[PATCH] KVM portability split : move mmu code to arch

[PATCH] KVM portability split : move mmu code to arch

[Zhang, Xiantao]

[-- Attachment #1: Type: text/plain, Size: 8151 bytes --]

According to privious decisions, mmu code should be moved to arch.  

>From 43a629932b6babcbf2af75299192c1d77c2393d5 Mon Sep 17 00:00:00 2001
From: Zhang Xiantao <xiantao.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
Date: Fri, 16 Nov 2007 13:16:40 +0800
Subject: [PATCH] KVM: MMU split for portability.
Since mmu code is very arch-denpendent, move them to archs.
1. For kvm_vm_ioctl_get_dirty_log, this ioctl should be first transfered
to arch-specific code, and will 
call the common code implemtend in kvm_get_dirty_log to perform common
task. 
2. For set_memory_region,  I moved the mmu-speicific operations to an
arch-ops. 
Signed-off-by: Zhang Xiantao <xiantao.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
---
 drivers/kvm/kvm.h      |    8 ++++
 drivers/kvm/kvm_main.c |   49 +++------------------------
 drivers/kvm/x86.c      |   85
+++++++++++++++++++++++++++++++++++++++++++++---
 3 files changed, 94 insertions(+), 48 deletions(-)

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index e34e246..2c1ee4b 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -526,6 +526,9 @@ int kvm_is_error_hva(unsigned long addr);
 int kvm_set_memory_region(struct kvm *kvm,
 			  struct kvm_userspace_memory_region *mem,
 			  int user_alloc);
+void kvm_arch_set_memory_region(struct kvm *kvm,
+			  struct kvm_userspace_memory_region *mem,
+			  int user_alloc);
 int __kvm_set_memory_region(struct kvm *kvm,
 			    struct kvm_userspace_memory_region *mem,
 			    int user_alloc);
@@ -631,6 +634,11 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu);
 
 int kvm_dev_ioctl_check_extension(long ext);
 
+int kvm_get_dirty_log(struct kvm *kvm,
+			struct kvm_dirty_log *log, int *is_dirty);
+int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
+				struct kvm_dirty_log *log);
+
 int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
 				   struct
 				   kvm_userspace_memory_region *mem,
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 0414e92..84eec47 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -362,29 +362,9 @@ int __kvm_set_memory_region(struct kvm *kvm,
 	if (mem->slot >= kvm->nmemslots)
 		kvm->nmemslots = mem->slot + 1;
 
-	if (!kvm->n_requested_mmu_pages) {
-		unsigned int n_pages;
-
-		if (npages) {
-			n_pages = npages * KVM_PERMILLE_MMU_PAGES /
1000;
-			kvm_mmu_change_mmu_pages(kvm,
kvm->n_alloc_mmu_pages +
-						 n_pages);
-		} else {
-			unsigned int nr_mmu_pages;
-
-			n_pages = old.npages * KVM_PERMILLE_MMU_PAGES /
1000;
-			nr_mmu_pages = kvm->n_alloc_mmu_pages - n_pages;
-			nr_mmu_pages = max(nr_mmu_pages,
-				        (unsigned int)
KVM_MIN_ALLOC_MMU_PAGES);
-			kvm_mmu_change_mmu_pages(kvm, nr_mmu_pages);
-		}
-	}
 
 	*memslot = new;
 
-	kvm_mmu_slot_remove_write_access(kvm, mem->slot);
-	kvm_flush_remote_tlbs(kvm);
-
 	kvm_free_physmem_slot(&old, &new);
 	return 0;
 
@@ -404,6 +384,8 @@ int kvm_set_memory_region(struct kvm *kvm,
 
 	mutex_lock(&kvm->lock);
 	r = __kvm_set_memory_region(kvm, mem, user_alloc);
+	if (r == 0)
+		kvm_arch_set_memory_region(kvm, mem, user_alloc);
 	mutex_unlock(&kvm->lock);
 	return r;
 }
@@ -419,19 +401,14 @@ int kvm_vm_ioctl_set_memory_region(struct kvm
*kvm,
 	return kvm_set_memory_region(kvm, mem, user_alloc);
 }
 
-/*
- * Get (and clear) the dirty memory log for a memory slot.
- */
-static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
-				      struct kvm_dirty_log *log)
+int kvm_get_dirty_log(struct kvm *kvm,
+			struct kvm_dirty_log *log, int *is_dirty)
 {
 	struct kvm_memory_slot *memslot;
 	int r, i;
 	int n;
 	unsigned long any = 0;
 
