[PATCH 029/104] KVM: Convert vm lock to a mutex

Avi Kivity
2007-09-17T08:31:11Z

From: Shaohua Li <shaohua.li-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>

This allows the kvm mmu to perform sleepy operations, such as memory
allocation.

Signed-off-by: Shaohua Li <shaohua.li-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Signed-off-by: Avi Kivity <avi-atKUWr5tajBWk0Htik3J/w@public.gmane.org>
---
drivers/kvm/kvm.h | 2 +-
drivers/kvm/kvm_main.c | 69 +++++++++++++++++++++++-------------------------
drivers/kvm/mmu.c | 9 +++---
drivers/kvm/svm.c | 8 +++---
drivers/kvm/vmx.c | 8 +++---
5 files changed, 46 insertions(+), 50 deletions(-)

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 0667183..1072c83 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -393,7 +393,7 @@ struct kvm_memory_slot {
};

struct kvm {
- spinlock_t lock; /* protects everything except vcpus */
+ struct mutex lock; /* protects everything except vcpus */
int naliases;
struct kvm_mem_alias aliases[KVM_ALIAS_SLOTS];
int nmemslots;
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 6035e6d..7aeaaba 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -363,7 +363,7 @@ static struct kvm *kvm_create_vm(void)
return ERR_PTR(-ENOMEM);

kvm_io_bus_init(&kvm->pio_bus);
- spin_lock_init(&kvm->lock);
+ mutex_init(&kvm->lock);
INIT_LIST_HEAD(&kvm->active_mmu_pages);
kvm_io_bus_init(&kvm->mmio_bus);
spin_lock(&kvm_lock);
@@ -489,7 +489,7 @@ static int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3)
struct page *page;
u64 pdpte[ARRAY_SIZE(vcpu->pdptrs)];

- spin_lock(&vcpu->kvm->lock);
+ mutex_lock(&vcpu->kvm->lock);
page = gfn_to_page(vcpu->kvm, pdpt_gfn);
if (!page) {
ret = 0;
@@ -510,7 +510,7 @@ static int load_pdptrs(struct kvm_vcpu *vcpu, unsigned long cr3)

memcpy(vcpu->pdptrs, pdpte, sizeof(vcpu->pdptrs));
out:
- spin_unlock(&vcpu->kvm->lock);
+ mutex_unlock(&vcpu->kvm->lock);

return ret;
}
@@ -570,9 +570,9 @@ void set_cr0(struct kvm_vcpu *vcpu, unsigned long cr0)
kvm_arch_ops->set_cr0(vcpu, cr0);
vcpu->cr0 = cr0;

- spin_lock(&vcpu->kvm->lock);
+ mutex_lock(&vcpu->kvm->lock);
kvm_mmu_reset_context(vcpu);
- spin_unlock(&vcpu->kvm->lock);
+ mutex_unlock(&vcpu->kvm->lock);
return;
}
EXPORT_SYMBOL_GPL(set_cr0);
@@ -611,9 +611,9 @@ void set_cr4(struct kvm_vcpu *vcpu, unsigned long cr4)
return;
}
kvm_arch_ops->set_cr4(vcpu, cr4);
- spin_lock(&vcpu->kvm->lock);
+ mutex_lock(&vcpu->kvm->lock);
kvm_mmu_reset_context(vcpu);
- spin_unlock(&vcpu->kvm->lock);
+ mutex_unlock(&vcpu->kvm->lock);
}
EXPORT_SYMBOL_GPL(set_cr4);

@@ -650,7 +650,7 @@ void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
}

vcpu->cr3 = cr3;
- spin_lock(&vcpu->kvm->lock);
+ mutex_lock(&vcpu->kvm->lock);
/*
* Does the new cr3 value map to physical memory? (Note, we
* catch an invalid cr3 even in real-mode, because it would
@@ -664,7 +664,7 @@ void set_cr3(struct kvm_vcpu *vcpu, unsigned long cr3)
inject_gp(vcpu);
else
vcpu->mmu.new_cr3(vcpu);
- spin_unlock(&vcpu->kvm->lock);
+ mutex_unlock(&vcpu->kvm->lock);
}
EXPORT_SYMBOL_GPL(set_cr3);

@@ -741,7 +741,7 @@ static int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
mem->flags &= ~KVM_MEM_LOG_DIRTY_PAGES;

raced:
- spin_lock(&kvm->lock);
+ mutex_lock(&kvm->lock);

memory_config_version = kvm->memory_config_version;
new = old = *memslot;
@@ -770,7 +770,7 @@ raced:
* Do memory allocations outside lock. memory_config_version will
* detect any races.
*/
- spin_unlock(&kvm->lock);
+ mutex_unlock(&kvm->lock);

/* Deallocate if slot is being removed */
if (!npages)
@@ -809,10 +809,10 @@ raced:
memset(new.dirty_bitmap, 0, dirty_bytes);
}

