[PATCH] KVM Portability : Spliting kvm_set_memory_region.

[PATCH] KVM Portability : Spliting kvm_set_memory_region.

[Zhang, Xiantao]

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From: Zhang Xiantao <xiantao.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Date: Tue, 20 Nov 2007 16:25:04 +0800
Subject: [PATCH] KVM Portability : Spliting kvm_set_memory_region.
Moving !user_alloc case to kvm_arch to avoid unnecessary
code logic in non-x86 platform.
Signed-off-by: Zhang Xiantao <xiantao.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/kvm/kvm.h      |    4 +++
 drivers/kvm/kvm_main.c |   38 ++++-------------------------------
 drivers/kvm/x86.c      |   51
++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 60 insertions(+), 33 deletions(-)

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 1901456..9b8bd9d 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -392,6 +392,10 @@ int kvm_set_memory_region(struct kvm *kvm,
 int __kvm_set_memory_region(struct kvm *kvm,
 			    struct kvm_userspace_memory_region *mem,
 			    int user_alloc);
+int kvm_arch_set_memory_region(struct kvm *kvm,
+				struct kvm_userspace_memory_region *mem,
+				struct kvm_memory_slot old,
+				int user_alloc);
 gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn);
 struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn);
 void kvm_release_page(struct page *page);
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 8a90f7d..4624761 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -290,33 +290,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
 		memset(new.rmap, 0, npages * sizeof(*new.rmap));
 
 		new.user_alloc = user_alloc;
-		if (user_alloc)
-			new.userspace_addr = mem->userspace_addr;
-		else {
-			down_write(&current->mm->mmap_sem);
-			new.userspace_addr = do_mmap(NULL, 0,
-						     npages * PAGE_SIZE,
-						     PROT_READ |
PROT_WRITE,
-						     MAP_SHARED |
MAP_ANONYMOUS,
-						     0);
-			up_write(&current->mm->mmap_sem);
-
-			if (IS_ERR((void *)new.userspace_addr))
-				goto out_free;
-		}
-	} else {
-		if (!old.user_alloc && old.rmap) {
-			int ret;
-
-			down_write(&current->mm->mmap_sem);
-			ret = do_munmap(current->mm, old.userspace_addr,
-					old.npages * PAGE_SIZE);
-			up_write(&current->mm->mmap_sem);
-			if (ret < 0)
-				printk(KERN_WARNING
-				       "kvm_vm_ioctl_set_memory_region:
"
-				       "failed to munmap memory\n");
-		}
+		new.userspace_addr = mem->userspace_addr;
 	}
 
 	/* Allocate page dirty bitmap if needed */
@@ -334,14 +308,12 @@ int __kvm_set_memory_region(struct kvm *kvm,
 
 	*memslot = new;
 
-	if (!kvm->n_requested_mmu_pages) {
-		unsigned int nr_mmu_pages =
kvm_mmu_calculate_mmu_pages(kvm);
-		kvm_mmu_change_mmu_pages(kvm, nr_mmu_pages);
+	r = kvm_arch_set_memory_region(kvm, mem, old, user_alloc);
+	if (r){
+		*memslot = old;
+		goto out_free;
 	}
 
-	kvm_mmu_slot_remove_write_access(kvm, mem->slot);
-	kvm_flush_remote_tlbs(kvm);
-
 	kvm_free_physmem_slot(&old, &new);
 	return 0;
 
diff --git a/drivers/kvm/x86.c b/drivers/kvm/x86.c
index 40871b5..6864d18 100644
--- a/drivers/kvm/x86.c
+++ b/drivers/kvm/x86.c
@@ -24,6 +24,7 @@
 #include <linux/fs.h>
 #include <linux/vmalloc.h>
 #include <linux/module.h>
+#include <linux/mman.h>
 