-	mutex_lock(&kvm->lock);
-
 	r = -EINVAL;
 	if (log->slot >= KVM_MEMORY_SLOTS)
 		goto out;
@@ -450,17 +427,11 @@ static int kvm_vm_ioctl_get_dirty_log(struct kvm
*kvm,
 	if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
 		goto out;
 
-	/* If nothing is dirty, don't bother messing with page tables.
*/
-	if (any) {
-		kvm_mmu_slot_remove_write_access(kvm, log->slot);
-		kvm_flush_remote_tlbs(kvm);
-		memset(memslot->dirty_bitmap, 0, n);
-	}
+	if (any)
+		*is_dirty = 1;
 
 	r = 0;
-
 out:
-	mutex_unlock(&kvm->lock);
 	return r;
 }
 
@@ -1404,10 +1375,6 @@ int kvm_init(void *opaque, unsigned int
vcpu_size,
 	int r;
 	int cpu;
 
-	r = kvm_mmu_module_init();
-	if (r)
-		goto out4;
-
 	kvm_init_debug();
 
 	r = kvm_arch_init(opaque);
@@ -1466,8 +1433,6 @@ int kvm_init(void *opaque, unsigned int vcpu_size,
 	kvm_preempt_ops.sched_in = kvm_sched_in;
 	kvm_preempt_ops.sched_out = kvm_sched_out;
 
-	kvm_mmu_set_nonpresent_ptes(0ull, 0ull);
-
 	return 0;
 
 out_free:
@@ -1486,7 +1451,6 @@ out_free_0:
 out:
 	kvm_arch_exit();
 	kvm_exit_debug();
-	kvm_mmu_module_exit();
 out4:
 	return r;
 }
@@ -1505,6 +1469,5 @@ void kvm_exit(void)
 	kvm_arch_exit();
 	kvm_exit_debug();
 	__free_page(bad_page);
-	kvm_mmu_module_exit();
 }
 EXPORT_SYMBOL_GPL(kvm_exit);
diff --git a/drivers/kvm/x86.c b/drivers/kvm/x86.c
index 49cde46..375d36f 100644
--- a/drivers/kvm/x86.c
+++ b/drivers/kvm/x86.c
@@ -926,6 +926,37 @@ static int kvm_vm_ioctl_set_irqchip(struct kvm
*kvm, struct kvm_irqchip *chip)
 	return r;
 }
 
+/*
+ * Get (and clear) the dirty memory log for a memory slot.
+ */
+int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
+				      struct kvm_dirty_log *log)
+{
+	int r;
+	int n;
+	struct kvm_memory_slot *memslot;
+	int is_dirty = 0;
+
+	mutex_lock(&kvm->lock);
+
+	r = kvm_get_dirty_log(kvm, log, &is_dirty);
+	if (r)
+		goto out;
+
+	/* If nothing is dirty, don't bother messing with page tables.
*/
+	if (is_dirty) {
+		kvm_mmu_slot_remove_write_access(kvm, log->slot);
+		kvm_flush_remote_tlbs(kvm);
+		memslot = &kvm->memslots[log->slot];
+		n = ALIGN(memslot->npages, BITS_PER_LONG) / 8;
+		memset(memslot->dirty_bitmap, 0, n);
+	}
+	r = 0;
+out:
+	mutex_unlock(&kvm->lock);
+	return r;
+}
+
 long kvm_arch_vm_ioctl(struct file *filp,
 		       unsigned int ioctl, unsigned long arg)
 {
@@ -1668,33 +1699,47 @@ EXPORT_SYMBOL_GPL(kvm_emulate_pio_string);
 
 int kvm_arch_init(void *opaque)
 {
+	int r;
 	struct kvm_x86_ops *ops = (struct kvm_x86_ops *)opaque;
 
+	r = kvm_mmu_module_init();
+	if (r)
+		goto out_fail;
+
 	kvm_init_msr_list();
 
 	if (kvm_x86_ops) {
 		printk(KERN_ERR "kvm: already loaded the other
module\n");
-		return -EEXIST;
+		r = -EEXIST;
+		goto out;
 	}
 
 	if (!ops->cpu_has_kvm_support()) {
 		printk(KERN_ERR "kvm: no hardware support\n");
-		return -EOPNOTSUPP;
+		r = -EOPNOTSUPP;
+		goto out;
 	}
 	if (ops->disabled_by_bios()) {
 		printk(KERN_ERR "kvm: disabled by bios\n");
-		return -EOPNOTSUPP;
+		r = -EOPNOTSUPP;
+		goto out;
 	}
 
