Commit 4514eda4 authored by David Hildenbrand's avatar David Hildenbrand Committed by Claudio Imbrenda
Browse files

KVM: s390: vsie: stop using "struct page" for vsie page 



Now that we no longer use page->index and the page refcount explicitly,
let's avoid messing with "struct page" completely.

Signed-off-by: default avatarDavid Hildenbrand <david@redhat.com>
Reviewed-by: default avatarClaudio Imbrenda <imbrenda@linux.ibm.com>
Reviewed-by: default avatarChristoph Schlameuss <schlameuss@linux.ibm.com>
Tested-by: default avatarChristoph Schlameuss <schlameuss@linux.ibm.com>
Message-ID: <20250107154344.1003072-5-david@redhat.com>
Signed-off-by: default avatarClaudio Imbrenda <imbrenda@linux.ibm.com>
parent 905f5ce0

arch/s390/include/asm/kvm_host.h

+3 −1
Original line number Diff line number Diff line
@@ -931,12 +931,14 @@ struct sie_page2 { 
	u8 reserved928[0x1000 - 0x928];			/* 0x0928 */

};



struct vsie_page;



struct kvm_s390_vsie {

	struct mutex mutex;

	struct radix_tree_root addr_to_page;

	int page_count;

	int next;

	struct page *pages[KVM_MAX_VCPUS];

	struct vsie_page *pages[KVM_MAX_VCPUS];

};



struct kvm_s390_gisa_iam {

arch/s390/kvm/vsie.c

+12 −19
Original line number Diff line number Diff line
@@ -599,7 +599,6 @@ void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, unsigned long start, 
	struct kvm *kvm = gmap->private;

	struct vsie_page *cur;

	unsigned long prefix;

	struct page *page;

	int i;



	if (!gmap_is_shadow(gmap))
@@ -609,10 +608,9 @@ void kvm_s390_vsie_gmap_notifier(struct gmap *gmap, unsigned long start, 
	 * therefore we can safely reference them all the time.

	 */

	for (i = 0; i < kvm->arch.vsie.page_count; i++) {

		page = READ_ONCE(kvm->arch.vsie.pages[i]);

		if (!page)

		cur = READ_ONCE(kvm->arch.vsie.pages[i]);

		if (!cur)

			continue;

		cur = page_to_virt(page);

		if (READ_ONCE(cur->gmap) != gmap)

			continue;

		prefix = cur->scb_s.prefix << GUEST_PREFIX_SHIFT;
@@ -1384,14 +1382,12 @@ static void put_vsie_page(struct vsie_page *vsie_page) 
static struct vsie_page *get_vsie_page(struct kvm *kvm, unsigned long addr)

{

	struct vsie_page *vsie_page;

	struct page *page;

	int nr_vcpus;



	rcu_read_lock();

	page = radix_tree_lookup(&kvm->arch.vsie.addr_to_page, addr >> 9);

	vsie_page = radix_tree_lookup(&kvm->arch.vsie.addr_to_page, addr >> 9);

	rcu_read_unlock();

	if (page) {

		vsie_page = page_to_virt(page);

	if (vsie_page) {

		if (try_get_vsie_page(vsie_page)) {

			if (vsie_page->scb_gpa == addr)

				return vsie_page;
@@ -1411,20 +1407,18 @@ static struct vsie_page *get_vsie_page(struct kvm *kvm, unsigned long addr) 


	mutex_lock(&kvm->arch.vsie.mutex);

	if (kvm->arch.vsie.page_count < nr_vcpus) {

		page = alloc_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO | GFP_DMA);

		if (!page) {

		vsie_page = (void *)__get_free_page(GFP_KERNEL_ACCOUNT | __GFP_ZERO | GFP_DMA);

		if (!vsie_page) {

			mutex_unlock(&kvm->arch.vsie.mutex);

			return ERR_PTR(-ENOMEM);

		}

		vsie_page = page_to_virt(page);

		__set_bit(VSIE_PAGE_IN_USE, &vsie_page->flags);

		kvm->arch.vsie.pages[kvm->arch.vsie.page_count] = page;

		kvm->arch.vsie.pages[kvm->arch.vsie.page_count] = vsie_page;

		kvm->arch.vsie.page_count++;

	} else {

		/* reuse an existing entry that belongs to nobody */

		while (true) {

			page = kvm->arch.vsie.pages[kvm->arch.vsie.next];

			vsie_page = page_to_virt(page);

			vsie_page = kvm->arch.vsie.pages[kvm->arch.vsie.next];

			if (try_get_vsie_page(vsie_page))

				break;

			kvm->arch.vsie.next++;
@@ -1438,7 +1432,8 @@ static struct vsie_page *get_vsie_page(struct kvm *kvm, unsigned long addr) 
	vsie_page->scb_gpa = ULONG_MAX;



	/* Double use of the same address or allocation failure. */

	if (radix_tree_insert(&kvm->arch.vsie.addr_to_page, addr >> 9, page)) {

	if (radix_tree_insert(&kvm->arch.vsie.addr_to_page, addr >> 9,

			      vsie_page)) {

		put_vsie_page(vsie_page);

		mutex_unlock(&kvm->arch.vsie.mutex);

		return NULL;
@@ -1519,20 +1514,18 @@ void kvm_s390_vsie_init(struct kvm *kvm) 
void kvm_s390_vsie_destroy(struct kvm *kvm)

{

	struct vsie_page *vsie_page;

	struct page *page;

	int i;



	mutex_lock(&kvm->arch.vsie.mutex);

	for (i = 0; i < kvm->arch.vsie.page_count; i++) {

		page = kvm->arch.vsie.pages[i];

		vsie_page = kvm->arch.vsie.pages[i];

		kvm->arch.vsie.pages[i] = NULL;

		vsie_page = page_to_virt(page);

		release_gmap_shadow(vsie_page);

		/* free the radix tree entry */

		if (vsie_page->scb_gpa != ULONG_MAX)

			radix_tree_delete(&kvm->arch.vsie.addr_to_page,

					  vsie_page->scb_gpa >> 9);

		__free_page(page);

		free_page((unsigned long)vsie_page);

	}

	kvm->arch.vsie.page_count = 0;

	mutex_unlock(&kvm->arch.vsie.mutex);