1 files changed, 22 insertions, 5 deletions

diff --git a/virt/kvm/kvm_main.c b/virt/kvm/kvm_main.c
index a25a73147f71..8db1d9361993 100644
--- a/virt/kvm/kvm_main.c
+++ b/virt/kvm/kvm_main.c
@@ -66,8 +66,8 @@
 MODULE_AUTHOR("Qumranet");
 MODULE_LICENSE("GPL");
 
-/* halt polling only reduces halt latency by 5-7 us, 500us is enough */
-static unsigned int halt_poll_ns = 500000;
+/* Architectures should define their poll value according to the halt latency */
+static unsigned int halt_poll_ns = KVM_HALT_POLL_NS_DEFAULT;
 module_param(halt_poll_ns, uint, S_IRUGO | S_IWUSR);
 
 /* Default doubles per-vcpu halt_poll_ns. */
@@ -2004,6 +2004,7 @@ void kvm_vcpu_block(struct kvm_vcpu *vcpu)
         if (vcpu->halt_poll_ns) {
                 ktime_t stop = ktime_add_ns(ktime_get(), vcpu->halt_poll_ns);
 
+                ++vcpu->stat.halt_attempted_poll;
                 do {
                         /*
                          * This sets KVM_REQ_UNHALT if an interrupt
@@ -2043,7 +2044,8 @@ out:
                 else if (vcpu->halt_poll_ns < halt_poll_ns &&
                         block_ns < halt_poll_ns)
                         grow_halt_poll_ns(vcpu);
-        }
+        } else
+                vcpu->halt_poll_ns = 0;
 
         trace_kvm_vcpu_wakeup(block_ns, waited);
 }
@@ -3156,10 +3158,25 @@ static void kvm_io_bus_destroy(struct kvm_io_bus *bus)
 static inline int kvm_io_bus_cmp(const struct kvm_io_range *r1,
                                  const struct kvm_io_range *r2)
 {
-        if (r1->addr < r2->addr)
+        gpa_t addr1 = r1->addr;
+        gpa_t addr2 = r2->addr;
+
+        if (addr1 < addr2)
                 return -1;
-        if (r1->addr + r1->len > r2->addr + r2->len)
+
+        /* If r2->len == 0, match the exact address.  If r2->len != 0,
+         * accept any overlapping write.  Any order is acceptable for
+         * overlapping ranges, because kvm_io_bus_get_first_dev ensures
+         * we process all of them.
+         */
+        if (r2->len) {
+                addr1 += r1->len;
+                addr2 += r2->len;
+        }
+
+        if (addr1 > addr2)
                 return 1;
+
         return 0;
 }