 #include <asm/uaccess.h>
 #include <asm/msr.h>
@@ -2647,3 +2648,53 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 	kvm_free_physmem(kvm);
 	kfree(kvm);
 }
+
+int kvm_arch_set_memory_region(struct kvm *kvm,
+				struct kvm_userspace_memory_region *mem,
+				struct kvm_memory_slot old,
+				int user_alloc)
+{
+	int npages = mem->memory_size >> PAGE_SHIFT;
+	struct kvm_memory_slot *memslot = &kvm->memslots[mem->slot];
+
+	/*To keep backward compatibility with older userspace,
+	 *x86 needs to hanlde !user_alloc case.
+	 */
+	if (!user_alloc) {
+		if (npages && !old.rmap) {
+			down_write(&current->mm->mmap_sem);
+			memslot->userspace_addr = do_mmap(NULL, 0,
+						     npages * PAGE_SIZE,
+						     PROT_READ |
PROT_WRITE,
+						     MAP_SHARED |
MAP_ANONYMOUS,
+						     0);
+			up_write(&current->mm->mmap_sem);
+
+			if (IS_ERR((void *)memslot->userspace_addr))
+				return PTR_ERR((void
*)memslot->userspace_addr);
+		} else {
+			if (!old.user_alloc && old.rmap) {
+				int ret;
+
+				down_write(&current->mm->mmap_sem);
+				ret = do_munmap(current->mm,
old.userspace_addr,
+						old.npages * PAGE_SIZE);
+				up_write(&current->mm->mmap_sem);
+				if (ret < 0)
+					printk(KERN_WARNING
+				       "kvm_vm_ioctl_set_memory_region:
"
+				       "failed to munmap memory\n");
+			}
+		}
+	}
+
+	if (!kvm->n_requested_mmu_pages) {
+		unsigned int nr_mmu_pages =
kvm_mmu_calculate_mmu_pages(kvm);
+		kvm_mmu_change_mmu_pages(kvm, nr_mmu_pages);
+	}
+
+	kvm_mmu_slot_remove_write_access(kvm, mem->slot);
+	kvm_flush_remote_tlbs(kvm);
+
+	return 0;
+}
-- 
1.5.1.2

[-- Attachment #2: 0002-KVM-Portability-Spliting-kvm_set_memory_region.patch --]
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From 5a3ce680733d3d85be10be4b01b2b88877a0cb88 Mon Sep 17 00:00:00 2001
From: Zhang Xiantao <xiantao.zhang@intel.com>
Date: Tue, 20 Nov 2007 16:25:04 +0800
Subject: [PATCH] KVM Portability : Spliting kvm_set_memory_region.
Moving !user_alloc case to kvm_arch to avoid unnecessary
code logic in non-x86 platform.
Signed-off-by: Zhang Xiantao <xiantao.zhang@intel.com>
---
 drivers/kvm/kvm.h      |    4 +++
 drivers/kvm/kvm_main.c |   38 ++++-------------------------------
 drivers/kvm/x86.c      |   51 ++++++++++++++++++++++++++++++++++++++++++++++++
 3 files changed, 60 insertions(+), 33 deletions(-)

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index 1901456..9b8bd9d 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -392,6 +392,10 @@ int kvm_set_memory_region(struct kvm *kvm,
 int __kvm_set_memory_region(struct kvm *kvm,
 			    struct kvm_userspace_memory_region *mem,
 			    int user_alloc);
+int kvm_arch_set_memory_region(struct kvm *kvm,
+				struct kvm_userspace_memory_region *mem,
+				struct kvm_memory_slot old,
+				int user_alloc);
 gfn_t unalias_gfn(struct kvm *kvm, gfn_t gfn);
 struct page *gfn_to_page(struct kvm *kvm, gfn_t gfn);
 void kvm_release_page(struct page *page);
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 8a90f7d..4624761 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -290,33 +290,7 @@ int __kvm_set_memory_region(struct kvm *kvm,
 		memset(new.rmap, 0, npages * sizeof(*new.rmap));
 
 		new.user_alloc = user_alloc;
-		if (user_alloc)
-			new.userspace_addr = mem->userspace_addr;
-		else {
-			down_write(&current->mm->mmap_sem);
-			new.userspace_addr = do_mmap(NULL, 0,
-						     npages * PAGE_SIZE,
-						     PROT_READ | PROT_WRITE,
-						     MAP_SHARED | MAP_ANONYMOUS,
-						     0);
-			up_write(&current->mm->mmap_sem);
-
-			if (IS_ERR((void *)new.userspace_addr))
-				goto out_free;
-		}
-	} else {
-		if (!old.user_alloc && old.rmap) {
-			int ret;
-
-			down_write(&current->mm->mmap_sem);
-			ret = do_munmap(current->mm, old.userspace_addr,
-					old.npages * PAGE_SIZE);
-			up_write(&current->mm->mmap_sem);
-			if (ret < 0)
-				printk(KERN_WARNING
-				       "kvm_vm_ioctl_set_memory_region: "
-				       "failed to munmap memory\n");
-		}
+		new.userspace_addr = mem->userspace_addr;
 	}
 
 	/* Allocate page dirty bitmap if needed */
@@ -334,14 +308,12 @@ int __kvm_set_memory_region(struct kvm *kvm,
 
 	*memslot = new;
 
-	if (!kvm->n_requested_mmu_pages) {
-		unsigned int nr_mmu_pages = kvm_mmu_calculate_mmu_pages(kvm);
-		kvm_mmu_change_mmu_pages(kvm, nr_mmu_pages);
+	r = kvm_arch_set_memory_region(kvm, mem, old, user_alloc);
+	if (r){
+		*memslot = old;
+		goto out_free;
 	}
 
