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authorLinus Torvalds <torvalds@linux-foundation.org>2018-01-31 21:01:08 +0300
committerLinus Torvalds <torvalds@linux-foundation.org>2018-01-31 21:01:08 +0300
commit5a87e37ee0943afe11504299e4b87d2e4d8d88d5 (patch)
treebd8b5af826eda948190d8ec3d1afd869f834a971 /virt
parent19e7b5f99474107e8d0b4b3e4652fa19ddb87efc (diff)
parentce53053ce378c21e7ffc45241fd67d6ee79daa2b (diff)
downloadlinux-5a87e37ee0943afe11504299e4b87d2e4d8d88d5.tar.xz
Merge branch 'work.get_user_pages_fast' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull get_user_pages_fast updates from Al Viro: "A bit more get_user_pages work" * 'work.get_user_pages_fast' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: kvm: switch get_user_page_nowait() to get_user_pages_unlocked() __get_user_pages_locked(): get rid of notify_drop argument get_user_pages_unlocked(): pass true to __get_user_pages_locked() notify_drop cris: switch to get_user_pages_fast() fold __get_user_pages_unlocked() into its sole remaining caller
Diffstat (limited to 'virt')
-rw-r--r--virt/kvm/kvm_main.c43
1 files changed, 12 insertions, 31 deletions
diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index 210bf820385a..d6b9370806f8 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -1322,17 +1322,6 @@ unsigned long kvm_vcpu_gfn_to_hva_prot(struct kvm_vcpu *vcpu, gfn_t gfn, bool *w
return gfn_to_hva_memslot_prot(slot, gfn, writable);
}
-static int get_user_page_nowait(unsigned long start, int write,
- struct page **page)
-{
- int flags = FOLL_NOWAIT | FOLL_HWPOISON;
-
- if (write)
- flags |= FOLL_WRITE;
-
- return get_user_pages(start, 1, flags, page, NULL);
-}
-
static inline int check_user_page_hwpoison(unsigned long addr)
{
int rc, flags = FOLL_HWPOISON | FOLL_WRITE;
@@ -1381,7 +1370,8 @@ static bool hva_to_pfn_fast(unsigned long addr, bool atomic, bool *async,
static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault,
bool *writable, kvm_pfn_t *pfn)
{
- struct page *page[1];
+ unsigned int flags = FOLL_HWPOISON;
+ struct page *page;
int npages = 0;
might_sleep();
@@ -1389,35 +1379,26 @@ static int hva_to_pfn_slow(unsigned long addr, bool *async, bool write_fault,
if (writable)
*writable = write_fault;
- if (async) {
- down_read(&current->mm->mmap_sem);
- npages = get_user_page_nowait(addr, write_fault, page);
- up_read(&current->mm->mmap_sem);
- } else {
- unsigned int flags = FOLL_HWPOISON;
-
- if (write_fault)
- flags |= FOLL_WRITE;
+ if (write_fault)
+ flags |= FOLL_WRITE;
+ if (async)
+ flags |= FOLL_NOWAIT;
- npages = get_user_pages_unlocked(addr, 1, page, flags);
- }
+ npages = get_user_pages_unlocked(addr, 1, &page, flags);
if (npages != 1)
return npages;
/* map read fault as writable if possible */
if (unlikely(!write_fault) && writable) {
- struct page *wpage[1];
+ struct page *wpage;
- npages = __get_user_pages_fast(addr, 1, 1, wpage);
- if (npages == 1) {
+ if (__get_user_pages_fast(addr, 1, 1, &wpage) == 1) {
*writable = true;
- put_page(page[0]);
- page[0] = wpage[0];
+ put_page(page);
+ page = wpage;
}
-
- npages = 1;
}
- *pfn = page_to_pfn(page[0]);
+ *pfn = page_to_pfn(page);
return npages;
}