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Commit 0de10343 authored by Zhang Xiantao's avatar Zhang Xiantao Committed by Avi Kivity
Browse files

KVM: Portability: Split kvm_set_memory_region() to have an arch callout 



Moving !user_alloc case to kvm_arch to avoid unnecessary
code logic in non-x86 platform.

Signed-off-by: default avatarZhang Xiantao <xiantao.zhang@intel.com>
Signed-off-by: default avatarAvi Kivity <avi@qumranet.com>
parent 3ad82a7e

drivers/kvm/kvm.h

+4 −0
Original line number Diff line number Diff line
@@ -391,6 +391,10 @@ 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_clean(struct page *page);

drivers/kvm/kvm_main.c

+5 −33
Original line number Diff line number Diff line
@@ -291,33 +291,7 @@ 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");

		}

	}



	/* Allocate page dirty bitmap if needed */
@@ -335,14 +309,12 @@ 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;

drivers/kvm/x86.c

+51 −0
Original line number Diff line number Diff line
@@ -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>
@@ -2637,3 +2638,53 @@ 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;

}