 	kvm_x86_ops = ops;
-
+	kvm_mmu_set_nonpresent_ptes(0ull, 0ull);
 	return 0;
+
+out:
+	kvm_mmu_module_exit();
+out_fail:
+	return r;
 }
 
 void kvm_arch_exit(void)
 {
 	kvm_x86_ops = NULL;
- }
+	kvm_mmu_module_exit();
+}
 
 int kvm_emulate_halt(struct kvm_vcpu *vcpu)
 {
@@ -2544,3 +2589,33 @@ void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
 	kvm_mmu_destroy(vcpu);
 	free_page((unsigned long)vcpu->pio_data);
 }
+
+void kvm_arch_set_memory_region(struct kvm *kvm,
+			  struct kvm_userspace_memory_region *mem,
+			  int user_alloc)
+{
+	unsigned long  npages = mem->memory_size >> PAGE_SHIFT;
+	struct kvm_memory_slot old = kvm->memslots[mem->slot];
+
+	if (!kvm->n_requested_mmu_pages) {
+		unsigned int n_pages;
+
+		if (npages) {
+			n_pages = npages * KVM_PERMILLE_MMU_PAGES /
1000;
+			kvm_mmu_change_mmu_pages(kvm,
kvm->n_alloc_mmu_pages +
+						 n_pages);
+		} else {
+			unsigned int nr_mmu_pages;
+
+			n_pages = old.npages * KVM_PERMILLE_MMU_PAGES /
1000;
+			nr_mmu_pages = kvm->n_alloc_mmu_pages - n_pages;
+			nr_mmu_pages = max(nr_mmu_pages,
+					(unsigned int)
KVM_MIN_ALLOC_MMU_PAGES);
+			kvm_mmu_change_mmu_pages(kvm, nr_mmu_pages);
+		}
+	}
+
+	kvm_mmu_slot_remove_write_access(kvm, mem->slot);
+	kvm_flush_remote_tlbs(kvm);
+}
+
-- 
1.5.0.5

[-- Attachment #2: 0002-KVM-MMU-split-for-portability.patch --]
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From 43a629932b6babcbf2af75299192c1d77c2393d5 Mon Sep 17 00:00:00 2001
From: Zhang Xiantao <xiantao.zhang@intel.com>
Date: Fri, 16 Nov 2007 13:16:40 +0800
Subject: [PATCH] KVM: MMU split for portability.
Since mmu code is very arch-denpendent, move them to archs.
Signed-off-by: Zhang Xiantao <xiantao.zhang@intel.com>
---
 drivers/kvm/kvm.h      |    8 ++++
 drivers/kvm/kvm_main.c |   49 +++------------------------
 drivers/kvm/x86.c      |   85 +++++++++++++++++++++++++++++++++++++++++++++---
 3 files changed, 94 insertions(+), 48 deletions(-)

diff --git a/drivers/kvm/kvm.h b/drivers/kvm/kvm.h
index e34e246..2c1ee4b 100644
--- a/drivers/kvm/kvm.h
+++ b/drivers/kvm/kvm.h
@@ -526,6 +526,9 @@ int kvm_is_error_hva(unsigned long addr);
 int kvm_set_memory_region(struct kvm *kvm,
 			  struct kvm_userspace_memory_region *mem,
 			  int user_alloc);
+void kvm_arch_set_memory_region(struct kvm *kvm,
+			  struct kvm_userspace_memory_region *mem,
+			  int user_alloc);
 int __kvm_set_memory_region(struct kvm *kvm,
 			    struct kvm_userspace_memory_region *mem,
 			    int user_alloc);
@@ -631,6 +634,11 @@ void kvm_arch_vcpu_put(struct kvm_vcpu *vcpu);
 
 int kvm_dev_ioctl_check_extension(long ext);
 
+int kvm_get_dirty_log(struct kvm *kvm,
+			struct kvm_dirty_log *log, int *is_dirty);
+int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
+				struct kvm_dirty_log *log);
+
 int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
 				   struct
 				   kvm_userspace_memory_region *mem,
diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
index 0414e92..84eec47 100644
--- a/drivers/kvm/kvm_main.c
+++ b/drivers/kvm/kvm_main.c
@@ -362,29 +362,9 @@ int __kvm_set_memory_region(struct kvm *kvm,
 	if (mem->slot >= kvm->nmemslots)
 		kvm->nmemslots = mem->slot + 1;
 