- spin_lock(&kvm->lock);
+ mutex_lock(&kvm->lock);

if (memory_config_version != kvm->memory_config_version) {
- spin_unlock(&kvm->lock);
+ mutex_unlock(&kvm->lock);
kvm_free_physmem_slot(&new, &old);
goto raced;
}
@@ -830,13 +830,13 @@ raced:
kvm_mmu_slot_remove_write_access(kvm, mem->slot);
kvm_flush_remote_tlbs(kvm);

- spin_unlock(&kvm->lock);
+ mutex_unlock(&kvm->lock);

kvm_free_physmem_slot(&old, &new);
return 0;

out_unlock:
- spin_unlock(&kvm->lock);
+ mutex_unlock(&kvm->lock);
out_free:
kvm_free_physmem_slot(&new, &old);
out:
@@ -854,14 +854,14 @@ static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
int n;
unsigned long any = 0;

- spin_lock(&kvm->lock);
+ mutex_lock(&kvm->lock);

/*
* Prevent changes to guest memory configuration even while the lock
* is not taken.
*/
++kvm->busy;
- spin_unlock(&kvm->lock);
+ mutex_unlock(&kvm->lock);
r = -EINVAL;
if (log->slot >= KVM_MEMORY_SLOTS)
goto out;
@@ -880,18 +880,18 @@ static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
goto out;

- spin_lock(&kvm->lock);
+ mutex_lock(&kvm->lock);
kvm_mmu_slot_remove_write_access(kvm, log->slot);
kvm_flush_remote_tlbs(kvm);
memset(memslot->dirty_bitmap, 0, n);
- spin_unlock(&kvm->lock);
+ mutex_unlock(&kvm->lock);

r = 0;

out:
- spin_lock(&kvm->lock);
+ mutex_lock(&kvm->lock);
--kvm->busy;
- spin_unlock(&kvm->lock);
+ mutex_unlock(&kvm->lock);
return r;
}

@@ -921,7 +921,7 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm,
< alias->target_phys_addr)
goto out;

- spin_lock(&kvm->lock);
+ mutex_lock(&kvm->lock);

p = &kvm->aliases[alias->slot];
p->base_gfn = alias->guest_phys_addr >> PAGE_SHIFT;
@@ -935,7 +935,7 @@ static int kvm_vm_ioctl_set_memory_alias(struct kvm *kvm,

kvm_mmu_zap_all(kvm);

- spin_unlock(&kvm->lock);
+ mutex_unlock(&kvm->lock);

return 0;

@@ -1900,12 +1900,12 @@ int kvm_setup_pio(struct kvm_vcpu *vcpu, struct kvm_run *run, int in,
vcpu->pio.cur_count = now;

for (i = 0; i < nr_pages; ++i) {
- spin_lock(&vcpu->kvm->lock);
+ mutex_lock(&vcpu->kvm->lock);
page = gva_to_page(vcpu, address + i * PAGE_SIZE);
if (page)
get_page(page);
vcpu->pio.guest_pages[i] = page;
- spin_unlock(&vcpu->kvm->lock);
+ mutex_unlock(&vcpu->kvm->lock);
if (!page) {
inject_gp(vcpu);
free_pio_guest_pages(vcpu);
@@ -2298,13 +2298,13 @@ static int kvm_vcpu_ioctl_translate(struct kvm_vcpu *vcpu,
gpa_t gpa;

vcpu_load(vcpu);
- spin_lock(&vcpu->kvm->lock);
+ mutex_lock(&vcpu->kvm->lock);
gpa = vcpu->mmu.gva_to_gpa(vcpu, vaddr);
tr->physical_address = gpa;
tr->valid = gpa != UNMAPPED_GVA;
tr->writeable = 1;
tr->usermode = 0;
- spin_unlock(&vcpu->kvm->lock);
+ mutex_unlock(&vcpu->kvm->lock);
vcpu_put(vcpu);

return 0;
@@ -2426,14 +2426,14 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
if (r < 0)
goto free_vcpu;

- spin_lock(&kvm->lock);
+ mutex_lock(&kvm->lock);
if (kvm->vcpus[n]) {
r = -EEXIST;
- spin_unlock(&kvm->lock);
+ mutex_unlock(&kvm->lock);
goto mmu_unload;
}
kvm->vcpus[n] = vcpu;
- spin_unlock(&kvm->lock);
+ mutex_unlock(&kvm->lock);

