* [PATCH] KVM: Remove user_alloc from struct kvm_memory_slot
@ 2013-02-07 9:55 Takuya Yoshikawa
2013-02-08 23:32 ` Marcelo Tosatti
2013-02-11 9:52 ` Gleb Natapov
0 siblings, 2 replies; 3+ messages in thread
From: Takuya Yoshikawa @ 2013-02-07 9:55 UTC (permalink / raw)
To: mtosatti, gleb; +Cc: kvm
This field was needed to differentiate memory slots created by the new
API, KVM_SET_USER_MEMORY_REGION, from those by the old equivalent,
KVM_SET_MEMORY_REGION, whose support was dropped long before:
commit b74a07beed0e64bfba413dcb70dd6749c57f43dc
KVM: Remove kernel-allocated memory regions
Although we also have private memory slots to which KVM allocates
memory with vm_mmap(), !user_alloc slots in other words, the slot id
should be enough for differentiating them.
Note: corresponding function parameters will be removed later.
Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
---
arch/x86/kvm/x86.c | 37 ++++++++++++++++---------------------
include/linux/kvm_host.h | 1 -
virt/kvm/kvm_main.c | 1 -
3 files changed, 16 insertions(+), 23 deletions(-)
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index 373e17a..3c5bb6f 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -6897,33 +6897,28 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
bool user_alloc)
{
int npages = memslot->npages;
- int map_flags = MAP_PRIVATE | MAP_ANONYMOUS;
- /* Prevent internal slot pages from being moved by fork()/COW. */
- if (memslot->id >= KVM_USER_MEM_SLOTS)
- map_flags = MAP_SHARED | MAP_ANONYMOUS;
-
- /*To keep backward compatibility with older userspace,
- *x86 needs to handle !user_alloc case.
+ /*
+ * Only private memory slots need to be mapped here since
+ * KVM_SET_MEMORY_REGION ioctl is no longer supported.
*/
- if (!user_alloc) {
- if (npages && !old.npages) {
- unsigned long userspace_addr;
+ if ((memslot->id >= KVM_USER_MEM_SLOTS) && npages && !old.npages) {
+ unsigned long userspace_addr;
- userspace_addr = vm_mmap(NULL, 0,
- npages * PAGE_SIZE,
- PROT_READ | PROT_WRITE,
- map_flags,
- 0);
+ /*
+ * MAP_SHARED to prevent internal slot pages from being moved
+ * by fork()/COW.
+ */
+ userspace_addr = vm_mmap(NULL, 0, npages * PAGE_SIZE,
+ PROT_READ | PROT_WRITE,
+ MAP_SHARED | MAP_ANONYMOUS, 0);
- if (IS_ERR((void *)userspace_addr))
- return PTR_ERR((void *)userspace_addr);
+ if (IS_ERR((void *)userspace_addr))
+ return PTR_ERR((void *)userspace_addr);
- memslot->userspace_addr = userspace_addr;
- }
+ memslot->userspace_addr = userspace_addr;
}
-
return 0;
}
@@ -6935,7 +6930,7 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
int nr_mmu_pages = 0, npages = mem->memory_size >> PAGE_SHIFT;
- if (!user_alloc && !old.user_alloc && old.npages && !npages) {
+ if ((mem->slot >= KVM_USER_MEM_SLOTS) && old.npages && !npages) {
int ret;
ret = vm_munmap(old.userspace_addr,
diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
index 0350e0d..722cae7 100644
--- a/include/linux/kvm_host.h
+++ b/include/linux/kvm_host.h
@@ -273,7 +273,6 @@ struct kvm_memory_slot {
unsigned long userspace_addr;
u32 flags;
short id;
- bool user_alloc;
};
static inline unsigned long kvm_dirty_bitmap_bytes(struct kvm_memory_slot *memslot)
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 2e93630..adc68fe 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -839,7 +839,6 @@ int __kvm_set_memory_region(struct kvm *kvm,
r = -ENOMEM;
if (change == KVM_MR_CREATE) {
- new.user_alloc = user_alloc;
new.userspace_addr = mem->userspace_addr;
if (kvm_arch_create_memslot(&new, npages))
--
1.7.5.4
^ permalink raw reply related [flat|nested] 3+ messages in thread
* Re: [PATCH] KVM: Remove user_alloc from struct kvm_memory_slot
2013-02-07 9:55 [PATCH] KVM: Remove user_alloc from struct kvm_memory_slot Takuya Yoshikawa
@ 2013-02-08 23:32 ` Marcelo Tosatti
2013-02-11 9:52 ` Gleb Natapov
1 sibling, 0 replies; 3+ messages in thread
From: Marcelo Tosatti @ 2013-02-08 23:32 UTC (permalink / raw)
To: Takuya Yoshikawa; +Cc: gleb, kvm
On Thu, Feb 07, 2013 at 06:55:57PM +0900, Takuya Yoshikawa wrote:
> This field was needed to differentiate memory slots created by the new
> API, KVM_SET_USER_MEMORY_REGION, from those by the old equivalent,
> KVM_SET_MEMORY_REGION, whose support was dropped long before:
>
> commit b74a07beed0e64bfba413dcb70dd6749c57f43dc
> KVM: Remove kernel-allocated memory regions
>
> Although we also have private memory slots to which KVM allocates
> memory with vm_mmap(), !user_alloc slots in other words, the slot id
> should be enough for differentiating them.
>
> Note: corresponding function parameters will be removed later.
