[PATCH 4/6] KVM: set_memory_region: Refactor prepare_memory_region()

Takuya Yoshikawa
2013-02-27T10:45:20Z

This patch drops the parameter old, a copy of the old memory slot, and
adds a new parameter named change to know the change being requested.

This not only cleans up the code but also removes extra copying of the
memory slot structure.

Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
---
arch/arm/kvm/arm.c | 4 ++--
arch/ia64/kvm/kvm-ia64.c | 4 ++--
arch/powerpc/kvm/powerpc.c | 4 ++--
arch/s390/kvm/kvm-s390.c | 4 ++--
arch/x86/kvm/x86.c | 10 ++++------
include/linux/kvm_host.h | 4 ++--
virt/kvm/kvm_main.c | 2 +-
7 files changed, 15 insertions(+), 17 deletions(-)

diff --git a/arch/arm/kvm/arm.c b/arch/arm/kvm/arm.c
index 24cb5f6..96ebab7 100644
--- a/arch/arm/kvm/arm.c
+++ b/arch/arm/kvm/arm.c
@@ -230,8 +230,8 @@ int kvm_arch_set_memory_region(struct kvm *kvm,

int kvm_arch_prepare_memory_region(struct kvm *kvm,
struct kvm_memory_slot *memslot,
- struct kvm_memory_slot old,
- struct kvm_userspace_memory_region *mem)
+ struct kvm_userspace_memory_region *mem,
+ enum kvm_mr_change change)
{
return 0;
}
diff --git a/arch/ia64/kvm/kvm-ia64.c b/arch/ia64/kvm/kvm-ia64.c
index 43701f0..5c2b07e 100644
--- a/arch/ia64/kvm/kvm-ia64.c
+++ b/arch/ia64/kvm/kvm-ia64.c
@@ -1560,8 +1560,8 @@ int kvm_arch_create_memslot(struct kvm_memory_slot *slot, unsigned long npages)

int kvm_arch_prepare_memory_region(struct kvm *kvm,
struct kvm_memory_slot *memslot,
- struct kvm_memory_slot old,
- struct kvm_userspace_memory_region *mem)
+ struct kvm_userspace_memory_region *mem,
+ enum kvm_mr_change change)
{
unsigned long i;
unsigned long pfn;
diff --git a/arch/powerpc/kvm/powerpc.c b/arch/powerpc/kvm/powerpc.c
index 22b3315..8aa51cd 100644
--- a/arch/powerpc/kvm/powerpc.c
+++ b/arch/powerpc/kvm/powerpc.c
@@ -412,8 +412,8 @@ int kvm_arch_create_memslot(struct kvm_memory_slot *slot, unsigned long npages)

int kvm_arch_prepare_memory_region(struct kvm *kvm,
struct kvm_memory_slot *memslot,
- struct kvm_memory_slot old,
- struct kvm_userspace_memory_region *mem)
+ struct kvm_userspace_memory_region *mem,
+ enum kvm_mr_change change)
{
return kvmppc_core_prepare_memory_region(kvm, memslot, mem);
}
diff --git a/arch/s390/kvm/kvm-s390.c b/arch/s390/kvm/kvm-s390.c
index 07ac302..4288780 100644
--- a/arch/s390/kvm/kvm-s390.c
+++ b/arch/s390/kvm/kvm-s390.c
@@ -974,8 +974,8 @@ int kvm_arch_create_memslot(struct kvm_memory_slot *slot, unsigned long npages)
/* Section: memory related */
int kvm_arch_prepare_memory_region(struct kvm *kvm,
struct kvm_memory_slot *memslot,
- struct kvm_memory_slot old,
- struct kvm_userspace_memory_region *mem)
+ struct kvm_userspace_memory_region *mem,
+ enum kvm_mr_change change)
{
/* 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
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index b2dcb6e..d692be2 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6906,23 +6906,21 @@ out_free:

int kvm_arch_prepare_memory_region(struct kvm *kvm,
struct kvm_memory_slot *memslot,
- struct kvm_memory_slot old,
- struct kvm_userspace_memory_region *mem)
+ struct kvm_userspace_memory_region *mem,
+ enum kvm_mr_change change)
{
- int npages = memslot->npages;
-
/*
* Only private memory slots need to be mapped here since
* KVM_SET_MEMORY_REGION ioctl is no longer supported.
*/
- if ((memslot->id >= KVM_USER_MEM_SLOTS) && npages && !old.npages) {
+ if ((memslot->id >= KVM_USER_MEM_SLOTS) && (change == KVM_MR_CREATE)) {
unsigned long userspace_addr;

/*
* MAP_SHARED to prevent internal slot pages from being moved
* by fork()/COW.
*/
- userspace_addr = vm_mmap(NULL, 0, npages * PAGE_SIZE,
+ userspace_addr = vm_mmap(NULL, 0, memslot->npages * PAGE_SIZE,
PROT_READ | PROT_WRITE,
MAP_SHARED | MAP_ANONYMOUS, 0);

diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 8eaf61f..caa72cf 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -479,8 +479,8 @@ void kvm_arch_free_memslot(struct kvm_memory_slot *free,
int kvm_arch_create_memslot(struct kvm_memory_slot *slot, unsigned long npages);
int kvm_arch_prepare_memory_region(struct kvm *kvm,
struct kvm_memory_slot *memslot,
- struct kvm_memory_slot old,
- struct kvm_userspace_memory_region *mem);
+ struct kvm_userspace_memory_region *mem,
+ enum kvm_mr_change change);
void kvm_arch_commit_memory_region(struct kvm *kvm,
struct kvm_userspace_memory_region *mem,
struct kvm_memory_slot old);
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index c7979ed..8f85bae 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -856,7 +856,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
slots = old_memslots;
}

- r = kvm_arch_prepare_memory_region(kvm, &new, old, mem);
+ r = kvm_arch_prepare_memory_region(kvm, &new, mem, change);
if (r)
goto out_slots;

--
1.7.4.1