Merge tag 'kvm-ppc-fixes-5.2-1' of git://git.kernel.org/pub/scm/linux/kernel/git/paulus/powerpc into kvm-master

PPC KVM fixes for 5.2

- Several bug fixes for the new XIVE-native code.
- Replace kvm->lock by other mutexes in several places where we hold a
  vcpu mutex, to avoid lock order inversions.
- Fix a lockdep warning on guest entry for radix-mode guests.
- Fix a bug causing user-visible corruption of SPRG3 on the host.

1 files changed, 14 insertions, 22 deletions

diff --git a/tools/io_uring/queue.c b/tools/io_uring/queue.c
index 88505e873ad9..321819c132c7 100644
--- a/tools/io_uring/queue.c
+++ b/tools/io_uring/queue.c
@@ -8,8 +8,8 @@
 #include "liburing.h"
 #include "barrier.h"
 
-static int __io_uring_get_completion(struct io_uring *ring,
-                                     struct io_uring_cqe **cqe_ptr, int wait)
+static int __io_uring_get_cqe(struct io_uring *ring,
+                              struct io_uring_cqe **cqe_ptr, int wait)
 {
         struct io_uring_cq *cq = &ring->cq;
         const unsigned mask = *cq->kring_mask;
@@ -39,34 +39,25 @@ static int __io_uring_get_completion(struct io_uring *ring,
                         return -errno;
         } while (1);
 
-        if (*cqe_ptr) {
-                *cq->khead = head + 1;
-                /*
-                 * Ensure that the kernel sees our new head, the kernel has
-                 * the matching read barrier.
-                 */
-                write_barrier();
-        }
-
         return 0;
 }
 
 /*
- * Return an IO completion, if one is readily available
+ * Return an IO completion, if one is readily available. Returns 0 with
+ * cqe_ptr filled in on success, -errno on failure.
  */
-int io_uring_get_completion(struct io_uring *ring,
-                            struct io_uring_cqe **cqe_ptr)
+int io_uring_peek_cqe(struct io_uring *ring, struct io_uring_cqe **cqe_ptr)
 {
-        return __io_uring_get_completion(ring, cqe_ptr, 0);
+        return __io_uring_get_cqe(ring, cqe_ptr, 0);
 }
 
 /*
- * Return an IO completion, waiting for it if necessary
+ * Return an IO completion, waiting for it if necessary. Returns 0 with
+ * cqe_ptr filled in on success, -errno on failure.
  */
-int io_uring_wait_completion(struct io_uring *ring,
-                             struct io_uring_cqe **cqe_ptr)
+int io_uring_wait_cqe(struct io_uring *ring, struct io_uring_cqe **cqe_ptr)
 {
-        return __io_uring_get_completion(ring, cqe_ptr, 1);
+        return __io_uring_get_cqe(ring, cqe_ptr, 1);
 }
 
 /*
@@ -78,7 +69,7 @@ int io_uring_submit(struct io_uring *ring)
 {
         struct io_uring_sq *sq = &ring->sq;
         const unsigned mask = *sq->kring_mask;
-        unsigned ktail, ktail_next, submitted;
+        unsigned ktail, ktail_next, submitted, to_submit;
         int ret;
 
         /*
@@ -100,7 +91,8 @@ int io_uring_submit(struct io_uring *ring)
          */
         submitted = 0;
         ktail = ktail_next = *sq->ktail;
-        while (sq->sqe_head < sq->sqe_tail) {
+        to_submit = sq->sqe_tail - sq->sqe_head;
+        while (to_submit--) {
                 ktail_next++;
                 read_barrier();
 
@@ -136,7 +128,7 @@ submit:
         if (ret < 0)
                 return -errno;
 
-        return 0;
+        return ret;
 }
 
 /*