Commit 7e066cb9 authored by Ge Yang's avatar Ge Yang Committed by Sean Christopherson
Browse files

KVM: SEV: Use long-term pin when registering encrypted memory regions 



When registering an encrypted memory region for SEV-MEM/SEV-ES guests,
pin the pages with FOLL_TERM so that the pages are migrated out of
MIGRATE_CMA/ZONE_MOVABLE.  Failure to do so violates the CMA/MOVABLE
mechanisms and can result in fragmentation due to unmovable pages, e.g.
can make CMA allocations fail.

Signed-off-by: default avatarGe Yang <yangge1116@126.com>
Reviewed-by: default avatarTom Lendacky <thomas.lendacky@amd.com>
Acked-by: default avatarDavid Hildenbrand <david@redhat.com>
Link: https://lore.kernel.org/r/1739241423-14326-1-git-send-email-yangge1116@126.com


[sean: massage changelog, make @flags an unsigned int]
Signed-off-by: default avatarSean Christopherson <seanjc@google.com>
parent a6136669

arch/x86/kvm/svm/sev.c

+8 −7
Original line number Diff line number Diff line
@@ -619,7 +619,7 @@ static int sev_launch_start(struct kvm *kvm, struct kvm_sev_cmd *argp) 


static struct page **sev_pin_memory(struct kvm *kvm, unsigned long uaddr,

				    unsigned long ulen, unsigned long *n,

				    int write)

				    unsigned int flags)

{

	struct kvm_sev_info *sev = to_kvm_sev_info(kvm);

	unsigned long npages, size;
@@ -660,7 +660,7 @@ static struct page **sev_pin_memory(struct kvm *kvm, unsigned long uaddr, 
		return ERR_PTR(-ENOMEM);



	/* Pin the user virtual address. */

	npinned = pin_user_pages_fast(uaddr, npages, write ? FOLL_WRITE : 0, pages);

	npinned = pin_user_pages_fast(uaddr, npages, flags, pages);

	if (npinned != npages) {

		pr_err("SEV: Failure locking %lu pages.\n", npages);

		ret = -ENOMEM;
@@ -745,7 +745,7 @@ static int sev_launch_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp) 
	vaddr_end = vaddr + size;



	/* Lock the user memory. */

	inpages = sev_pin_memory(kvm, vaddr, size, &npages, 1);

	inpages = sev_pin_memory(kvm, vaddr, size, &npages, FOLL_WRITE);

	if (IS_ERR(inpages))

		return PTR_ERR(inpages);
@@ -1240,7 +1240,7 @@ static int sev_dbg_crypt(struct kvm *kvm, struct kvm_sev_cmd *argp, bool dec) 
		if (IS_ERR(src_p))

			return PTR_ERR(src_p);



		dst_p = sev_pin_memory(kvm, dst_vaddr & PAGE_MASK, PAGE_SIZE, &n, 1);

		dst_p = sev_pin_memory(kvm, dst_vaddr & PAGE_MASK, PAGE_SIZE, &n, FOLL_WRITE);

		if (IS_ERR(dst_p)) {

			sev_unpin_memory(kvm, src_p, n);

			return PTR_ERR(dst_p);
@@ -1305,7 +1305,7 @@ static int sev_launch_secret(struct kvm *kvm, struct kvm_sev_cmd *argp) 
	if (copy_from_user(&params, u64_to_user_ptr(argp->data), sizeof(params)))

		return -EFAULT;



	pages = sev_pin_memory(kvm, params.guest_uaddr, params.guest_len, &n, 1);

	pages = sev_pin_memory(kvm, params.guest_uaddr, params.guest_len, &n, FOLL_WRITE);

	if (IS_ERR(pages))

		return PTR_ERR(pages);
@@ -1779,7 +1779,7 @@ static int sev_receive_update_data(struct kvm *kvm, struct kvm_sev_cmd *argp) 


	/* Pin guest memory */

	guest_page = sev_pin_memory(kvm, params.guest_uaddr & PAGE_MASK,

				    PAGE_SIZE, &n, 1);

				    PAGE_SIZE, &n, FOLL_WRITE);

	if (IS_ERR(guest_page)) {

		ret = PTR_ERR(guest_page);

		goto e_free_trans;
@@ -2675,7 +2675,8 @@ int sev_mem_enc_register_region(struct kvm *kvm, 
		return -ENOMEM;



	mutex_lock(&kvm->lock);

	region->pages = sev_pin_memory(kvm, range->addr, range->size, &region->npages, 1);

	region->pages = sev_pin_memory(kvm, range->addr, range->size, &region->npages,

				       FOLL_WRITE | FOLL_LONGTERM);

	if (IS_ERR(region->pages)) {

		ret = PTR_ERR(region->pages);

		mutex_unlock(&kvm->lock);