[PATCH] KVM: SVM: Change flag passed to GUP fast in sev_pin_memory()

From: Janakarajan Natarajan
Date: Thu Apr 23 2020 - 11:24:39 EST


When trying to lock read-only pages, sev_pin_memory() fails because FOLL_WRITE
is used as the flag for get_user_pages_fast().

Commit 73b0140bf0fe ("mm/gup: change GUP fast to use flags rather than a write
'bool'") updated the get_user_pages_fast() call sites to use flags, but
incorrectly updated the call in sev_pin_memory(). As the original coding of this
call was correct, revert the change made by that commit.

Fixes: 73b0140bf0fe ("mm/gup: change GUP fast to use flags rather than a write 'bool'")
Signed-off-by: Janakarajan Natarajan <Janakarajan.Natarajan@xxxxxxx>
---
arch/x86/kvm/svm/sev.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/arch/x86/kvm/svm/sev.c b/arch/x86/kvm/svm/sev.c
index cf912b4aaba8..89f7f3aebd31 100644
--- a/arch/x86/kvm/svm/sev.c
+++ b/arch/x86/kvm/svm/sev.c
@@ -345,7 +345,7 @@ static struct page **sev_pin_memory(struct kvm *kvm, unsigned long uaddr,
return NULL;

/* Pin the user virtual address. */
- npinned = get_user_pages_fast(uaddr, npages, FOLL_WRITE, pages);
+ npinned = get_user_pages_fast(uaddr, npages, write ? FOLL_WRITE : 0, pages);
if (npinned != npages) {
pr_err("SEV: Failure locking %lu pages.\n", npages);
goto err;
--
2.17.1