-	if (!kvm->n_requested_mmu_pages) {
-		unsigned int n_pages;
-
-		if (npages) {
-			n_pages = npages * KVM_PERMILLE_MMU_PAGES / 1000;
-			kvm_mmu_change_mmu_pages(kvm, kvm->n_alloc_mmu_pages +
-						 n_pages);
-		} else {
-			unsigned int nr_mmu_pages;
-
-			n_pages = old.npages * KVM_PERMILLE_MMU_PAGES / 1000;
-			nr_mmu_pages = kvm->n_alloc_mmu_pages - n_pages;
-			nr_mmu_pages = max(nr_mmu_pages,
-				        (unsigned int) KVM_MIN_ALLOC_MMU_PAGES);
-			kvm_mmu_change_mmu_pages(kvm, nr_mmu_pages);
-		}
-	}
 
 	*memslot = new;
 
-	kvm_mmu_slot_remove_write_access(kvm, mem->slot);
-	kvm_flush_remote_tlbs(kvm);
-
 	kvm_free_physmem_slot(&old, &new);
 	return 0;
 
@@ -404,6 +384,8 @@ int kvm_set_memory_region(struct kvm *kvm,
 
 	mutex_lock(&kvm->lock);
 	r = __kvm_set_memory_region(kvm, mem, user_alloc);
+	if (r == 0)
+		kvm_arch_set_memory_region(kvm, mem, user_alloc);
 	mutex_unlock(&kvm->lock);
 	return r;
 }
@@ -419,19 +401,14 @@ int kvm_vm_ioctl_set_memory_region(struct kvm *kvm,
 	return kvm_set_memory_region(kvm, mem, user_alloc);
 }
 
-/*
- * Get (and clear) the dirty memory log for a memory slot.
- */
-static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
-				      struct kvm_dirty_log *log)
+int kvm_get_dirty_log(struct kvm *kvm,
+			struct kvm_dirty_log *log, int *is_dirty)
 {
 	struct kvm_memory_slot *memslot;
 	int r, i;
 	int n;
 	unsigned long any = 0;
 
-	mutex_lock(&kvm->lock);
-
 	r = -EINVAL;
 	if (log->slot >= KVM_MEMORY_SLOTS)
 		goto out;
@@ -450,17 +427,11 @@ static int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
 	if (copy_to_user(log->dirty_bitmap, memslot->dirty_bitmap, n))
 		goto out;
 
-	/* If nothing is dirty, don't bother messing with page tables. */
-	if (any) {
-		kvm_mmu_slot_remove_write_access(kvm, log->slot);
-		kvm_flush_remote_tlbs(kvm);
-		memset(memslot->dirty_bitmap, 0, n);
-	}
+	if (any)
+		*is_dirty = 1;
 
 	r = 0;
-
 out:
-	mutex_unlock(&kvm->lock);
 	return r;
 }
 
@@ -1404,10 +1375,6 @@ int kvm_init(void *opaque, unsigned int vcpu_size,
 	int r;
 	int cpu;
 
-	r = kvm_mmu_module_init();
-	if (r)
-		goto out4;
-
 	kvm_init_debug();
 
 	r = kvm_arch_init(opaque);
@@ -1466,8 +1433,6 @@ int kvm_init(void *opaque, unsigned int vcpu_size,
 	kvm_preempt_ops.sched_in = kvm_sched_in;
 	kvm_preempt_ops.sched_out = kvm_sched_out;
 
-	kvm_mmu_set_nonpresent_ptes(0ull, 0ull);
-
 	return 0;
 
 out_free:
@@ -1486,7 +1451,6 @@ out_free_0:
 out:
 	kvm_arch_exit();
 	kvm_exit_debug();
-	kvm_mmu_module_exit();
 out4:
 	return r;
 }
@@ -1505,6 +1469,5 @@ void kvm_exit(void)
 	kvm_arch_exit();
 	kvm_exit_debug();
 	__free_page(bad_page);
-	kvm_mmu_module_exit();
 }
 EXPORT_SYMBOL_GPL(kvm_exit);
diff --git a/drivers/kvm/x86.c b/drivers/kvm/x86.c
index 49cde46..375d36f 100644
--- a/drivers/kvm/x86.c
+++ b/drivers/kvm/x86.c
@@ -926,6 +926,37 @@ static int kvm_vm_ioctl_set_irqchip(struct kvm *kvm, struct kvm_irqchip *chip)
 	return r;
 }
 
