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[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-changelog] [xen stable-4.4] x86: make hypercall preemption checks consistent
commit a2dba07f50af42863be0d50fc1a520950531527d
Author: Jan Beulich <jbeulich@xxxxxxxx>
AuthorDate: Fri Apr 4 10:40:37 2014 +0200
Commit: Jan Beulich <jbeulich@xxxxxxxx>
CommitDate: Fri Apr 4 10:40:37 2014 +0200
x86: make hypercall preemption checks consistent
- never preempt on the first iteration (ensure forward progress)
- never preempt on the last iteration (pointless/wasteful)
Signed-off-by: Jan Beulich <jbeulich@xxxxxxxx>
Reviewed-by: Andrew Cooper <andrew.cooper3@xxxxxxxxxx>
Reviewed-by: Tim Deegan <tim@xxxxxxx>
Acked-by: Keir Fraser <keir@xxxxxxx>
master commit: fd7bfce0395ace266159760e35dc49f7af3b90ce
master date: 2014-03-13 14:27:51 +0100
---
xen/arch/x86/mm.c | 4 ++--
xen/arch/x86/mm/hap/hap.c | 4 +++-
xen/arch/x86/mm/p2m-pod.c | 6 ++++--
xen/arch/x86/mm/shadow/common.c | 4 +++-
xen/arch/x86/traps.c | 14 +++++++-------
xen/arch/x86/x86_64/compat/traps.c | 14 +++++++-------
6 files changed, 26 insertions(+), 20 deletions(-)
diff --git a/xen/arch/x86/mm.c b/xen/arch/x86/mm.c
index 172c68c..fdc5ed3 100644
--- a/xen/arch/x86/mm.c
+++ b/xen/arch/x86/mm.c
@@ -2934,7 +2934,7 @@ long do_mmuext_op(
for ( i = 0; i < count; i++ )
{
- if ( curr->arch.old_guest_table || hypercall_preempt_check() )
+ if ( curr->arch.old_guest_table || (i && hypercall_preempt_check()) )
{
rc = -EAGAIN;
break;
@@ -3481,7 +3481,7 @@ long do_mmu_update(
for ( i = 0; i < count; i++ )
{
- if ( curr->arch.old_guest_table || hypercall_preempt_check() )
+ if ( curr->arch.old_guest_table || (i && hypercall_preempt_check()) )
{
rc = -EAGAIN;
break;
diff --git a/xen/arch/x86/mm/hap/hap.c b/xen/arch/x86/mm/hap/hap.c
index 5f75636..b8c5422 100644
--- a/xen/arch/x86/mm/hap/hap.c
+++ b/xen/arch/x86/mm/hap/hap.c
@@ -326,7 +326,7 @@ hap_set_allocation(struct domain *d, unsigned int pages,
int *preempted)
else
pages -= d->arch.paging.hap.p2m_pages;
- while ( d->arch.paging.hap.total_pages != pages )
+ for ( ; ; )
{
if ( d->arch.paging.hap.total_pages < pages )
{
@@ -355,6 +355,8 @@ hap_set_allocation(struct domain *d, unsigned int pages,
int *preempted)
d->arch.paging.hap.total_pages--;
free_domheap_page(pg);
}
+ else
+ break;
/* Check to see if we need to yield and try again */
if ( preempted && hypercall_preempt_check() )
diff --git a/xen/arch/x86/mm/p2m-pod.c b/xen/arch/x86/mm/p2m-pod.c
index 81645c4..d14565d 100644
--- a/xen/arch/x86/mm/p2m-pod.c
+++ b/xen/arch/x86/mm/p2m-pod.c
@@ -242,7 +242,8 @@ p2m_pod_set_cache_target(struct p2m_domain *p2m, unsigned
long pod_target, int p
p2m_pod_cache_add(p2m, page, order);
- if ( hypercall_preempt_check() && preemptible )
