From: ehrhardt@linux.vnet.ibm.com
To: kvm@vger.kernel.org, avi@redhat.com
Cc: ehrhardt@linux.vnet.ibm.com, borntraeger@de.ibm.com,
cotte@de.ibm.com, heiko.carstens@de.ibm.com,
schwidefsky@de.ibm.com, mtosatti@redhat.com
Subject: [PATCH 3/3] kvm-s390: streamline memslot handling - rebased
Date: Tue, 2 Jun 2009 16:26:11 +0200 [thread overview]
Message-ID: <1243952771-32428-4-git-send-email-ehrhardt@linux.vnet.ibm.com> (raw)
In-Reply-To: <1243952771-32428-1-git-send-email-ehrhardt@linux.vnet.ibm.com>
From: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
As requested this is a rebased patch on top of the already applied v3
of the patch series.
*updates to applied version*
- ensure the wait_on_bit waiter is notified
- ensure dropping vcpu all requests while freeing a vcpu
- kickout only scheduled vcpus (its superfluous and wait might hang forever on
not running vcpus)
- kvm_arch_set_memory_region waits until the bit is consumed by the vcpu
This patch relocates the variables kvm-s390 uses to track guest mem addr/size.
As discussed dropping the variables at struct kvm_arch level allows to use the
common vcpu->request based mechanism to reload guest memory if e.g. changes
via set_memory_region.
The kick mechanism introduced in this series is used to ensure running vcpus
leave guest state to catch the update.
Signed-off-by: Christian Ehrhardt <ehrhardt@linux.vnet.ibm.com>
---
[diffstat]
arch/s390/kvm/kvm-s390.c | 27 ++++++++++++++++++++-------
arch/s390/kvm/kvm-s390.h | 7 +++++++
virt/kvm/kvm_main.c | 4 ++++
3 files changed, 31 insertions(+), 7 deletions(-)
Index: kvm/arch/s390/kvm/kvm-s390.c
===================================================================
--- kvm.orig/arch/s390/kvm/kvm-s390.c
+++ kvm/arch/s390/kvm/kvm-s390.c
@@ -674,6 +674,12 @@ long kvm_arch_vcpu_ioctl(struct file *fi
return -EINVAL;
}
+static int wait_bit_schedule(void *word)
+{
+ schedule();
+ return 0;
+}
+
/* Section: memory related */
int kvm_arch_set_memory_region(struct kvm *kvm,
struct kvm_userspace_memory_region *mem,
@@ -681,6 +687,7 @@ int kvm_arch_set_memory_region(struct kv
int user_alloc)
{
int i;
+ struct kvm_vcpu *vcpu;
/* A few sanity checks. We can have exactly one memory slot which has
to start at guest virtual zero and which has to be located at a
@@ -706,13 +713,19 @@ int kvm_arch_set_memory_region(struct kv
/* request update of sie control block for all available vcpus */
for (i = 0; i < KVM_MAX_VCPUS; ++i) {
- if (kvm->vcpus[i]) {
- if (test_and_set_bit(KVM_REQ_MMU_RELOAD,
- &kvm->vcpus[i]->requests))
- continue;
- kvm_s390_inject_sigp_stop(kvm->vcpus[i],
- ACTION_VCPUREQUEST_ON_STOP);
- }
+ vcpu = kvm->vcpus[i];
+ if (!vcpu)
+ continue;
+
+ if (!test_and_set_bit(KVM_REQ_MMU_RELOAD, &vcpu->requests))
+ continue;
+
+ if (vcpu->cpu == -1)
+ continue;
+
+ kvm_s390_inject_sigp_stop(vcpu, ACTION_VCPUREQUEST_ON_STOP);
+ wait_on_bit(&vcpu->requests, KVM_REQ_MMU_RELOAD,
+ wait_bit_schedule, TASK_UNINTERRUPTIBLE);
}
return 0;
Index: kvm/arch/s390/kvm/kvm-s390.h
===================================================================
--- kvm.orig/arch/s390/kvm/kvm-s390.h
+++ kvm/arch/s390/kvm/kvm-s390.h
@@ -92,6 +92,13 @@ static inline unsigned long kvm_s390_han
if (!vcpu->requests)
return 0;
+ /* requests that can be handled at all levels */
+ if (test_and_clear_bit(KVM_REQ_MMU_RELOAD, &vcpu->requests)) {
+ smp_mb__after_clear_bit();
+ wake_up_bit(&vcpu->requests, KVM_REQ_MMU_RELOAD);
+ kvm_s390_vcpu_set_mem(vcpu);
+ }
+
return vcpu->requests;
}
Index: kvm/virt/kvm/kvm_main.c
===================================================================
--- kvm.orig/virt/kvm/kvm_main.c
+++ kvm/virt/kvm/kvm_main.c
@@ -1682,6 +1682,10 @@ static int kvm_vcpu_release(struct inode
{
struct kvm_vcpu *vcpu = filp->private_data;
+ clear_bit(KVM_REQ_MMU_RELOAD, &vcpu->requests);
+ smp_mb__after_clear_bit();
+ wake_up_bit(&vcpu->requests, KVM_REQ_MMU_RELOAD);
+
kvm_put_kvm(vcpu->kvm);
return 0;
}
next prev parent reply other threads:[~2009-06-02 14:26 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2009-06-02 14:26 [PATCH 0/3] kvm-s390: revised version of kvm-s390 guest memory handling - rebased ehrhardt
2009-06-02 14:26 ` [PATCH 1/3] kvm-s390: infrastructure to kick vcpus out of guest state " ehrhardt
2009-06-02 14:26 ` [PATCH 2/3] kvm-s390: update vcpu->cpu " ehrhardt
2009-06-02 14:26 ` ehrhardt [this message]
2009-06-05 20:53 ` [PATCH 3/3] kvm-s390: streamline memslot handling " Marcelo Tosatti
2009-06-08 10:51 ` Christian Ehrhardt
2009-06-08 11:10 ` Avi Kivity
2009-06-08 12:05 ` Christian Ehrhardt
2009-06-08 12:09 ` Avi Kivity
2009-06-09 0:56 ` Marcelo Tosatti
2009-06-14 12:04 ` Avi Kivity
2009-06-15 13:47 ` Christian Ehrhardt
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