+/*
+ * Get (and clear) the dirty memory log for a memory slot.
+ */
+int kvm_vm_ioctl_get_dirty_log(struct kvm *kvm,
+				      struct kvm_dirty_log *log)
+{
+	int r;
+	int n;
+	struct kvm_memory_slot *memslot;
+	int is_dirty = 0;
+
+	mutex_lock(&kvm->lock);
+
+	r = kvm_get_dirty_log(kvm, log, &is_dirty);
+	if (r)
+		goto out;
+
+	/* If nothing is dirty, don't bother messing with page tables. */
+	if (is_dirty) {
+		kvm_mmu_slot_remove_write_access(kvm, log->slot);
+		kvm_flush_remote_tlbs(kvm);
+		memslot = &kvm->memslots[log->slot];
+		n = ALIGN(memslot->npages, BITS_PER_LONG) / 8;
+		memset(memslot->dirty_bitmap, 0, n);
+	}
+	r = 0;
+out:
+	mutex_unlock(&kvm->lock);
+	return r;
+}
+
 long kvm_arch_vm_ioctl(struct file *filp,
 		       unsigned int ioctl, unsigned long arg)
 {
@@ -1668,33 +1699,47 @@ EXPORT_SYMBOL_GPL(kvm_emulate_pio_string);
 
 int kvm_arch_init(void *opaque)
 {
+	int r;
 	struct kvm_x86_ops *ops = (struct kvm_x86_ops *)opaque;
 
+	r = kvm_mmu_module_init();
+	if (r)
+		goto out_fail;
+
 	kvm_init_msr_list();
 
 	if (kvm_x86_ops) {
 		printk(KERN_ERR "kvm: already loaded the other module\n");
-		return -EEXIST;
+		r = -EEXIST;
+		goto out;
 	}
 
 	if (!ops->cpu_has_kvm_support()) {
 		printk(KERN_ERR "kvm: no hardware support\n");
-		return -EOPNOTSUPP;
+		r = -EOPNOTSUPP;
+		goto out;
 	}
 	if (ops->disabled_by_bios()) {
 		printk(KERN_ERR "kvm: disabled by bios\n");
-		return -EOPNOTSUPP;
+		r = -EOPNOTSUPP;
+		goto out;
 	}
 
 	kvm_x86_ops = ops;
-
+	kvm_mmu_set_nonpresent_ptes(0ull, 0ull);
 	return 0;
+
+out:
+	kvm_mmu_module_exit();
+out_fail:
+	return r;
 }
 
 void kvm_arch_exit(void)
 {
 	kvm_x86_ops = NULL;
- }
+	kvm_mmu_module_exit();
+}
 
 int kvm_emulate_halt(struct kvm_vcpu *vcpu)
 {
@@ -2544,3 +2589,33 @@ void kvm_arch_vcpu_uninit(struct kvm_vcpu *vcpu)
 	kvm_mmu_destroy(vcpu);
 	free_page((unsigned long)vcpu->pio_data);
 }
+
+void kvm_arch_set_memory_region(struct kvm *kvm,
+			  struct kvm_userspace_memory_region *mem,
+			  int user_alloc)
+{
+	unsigned long  npages = mem->memory_size >> PAGE_SHIFT;
+	struct kvm_memory_slot old = kvm->memslots[mem->slot];
+
+	if (!kvm->n_requested_mmu_pages) {
+		unsigned int n_pages;
+
+		if (npages) {
+			n_pages = npages * KVM_PERMILLE_MMU_PAGES / 1000;
+			kvm_mmu_change_mmu_pages(kvm, kvm->n_alloc_mmu_pages +
+						 n_pages);
+		} else {
+			unsigned int nr_mmu_pages;
+
+			n_pages = old.npages * KVM_PERMILLE_MMU_PAGES / 1000;
+			nr_mmu_pages = kvm->n_alloc_mmu_pages - n_pages;
+			nr_mmu_pages = max(nr_mmu_pages,
+					(unsigned int) KVM_MIN_ALLOC_MMU_PAGES);
+			kvm_mmu_change_mmu_pages(kvm, nr_mmu_pages);
+		}
+	}
+
+	kvm_mmu_slot_remove_write_access(kvm, mem->slot);
+	kvm_flush_remote_tlbs(kvm);
+}
+
-- 
1.5.0.5


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Re: [PATCH] KVM portability split : move mmu code to arch

[Zhang, Xiantao]