>
> Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
Reviewed-by: Marcelo Tosatti <mtosatti@redhat.com>
^ permalink raw reply [flat|nested] 3+ messages in thread
* Re: [PATCH] KVM: Remove user_alloc from struct kvm_memory_slot
2013-02-07 9:55 [PATCH] KVM: Remove user_alloc from struct kvm_memory_slot Takuya Yoshikawa
2013-02-08 23:32 ` Marcelo Tosatti
@ 2013-02-11 9:52 ` Gleb Natapov
1 sibling, 0 replies; 3+ messages in thread
From: Gleb Natapov @ 2013-02-11 9:52 UTC (permalink / raw)
To: Takuya Yoshikawa; +Cc: mtosatti, kvm
On Thu, Feb 07, 2013 at 06:55:57PM +0900, Takuya Yoshikawa wrote:
> This field was needed to differentiate memory slots created by the new
> API, KVM_SET_USER_MEMORY_REGION, from those by the old equivalent,
> KVM_SET_MEMORY_REGION, whose support was dropped long before:
>
> commit b74a07beed0e64bfba413dcb70dd6749c57f43dc
> KVM: Remove kernel-allocated memory regions
>
> Although we also have private memory slots to which KVM allocates
> memory with vm_mmap(), !user_alloc slots in other words, the slot id
> should be enough for differentiating them.
>
> Note: corresponding function parameters will be removed later.
>
Applied. Thanks.
> Signed-off-by: Takuya Yoshikawa <yoshikawa_takuya_b1@lab.ntt.co.jp>
> ---
> arch/x86/kvm/x86.c | 37 ++++++++++++++++---------------------
> include/linux/kvm_host.h | 1 -
> virt/kvm/kvm_main.c | 1 -
> 3 files changed, 16 insertions(+), 23 deletions(-)
>
> diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
> index 373e17a..3c5bb6f 100644
> --- a/arch/x86/kvm/x86.c
> +++ b/arch/x86/kvm/x86.c
> @@ -6897,33 +6897,28 @@ int kvm_arch_prepare_memory_region(struct kvm *kvm,
> bool user_alloc)
> {
> int npages = memslot->npages;
> - int map_flags = MAP_PRIVATE | MAP_ANONYMOUS;
>
> - /* Prevent internal slot pages from being moved by fork()/COW. */
> - if (memslot->id >= KVM_USER_MEM_SLOTS)
> - map_flags = MAP_SHARED | MAP_ANONYMOUS;
> -
> - /*To keep backward compatibility with older userspace,
> - *x86 needs to handle !user_alloc case.
> + /*
> + * Only private memory slots need to be mapped here since
> + * KVM_SET_MEMORY_REGION ioctl is no longer supported.
> */
> - if (!user_alloc) {
> - if (npages && !old.npages) {
> - unsigned long userspace_addr;
> + if ((memslot->id >= KVM_USER_MEM_SLOTS) && npages && !old.npages) {
> + unsigned long userspace_addr;
>
> - userspace_addr = vm_mmap(NULL, 0,
> - npages * PAGE_SIZE,
> - PROT_READ | PROT_WRITE,
> - map_flags,
> - 0);
> + /*
> + * MAP_SHARED to prevent internal slot pages from being moved
> + * by fork()/COW.
> + */
> + userspace_addr = vm_mmap(NULL, 0, npages * PAGE_SIZE,
> + PROT_READ | PROT_WRITE,
> + MAP_SHARED | MAP_ANONYMOUS, 0);
>
> - if (IS_ERR((void *)userspace_addr))
> - return PTR_ERR((void *)userspace_addr);
> + if (IS_ERR((void *)userspace_addr))
> + return PTR_ERR((void *)userspace_addr);
>
> - memslot->userspace_addr = userspace_addr;
> - }
> + memslot->userspace_addr = userspace_addr;
> }
>
> -
> return 0;
> }
>
> @@ -6935,7 +6930,7 @@ void kvm_arch_commit_memory_region(struct kvm *kvm,
>
> int nr_mmu_pages = 0, npages = mem->memory_size >> PAGE_SHIFT;
>
> - if (!user_alloc && !old.user_alloc && old.npages && !npages) {
> + if ((mem->slot >= KVM_USER_MEM_SLOTS) && old.npages && !npages) {
> int ret;
>
> ret = vm_munmap(old.userspace_addr,
> diff --git a/include/linux/kvm_host.h b/include/linux/kvm_host.h
> index 0350e0d..722cae7 100644
> --- a/include/linux/kvm_host.h
> +++ b/include/linux/kvm_host.h
> @@ -273,7 +273,6 @@ struct kvm_memory_slot {
> unsigned long userspace_addr;
> u32 flags;
> short id;
> - bool user_alloc;
> };
>
> static inline unsigned long kvm_dirty_bitmap_bytes(struct kvm_memory_slot *memslot)
> diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
> index 2e93630..adc68fe 100644
> --- a/virt/kvm/kvm_main.c
> +++ b/virt/kvm/kvm_main.c
> @@ -839,7 +839,6 @@ int __kvm_set_memory_region(struct kvm *kvm,
>
> r = -ENOMEM;
> if (change == KVM_MR_CREATE) {
> - new.user_alloc = user_alloc;
> new.userspace_addr = mem->userspace_addr;
>
> if (kvm_arch_create_memslot(&new, npages))
> --
> 1.7.5.4
--
Gleb.
^ permalink raw reply [flat|nested] 3+ messages in thread
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2013-02-07 9:55 [PATCH] KVM: Remove user_alloc from struct kvm_memory_slot Takuya Yoshikawa
2013-02-08 23:32 ` Marcelo Tosatti
2013-02-11 9:52 ` Gleb Natapov
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