-	kvm_mmu_slot_remove_write_access(kvm, mem->slot);
-	kvm_flush_remote_tlbs(kvm);
-
 	kvm_free_physmem_slot(&old, &new);
 	return 0;
 
diff --git a/drivers/kvm/x86.c b/drivers/kvm/x86.c
index 40871b5..6864d18 100644
--- a/drivers/kvm/x86.c
+++ b/drivers/kvm/x86.c
@@ -24,6 +24,7 @@
 #include <linux/fs.h>
 #include <linux/vmalloc.h>
 #include <linux/module.h>
+#include <linux/mman.h>
 
 #include <asm/uaccess.h>
 #include <asm/msr.h>
@@ -2647,3 +2648,53 @@ void kvm_arch_destroy_vm(struct kvm *kvm)
 	kvm_free_physmem(kvm);
 	kfree(kvm);
 }
+
+int kvm_arch_set_memory_region(struct kvm *kvm,
+				struct kvm_userspace_memory_region *mem,
+				struct kvm_memory_slot old,
+				int user_alloc)
+{
+	int npages = mem->memory_size >> PAGE_SHIFT;
+	struct kvm_memory_slot *memslot = &kvm->memslots[mem->slot];
+
+	/*To keep backward compatibility with older userspace,
+	 *x86 needs to hanlde !user_alloc case.
+	 */
+	if (!user_alloc) {
+		if (npages && !old.rmap) {
+			down_write(&current->mm->mmap_sem);
+			memslot->userspace_addr = do_mmap(NULL, 0,
+						     npages * PAGE_SIZE,
+						     PROT_READ | PROT_WRITE,
+						     MAP_SHARED | MAP_ANONYMOUS,
+						     0);
+			up_write(&current->mm->mmap_sem);
+
+			if (IS_ERR((void *)memslot->userspace_addr))
+				return PTR_ERR((void *)memslot->userspace_addr);
+		} else {
+			if (!old.user_alloc && old.rmap) {
+				int ret;
+
+				down_write(&current->mm->mmap_sem);
+				ret = do_munmap(current->mm, old.userspace_addr,
+						old.npages * PAGE_SIZE);
+				up_write(&current->mm->mmap_sem);
+				if (ret < 0)
+					printk(KERN_WARNING
+				       "kvm_vm_ioctl_set_memory_region: "
+				       "failed to munmap memory\n");
+			}
+		}
+	}
+
+	if (!kvm->n_requested_mmu_pages) {
+		unsigned int nr_mmu_pages = kvm_mmu_calculate_mmu_pages(kvm);
+		kvm_mmu_change_mmu_pages(kvm, nr_mmu_pages);
+	}
+
+	kvm_mmu_slot_remove_write_access(kvm, mem->slot);
+	kvm_flush_remote_tlbs(kvm);
+
+	return 0;
+}
-- 
1.5.1.2


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Re: [PATCH] KVM Portability : Spliting kvm_set_memory_region.

[Avi Kivity]

Zhang, Xiantao wrote:
> From: Zhang Xiantao <xiantao.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> Date: Tue, 20 Nov 2007 16:25:04 +0800
> Subject: [PATCH] KVM Portability : Spliting kvm_set_memory_region.
> Moving !user_alloc case to kvm_arch to avoid unnecessary
> code logic in non-x86 platform.
> Signed-off-by: Zhang Xiantao <xiantao.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
>   

Applied this and the previous patch; thanks.

-- 
error compiling committee.c: too many arguments to function


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Re: [PATCH] KVM Portability : Spliting kvm_set_memory_region.

[Carsten Otte]

Zhang, Xiantao wrote:
> From: Zhang Xiantao <xiantao.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> Date: Tue, 20 Nov 2007 16:25:04 +0800
> Subject: [PATCH] KVM Portability : Spliting kvm_set_memory_region.
> Moving !user_alloc case to kvm_arch to avoid unnecessary
> code logic in non-x86 platform.
> Signed-off-by: Zhang Xiantao <xiantao.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> ---
>  drivers/kvm/kvm.h      |    4 +++
>  drivers/kvm/kvm_main.c |   38 ++++-------------------------------
>  drivers/kvm/x86.c      |   51
> ++++++++++++++++++++++++++++++++++++++++++++++++
>  3 files changed, 60 insertions(+), 33 deletions(-)

I don't think we'll want the rmap part in common for s390, but I am 
not sure just yet. If it turns out to be the case, I might submit an 
add on patch that moves it to arch on day. Other then that, this split 
looks good to me. Well done, Xiantao!

Acked-by: Carsten Otte <cotte-tA70FqPdS9bQT0dZR+AlfA@public.gmane.org>

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