Zhang, Xiantao wrote:
> According to privious decisions, mmu code should be moved to arch.
> 
>> From 43a629932b6babcbf2af75299192c1d77c2393d5 Mon Sep 17 00:00:00
>> 2001 
> From: Zhang Xiantao <xiantao.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> Date: Fri, 16 Nov 2007 13:16:40 +0800
> Subject: [PATCH] KVM: MMU split for portability.
> Since mmu code is very arch-denpendent, move them to archs.
> 1. For kvm_vm_ioctl_get_dirty_log, this ioctl should be first
> transfered to arch-specific code, and will
> call the common code implemtend in kvm_get_dirty_log to perform common
> task.
> 2. For set_memory_region,  I moved the mmu-speicific operations to an
> arch-ops.
> Signed-off-by: Zhang Xiantao <xiantao.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> ---

BTW, this patch is based on privious sent  "[kvm-devel] [PATCH] Split
kvm_create_vm and kvm_destory_vm tosupport arch", but they are not
interdependent. 
You can apply them separately.:)
Xiantao

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Re: [PATCH] KVM portability split : move mmu code to arch

[Avi Kivity]

Zhang, Xiantao wrote:
> According to privious decisions, mmu code should be moved to arch.  
>
> >From 43a629932b6babcbf2af75299192c1d77c2393d5 Mon Sep 17 00:00:00 2001
> From: Zhang Xiantao <xiantao.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> Date: Fri, 16 Nov 2007 13:16:40 +0800
> Subject: [PATCH] KVM: MMU split for portability.
> Since mmu code is very arch-denpendent, move them to archs.
> 1. For kvm_vm_ioctl_get_dirty_log, this ioctl should be first transfered
> to arch-specific code, and will 
> call the common code implemtend in kvm_get_dirty_log to perform common
> task. 
> 2. For set_memory_region,  I moved the mmu-speicific operations to an
> arch-ops. 
> Signed-off-by: Zhang Xiantao <xiantao.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org>
> ---
>  drivers/kvm/kvm.h      |    8 ++++
>  drivers/kvm/kvm_main.c |   49 +++------------------------
>  drivers/kvm/x86.c      |   85
> +++++++++++++++++++++++++++++++++++++++++++++---
>  3 files changed, 94 insertions(+), 48 deletions(-)
>
> diff --git a/drivers/kvm/kvm_main.c b/drivers/kvm/kvm_main.c
> index 0414e92..84eec47 100644
> --- a/drivers/kvm/kvm_main.c
> +++ b/drivers/kvm/kvm_main.c
> @@ -362,29 +362,9 @@ int __kvm_set_memory_region(struct kvm *kvm,
>  	if (mem->slot >= kvm->nmemslots)
>  		kvm->nmemslots = mem->slot + 1;
>  
> -	if (!kvm->n_requested_mmu_pages) {
> -		unsigned int n_pages;
> -
> -		if (npages) {
> -			n_pages = npages * KVM_PERMILLE_MMU_PAGES /
> 1000;
> -			kvm_mmu_change_mmu_pages(kvm,
> kvm->n_alloc_mmu_pages +
> -						 n_pages);
> -		} else {
> -			unsigned int nr_mmu_pages;
> -
> -			n_pages = old.npages * KVM_PERMILLE_MMU_PAGES /
>   

We rely on the values in 'old' here...

> 1000;
> -			nr_mmu_pages = kvm->n_alloc_mmu_pages - n_pages;
> -			nr_mmu_pages = max(nr_mmu_pages,
> -				        (unsigned int)
> KVM_MIN_ALLOC_MMU_PAGES);
> -			kvm_mmu_change_mmu_pages(kvm, nr_mmu_pages);
> -		}
> -	}
>  
>  	*memslot = new;
>  
> -	kvm_mmu_slot_remove_write_access(kvm, mem->slot);
> -	kvm_flush_remote_tlbs(kvm);
> -
>  	kvm_free_physmem_slot(&old, &new);
>  	return 0;
>  
> @@ -404,6 +384,8 @@ int kvm_set_memory_region(struct kvm *kvm,
>  
>  	mutex_lock(&kvm->lock);
>  	r = __kvm_set_memory_region(kvm, mem, user_alloc);
> +	if (r == 0)
> +		kvm_arch_set_memory_region(kvm, mem, user_alloc);
>   

But 'old' does not longer exist here.  You recalculate it from  
kvm->memslots[] but the value is not longer identical to the 'old' value.

Suggest changing this code not to rely on 'old' at all; instead 
recalculate nr_mmu_pages from kvm->memslots[] each time.  That will make 
the code more robust, enabling the movement later.


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


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