/* Now it's all set up, let userspace reach it */
r = create_vcpu_fd(vcpu);
@@ -2442,9 +2442,9 @@ static int kvm_vm_ioctl_create_vcpu(struct kvm *kvm, int n)
return r;

unlink:
- spin_lock(&kvm->lock);
+ mutex_lock(&kvm->lock);
kvm->vcpus[n] = NULL;
- spin_unlock(&kvm->lock);
+ mutex_unlock(&kvm->lock);

mmu_unload:
vcpu_load(vcpu);
@@ -2945,8 +2945,7 @@ static void decache_vcpus_on_cpu(int cpu)
int i;

spin_lock(&kvm_lock);
- list_for_each_entry(vm, &vm_list, vm_list) {
- spin_lock(&vm->lock);
+ list_for_each_entry(vm, &vm_list, vm_list)
for (i = 0; i < KVM_MAX_VCPUS; ++i) {
vcpu = vm->vcpus[i];
if (!vcpu)
@@ -2967,8 +2966,6 @@ static void decache_vcpus_on_cpu(int cpu)
mutex_unlock(&vcpu->mutex);
}
}
- spin_unlock(&vm->lock);
- }
spin_unlock(&kvm_lock);
}

diff --git a/drivers/kvm/mmu.c b/drivers/kvm/mmu.c
index 396c736..e303b41 100644
--- a/drivers/kvm/mmu.c
+++ b/drivers/kvm/mmu.c
@@ -275,10 +275,9 @@ static int mmu_topup_memory_caches(struct kvm_vcpu *vcpu)
r = __mmu_topup_memory_caches(vcpu, GFP_NOWAIT);
kvm_mmu_free_some_pages(vcpu);
if (r < 0) {
- spin_unlock(&vcpu->kvm->lock);
+ mutex_unlock(&vcpu->kvm->lock);
r = __mmu_topup_memory_caches(vcpu, GFP_KERNEL);
- spin_lock(&vcpu->kvm->lock);
- kvm_mmu_free_some_pages(vcpu);
+ mutex_lock(&vcpu->kvm->lock);
}
return r;
}
@@ -1069,7 +1068,7 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu)
{
int r;

- spin_lock(&vcpu->kvm->lock);
+ mutex_lock(&vcpu->kvm->lock);
r = mmu_topup_memory_caches(vcpu);
if (r)
goto out;
@@ -1077,7 +1076,7 @@ int kvm_mmu_load(struct kvm_vcpu *vcpu)
kvm_arch_ops->set_cr3(vcpu, vcpu->mmu.root_hpa);
kvm_mmu_flush_tlb(vcpu);
out:
- spin_unlock(&vcpu->kvm->lock);
+ mutex_unlock(&vcpu->kvm->lock);
return r;
}
EXPORT_SYMBOL_GPL(kvm_mmu_load);
diff --git a/drivers/kvm/svm.c b/drivers/kvm/svm.c
index 3997bbd..9a840e0 100644
--- a/drivers/kvm/svm.c
+++ b/drivers/kvm/svm.c
@@ -941,21 +941,21 @@ static int pf_interception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
if (is_external_interrupt(exit_int_info))
push_irq(vcpu, exit_int_info & SVM_EVTINJ_VEC_MASK);

- spin_lock(&vcpu->kvm->lock);
+ mutex_lock(&vcpu->kvm->lock);

fault_address = svm->vmcb->control.exit_info_2;
error_code = svm->vmcb->control.exit_info_1;
r = kvm_mmu_page_fault(vcpu, fault_address, error_code);
if (r < 0) {
- spin_unlock(&vcpu->kvm->lock);
+ mutex_unlock(&vcpu->kvm->lock);
return r;
}
if (!r) {
- spin_unlock(&vcpu->kvm->lock);
+ mutex_unlock(&vcpu->kvm->lock);
return 1;
}
er = emulate_instruction(vcpu, kvm_run, fault_address, error_code);
- spin_unlock(&vcpu->kvm->lock);
+ mutex_unlock(&vcpu->kvm->lock);

switch (er) {
case EMULATE_DONE:
diff --git a/drivers/kvm/vmx.c b/drivers/kvm/vmx.c
index 8c87d20..5b77d9b 100644
--- a/drivers/kvm/vmx.c
+++ b/drivers/kvm/vmx.c
@@ -1711,19 +1711,19 @@ static int handle_exception(struct kvm_vcpu *vcpu, struct kvm_run *kvm_run)
if (is_page_fault(intr_info)) {
cr2 = vmcs_readl(EXIT_QUALIFICATION);

- spin_lock(&vcpu->kvm->lock);
+ mutex_lock(&vcpu->kvm->lock);
r = kvm_mmu_page_fault(vcpu, cr2, error_code);
if (r < 0) {
- spin_unlock(&vcpu->kvm->lock);
+ mutex_unlock(&vcpu->kvm->lock);
return r;
}
if (!r) {
- spin_unlock(&vcpu->kvm->lock);
+ mutex_unlock(&vcpu->kvm->lock);
return 1;
}

er = emulate_instruction(vcpu, kvm_run, cr2, error_code);
- spin_unlock(&vcpu->kvm->lock);
+ mutex_unlock(&vcpu->kvm->lock);

switch (er) {