[PATCH 0/2] kvm: minor cleanups in kvm_close and kvm_irqchip_release_virq

[PATCH 0/2] kvm: minor cleanups in kvm_close and kvm_irqchip_release_virq

[Bin Guo]

Two small cleanups in kvm-all.c:

- Patch 1 removes a redundant null/fd check in kvm_close() that
  can never be true once the early-return guard at function entry
  has already passed.

- Patch 2 fixes an off-by-one in kvm_irqchip_release_virq(): after
  a swap-remove the newly placed entry at the same index was never
  re-examined, so a duplicate GSI could be silently left in the
  routing table.

Bin Guo (2):
  kvm: remove redundant check in kvm_close
  kvm: fix kvm_irqchip_release_virq loop after swap-remove

 accel/kvm/kvm-all.c | 12 ++++++------
 1 file changed, 6 insertions(+), 6 deletions(-)

-- 
2.50.1 (Apple Git-155)

[PATCH 1/2] kvm: remove redundant check in kvm_close

[Bin Guo]

In kvm_close(), the condition `!kvm_state || kvm_state->fd == -1` is
checked at the function entry, causing an early return if either is
true. Later in the function, the same condition is redundantly checked
again before closing vmfd and fd.

Remove the redundant second check since it can never be true at that
point.

Signed-off-by: Bin Guo <guobin@linux.alibaba.com>
---
 accel/kvm/kvm-all.c | 11 +++++------
 1 file changed, 5 insertions(+), 6 deletions(-)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 92af42503b..70bc2c86a2 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -769,12 +769,11 @@ void kvm_close(void)
         cpu->kvm_vcpu_stats_fd = -1;
     }
 
-    if (kvm_state && kvm_state->fd != -1) {
-        close(kvm_state->vmfd);
-        kvm_state->vmfd = -1;
-        close(kvm_state->fd);
-        kvm_state->fd = -1;
-    }
+    close(kvm_state->vmfd);
+    kvm_state->vmfd = -1;
+    close(kvm_state->fd);
+    kvm_state->fd = -1;
+
     kvm_state = NULL;
 }
 
-- 
2.50.1 (Apple Git-155)

[PATCH 2/2] kvm: fix kvm_irqchip_release_virq loop after swap-remove

[Bin Guo]

In kvm_irqchip_release_virq(), when an entry matching the target GSI is
found, the code removes it by swapping in the last entry:

    s->irq_routes->nr--;
    *e = s->irq_routes->entries[s->irq_routes->nr];

However, the loop then increments `i` unconditionally, which means the
newly-swapped entry at position `i` is never re-checked. If that entry
also has `gsi == virq`, it will be skipped and left in the routing
table.

Fix this by decrementing `i` after the swap, so the same index is
re-examined in the next iteration.

Signed-off-by: Bin Guo <guobin@linux.alibaba.com>
---
 accel/kvm/kvm-all.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/accel/kvm/kvm-all.c b/accel/kvm/kvm-all.c
index 70bc2c86a2..3c5b62c97e 100644
--- a/accel/kvm/kvm-all.c
+++ b/accel/kvm/kvm-all.c
@@ -2278,6 +2278,7 @@ void kvm_irqchip_release_virq(KVMState *s, int virq)
         if (e->gsi == virq) {
             s->irq_routes->nr--;
             *e = s->irq_routes->entries[s->irq_routes->nr];
+            i--;
         }
     }
     clear_gsi(s, virq);
-- 
2.50.1 (Apple Git-155)