFIOREQ_OFF);
if ( rc )
goto fail_map;
--
2.11.0
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