+ if ( preemptible && pod_target != p2m->pod.count &&
+ hypercall_preempt_check() )
{
ret = -EAGAIN;
goto out;
@@ -286,7 +287,8 @@ p2m_pod_set_cache_target(struct p2m_domain *p2m, unsigned
long pod_target, int p
put_page(page+i);
- if ( hypercall_preempt_check() && preemptible )
+ if ( preemptible && pod_target != p2m->pod.count &&
+ hypercall_preempt_check() )
{
ret = -EAGAIN;
goto out;
diff --git a/xen/arch/x86/mm/shadow/common.c b/xen/arch/x86/mm/shadow/common.c
index 11c6b62..f4d4a50 100644
--- a/xen/arch/x86/mm/shadow/common.c
+++ b/xen/arch/x86/mm/shadow/common.c
@@ -1674,7 +1674,7 @@ static unsigned int sh_set_allocation(struct domain *d,
SHADOW_PRINTK("current %i target %i\n",
d->arch.paging.shadow.total_pages, pages);
- while ( d->arch.paging.shadow.total_pages != pages )
+ for ( ; ; )
{
if ( d->arch.paging.shadow.total_pages < pages )
{
@@ -1709,6 +1709,8 @@ static unsigned int sh_set_allocation(struct domain *d,
d->arch.paging.shadow.total_pages--;
free_domheap_page(sp);
}
+ else
+ break;
/* Check to see if we need to yield and try again */
if ( preempted && hypercall_preempt_check() )
diff --git a/xen/arch/x86/traps.c b/xen/arch/x86/traps.c
index 0bd43b9..4d27e12 100644
--- a/xen/arch/x86/traps.c
+++ b/xen/arch/x86/traps.c
@@ -3595,13 +3595,6 @@ long
do_set_trap_table(XEN_GUEST_HANDLE_PARAM(const_trap_info_t) traps)
for ( ; ; )
{
- if ( hypercall_preempt_check() )
- {
- rc = hypercall_create_continuation(
- __HYPERVISOR_set_trap_table, "h", traps);
- break;
- }
-
if ( copy_from_guest(&cur, traps, 1) )
{
rc = -EFAULT;
@@ -3622,6 +3615,13 @@ long
do_set_trap_table(XEN_GUEST_HANDLE_PARAM(const_trap_info_t) traps)
init_int80_direct_trap(curr);
guest_handle_add_offset(traps, 1);
+
+ if ( hypercall_preempt_check() )
+ {
+ rc = hypercall_create_continuation(
+ __HYPERVISOR_set_trap_table, "h", traps);
+ break;
+ }
}
return rc;
diff --git a/xen/arch/x86/x86_64/compat/traps.c
b/xen/arch/x86/x86_64/compat/traps.c
index 21a82b9..5f0ea0a 100644
--- a/xen/arch/x86/x86_64/compat/traps.c
+++ b/xen/arch/x86/x86_64/compat/traps.c
@@ -329,13 +329,6 @@ int
compat_set_trap_table(XEN_GUEST_HANDLE(trap_info_compat_t) traps)
for ( ; ; )
{
- if ( hypercall_preempt_check() )
- {
- rc = hypercall_create_continuation(
- __HYPERVISOR_set_trap_table, "h", traps);
- break;
- }
-
if ( copy_from_guest(&cur, traps, 1) )
{
rc = -EFAULT;
@@ -353,6 +346,13 @@ int
compat_set_trap_table(XEN_GUEST_HANDLE(trap_info_compat_t) traps)
init_int80_direct_trap(current);
guest_handle_add_offset(traps, 1);
+
+ if ( hypercall_preempt_check() )
+ {
+ rc = hypercall_create_continuation(
+ __HYPERVISOR_set_trap_table, "h", traps);
+ break;
+ }
}
return rc;
--
generated by git-patchbot for /home/xen/git/xen.git#stable-4.4
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